Design of active power filter for narrow-band power line communications

In power line communication (PLC), couplers such as coupling transformers and band-pass matching coupling circuits are usually required for coupling, band-pass filtering, and impedance matching. However, the cost and size of transformers prevent them from being an economic and compact solution for PLC couplers. In addition, passive band-pass matching coupling circuits need accurate impedance matching and possibly incur power losses. In this paper, a 6th order multiple feedback (MFB) active power filter with the minimum number of components was designed for narrow-band PLC, which has high input impedance and low output impedance, allowing outstanding performance in main voltage isolation, suppressing the current-harmonics and compensating the reactive power simultaneously. Finally, simulations were conducted in the range of 95 kHz-125 kHz (CENELEC “B-band”), which confirmed that the new filter met the CENELEC requirements for transmission and disturbance levels

Design of active power filter for narrow-band power line communications

In power line communication (PLC), couplers such as coupling transformers and band-pass matching coupling circuits are usually required for coupling, band-pass filtering, and impedance matching. However, the cost and size of transformers prevent them from being an economic and compact solution for PLC couplers. In addition, passive band-pass matching coupling circuits need accurate impedance matching and possibly incur power losses. In this paper, a 6th order multiple feedback (MFB) active power filter with the minimum number of components was designed for narrow-band PLC, which has high input impedance and low output impedance, allowing outstanding performance in main voltage isolation, suppressing the current-harmonics and compensating the reactive power simultaneously. Finally, simulations were conducted in the range of 95 kHz-125 kHz (CENELEC “B-band”), which confirmed that the new filter met the CENELEC requirements for transmission and disturbance levels

The P50 value detected by the oxygenation-dissociation analyser and blood gas analyser

AbstractOxygen tension at 50% haemoglobin saturation (P50), which reflects the degree of peripheral oxygen offloading and tissue oxygenation, plays an important role in the diagnosis and treatment of disease, as well as in transfusion research. Blood gas analysers are commonly used in clinical and obtain P50 values through complex calculations and analysis. Oxygenation-dissociation analysers are specially designed to record the oxygen dissociation curves and obtain P50 values of whole blood, red blood cells (RBCs), and stroma-free haemoglobin. However, whether the two equipment obtain comparable data is still uncertain. Herein, we used both equipment to detect P50 values of blood and stroma-free haemoglobin from human and bovine sources, venous and arterial blood of beagle and rat, and stored rat blood. For human blood, both analysers yielded similar data. P50 of the stroma-free haemoglobin and bovine blood could only be properly detected by oxygenation-dissociation analysers. Blood gas analysers showed different P50 values, while oxygenation-dissociation analysers got similar P50 values for arterial and venous samples. Oxygenation-dissociation analysers distinguished changes in P50 values during RBCs storage. Compared with the blood gas analysers, oxygenation-dissociation analysers had a stronger detection capability in P50 measurement with regard to both sample types and species

Magnetic Anomaly Detection Based on a Compound Tri-Stable Stochastic Resonance System

In the case of strong background noise, a tri-stable stochastic resonance model has higher noise utilization than a bi-stable stochastic resonance (BSR) model for weak signal detection. However, the problem of severe system parameter coupling in a conventional tri-stable stochastic resonance model leads to difficulty in potential function regulation. In this paper, a new compound tri-stable stochastic resonance (CTSR) model is proposed to address this problem by combining a Gaussian Potential model and the mixed bi-stable model. The weak magnetic anomaly signal detection system consists of the CTSR system and judgment system based on statistical analysis. The system parameters are adjusted by using a quantum genetic algorithm (QGA) to optimize the output signal-to-noise ratio (SNR). The experimental results show that the CTSR system performs better than the traditional tri-stable stochastic resonance (TTSR) system and BSR system. When the input SNR is -8 dB, the detection probability of the CTSR system approaches 80%. Moreover, this detection system not only detects the magnetic anomaly signal but also retains information on the relative motion (heading) of the ferromagnetic target and the magnetic detection device

Spatial and Temporal Variability of Soil Moisture and Its Driving Factors in the Northern Agricultural Regions of China

Soil moisture, as an important variable affecting water–heat exchange between land and atmosphere, is an important feedback to climate change. Soil moisture is of great concern in Northern China, where arable land is extensive, but water resources are distributed unevenly and extremely sensitive to climate change. Using measured soil moisture data collected by the China Meteorological Administration from 164 stations during 1980–2021, we explored the drivers of soil moisture variation by analyzing its spatiotemporal variability using linear regression, partial correlation analysis, and geostatistical methods. The results indicated that (1) soil moisture increased from northwest to southeast in Northern China, with the lowest soil moisture in the IM; (2) the overall trend of soil moisture in most regions decreased, especially in the arid northwest and northeast China. However, soil moisture in some regions began to increase gradually in recent years, such as in northwestern Xinjiang and the central-eastern part of IM; and (3) soil moisture in the whole region was negatively correlated with temperature and sunshine duration and positively correlated with precipitation and relative humidity. The results of the study can provide valuable guidance for timely agricultural irrigation and the adjustment of cropping structures, thereby ensuring agricultural production and food security

Pharmacokinetic and pharmacodynamic modeling of oral mitiglinide on glucose lowering in healthy Chinese volunteers

Abstract Background Mitiglinide is a widely used agent for diabetic treatment. We established a pharmacokinetic-pharmacodynamic (PK-PD) model to illustrate the relationship between mitiglinide plasma concentration and its glucose lowering effects in healthy volunteers. Methods The volunteers participated in the test after the administration of a single dose of 10 mg mitiglinide. The drug concentration in Plasma and the values of glucose levels were determined by LC-MS/MS assay and hexokinase method. A PK-PD model was established with a series of equations to describe the relationship between plasma medicine and glucose, and the equations were solved numerically and fitted to the data with the Phoenix NLME software. Results The results of the two-compartment model analysis were based on the maximum likelihood criterion and visual inspection of the fittings. The terminal elimination half-life (t 1/2) was 1.69 ± 0.16 h and the CL/F was 7.80 ± 1.84 L/h. The plasma glucose levels began to decline by 0.2 h, and hit its bottom decreasing values of 2.6 mg/L at 0.5 h after administration. The calculated parameter and fitting curve indicated that the model established in our experiment fitted well. Conclusions A PK/PD model illustrates that the relationship between mitiglinide concentration in plasma and glucose lowering effect in healthy volunteers was established. The results of our experiment suggested that the model can be used reasonably to predict the relationship between PK and PD in mitiglinide, which could be used in diabetes mellitus dosage control in clinical trials and other fields

PEG-conjugated bovine haemoglobin enhances efficiency of chemotherapeutic agent doxorubicin with alleviating DOX-induced splenocardiac toxicity in the breast cancer

AbstractDoxorubicin (DOX) is an effective chemotherapeutic agent widely used for cancer treatment. However, hypoxia in tumour tissue and obvious adverse effects particularly cardiotoxicity restricts the clinical usage of DOX. Our study is based on the co-administration of haemoglobin-based oxygen carriers (HBOCs) and DOX in a breast cancer model to investigate HBOCs’ ability to enhance chemotherapeutic effectiveness and its capabilities to alleviate the side effects induced by DOX. In an in-vitro study, the results suggested the cytotoxicity of DOX was significantly improved when combined with HBOCs in a hypoxic environment, and produced more γ-H2AX indicating higher DNA damage than free DOX did. Compared with administration of free DOX, combined therapy exhibited a stronger tumour suppressive effect in an in-vivo study. Further mechanism studies showed that the expression of various proteins such as hypoxia-inducible factor-1α (HIF-1α), CD31, CD34, and vascular endothelial growth factor (VEGF) in tumour tissues was also significantly reduced in the combined treatment group. In addition, HBOCs can significantly reduce the splenocardiac toxicity induced by DOX, according to the results of the haematoxylin and eosin (H&E) staining and histological investigation. This study suggested that PEG-conjugated bovine haemoglobin may not only reduce the hypoxia in tumours and increase the efficiency of chemotherapeutic agent DOX, but also alleviate the irreversible heart toxicity caused by DOX-inducted splenocardiac dysregulation

Recapitulating lipid accumulation and related metabolic dysregulation in human liver-derived organoids

Fatty liver disease has grown into a major global health burden, attributed to multi-factors including sedentary lifestyle, obesogenic diet and prevalence of metabolic disorders. The lack of robust experimental models is hampering the research and therapeutic development for fatty liver disease. This study aims to develop an organoid-based 3D culture model to recapitulate key features of fatty liver disease focusing on intracellular lipid accumulation and metabolic dysregulation. We used human liver-derived intrahepatic cholangiocyte organoids and hepatocyte differentiated organoids. These organoids were exposed to lactate, pyruvate, and octanoic acid (LPO) for inducing lipid accumulation and mitochondrial impairment. Lipid accumulation resulted in alternations of gene transcription with major effects on metabolic pathways, including triglyceride and glucose level increase, which is consistent with metabolic changes in fatty liver disease patients. Interestingly, lipid accumulation affected mitochondria as shown by morphological transitions, alternations in expression of mitochondrial encoded genes, and reduction of ATP production. Meanwhile, we found treatment with obeticholic acid and metformin can alleviate fat accumulation in organoids. This study demonstrated that LPO exposure can induce lipid accumulation and associated metabolic dysregulation in human liver-derived organoids. This provides an innovative model for studying fatty liver disease and testing potential therapeutics. Key messages: Lactate, pyruvate, and octanoic acid induce lipid accumulation in liver organoids.Organoids of human compared to mouse origin are more efficient in lipid accumulation.Lipid accumulation dysregulates metabolic pathway and impairs mitochondrial function.Demonstrating a proof-of-concept for testing medications in organoids