Intermittent Convective Therapies in Patients with Acute Kidney Injury: A Systematic Review with Meta-Analysis

<b><i>Introduction:</i></b> In critically ill patients requiring intermittent renal replacement therapy (RRT), the benefits of convective versus diffusive clearance remain uncertain. We conducted a systematic review and meta-analysis to determine the safety, clinical efficacy, and clearance efficiency of hemofiltration (HF) and hemodiafiltration (HDF) compared to hemodialysis (HD) in patients with acute kidney injury (AKI) receiving intermittent RRT. <b><i>Method:</i></b> We searched Medline, Embase, Cochrane Library, and PROSPERO. We included clinical trials and observational studies that reported the use of intermittent HF or HDF in adult patients with AKI. The following outcomes were included: mortality, renal recovery, clearance efficacy, intradialytic hemodynamic stability, circuit loss, and inflammation modulation. <b><i>Results:</i></b> A total of 3,169 studies were retrieved and screened. Four randomized controlled trials and 4 observational studies were included (<i>n</i>: 615 patients). Compared with conventional HD, intermittent convective therapies had no effect on in-hospital mortality (relative risk, 1.23; 95% confidence interval (CI), 0.76–1.99), renal recovery at 30 days (RR, 0.98; 95% CI, 0.82–1.16), time-to-renal recovery (mean difference [MD], 0.77; 95% CI, −6.56 to 8.10), and number of dialysis sessions until renal recovery (MD, −1.34; 95% CI, −3.39 to 0.72). The overall quality of included studies was low, and dialysis parameters were suboptimal for all included studies. <b><i>Conclusion:</i></b> This meta-analysis suggests that there is no significant difference in short-term mortality and renal recovery in patients with severe AKI when treated with intermittent HF or HDF compared to conventional HD. This systematic review emphasizes the need for further trials evaluating optimal convective parameters in AKI patients treated with intermittent dialysis.

Integrated Magnetics Design for a Full-Bridge Phase-Shifted Converter

In this study, an optimization procedure was proposed for the magnetic component of an integrated transformer applied in a center-tap phase-shifted full-bridge converter. To accommodate high power–density 0demand, a transformer and an output inductor were integrated into a magnetic component to reduce the volume of the magnetic material and the primary and secondary windings of the transformer were wound on the magnetic legs to reduce conduction loss attributable to the alternating-current resistor. With a focus on the integrated transformer applied in a phase-shifted full-bridge converter, circuit operation in each time interval was analyzed, and a design procedure was established for the integrated magnetic component. In addition, the manner in which output inductance was affected by the mutual inductance between the transformer and the output inductor in the integrated transformer during various operation intervals was discussed and, to minimize circuit loss, a design optimization procedure for the magnetic core was proposed. Finally, the integrated transformer was applied in a phase-shifted full-bridge converter to achieve an input voltage of 400 V, an output voltage of 12 V, output power of 1.7 kW, an output frequency of 80 kHz, and a maximum conversion efficiency of 96.7%.

Symmetrical Loss of Excitation Fault Diagnosis in an Asynchronized High-Voltage Generator

As a new type of generator, an asynchronized high-voltage generator has the characteristics of an asynchronous generator and high voltage generator. The effect of the loss of an excitation fault for an asynchronized high-voltage generator and its fault diagnosis technique are still in the research stage. Firstly, a finite element model of the asynchronized high-voltage generator considering the field-circuit-movement coupling is established. Secondly, the three phase short-circuit loss of excitation fault, three phase open-circuit loss of excitation fault, and three phase short-circuit fault on the stator side are analyzed by the simulation method that is applied abroad at present. The fault phenomenon under the stator three phase short-circuit fault is similar to that under the three phase short-circuit loss of excitation. Then, a symmetrical loss of the excitation fault diagnosis system based on wavelet packet analysis and the Back Propagation neural network (BP neural network) is established. At last, we confirm that this system can eliminate the interference of the stator three phase short-circuit fault, accurately diagnose the symmetrical loss of the excitation fault, and judge the type of symmetrical loss of the excitation fault. It saves time to find the fault cause and improves the stability of system operation.

Treatment of Cognitive Impairment

There are lifestyle strategies that may help preserve cognition in old age and in MCI. While the evidence is still suggestive rather than definitive it is strong enough to make suggestions to patients and families. Cognitive interventions such as computer-based cognitive stimulation and brain fitness programs may be helpful, although more generalized cognitive activities such as taking a college course or learning a new skill may be equally helpful. Aerobic exercise has the best track record to date among lifestyle interventions. Having a variety of leisure activities that combine psychological, physical, and social activities is advised. As far as well can tell, diets that are helpful for preventing heart disease such as the Mediterranean diet also may be good for cognition. The mechanisms for many of these strategies likely involve 1) the brain compensating for circuit loss by engaging new circuits to solve problems and 2) improvements in vascular health.

A Novel Method for Measuring the Open-Circuit Loss and Short–Circuit Loss of Distribution Transformers Online

The paper proposes a novel method for online measuring the open-circuit loss (OCL) and the short-circuit loss (SCL) of distribution transformer DT, based on the consideration of the drawbacks of the offline measuring method, which is regarded as the mainly and traditionally used methods for measuring the OCL and the SCL of DT. The novel method avoids the drawbacks of the offline method which is not cost-effective and is not good for the reliability of the power supply. Firstly, the relation expression of the short-circuit impedance with respect to the voltage and current of the primary and secondary side is developed from the analysis of the equivalent circuit model of DT, and the relations between the SCL and OCL and the short-circuit impedance are also deduced according to power balance. Then, the online short-circuit impedance is computed by using linear regression technique and the value of online voltage and current of DT. Furthermore, according to the developed relations, the online OCL and the SCL of DT can be acquired by using the obtained short-circuit impedance. Numerical simulations have been carried out on Matlab/smulink and results verified feasibility and effectiveness of the novel method for online measuring the OCL and the SCL of DT.