Experimental investigation of the isothermal section at 400 °C of the MgCeSr ternary system

AbstractThe objective of this study is to determine the isothermal section at 400 °C of the MgCeSr system. In this study, the constitution of the CeSr system and the MgCeSr system have been investigated over the entire composition range using X-ray diffraction (XRD), field emission scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). No any new binary compound has been found in the CeSr system and no ternary compound has been found in the MgCeSr system also. Nine three-phase regions have been experimentally observed. Six binary phases Mg2Sr, Mg23Sr6, Mg38Sr9, Mg17Sr2, Mg12Ce, Mg41Ce5 are detected dissolving about 3–7 at.% the third element. This study first detected the experimental data of the CeSr binary system and determined the isothermal section at 400 °C of the MgCeSr ternary system

Clinical features of febrile seizures in children with COVID-19: an observational study from a tertiary care hospital in China

BackgroundFebrile seizures are a common neurologic manifestation in children with coronavirus disease 2019 (COVID-19). Compared to seasonal respiratory viruses, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a pronounced neurological impact, with the result that febrile seizures with COVID-19 may exhibit unique clinical features.Materials and methodsWe conducted a retrospective study in a tertiary care hospital in China. We collected medical record information on febrile seizures with COVID-19, including demographic characteristics, clinical features, laboratory tests, and disease burden. Subsequently, the data were then analyzed descriptively.ResultsA total of 103 children diagnosed with febrile seizures and positive COVID-19 PCR results were included in our study. Among them, 81 (78.6%) were males and 22 (21.4%) were females. The age of onset of febrile seizures ranged from 14 to 57 months, with a mean age of 34.9 ± 6.24 months. Complex febrile seizures were observed in 34 (33%) cases. Antiseizure medications were administered to 24 (23.3%) patients. Laboratory tests showed a white blood cell count of (27.05 ± 8.20) × 103/µl, a neutrophil count of (20.09 ± 5.66) × 103/µl and a lymphocyte count of (6.44 ± 1.86) × 103/µl. A creatine kinase level was significantly elevated, with a mean value of (412.00 ± 158.96) U/L. The mean length of stay was 4.36 days. Twelve patients (11.7%) required intensive care services, but there were no deaths or patients remaining on antiseizure medications after discharge.ConclusionIn the post-epidemic era of COVID-19, pediatric clinicians should be aware of the changing clinical features of febrile seizures associated with COVID-19. The average age of onset has increased, with a higher proportion of males. Length of stay and hospitalization costs did not increase significantly. The prognosis remained favorable, although a small number of children required intensive care services during the acute phase

Investigations on the micellization of amphiphilic dendritic copolymers: from unimers to micelles

Since the micellization kinetics is influenced by polymer structure, the spherical three-dimensional topology of amphiphilic dendritic copolymers (ADPs) which hinders the phase separation during micellization is assumed to make the micellization kinetics different. In the literatures, most of the attention has been paid to the morphology transition or the morphology at equilibrium and the micellization kinetics of ADPs is rarely reported. In this study, the micellization processes of amphiphilic dendritic copolymers from unimers to the final equilibrium micelles were monitored by laser light scattering. Based on the closed association mechanism, the thermodynamics of micellization was analysed. The negative thermodynamic quantities indicate that the micellization of ADPs is driven by enthalpy. Based on the change of scattering intensity and hydrodynamic radius (Rh) with time, the detailed micellization kinetics was analysed, which contains two steps. By controlling the temperature and type of solvent, a system in which the concentration has little influence on Rh is obtained. The relaxation times of the two steps decrease with concentration, indicating that at higher concentration the rate of micellization is quicker. With the increasing mass fraction of the hydrophobic part, the relaxation times decrease and the driving force of micellization increases

The permeability effect of microcystin-RR on Escherichia coli and Bacillus subtilis

Microcystins are a kind of cyclic hepatoxins produced by many species of cyanobacteria. Most previous work have been done on the toxic effects of microcystins on animals and plants. However, the reports about the effect of microcystins on microbial cells are very limited. In this work, the permeability of MC-RR on the cell outer membrane of Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) was discussed. The permeability effect of MC-RR on the cell outer membrane of E. coli and B. subtilis under different concentrations was demonstrated by a rapid and sustained reduction in the A(675) values of lysozyme-treated cells. The decrease of the absorbance values showed a time-and dose-effect. The extravasations of protein and carbonhydrate increased with the increment of the treated-concentration of MC-RR. The results showed that MC-RR could increase the permeability of cell outer membranes of E. coli and B. subtilis. The synergistic effects of MC-RR and lysozyme on bacteria indicated that MC-RR might play an ecological role in bacteria in combination with other substances in some aquatic environments.Microcystins are a kind of cyclic hepatoxins produced by many species of cyanobacteria. Most previous work have been done on the toxic effects of microcystins on animals and plants. However, the reports about the effect of microcystins on microbial cells are very limited. In this work, the permeability of MC-RR on the cell outer membrane of Escherichia coli (E. coli) and Bacillus subtilis (B. subtilis) was discussed. The permeability effect of MC-RR on the cell outer membrane of E. coli and B. subtilis under different concentrations was demonstrated by a rapid and sustained reduction in the A(675) values of lysozyme-treated cells. The decrease of the absorbance values showed a time-and dose-effect. The extravasations of protein and carbonhydrate increased with the increment of the treated-concentration of MC-RR. The results showed that MC-RR could increase the permeability of cell outer membranes of E. coli and B. subtilis. The synergistic effects of MC-RR and lysozyme on bacteria indicated that MC-RR might play an ecological role in bacteria in combination with other substances in some aquatic environments

Combination of hydrodechlorination and biodegradation for the abatement of chlorophenols

A method for abatement for chlorophenols (CPs) in contaminated water based on successive steps of catalytic hydrodechlorination (HDC) over Pd/C at ambient temperature and pressure, followed by aerobic biodegradation using yeast Candida tropicalis (C. tropicalis) was studied. The results showed that 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) could be easily and completely dechlorinated under mild conditions, ultimately yielding phenol as product. Subsequently, phenol (0-900 mg L-1) could be completely degraded by C. tropicalis within 30 h. Moreover, during the biodegradation of phenol, definite mass of ethanol (&lt;= 0.5%) caused a modest increase in the duration of the lag phase, but led to a great increase in the maximum degradation rates. This means that CPs with higher concentration could be efficiently detoxified under mild conditions by a combination of HDC and biodegradation in water or water-ethanol systems.A method for abatement for chlorophenols (CPs) in contaminated water based on successive steps of catalytic hydrodechlorination (HDC) over Pd/C at ambient temperature and pressure, followed by aerobic biodegradation using yeast Candida tropicalis (C. tropicalis) was studied. The results showed that 4-chlorophenol (4-CP) and 2,4-dichlorophenol (2,4-DCP) could be easily and completely dechlorinated under mild conditions, ultimately yielding phenol as product. Subsequently, phenol (0-900 mg L-1) could be completely degraded by C. tropicalis within 30 h. Moreover, during the biodegradation of phenol, definite mass of ethanol (<= 0.5%) caused a modest increase in the duration of the lag phase, but led to a great increase in the maximum degradation rates. This means that CPs with higher concentration could be efficiently detoxified under mild conditions by a combination of HDC and biodegradation in water or water-ethanol systems

Study on the spatial specificity of phenolics in fruit of different jujube varieties

Abstract Phenol, an important bioactive substance in jujube fruit, is one of the most important indexes of fruit quality. In order to clarify the phenolic substance composition, content and distribution characteristics of different varieties of jujube fruits, this study measured and compared the content of total phenols, total flavonoids and phenolic substance composition in different parts of fruits of six jujube varieties, and combined with the principal component analysis, the results showed that: Fourteen phenolic substances were identified in the fruits of different jujube varieties, and proanthocyanidins, epicatechin, catechin and rutin were the main components, accounting for 58.60%, 16.08%, 13.56% and 5.57% of the total phenolic substances, respectively. The total phenolic and total flavonoid contents of jujube fruits of each variety were between 18.11 and 21.45 mg GAE/g DW and 10.56–20.25 mg RE/g DW, respectively, and the differences in the contents between the varieties were significant, and the contents of ‘Junzao’ and ‘Jinlingyuanzao’ were higher than those of other varieties.The phenolic content of different parts of jujube fruits showed spatial distribution differences, manifested as the total phenols, total flavonoids and their fractions of the peel were significantly higher than that of the pulp, while the content of the pulp near the kernel was significantly higher than that of other parts of the pulp, This study provides a theoretical basis for analysing the differences in phenolic substances in jujube fruits