Ferric Oxide Nanocrystals-Embedded Co/Fe-MOF with Self-Tuned d-Band Centers for Boosting Urea-Assisted Overall Water Splitting.

A novel semiconductive Co/Fe-MOF embedded with Fe2 O3 nanocrystals (Fe2 O3 @CoFe-MOF) is developed as a trifunctional electrocatalyst for the urea oxidation reaction (UOR), oxygen evolution reaction (OER), and hydrogen evolution reaction for enhancing the efficiency of the hydrogen production via the urea-assisted overall water splitting. Fe2 O3 @CoFe-TPyP-MOF comprises unsaturated metal-nitrogen coordination sites, affording enriched defects, self-tuned d-band centers, and efficient π-π interaction between different layers. Density functional theory calculation confirms that the adsorption of urea can be optimized at Fe2 O3 @CoFe-TPyP-MOF, realizing the efficient adsorption of intermediates and desorption of the final product of CO2 and N2 characterized by the in situ Fourier transform infrared spectroscopy. The two-electrode urea-assisted water splitting device-assembled with Fe2 O3 @CoFe-TPyP-MOF illustrates a low cell voltage of 1.41 V versus the reversible hydrogen electrode at the current density of 10 mA cm-2 , attaining the hydrogen production rate of 13.13 µmol min-1 in 1 m KOH with 0.33 m urea. The in situ electrochemical Raman spectra and other basic characterizations of the used electrocatalyst uncover that Fe2 O3 @CoFe-TPyP-MOF undergoes the reversible structural reconstruction after the UOR test, while it demonstrates the irreversible reconstruction after the OER measurement. This work redounds the progress of urea-assisted water spitting for hydrogen production.

A New Species of Diploderma (Reptilia: Squamata: Agamidae) from the upper Salween River in Eastern Tibet, China.

A new species of Diploderma is described from the upper Salween River Valley in eastern Tibet, China based on morphological and genetic data. The new species is morphologically most similar and phylogenetically closely related to D. laeviventre, but it can be easily diagnosed by having distinct conical scales on the post rictal region of the head, distinctively keeled ventral head and body scales, and different coloration of gular spots and dorsolateral stripes in both sexes. The taxonomic discovery further highlights the underestimated diversity of the genus and the importance of habitat conservation of the neglected hot-dry valley ecosystems in the Hengduan Mountain Region of China.

Amolops caelumnoctis Rao amp; Wilkinson, 2007, a Junior Synonym of A. splendissimus Orlov amp; Ho, 2007 (Amphibia: Anura: Ranidae).

Amolops splendissimus Orlov and Ho, 2007 and A. caelumnoctis Rao and Wilkinson, 2007 were described almost simultaneously from either side of the China-Vietnam border. The two species share a strong morphological resemblance, and their taxonomic distinctiveness has been questioned, yet no one has confirmed the taxonomic relationship and status between the two taxa. To resolve this taxonomic issue, we collected additional topotypic and near-topotypic specimens of A. splendissimus and A. caelumnoctis from both China (A. caelumnoctis: Wenshan County, Yunnan Province; type locality Luchun County, Yunnan Province), and Vietnam (A. splendissimus: Tam Duong District, Lai Chau Province; type locality Mount Ky Quan San, Bat Xat, Lao Cai Province). Molecular analysis based on a 16S rRNA fragment revealed minimal genetic divergences between the two taxa (0.0%0.4% uncorrected p-distance), and both species are closely related to A. viridimaculatus (2.1%2.3%) and A. medogensis (3.5%3.7%). Morphological comparisons between the newly collected specimens and the original descriptions of both species further support the lack of distinctiveness of the two species, hence, we conclude that A. caelumnoctis is a junior synonym of A. splendissimus.

Has COVID-19 Changed the Hedge Effectiveness of Bitcoin?

The Bitcoin market has become a research hotspot after the outbreak of Covid-19. In this paper, we focus on the relationships between the Bitcoin spot and futures. Specifically, we adopt the vector autoregression-dynamic correlation coefficient-generalized autoregressive conditional heteroskedasticity (VAR-DCC-GARCH) model and vector autoregression-Baba, Engle, Kraft, and Kroner-generalized autoregressive conditional heteroskedasticity (VAR-BEKK-GARCH) models and calculate the hedging effectiveness (HE) value to investigate the dynamic correlation and volatility spillover and assess the risk reduction of the Bitcoin futures to spot. The empirical results show that the Bitcoin spot and futures markets are highly connected; second, there exists a bi-directional volatility spillover between the spot and futures market; third, the HE value is equal to 0.6446, which indicates that Bitcoin futures can indeed hedge the risks in the Bitcoin spot market. Furthermore, we update the data to the post-Covid-19 period to do the robustness checks. The results do not change our conclusion that Bitcoin futures can hedge the risks in the Bitcoin spot market, and besides, the post-Covid-19 results indicate that the hedging ability of Bitcoin futures increased. Finally, we test whether the gold futures can be used as a Bitcoin spot market hedge, and we further control other cryptocurrencies to illustrate the hedging ability of the Bitcoin futures to the Bitcoin spot. Overall, the empirical results in this paper will surely benefit the related investors in the Bitcoin market.

Review of the emGekko/em (emJaponigekko/em) emsubpalmatus/em complex (Squamata, Sauria, Gekkonidae), with description of a new species from China.

The gecko species Gekko (Japonigekko) subpalmatus was previously recorded with a relatively wide distribution from eastern, southern, and southeastern China. However, the populations in southern China are currently recognized as another valid species G. (J.) melli. In this study, we conduct a detailed morphological examination and phylogenetic analysis of the populations currently treated as G. (J.) subpalmatus or G. (J.) melli, which are collectively designated as the G. (J.) subpalmatus complex. Our results reveal that the G. (J.) subpalmatus complex comprises three evolutionarily independent taxa. The populations from Zhejiang, eastern China are G. (J.) subpalmatus, those from southern China are G. (J.) melli, while those from the Sichuan Basin, southwestern China represent a cryptic species, Gekko (Japonigekko) cib sp. nov.. Gekko (Japonigekko) cib sp. nov. can be distinguished from all congeners, by its divergence from other complex members in the CYTB and 16S genes, and a combination of morphological characteristics, especially in hemipenial morphology. Historic records of G. (J.) subpalmatus complex are also reviewed.

Investor attention and cryptocurrency: Evidence from the Bitcoin market.

This paper adds to the growing literature of cryptocurrency and behavioral finance. Specifically, we investigate the relationships between the novel investor attention and financial characteristics of Bitcoin, i.e., return and realized volatility, which are the two most important characteristics of one certain asset. Our empirical results show supports in the behavior finance area and argue that investor attention is the granger cause to changes in Bitcoin market both in return and realized volatility. Moreover, we make in-depth investigations by exploring the linear and non-linear connections of investor attention on Bitcoin. The results indeed demonstrate that investor attention shows sophisticated impacts on return and realized volatility of Bitcoin. Furthermore, we conduct one basic and several long horizons out-of-sample forecasts to explore the predictive ability of investor attention. The results show that compared with the traditional historical average benchmark model in forecasting technologies, investor attention improves prediction accuracy in Bitcoin return. Finally, we build economic portfolios based on investor attention and argue that investor attention can further generate significant economic values. To sum up, investor attention is a non-negligible pricing factor for Bitcoin asset.

Synthesis and evaluation of new phenyl acrylamide derivatives as potent non-nucleoside anti-HBV agents.

As a continuation of our previous work, a series of new phenyl acrylamide derivatives (4Aa-g, 4Ba-t, 5 and 6a-c) were designed and synthesized as non-nucleoside anti-HBV agents. Among them, compound 4Bs could potently inhibit HBV DNA replication in wild-type and lamivudine (3TC)/entecavir resistant HBV mutant strains with IC50 values of 0.19 and 0.18 µM, respectively. Notably, the selective index value of 4Bs was above 526, indicating the favorable safety profile. Interestingly, unlike nucleoside analogue 3TC, 4Bs could significantly inhibit 3.5 kb pgRNA expression. Molecular docking study revealed that 4Bs could fit well into the dimer-dimer interface of HBV core protein by hydrophobic, π-π and H-bond interactions. Considering the potent anti-HBV activity, low toxicity and diverse anti-HBV mechanism from that of nucleoside anti-HBV agent 3TC, compound 4Bs might be a promising lead to develop novel non-nucleoside anti-HBV therapeutic agents, and warranted further investigation.

Discovery of novel quinazolinone derivatives as potential anti-HBV and anti-HCC agents.

As a continuation of earlier works, a series of novel quinazolinone derivatives (5a-s) were synthesized and evaluated for their in vitro anti-HBV and anti-hepatocellular carcinoma cell (HCC) activities. Among them, compounds 5j and 5k exhibited most potent inhibitory effect on HBV DNA replication in both drug sensitive and resistant (lamivudine and entecavir) HBV strains. Interestingly, besides the anti-HBV effect, compound 5k could significantly inhibit the proliferation of HepG2, HUH7 and SK- cells, with IC50 values of 5.44, 6.42 and 6.75 µM, respectively, indicating its potential anti-HCC activity. Notably, the in vitro anti-HCC activity of 5k were more potent than that of positive control 5-fluorouracil and sorafenib. Further studies revealed that compound 5k could induce HepG2 cells apoptosis by dose-dependently upregulating Bad and Bax expression and decreasing Bcl-2 and Bcl-xl protein level. Considering the potent anti-HBV and anti-HCC effect, compound 5k might be a promising lead to develop novel therapeutic agents towards HBV infection and HBV-induced HCC.

Synthesis and assessment of phenylacrylamide derivatives as potential anti-oxidant and anti-inflammatory agents.

Oxidative stress and inflammation are major causes of numerous life-threatening human diseases. In the present study, we synthesized a series of phenylacrylamide derivatives as novel anti-oxidant and anti-inflammatory agents. Biological evaluation showed that compound 6a could more potently protect HBZY-1 mesangial cells from H2O2-caused oxidative stress than positive controls resveratrol and sulforaphane by dose- and time-dependently impairing the ROS accumulation. Preliminary anti-oxidant mechanism studies indicated that compound 6a could activate Nrf2 and increase the protein and mRNA expression of downstream anti-oxidant enzymes, ie. NQO-1, HO-1, GCLM and GCLC. Notably, 6a could inhibit the production of NO and the activity of NF-κB in LPS-stimulated HBZY-1 mesangial cells, indicating its potential anti-inflammatory activity. Interestingly, both effects could be significantly attenuated by Nrf2 inhibitor TRG, HO-1 inhibitor ZnPP or GCL inhibitor BSO at non-toxic concentrations, confirming that the anti-oxidant and anti-inflammatory activity of 6a is related to the activation of Nrf2 signaling pathway. These results, together with the relatively safety profile, indicated that compound 6a could be a promising lead to develop novel anti-oxidant and anti-inflammatory agents, thus preventing diseases induced by oxidative stress and inflammation.

Assessment of quinazolinone derivatives as novel non-nucleoside hepatitis B virus inhibitors.

Hepatitis B virus (HBV) infection is a worldwide public health issue. Search for novel non-nucleoside anti-HBV agents is of great importance. In the present study, a series of quinazolinones derivatives (4a-t and 5a-f) were synthesized and evaluated as novel anti-HBV agents. Among them, compounds 5e and 5f could significantly inhibit HBV DNA replication with IC50 values of 1.54 µM and 0.71 µM, respectively. Interestingly, the selective index values of 5f was higher than that of lead compound K284-1405, suggesting 5f possessed relatively safety profile than K284-1405. Notably, 5e and 5f exhibited remarkably anti-HBV activities against lamivudine and entecavir resistant HBV strain with IC50 values of 1.90 and 0.84 µM, confirming their effectiveness against resistant HBV strain. In addition, molecular docking studies indicated that compounds 5e and 5f could well fit into the dimer-dimer interface of HBV core protein dominated by hydrophobic interactions. Notably, their binding modes were different from the lead compound K284-1405, which may be attributed to the additional substituent groups in the quinazolinone scaffold. Taken together, 5e and 5f possessed novel chemical structure and potent anti-HBV activity against both drug sensitive and resistant HBV strains, thus warranting further research as potential non-nucleoside anti-HBV candidates.

Synthesis and biological evaluation of bifendate derivatives bearing acrylamide moiety as novel antioxidant agents.

Oxidative stress plays a significant role in the pathogenesis of various human diseases. In this study, a series of bifendate derivatives bearing acrylamide moiety were synthesized and evaluated as anti-oxidant agents. Biological evaluation indicated that compounds 6a and 6e displayed more potent cytoprotective effect against H2O2-induced HBZY-1 mesangial cells death than lead compound bifendate and positive control resveratrol and sulforaphane. Preliminary anti-oxidant mechanism studies showed that compound 6e could diminish the ROS accumulation by dose- and time-dependently activating Nrf2 and increasing the expression of downstream detoxification enzymes NQO-1, HO-1, GCLM and GCLC at protein and mRNA levels, thus displaying potent anti-oxidant activity. Interestingly, the Nrf2 activating effect of 6e is achieved, at least partly, in Michael acceptor and Keap1-dependent manners. These results, together with the low intrinsic cytotoxicity, suggested that compound 6e might be a promising lead for the development of novel anti-oxidant agents to prevent diseases induced by oxidative stress.

Assessment of a bifendate derivative bearing a 6,7-dihydro-dibenzo[c,e]azepine scaffold as a potential anti-metastatic agent.

Multidrug resistance (MDR) and metastasis are major causes of mortality in patients with cancer. We recently reported a bifendate derivative bearing a dibenzo[c,e]azepine scaffold (4i) as a P-gp and BCRP-medicated MDR reversal agent. As a continuation of the previous research, its ability to inhibit cancer metastasis was investigated in MDA-MB-231 cells in the present work. Wound-healing and chamber migration assays showed that 4i could significantly attenuate the migration of MDA-MB-231 cells. Additionally, 4i obviously suppressed the invasive activity of MDA-MB-231 cells, thus displaying potential anti-metastasis activity. Preliminary mechanism studies indicated that the anti-metastasis activity of 4i was associated with the inhibitory effect on the activity and expression of MMP-2 and MMP-9. These results, together with the previous findings, suggest that compound 4i could be a promising lead for the development of novel anti-cancer agents with anti-MDR and metastatic activities.

Carbon price volatility: The case of China.

Based on carbon spot prices selected from seven carbon pilots, we assess the financial performances related to carbon volatility in China on the overall perspective. According to the results, the Chinese carbon market fluctuated severely at the beginning of carbon trading, but has stabilised in general, despite several dramatic changes related to 'yearly compliance events'. Long-term memory exists in the volatility series. Moreover, asymmetry exists in the Chinese carbon market, and volatility reacts more severely to good news than to bad news. Finally, we discuss our empirical results, and make certain suggestions regarding firms' awareness, international cooperation and individual investors not only for policy makers in China but also for other developing countries who are contemplating either commencing carbon trading or improving the current market.

Design, synthesis and evaluation of novel phenyl propionamide derivatives as non-nucleoside hepatitis B virus inhibitors.

As an ongoing search for potent non-nucleoside anti-HBV agents with novel structures, we described a series of phenyl propionamide derivatives (3a-b, 4a-e, 7a-g, 8a-h and 9a-b) by pharmacophore fusion strategy in the present work. All the compounds exhibited an anti-HBV activity to some extent. Among them, compounds 8d and 9b displayed most potent anti-HBV activity with IC50 values on HBV DNA replication of 0.46 and 0.14 µM, respectively. And the selective index values of 8d and 9b were more than 217.39 and 153.14, suggesting that 8d and 9b exhibited favorable safety profiles. Interestingly, 8d and 9b possessed significantly antiviral activities against lamivudine and entecavir resistant HBV mutants with IC50 values of 0.77 and 0.32 µM. Notably, preliminary anti-HBV action mechanism studies showed that 8d could inhibit intracellular HBV pgRNA and RT activity of the HBV polymerase. Molecular docking studies suggested that compound 8d could fit into the dimer-dimer interface of HBV core protein by hydrophobic interaction. In addition, in silico prediction of physicochemical properties showed that 8d conformed well to the Lipinski's rule of five, suggesting its potential for use as a drug like molecule. Taken together, 8d possessed significantly anti-HBV activity, low toxicity, diverse anti-HBV mechanism and favorable physicochemical properties, and warranted further investigation as a promising non-nucleoside anti-HBV candidate.