Research on the Relative Placement Angle of the Induction Heater and the Channel in a Four-Channel Induction-Heating Tundish.

In order to optimize the application effect of induction heating (IH) tundishes, a four-channel IH tundish is taken as the research object. Based on numerical simulation methods, the influence of different relative placement angles of induction heaters and channels on the electromagnetic field, flow field and temperature field of the tundish is investigated. We focus on comparing the magnetic flux density (B) and electromagnetic force (EMF) distribution of the channel. The results show that regardless of the relative placement angle between the heater and the channel, the distribution of B in the central circular cross-section of the channel is eccentric. When the heater rotates around channel 1 towards the bottom of the tundish, the distribution of B in the central circular cross-section of the channel changes from a horizontal eccentricity to a vertical one. Through the analysis of the B contour in the longitudinal section of the channel, the difference in effective magnetic flux density area (ΔAB) between the upper and lower parts of the channel can be obtained, thereby quantitatively analyzing the distribution of B in this section. The distribution pattern of ΔAB is consistent with the distribution pattern of the electromagnetic force in the vertical direction (FZ) of the channel centerline. The ΔAB and FZ of channel 1 gradually increase as the heater rotates downwards, while those of channel 2 reach their maximum value at a rotation angle of 60°. Compared to the conventional placement, when the heater rotation angle is 60°, the outlet flow velocities at channel 1 and channel 2 decrease by 15% and 12%, respectively. However, the outlet temperature at channel 2 increases by 1.96 K, and the molten steel flow at the outlet of channel 1 and channel 2 no longer exhibits significant downward flow. This shows that when the heater rotation angle is 60°, it has a dual advantage. On the one hand, it is helpful to reduce the erosion of the molten steel on the channel and the bottom of the discharging chamber, and on the other hand, it can more effectively exert the heating effect of the induction heater on the molten steel in the channel. This presents a new approach to enhance the application effectiveness of IH tundish.

Twist angle-dependent valley polarization switching in heterostructures.

The twist engineering of moiré superlattice in van der Waals heterostructures of transition metal dichalcogenides can manipulate valley physics of interlayer excitons (IXs), paving the way for next-generation valleytronic devices. However, the twist angle-dependent control of excitonic potential on valley polarization is not investigated so far in electrically controlled heterostructures and the physical mechanism underneath needs to be explored. Here, we demonstrate the dependence of both polarization switching and degree of valley polarization on the moiré period. We also find the mechanisms to reveal the modulation of twist angle on the exciton potential and the electron-hole exchange interaction, which elucidate the experimentally observed twist angle-dependent valley polarization of IXs. Furthermore, we realize the valley-addressable devices based on polarization switch. Our work demonstrates the manipulation of the valley polarization of IXs by tunning twist angle in electrically controlled heterostructures, which opens an avenue for electrically controlling the valley degrees of freedom in twistronic devices.

Determining the chemical profile of Caragana jubata (Pall.) Poir. by UPLC-QTOF-MS analysis and evaluating its anti-ischemic stroke effects.

ETHNOPHARMACOLOGICAL RELEVANCE: Caragana jubata, belonging to the Leguminosae family, is a shrubby medicinal plant distributed in high-altitude areas of China. The red heartwood of C. jubata is the original source of 'zuomuxing', a Tibetan medicine that promotes blood circulation and removes blood stasis to treat different diseases associated with the blood. AIM OF THE STUDY: To date, research on the chemical constituents of C. jubata remains very limited. The anti-ischemic stroke (anti-IS) effects of this plant have not been studied. The aim of the present study was to analyze the chemical profile of C. jubata, establish various anti-IS models to comprehensively evaluate the anti-IS effects of C. jubata, and explore the mechanism of action. MATERIALS AND METHODS: Ultraperformance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) was chosen to analyze the chemical profile. A middle cerebral artery occlusion reperfusion (MCAO/R) model, zebrafish cerebral thrombosis model, and oxygen-glucose deprivation/reperfusion (OGD/R) model in PC12/BV2 cells were used to thoroughly evaluate the anti-IS effects of C. jubata. Additionally, western blotting and immunofluorescence staining were used to detect the mechanism of action. RESULTS: Fifty-three compounds were identified from a 95% ethanol extract of C. jubata (ECJ) by UPLC-QTOF-MS analysis. 17 and 7 compounds were identified from C. jubata and the genus Caragana for the first time. ECJ was found to attenuate infarct size and reduce brain edema and neurological scores in MCAO/R rats. ECJ notably reduced the zebrafish cerebral thrombosis incidence in a dose-dependent manner compared with that in the model group. Surprisingly, compared to the positive control drug aspirin, 50 µg/ml ECJ exhibited a better therapeutic effect than aspirin at 30 µg/ml. Additionally, ECJ significantly increased the viability of PC12/BV2 cells injured by OGD/R. Moreover, ECJ inhibited the protein expression of M1 markers (TNF-α, iNOS, and IL-1ß) and increased that of M2 markers (Arg-1 and CD206) in OGD/R-injured BV2 cells. ECJ significantly decreased the immunofluorescence intensity of CD16 and increased that of CD206. CONCLUSIONS: The results from UPLC-QTOF-MS analysis showed that ECJ was rich in flavonoids. The results from pharmacological experiments verified the anti-IS effects of C. jubata in vivo and in vitro for the first time. In addition, ECJ could regulate the polarization of microglia. The present study highlights the medicinal value of C. jubata, thus providing a theoretical basis for the further development of new drugs from C. jubata to treat IS.

A new biphenanthrene with cytotoxic activity from Liparis nervosa (Thunb.) Lindl.

2,7,2'-Trihydroxy-3,4,4'7'-tetramethoxy-1,1'-biphenanthrene (1), a previously undescribed biphenanthrene, and five known phenanthrenes, i.e. 2,5-dihydroxy-4-methoxy-9,10-dihydroxyphenanthrene (2), 2,4-dihydroxy -7-methoxy-9,10-dihydroxyphenanthrene (3), 7-hydroxy-2-methoxy-phenanthrene-1,4-dione (4), 7-hydroxy-2-methoxy-9,10-dihydro-phenanthrene-1,4-dione (5), and 4,4',7,7'-tetrahydroxy-2,2'-dimethoxy-9,9',10,10'-tetrahydro-1,1'-biphenanthrene (6) were isolated from the whole plant (stems, leaves, roots and fruits) of Liparis nervosa (Thunb.) Lindl., which is a medicinal plant of the genus Liparis in the Orchidaceae family. The structures of isolates were identified using spectroscopic methods, including NMR and mass spectrometry. Additionally, the cytotoxic potency of all the isolates against human lung cancer A549 cell line was evaluated by an MTT assay. All the isolated compounds showed cytotoxic activities with IC50 values in the range of 10.20 ± 0.81 to 42.41 ± 2.34 µM. The obtained data highlight the importance of L. nervosa as a source of natural lead compounds for cancer therapy.

A novel ABCD1 gene mutation in a Chinese patient with X-linked adrenoleukodystrophy.

BACKGROUND: X-linked adrenoleukodystrophy (X-ALD) (OMIM: 300100) is a recessive neurodegenerative disorder caused by defects in the ABCD1 gene on chromosome Xq28. Childhood cerebral ALD (CCALD) is the most frequent phenotype. OBJECTIVE: We describe an affected boy who developed normally until he was 8 years old then suffered progressive neurological deficits that ultimately led to death. METHODS: Diagnosis was based on clinical symptoms, an abnormal very long chain fatty acid profile in plasma, typical CCALD MRI pattern, and molecular analysis. RESULTS: Direct sequencing of the ABCD1 gene in this patient identified a novel splicing mutation (IVS1+1G>A) in intron 1, which is considered to be the pathogenic mutation. CONCLUSION: We have identified a novel ABCD1 mutation as the likely cause of CCALD in a Chinese patient.

[Evaluation on cost-effectiveness of snail control project by environmental modification in hilly regions].

OBJECTIVE: To evaluate the cost-effectiveness of the snail control project by environmental modification in order to provide the evidence for quickly interrupting the transmission of schistosomiasis in hilly regions. METHODS: Field investigations were carried out. The changes of the snail habitat areas were compared before and after the snail control project. The direct costs of the snail control were calculated. The reduction rates of snail area and snail density were regarded as the evaluation indexes of the effectiveness. The costs for reduction of 1% of snail area and 1% of snail density were used as the unit for cost-effectiveness analysis. RESULTS: After the 15 projects were implemented, there were no snails in 12 areas. The reduction rates of snail areas were 72.22% to 100%. The reduction rates of the snail area and density were both 100% in the areas with digging new ditches to fill up the old ones and building reservoirs. The total cost of 15 projects was 1 450 800 Yuan. The average cost per unit was 0.56 Yuan/m2. After the snail control project by digging new ditches to fill up the old ones was implemented, the costs of snail area and density decreased by one unit were 300 -700 Yuan, by building reservoirs, the costs were 600 -2 600 Yuan, by building fishpond, the costs were 1 200 - 1 500 Yuan, by watershed comprehensive measures, the costs were 900 - 2 700 Yuan. The cost of digging new ditches to fill up the old ones was significantly lower than that of building reservoirs or watershed comprehensive measures, but there was no significant difference between building reservoirs and watershed comprehensive measures. CONCLUSIONS: In hilly regions, the implementation of snail control project by environmental modification combined with construction of water conservancy is effective, and the cost-effectiveness of the snail control with digging new ditches to fill up the old ones is excellent.