Marine microplastic pollution and plastic pollution are two different things but they are related. In the past 10 years, several countries and regions have issued a ban on microbeads. We analyze the ...above countries or regions according to three aspects: whether there is special legislation for marine microplastic pollution, the subject of the regulations, and the prevention and control measures. The common feature of the policy documents of these countries is that they target the ban of only microbeads and no other types of microplastics. Based on a comparative study, we found three dilemmas in the regulation of marine microplastic pollution. We conducted a comparative analysis of the legislation or policy documents of the above-mentioned countries and regions in order to identify how they solve the above difficulties. We summarized three legislative and policy regulation models and analyzed their respective advantages. Based on legal theories and empirical methods, some observations and suggestions are made regarding the regulation of primary and secondary microplastic pollution, especially in China’s situation.
This paper introduces a new approach to constructing optimal mean-variance portfolios. The approach relies on a novel unconstrained regression representation of the mean-variance optimization problem ...combined with high-dimensional sparse-regression methods. Our estimated portfolio, under a mild sparsity assumption, controls for risk and attains the maximum expected return as both the numbers of assets and observations grow. The superior properties of our approach are demonstrated through comprehensive simulation and empirical analysis. Notably, using our strategy, we find that investing in individual stocks, in addition to the Fama-French three-factor portfolios, leads to substantially improved performance.
The purpose of this study is to understand how consumers perceive amenities and their impact on promoting positive consumer emotions and comprehend the role of amenities in fostering urban ...consumption. We collected over 120,000 comments spanning 60 months (2015-2019) from 18 urban shopping centers in Shanghai. By applying text mining methods, we constructed a panel data model on the perception of four types of amenities and consumer emotions. Results indicate that different perceptions of amenities yield significantly different effects on consumer emotions. Specifically, we found that perceptions of cultural and safeguarded amenities significantly influence consumer emotions, albeit with different directions of impact. In contrast, perceptions of commercial and natural amenities did not significantly affect consumer emotions. The findings of this study provide a key reference for how to scientifically plan and reasonably introduce the types of amenities in urban consumption space, so as to reflect the promoting effect of amenities on urban consumption.
Hepatitis B virus (HBV) chronically infects more than 240 million people worldwide, resulting in chronic hepatitis, cirrhosis, and hepatocellular carcinoma. HBV vaccine is effective to prevent new ...HBV infection but does not offer therapeutic benefit to hepatitis B patients. Neither are current antiviral drugs curative of chronic hepatitis B. A more thorough understanding of HBV infection and replication holds a great promise for identification of novel antiviral drugs and design of optimal strategies towards the ultimate elimination of chronic hepatitis B. Recently, we have developed a robust HBV cell culture system and discovered that human apolipoprotein E (apoE) is enriched on the HBV envelope and promotes HBV infection and production. In the present study, we have determined the role of the low-density lipoprotein receptor (LDLR) in HBV infection. A LDLR-blocking monoclonal antibody potently inhibited HBV infection in HepG2 cells expressing the sodium taurocholate cotransporting polypeptide (NTCP) as well as in primary human hepatocytes. More importantly, small interfering RNAs (siRNAs)-mediated knockdown of LDLR expression and the CRISPR/Cas9-induced knockout of the LDLR gene markedly reduced HBV infection. A recombinant LDLR protein could block heparin-mediated apoE pulldown, suggesting that LDLR may act as an HBV cell attachment receptor via binding to the HBV-associated apoE. Collectively, these findings demonstrate that LDLR plays an important role in HBV infection probably by serving as a virus attachment receptor.
Co‐based spinel oxides, which are of mixing valences with the presence of both Co2+ and Co3+ at different atom locations, are considered as promising catalysts for the electrochemical oxidation of ...5‐hydroxymethylfurfural (HMF). Identifying the role of each atom site in the electroxidation of HMF is critical to design the advanced electrocatalysts. In this work, we found that Co2+Td in Co3O4 is capable of chemical adsorption for acidic organic molecules, and Co3+Oh play a decisive role in HMF oxidation. Thereafter, the Cu2+ was introduced in spinel oxides to enhance the exposure degree of Co3+ and to boost acidic adsorption and thus to enhance the electrocatalytic activity for HMF electrooxidation significantly.
The exploration of optimal geometrical site in Co3O4 for electrochemical HMF oxidation by the building tetrahedral (Zn2+) and octahedral (Al3+) blocks is described. The electrochemical results demonstrate that Co3+Oh are the best geometrical sites for HMF oxidation, and the chemical adsorption for acidic organic molecules is dominated by Co2+Td. The exposure degree of Co3+ is improved by Cu2+ and thus results in a record activity.
We study the estimation of (joint) moments of microstructure noise based on high frequency data. The estimation is conducted under a nonparametric setting, which allows the underlying price process ...to have jumps, the observation times to be irregularly spaced, and the noise to be dependent on the price process and to have diurnal features. Estimators of arbitrary orders of (joint) moments are provided, for which we establish consistency as well as central limit theorems. In particular, we provide estimators of autocovariances and autocorrelations of the noise. Simulation studies demonstrate excellent performance of our estimators in the presence of jumps, irregular observation times, and even rounding. Empirical studies reveal (moderate) positive autocorrelations of microstructure noise for the stocks tested.
Leaf pigment content retrieval is an essential research field in remote sensing. However, retrieval studies on anthocyanins are quite rare compared to those on chlorophylls and carotenoids. Given the ...critical physiological significance of anthocyanins, this situation should be improved. In this study, using the reflectance, partial least squares regression (PLSR) and Gaussian process regression (GPR) were sought to retrieve the leaf anthocyanin content. To our knowledge, this is the first time that PLSR and GPR have been employed in such studies. The results showed that, based on the logarithmic transformation of the reflectance (log(1/
)) with 564 and 705 nm, the GPR model performed the best (R
/RMSE (nmol/cm
): 0.93/2.18 in the calibration, and 0.93/2.20 in the validation) of all the investigated methods. The PLSR model involved four wavelengths and achieved relatively low accuracy (R
/RMSE (nmol/cm
): 0.87/2.88 in calibration, and 0.88/2.89 in validation). GPR apparently outperformed PLSR. The reason was likely that the non-linear property made GPR more effective than the linear PLSR in characterizing the relationship for the absorbance vs. content of anthocyanins. For GPR, selected wavelengths around the green peak and red edge region (one from each) were promising to build simple and accurate two-wavelength models with R
> 0.90.
Recent studies have indicated a protective role of physiological autophagy in ischemic heart disease. However, the underlying mechanisms of autophagy regulation after ischemia are poorly understood. ...Exosomes are nano-sized vesicles released from cells that play critical roles in mediating cell-to-cell communication through the transfer of microRNAs. In this study, we observed that miR-30a was highly enriched in exosomes from the serum of acute myocardial infarction (AMI) patients in vivo and culture medium of cardiomyocytes after hypoxic stimulation in vitro. We also found that hypoxia inducible factor (HIF)-1α regulates miR-30a, which efficiently transferred via exosomes between cardiomyocytes after hypoxia. Inhibition of miR-30a or release of exosomes increased the expression of the core autophagy regulators beclin-1, Atg12, and LC3II/LC3I, which contributed to maintaining the autophagic response in cardiomyocytes after hypoxia. Taken together, the present study showed that exosomes from hypoxic cardiomyocytes regulate autophagy by transferring miR-30a in a paracrine manner, which revealed a new pathway of autophagy regulation that might comprise a promising strategy to treat ischemic heart disease.
Key messages
miR-30a is highly enriched in exosomes from the serum of AMI patients.
Hypoxia induces miR-30a upregulation and enrichment into exosomes.
MiR-30a is efficiently transferred via exosomes between hypoxic cardiomyocytes.
Inhibition of exosome release contributes to maintaining of autophagy after hypoxia.
Inhibition of miR-30a augments autophagy after hypoxia.
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