25 research outputs found
Equilibrium Melting Temperature of Polymorphic Poly(L-lactide) and Its Supercooling Dependence on Growth Kinetics
In this study, the isothermal crystallization process of poly(l-lactide) (PLLA) has been investigated using in situ XRD, differential scanning calorimetry (DSC), and polarized optical microscopy (POM). Linear and nonlinear extrapolation methods have been deployed to estimate the equilibrium melting temperature ( T m 0 ), which is used for analyzing the supercooling dependence of the PLLA spherulitic growth rate (G). A double-melting behavior observed for PLLA under crystallization Tc < 120 °C has been attributed to the formation of both α′ and α crystals. The T m 0 values of both α′ and α crystals have been evaluated using the linear method (172.8 °C) and nonlinear method (196.4 °C), with the nonlinear estimate being 23.6 °C higher. A discontinuity in the temperature dependence of spherulite growth rate is observed around 128.3 °C. Regime II–III transition is found to occur at 128.3 °C when T m 0 = 196.4 °C as estimated by the nonlinear extrapolation method
Comprehensive overview of different medicinal parts from Morus alba L.: chemical compositions and pharmacological activities
Morus alba L., a common traditional Chinese medicine (TCM) with a centuries-old medicinal history, owned various medicinal parts like Mori folium, Mori ramulus, Mori cortex and Mori fructus. Different medical parts exhibit distinct modern pharmacological effects. Mori folium exhibited analgesic, anti-inflammatory, hypoglycemic action and lipid-regulation effects. Mori ramulus owned anti-bacterial, anti-asthmatic and diuretic activities. Mori cortex showed counteraction action of pain, inflammatory, bacterial, and platelet aggregation. Mori fructus could decompose fat, lower blood lipids and prevent vascular sclerosis. The main chemical components in Morus alba L. covered flavonoids, phenolic compounds, alkaloids, and amino acids. This article comprehensively analyzed the recent literature related to chemical components and pharmacological actions of M. alba L., summarizing 198 of ingredients and described the modern activities of different extracts and the bioactive constituents in the four parts from M. alba L. These results fully demonstrated the medicinal value of M. alba L., provided valuable references for further comprehensive development, and layed the foundation for the utilization of M. alba L
In silico Identification and Mechanism Exploration of Hepatotoxic Ingredients in Traditional Chinese Medicine
Backgrounds and AimsRecently, a growing number of hepatotoxicity cases aroused by Traditional Chinese Medicine (TCM) have been reported, causing increasing concern. To date, the reported predictive models for drug induced liver injury show low prediction accuracy and there are still no related reports for hepatotoxicity evaluation of TCM systematically. Additionally, the mechanism of herb induced liver injury (HILI) still remains unknown. The aim of the study was to identify potential hepatotoxic ingredients in TCM and explore the molecular mechanism of TCM against HILI.Materials and MethodsIn this study, we developed consensus models for HILI prediction by integrating the best single classifiers. The consensus model with best performance was applied to identify the potential hepatotoxic ingredients from the Traditional Chinese Medicine Systems Pharmacology database (TCMSP). Systems pharmacology analyses, including multiple network construction and KEGG pathway enrichment, were performed to further explore the hepatotoxicity mechanism of TCM.Results16 single classifiers were built by combining four machine learning methods with four different sets of fingerprints. After systematic evaluation, the best four single classifiers were selected, which achieved a Matthews correlation coefficient (MCC) value of 0.702, 0.691, 0.659, and 0.717, respectively. To improve the predictive capacity of single models, consensus prediction method was used to integrate the best four single classifiers. Results showed that the consensus model C-3 (MCC = 0.78) outperformed the four single classifiers and other consensus models. Subsequently, 5,666 potential hepatotoxic compounds were identified by C-3 model. We integrated the top 10 hepatotoxic herbs and discussed the hepatotoxicity mechanism of TCM via systems pharmacology approach. Finally, Chaihu was selected as the case study for exploring the molecular mechanism of hepatotoxicity.ConclusionOverall, this study provides a high accurate approach to predict HILI and an in silico perspective into understanding the hepatotoxicity mechanism of TCM, which might facilitate the discovery and development of new drugs
Multimodal Discourse Analysis of the Poster of the Movie Octagonal
With the development of multimedia and the Internet, meanings are expressed in diverse forms. A movie poster is a multimodal discourse that integrates text, image, color, composition, and other elements, which not only gives the audience visual aesthetic enjoyment but also conveys the theme of the movie in a highly concise and effective way. Based on the theory of Visual Grammar, this study taking the poster of the recent popular movie Octagonal as the research object, conducted a multimodal discourse analysis on the poster in a qualitative way. It studied the expression of the meaning of the poster from three dimensions, namely representational meaning, interactive meaning and compositional meaning, and explored the role of the design of the poster in conveying the theme of the movie
Toxicological effects of copper on bioaccumulation and mRNA expression of antioxidant, immune, and apoptosis-related genes in Chinese striped-necked turtle (Mauremys sinensis)
Heavy metals are among the most ubiquitous environmental pollutants of recent decades. Copper is commonly used to control algal blooms or macrophyte and waste infestations, its ambient concentration has increased significantly, indicating possible environmental risk. To investigate the effects of copper exposure on bioaccumulation, antioxidant defense, immune response, and apoptosis in the Chinese Striped-necked Turtle Mauremys sinensis, three experimental groups, control (0.0 mg/L), Cu2 (2 mg/L) and Cu4 (4 mg/L) were designed, and sampled at 14 and 28 days. Results showed that copper accumulates in different organs depending on the concentration and exposure time, Liver > Kidney > Gut > Heart > Brain > Muscle and the time order was 28 days > 14 days. The liver enzymes AST, ALT, and ALP decreased when the turtles were exposed to copper stress, while the contents of bilirubin TBIL, DBIL, IBIL, and LDH showed a significant upward trend. Similarly, the mRNA expression level of acetylcholinesterase AChE in the brain was significantly downregulated upon copper exposure. An upward trend was noticed in the liver Metallothionein MT mRNA expression levels compared to the control group. The mRNA expression levels of antioxidant enzymes CAT, SOD, MnSOD, and GSH-PX1 in the liver increased initially and then significantly decreased. Furthermore, the relative mRNA expression levels of inflammatory cytokines IL-1β, IL-8, TNF-α, and IFN-γ involved in inflammatory response significantly upregulated. Copper significantly increased the hepatic mRNA transcription of heat shock proteins HSP70 and HSP90 at different exposure durations. In addition, the relative mRNA levels of caspase3, caspase8, and caspase9 related to the caspase-dependent apoptotic pathway significantly increased under copper stress. These results explain that copper toxicity causes bioaccumulation, promotes oxidative stress, obstructs immunity, and induces inflammation and apoptosis by altering their gene expression levels in M. sinensis
Microbial ecological clusters structured by environments drive maize residue decomposition at the continental scale
International audienceEnvironmental factors (e.g., climate and edaphic factors) indirectly regulate residue decomposition via microbial communities. Microbial ecological clusters (eco-clusters) structured by specific environmental factors have consequences for ecosystem functions. However, less is known about how microbial eco-clusters affect residue decomposition, especially over broad geographic scales. We collected agricultural soils from adjacent pairs of upland and paddy fields along a latitudinal gradient from the cold-temperature zone to the tropical zone, and conducted a microcosm experiment with 13C-labelled maize residue to explore the continental pattern of maize residue-derived 13CO2 (RDC), and whether and how microbial eco-clusters drive and predict RDC. Results showed that RDC decreased with latitude in both upland and paddy fields. Further, we identified 21 well-defined eco-clusters according to microbial environmental preferences, which explained 51.15 % of the spatial variations in RDC. The eco-clusters of high-total annual precipitation (TAP), high-mean annual temperature (MAT), low-pH, and some low-nutrient-associated exerted a positive effect on RDC. These eco-clusters contained many taxa belonging to the Actinobacteriota, Firmicutes, and Sordariomycetes, and their relative abundance decreased with latitude. Upland soils displayed 2.40-fold of RDC over paddy soils. Low-pH and high-organic matter (OM) eco-clusters were found to be the most prominent predictors of RDC in upland and paddy fields, respectively. Finally, we constructed a continental atlas of RDC in both upland and paddy fields based on eco-clusters and high-resolution climate and soil data. Overall, our study provides important evidence that historical environment-shaped microbial eco-clusters can drive and predict residue decomposition, providing new insights into how environmental factors indirectly regulate residue decomposition