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Morphology-dependent properties are significant in chemistry and material sciences. This laboratory experiment, designed for upper-division undergraduates in chemistry and related majors, emphasizes the concepts of the shape-controlled synthesis of crystal particles and the influences of crystal particle morphologies on their reaction performances. Cu[subscript 2]O particles with different morphologies, cubic and truncated octahedral, were synthesized under mild conditions. The resulting products were examined with XRD and SEM to characterize their phase components and surface morphologies. The activity differences of these products in the reduction of ferric thiocyanate solution, K[subscript (n-3)][Fe(SCN)[subscript n]], were measured and compared. The truncated octahedral Cu[subscript 2]O particles showed higher activity than the cubic ones, which is attributed to differences in their shapes and exposed facets. This experiment can help undergraduates realize that the performances of crystal particles are related not only to their structures and dimensions but also to their morphologies.

Background: Fungal toxins are highly toxic and widely distributed, presenting a considerable threat to global agricultural development. Addressing the issue of aflatoxin B1 (AFB1) contamination in feed, it is crucial to ascertain the effectiveness and mechanisms of microbial strains in degradation. Results: This study used isotope tracing and nuclear magnetic resonance (NMR) to investigate the degradation products of Bacillus amyloliquefaciens YUAD7 in complex substrates. By tracing 14C34-AFB1 and utilizing NMR, ultra-performance liquid chromatography–quadrupole time-of-flight/mass spectrometry (UPLC–Q-TOF/MS) purification and identification techniques, it was confirmed that AFB1 was degraded by YUAD7 into C12H14O4, C5H12N2O2, C10H14O2, and C4H12N2O, effectively removing 99.7% of AFB1 (100 μg/kg) from alfalfa silage. YUAD7 targeted the ester bond in the vanillin lactone ring structure, the ether bond in the furan ring structure, and the unsaturated carbon–carbon double bond in the furan ring structure during AFB1 degradation, disrupting the toxic sites responsible for AFB1's carcinogenic, teratogenic, and mutagenic effects and achieving biodegradation. Moreover, B. amyloliquefaciens YUAD7 transformed AFB1 through processes like hydrogenation, enzyme modification, and the loss of the -CO group while also being associated with metabolic pathways such as alanine, aspartate, glutamate metabolism, glutathione metabolism, cysteine and methionine metabolism, and pentose and glucuronate interconversions. Conclusions: The utilization of isotope tracing allowed for rapid identification of degradation products in complex substrates, while NMR elucidated the structures of these products. This deepens our understanding of AFB1 biodegradation mechanisms, providing technical support for the practical application of these bacteria in degradation, and new insights into studying the biological degradation mechanism. B. amyloliquefaciens YUAD7 can be used as a potential strain for degrading AFB1 in large-scale silage. [ABSTRACT FROM AUTHOR]

Reducing the fossil fuel consumption of aluminum smelting production, which consumes around 8% of electricity annually, is of great significance for China's energy sector. One possible solution is to integrate wind power as supply for aluminum smelter loads. Based on this background, this paper studies an actual industrial case—an isolated power system for aluminum production with integrated wind penetration levels as high as 30%. However, due to the integration of wind power, frequency stability issues become critical in such a system. Therefore, a demand-side frequency control scheme responding to frequency deviations of the system is proposed in this paper to control the load power of aluminum smelters. The scheme is designed based on the relationship between the DC voltage supply for aluminum smelting loads and the commutation voltage drop which can be adjusted by changing the inductance value of the saturable reactors. Finally, simulations under both N-1 and N-2 contingency scenarios demonstrate the effectiveness of the proposed control scheme considering various wind power outputs. [ABSTRACT FROM AUTHOR]

Objective: To study the effect of repeated administration of Zhuhong ointment on renal antioxidant capability of ulcerous skin in rats, in order to further discuss the mechanism of mercury contained in Zhuhong ointment on the antioxidant capability of kidney in skin ulcer rats., Method: Eighty SD rats were randomly divided into eight groups: Zhuhong ointment A, B, C, D, E (1.219, 0.609, 0.305, 0.152, 0.76 g x kg(-1)) groups, the vaseline group, the ulcer model group and the impairment control group. The levels of NAG and RBP of toxicity for early kidney tubular injury and T-AOC, SOD, GSH-PX and GSH in kidney were determined after consecutive administration for 14 days., Result: Compared with ulcer model group, the levels of RBP in groups A, B, C and D increased, while the levels of NAG increased only in the group A. The level of T-AOC increased in groups A, B and C. The level of T-SOD increased in the group E, while it dropped down greatly in the group A. The level of GSH-PX increased in groups A, B and C. The content of GSH increased in every dose groups., Conclusion: Antioxidant capacity in rats can be increased in a reasonable dose of Zhuhong ointment, but some antioxidant activity can be notably inhibited by with the increase of dose.

Objective: To study the effects of Zhuhong ointment on accumulation in the body of mercury and the pathological morphology changes of kidney, via the measurement of related indicators of the skin-impaired model rat., Method: Eighty-eight SD rats were randomly divided into the impairment control group, and high-, middle-, low-dose Zhuhong ointment groups. Each group was treated by corresponding methods for 4 weeks, and recovering for 4 weeks. Urinary potein (PRO), pH, Beta N-acetyl aminoglycosidase enzymes (NAG) and beta2-microglobulin (beta2-MG) contents in urine were taken as monitoring indexes, blood urea nitrogen (BUN) and serum creatinine (SCr) in blood and the levels of mercury in urine, blood and kidney were tested, and the pathological morphology changes of kidney were observed., Result: After treatment for 4 weeks, compared with impairment control group, the levels of mercury in urine, blood and kidney in every dose group increased significantly (P < 0.01). And the relation exists between toxicity and dose on Zhuhong ointment. After recovery for 4 weeks, the levels of mercury in urine and blood in every dose group restore normal, while the level of mercury in kidney in high- dose group still increased (P < 0.01). The level of NAG increased only in high-dose group. There was no significant difference in NAG contents between Zhuhong ointment groups and the impairment control group (P < 0.05)., Conclusion: Excess using Zhuhong ointment repeatedly may lead to accumulation of mercury and pathological morphology changes of kidney. So the levels of mercury in the body and related indicators of renal functions should be tested in clinical when long-term using Zhuhong ointment.