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1.
Front Plant Sci ; 15: 1395628, 2024.
Article in English | MEDLINE | ID: mdl-38817929

ABSTRACT

Plant epiphytic microorganisms have established a unique symbiotic relationship with plants, which has a significant impact on their growth, immune defense, and environmental adaptation. However, the impact of fertilization methods on the epiphytic microbial community and their correlation with the yield and quality of medicinal plant was still unclear. In current study, we conducted a field fertilization experiment and analyzed the composition of epiphytic bacterial and fungal communities employing high throughput sequencing data in different organs (roots, stems, and leaves) of Salvia miltiorrhiza, as well as their correlation with plant growth. The results showed that fertilization significantly affected the active ingredients and hormone content, soil physicochemical properties, and the composition of epiphytic microbial communities. After fertilization, the plant surface was enriched with a core microbial community mainly composed of bacteria from Firmicutes, Proteobacteria, and Actinobacteria, as well as fungi from Zygomycota and Ascomycota. Additionally, plant growth hormones were the principal factors leading to alterations in the epiphytic microbial community of S. miltiorrhiza. Thus, the most effective method of fertilization involved the application of base fertilizer in combination with foliar fertilizer. This study provides a new perspective for studying the correlation between microbial community function and the quality of S. miltiorrhiza, and also provides a theoretical basis for the cultivation and sustainable development of high-quality medicinal plants.

2.
PLoS One ; 18(11): e0289750, 2023.
Article in English | MEDLINE | ID: mdl-37972042

ABSTRACT

This paper aims to effectively reduce CO2 emissions by examining the impact of three distinct incentive and constraint policies on the quality of rating and certification information in China's green bond issuance market. To accomplish this, the government has implemented incentives, while regulators have introduced constraints to curb the spread of inflated rating and certification information. We build on the integrated rating and certification regulation mechanism by presenting a two-stage Stackelberg game model that involves four key participants: the China Securities Regulatory Commission, local governments, green evaluation and certification agencies, and credit rating agencies. We incorporate environmental effects indicators into the expected utility of rating and certification agencies to investigate the equilibrium conditions under three policy scenarios: a single financial incentive policy, a single regulatory constraint policy, and a combined incentive and constraint policy. The paper employs Stackelberg game theory to analyze how different policies mitigate the occurrence of "inflated" ratings and "greenwashing" in certifications. Numerical analysis is conducted to validate the theoretical findings. Moreover, we assess the impact of these policies on the quality of rating and evaluation information, using data from China's green bond issuance market between 2016 and 2021. Our research offers valuable management insights and regulatory recommendations for both regulators and local governments.


Subject(s)
Fiscal Policy , Motivation , Humans , Policy , Certification , China , Local Government
3.
PLoS One ; 16(12): e0259759, 2021.
Article in English | MEDLINE | ID: mdl-34855760

ABSTRACT

We developed a dual-reputational rating shopping model to introduce public and institutional reputations. Investor's and regulator's penalty rates are described as public and institutional reputations, respectively. We achieved the available conditions of single-rating and dual-rating regulations to prevent rating inflation in this model. To examine the regulatory effects of different types of regulations on Chinese corporate bond ratings, we utilize panel ordered logit models. Theoretical analysis and empirical tests show that, when the reputation effect is low, the single-rating regulation is better at improving rating quality, and when the reputation effect is high, the dual-rating regulation induces rating agencies to provide more accurate ratings. Compared to the regulatory effects of the single-rating and the multi-rating regulations, the dual-rating regulation most effectively improves the rating quality of corporate bonds and prevents rating inflation.


Subject(s)
Investments , Models, Economic , China , Investments/legislation & jurisprudence , Investments/organization & administration
4.
Food Chem ; 344: 128726, 2021 May 15.
Article in English | MEDLINE | ID: mdl-33280961

ABSTRACT

Mother liquor sugar (MLS), as the by-product of stevia production, contained ~65% steviol glycosides (SGs). Recovery of the SGs from MLS was achieved by crystallization coupled with reversed-phase chromatography. Crystallization was done by dissolving MLS in methanol solution and SGs were crystallized due to the polarity difference from the medium. Composition of SGs crystals differed with various temperature, time, solid-to-liquid ratio and water content. SGs were 42.25% recovered with high purity of 96.89% under optimal conditions (solid-to-liquid ratio = 1:5 (w/v), T = 25 °C, t = 24 h) in absolute methanol. The liquid phase after crystallization was subsequently subjected to reversed-phase chromatography, whereby the impurities were firstly eluted with 35% (v/v) ethanol solution and the purified SGs were then desorbed by absolute ethanol, finally recovering 95.20% of SGs in the purity of 98.08%. The total SGs recovery of the whole procedure was 97.23%. The two-step purification was easy-to-operate and feasible to scale-up for industrial application.


Subject(s)
Chromatography, Reverse-Phase/methods , Crystallization/methods , Diterpenes, Kaurane/chemistry , Diterpenes, Kaurane/isolation & purification , Glucosides/chemistry , Glucosides/isolation & purification , Stevia/chemistry , Ethanol/chemistry , Plant Leaves/chemistry
5.
PLoS One ; 15(5): e0232804, 2020.
Article in English | MEDLINE | ID: mdl-32437354

ABSTRACT

This article adds to the existing literature on global rating agencies (GRAs, i.e., the S&P, Moody's, and Fitch) and domestic rating agencies (DRAs). In our research, we introduce the reputation, rating cost and rating accuracy of rating agencies to improve the Hotelling model. According to the theoretical analysis and empirical tests, the results show that the open policy of the Chinese rating industry contributes to higher rating quality in the domestic bond market. This open policy leads to rating convergence between DRAs and GRAs from in the long term.


Subject(s)
Capital Financing/economics , Investments/economics , Organizations/economics , Capital Financing/classification , China , Humans , Investments/classification , Organizations/classification , Policy
6.
J Cancer ; 11(3): 648-656, 2020.
Article in English | MEDLINE | ID: mdl-31942188

ABSTRACT

Programmed death receptor-1 (PD-1) and T cell immunoglobulin and mucin domain-containing protein-3 (Tim-3) play important roles in tumor immune evasion. PD-1 blockade could produce an effective antitumor effect in many solid tumors except prostate cancer (PCa) because of rare programmed death ligand-1 (PD-L1) expression on PCa cells. Streptavidin (SA)-GM-CSF surface-anchored tumor cell (Anchored GM-CSF) vaccines could increase the number of tumor-infiltrating lymphocytes (TILs) and induce specific antitumor immune responses. The Anchored-GM-CSF vaccine and anti-PD-1 antibodies exerted synergistic effects in mouse models of PCa metastasis. However, the response rate was low due to the presence of other negative regulatory pathways. Tim-3 expression could be upregulated at resistance to combination therapy with anti-PD-1 antibodies and the Anchored GM-CSF vaccine. Sequential administration of anti-PD-1 and anti-Tim-3 antibodies could further improve the efficacy of the Anchored GM-CSF vaccine therapy, and tumor regression was noted in over 60% of animals. This triple therapy improved the specific cytotoxic activity, proliferation and secretion of CD8+ TILs and reduced the production of tumor-promoting cytokines. These findings indicated that this triple therapy could induce a robust antitumor immune response in mouse models of PCa.

7.
PLoS One ; 13(10): e0205415, 2018.
Article in English | MEDLINE | ID: mdl-30332467

ABSTRACT

Economic cycles may lead to changes in corporate bond credit ratings. This paper utilizes the Markov model to describe transition probability matrixes of economic states for the separation of economic cycles. We develop a new model, which we term the Markov rating shopping dual reputation model, incorporating two reputation effects. This model is well suited to analyze the conditions of the dual rating incentive regulation and the constraint regulation for preventing rating inflation in collusion among credit rating agencies. Then, we apply the Markov regime switching-vector auto-regression (MS-VAR) to estimate the transition probability matrixes of America, England, Japan and China. Based on the numerical analysis and the simulations, the results show that a dual rating regulation can prevent the collusion of inflated ratings, as well as increased rating fees with the separation of economic cycles; additionally, when separating the economic cycles, a constraint regulation is more effective at reducing the risk of rating inflation in collusion and regulatory cost.


Subject(s)
Gross Domestic Product/legislation & jurisprudence , Inflation, Economic/legislation & jurisprudence , Models, Economic , China , England , Humans , Japan , Markov Chains , United States
8.
PLoS One ; 13(5): e0196792, 2018.
Article in English | MEDLINE | ID: mdl-29723295

ABSTRACT

The fat-tail financial data and cyclical financial market makes it difficult for the fixed structure model based on Gaussian distribution to characterize the dynamics of corporate bonds spreads. Using a flexible structure model based on generalized error distribution, this paper focuses on the impact of macro-level factors on the spreads of corporate bonds in China. It is found that in China's corporate bonds market, macroeconomic conditions have obvious structural transformational effects on bonds spreads, and their structural features remain stable with the downgrade of bonds ratings. The impact of macroeconomic conditions on spreads is significant for different structures, and the differences between the structures increase as ratings decline. For different structures, the persistent characteristics of bonds spreads are obviously stronger than those of recursive ones, which suggest an obvious speculation in bonds market. It is also found that the structure switching of bonds with different ratings is not synchronous, which indicates the shift of investment between different grades of bonds.


Subject(s)
Investments/economics , Models, Econometric , China , Costs and Cost Analysis/economics , Economics/trends , Markov Chains , Professional Corporations/economics , Risk , Statistical Distributions
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