Dependences and risk spillover effects between Bitcoin, crude oil and other traditional financial markets during the COVID-19 outbreak.

This study examines the relationship and risk spillover between Bitcoin, crude oil, and six traditional markets (the US stock, Chinese stock, gold, bond, currency, and real estate markets) from 2019 to 2020, during which the coronavirus disease 2019 (COVID-19) outbreak occurred as well. We first discuss the static relationship between Bitcoin and these markets using a quantile-on-quantile model and examine the dynamic relationship using a time-varying copula model. A conditional value-at-risk model is subsequently used to estimate the risk spillover between the markets studied. The empirical results reveal that the relationship between these markets is always time-varying, and the COVID-19 outbreak has revealed such changes in the relationship between Bitcoin and other traditional financial markets. The risk of all single markets has enhanced because of the pandemic. Further, the risk spillover of these markets has also changed dramatically since the COVID-19 outbreak during which the Bitcoin market has played an important role and exerted a significant impact on the crude oil market, and the four other markets (US stock, gold, Chinese stock, and real estate markets). Overall, our findings indicate that investors and policymakers need to be made aware of the risk spillover between Bitcoin, crude oil, and other traditional markets and that flexible hedge strategies and policies should be implemented in response to the challenges and economic recession observed following the COVID-19 outbreak.

Preventive effect of swim bladder hydrolysates on cyclophosphamide-induced ovarian injury in mice.

AIMS: This study aimed to prepare swim bladder hydrolysate (SBH) with Mn  < 4000 Da, and investigate its effects on cyclophosphamide (CTX)-mediated ovarian injury in mice. METHODS: Hydrolysates were prepared by heating extraction, enzymatic hydrolysis and ultrafiltration. Mn and distribution of SBH were analyzed via gel filtration chromatography and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Changes in the mouse oestrus cycle were determined by cytological examination. The number of follicles was examined using histopathology. Enzyme-linked immunosorbent assays (ELISAs) were used to determine the serum sex hormone levels. RESULTS: The Mn of SBH, prepared by heating extraction, enzymatic hydrolysis, ultrafiltration, and from different batches, was below 4000 Da, and the preparation process was stable. Compared with the control group, the low-, middle-, and high-dose SBH treatment groups showed different trends in oestrus duration, serum sex hormone levels, and the number of primordial and secondary follicles. The oestrus cycle duration of the high-dose SBH group was longer than that of the model group. The serum luteinizing hormone, follicle-stimulating hormone, and anti-Müllerian hormone levels in the middle-dose group were the closest to those of control group. The number of primordial and secondary follicles in the medium-dose group was significantly higher than that in the model group and closest to those of control group. CONCLUSION: After heating extraction, trypsin/Flavourzyme hydrolysis and ultrafiltration, a hydrolysate with Mn below 4000 Da could be prepared. We found that a moderate (400 mg/kg) SBH dose resulted in the greatest effect on ovarian injury remission in mice.

A newly identified polyunsaturated macamide alleviates dextran sulfate sodium-induced colitis in mice.

Macamides are a class of bioactive amide alkaloids found only in maca (Lepidium meyenii). Recent studies have shown that macamide-rich extracts possess various biological activities, such as antioxidative, immune-enhancing, and reproductive health-improving activities. In the present study, N-benzyl docosahexaenamide (NB-DHA), a newly identified macamide with the highest degree of unsaturation among all identified macamides, was identified from the maca extract. Microalgae oil, a docosahexaenoic acid-rich substance, was used as the starting material for the synthesis of NB-DHA. The effects of NB-DHA in colitis-induced mice were evaluated. NB-DHA significantly alleviated weight loss, shortening of colon length, and occult blood occurrence in mice with dextran sulfate sodium-induced colitis. Histological analysis revealed that following the administration of NB-DHA in mice with colitis, the infiltration of inflammatory cells and levels of proinflammatory factors, such as tumor necrosis factor-α, interleukin (IL)-1ß, IL-6, and myeloperoxidase, decreased, whereas the level of the anti-inflammatory factor IL-10 increased. Furthermore, the decreased expression of intestinal tight junction proteins caused by colitis was upregulated by the administration of NB-DHA. These results indicate that NB-DHA could be developed as a therapeutic agent for ulcerative colitis.