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Objective: This study aimed to optimize the preparation process of polysaccharides from lemon peel and screen out the components with high hypoglycemic activity. Methods: Ultrasonic assisted enzymatic extraction of lemon peel polysaccharide, combined with response surface test to explore the best extraction process, through DEAE-52 anion chromatography and Sephadex G-100 gel column chromatography separation and purification to obtain a homogeneous polysaccharide fraction (named as LPs-1a). The effective hypoglycemic components of lemon peel polysaccharides were screened by α-glucosidase and their relative molecular weight, monosaccharide composition and characteristic groups were analyzed. Results: The optimal extraction process of lemon peel polysaccharide was ultrasonic treatment for at 55 ℃ for 44 min with solid-liquid ratio 1∶20 (g/mL) and cellulase addition rate 1.1%. Under the control of these conditions, the yield of lemon peel polysaccharide was 6.83%, which was close to the predicted value. The LPs-1a fraction significantly inhibited the activity of α-glucosidase with （1.22±0.04） mg/mL of IC50(P＜0.05). The relative molecular weight of this component was 195 260, and it was connected by α-glycosidic bonds and β-glycosidic bonds with a pyranose ring. The morphology of the polysaccharide was fibrous, and it was composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose and arabinose Conclusion: Ultrasound-assisted enzymatic method is helpful in screening the highly hypoglycemic active components of lemon peel polysaccharides.

Thermistors with negative temperature coefficient (NTC) of resistivity are important components for temperature sensors and actuators. High material constant (B value) of NTC thermistor, i.e. high-temperature sensitivity, is one of key focuses. Herein, Bi/Mg modified NiO based ceramics for NTC thermistors were prepared by conventional solid-state reaction method. Introduction of Bi2O3 significantly enhances the sintering ability of ceramics and reduces the sintering temperature from 1380 to 1250°C. Mg-doping (i.e. preparation of Ni1-xMgxO ceramics, where x=0, 0.02, 0.05, 0.07 and 0.1) has significant effect on room temperature resistivity (ρ25). Phase composition, microstructure, electrical property and electrical stability were investigated. All prepared ceramics have the phase with rock-salt structure and show typical NTC characteristics with B values higher than 5300K. The electrical stability with an optimized resistance-change rate of 1.02%after being aged at 150°C for 500 h is achieved. The electrical properties of the ceramics were analysed by combining X-ray photoelectron spectra with complex impedance spectra.

The novel coronavirus disease 2019 (COVID‐19) causes severe respiratory illness and is involved in ischemic stroke. Aimed to investigate the inflammatory markers and possible prognosis of COVID‐19‐related ischemic stroke in a special outbreak period after lifting of COVID‐19 control measures in China, we conducted a multicenter retrospective analysis in southern China at three centers in Shenzhen. We included patients diagnosed with acute ischemic stroke or transient ischemic attack after infection with COVID‐19 as the COVID‐19‐related ischemic stroke group and those only diagnosed with acute ischemic stroke or transient ischemic attack as the control group. In this study, the proportion of female patients, admission heart rate, and comorbid coronary heart disease and the proportion of cryptogenic stroke were higher, while the history of prior stroke was lower in the COVID‐19‐related ischemic stroke group. The COVID‐19‐related ischemic stroke group also exhibited elevated levels of monocytes, fibrinogen, alanine aminotransferase, direct bilirubin, monocyte‐to‐lymphocyte ratio (MLR), and fibrinogen‐to‐albumin ratio (FAR) but decreased levels of lymphocytes, albumin, and high‐density lipoprotein. However, there were no statistically significant differences in the modified Rankin scale (mRS), National Institutes of Health Stroke Scale (NIHSS), and mortality rate between the two groups at discharge. Our study is the first to show the alteration in inflammatory markers but no difference in discharge prognosis between the non‐COVID‐19 and the COVID‐19‐related ischemic stroke patients, during China's COVID‐19 relaxation period. [ABSTRACT FROM AUTHOR]

This scoping review aims to investigate longitudinal changes in minerals and vitamins concentrations in human milk among the Chinese population. Following the PRISMA-ScR guidelines, a comprehensive and systematic literature search was conducted using both English and Chinese databases. Data were extracted and categorized into six defined lactation stages. We found that the concentration of most minerals decreased throughout the lactation period, although calcium (Ca) and magnesium (Mg) fluctuated slightly across lactation periods. Fat-soluble vitamins also showed a decline throughout the lactation period, while water-soluble vitamins exhibited an increasing trend. However, folic acid, biotin, and pantothenic acid demonstrated a downward trend. Overall, this review has identified the longitudinal changes in minerals and vitamins concentrations in human milk among the Chinese population. In order to conduct a more in-depth examination of maternal characteristics and nutritional factors of the composition of human milk, it is recommended to utilize standardized protocols for the collection and analysis of human milk samples. [ABSTRACT FROM AUTHOR]

The low sintering temperature (LST) is a great significance for the fabrication of sensors and electronic components. To exploit a system of LST negative temperature coefficient (NTC) thermistors, Mn/La co-doped WO3 ceramics (MnxLa0.03WO3+δ, x ≤ 0.1, denoted as xMLW) were prepared in this work by a traditional solid-state reaction technology. The phase component, microstructure, and electrical property of the prepared xMLW ceramics were investigated. The xMLW ceramics have the main phase with lattice structure as that of monoclinic WO3 with a space group of P21/n, and show typical NTC characteristics. By varying the concentration of Mn cations, the xMLW ceramics have adjustable room temperature resistivity (ρ25) ranging from 770 Ω·cm to 7.017 kΩ·cm and high thermal-sensitivity constants (B value) ranging from 2695 to 4219 K. The electrical conduction and NTC feature of the ceramics are discussed by analyzing impedance spectrum and lattice defect. [ABSTRACT FROM AUTHOR]

The negative temperature coefficient (NTC) thermosensitive ceramics with low sintering temperature are of great significance in the research and application of low-temperature co-firing sensitive components. In this work, bismuth-modified samarium cuprate (BixSm2-xCuO4, denoted as xBSCO, x ≤ 0.1) thermistors were prepared by a solid-state reaction method. All ceramics were sintered below 950 °C and show typical NTC effect. The phase component, microstructure, electrical properties of prepared ceramics were investigated. The substitution of Bi-ions reduces the room temperature resistivity (ρ25) of the ceramics. For various contents of Bi-ions, ρ25 of xBSCO ranges from 76 Ω cm to 1297 Ω cm, and all the ceramics have high temperature sensitivity with NTC material constants (B values) between 2237 and 5150 K. The temperature coefficient of resistance at 25 °C (TCR25) of xBSCO is in the range − 5.48% K−1 to − 2.30% K−1. The effect of Bi doping on the structure and property of Sm2CuO4 ceramics is discussed basing on the perspective of band structure. [ABSTRACT FROM AUTHOR]