15 research outputs found
Carbon-nitrogen/graphene composite as metal-free electrocatalyst for the oxygen reduction reaction
Carbon-nitrogen/graphene composite as metal-free electrocatalyst for the oxygen reduction reaction
Mix design of equal strength high volume fly ash concrete with artificial neural network
High volume fly ash concrete (HVFAC) has been widely used, and the mix proportion of HVFAC is usually designed based on the required compressive strength. Therefore, the research of HVFAC under the condition of equal strength has more engineering application value. However, in the current mix proportion design standard, there is no special discussion on the mix proportion design method of HVFAC. In this study, the compressive strength of HVFAC affected by four factors (water-binder ratio, FA content, curing method and curing age) was systematically studied. Based on 594 sets of strength data obtained from experiments, the method to determine the key mix proportion parameters (water-binder ratio and FA content) of equal strength HVFAC was proposed through machine learning algorithms (ML). Two ML methods (i.e., a multiple linear regression (MLR) and an artificial neural networks (ANN)) were developed to predict the HVFAC compressive strength and then their performances were compared. Through comparison, it was found that the mean absolute error and root mean squared error of the ANN model were both lower than the MLR model, and the ANN model has lower error and higher accuracy. In addition, the reliability of the proposed ANN model was verified with data in other literatures, the results showed the errors between the predicted values and the measured values are lower than 25%. The weight contribution rate of each factor to the strength was calculated. Among the four factors, the curing age had the greatest impact on the compressive strength, which contributes up to 60.3%. The influence degree of FA content is greater than that of water-binder ratio. With the development of curing age, the influence degree of FA content and water-binder ratio on the strength gradually decreases while the curing method increases. Finally, according to the ANN prediction results, the key mix parameters design method for equal strength HVFAC under multi-factor conditions was proposed, which provide guidance for concrete preparation in actual engineering
Microbiome-Metabolome Responses to a High-Grain Diet Associated with the Hind-Gut Health of Goats
Studies on the effect of a high-concentrate (HC) diet on the hindgut microbiota and metabolome of ruminants are rarely reported. We used 454 pyrosequencing of 16S rDNA genes and gas chromatography-mass spectrometry to evaluate the effects of long-term feeding (HL) or short-term (HS) feeding of an HC diet on changes in bacterial microbiota and their metabolites in the hindgut, with Guanzhong goat as a ruminant model. Results indicated that an HC diet decreased bacterial diversity and induced metabolic disorder in the hindgut. The levels of lactate, endotoxin (lipopolysaccharide, LPS), and volatile fatty acid concentrations were higher in the intestinal digesta of the HC goats than in those of the LC goats (P < 0.05). The level of beta-alanine decreased, whereas the levels of stigmasterol and quinic acid decreased in the cecal and colonic digesta of the HC goats. At the genus level, the abundance of Clostridium and Turicibacter was significantly increased in both the colonic and cecal digesta of the HC goats. Several potential relationships between metabolites and several microbial species were revealed in this study. The mRNA expression of the genes functionally associated with nutrients transport, including NHE2, NHE3, MCT1, and MCT4 were significantly downregulated in the colonic mucosa by the HC diet (P < 0.05). The expression levels of the genes related to the inflammatory response, including TLR4, MYD88, TNF-α, and IL-1β were markedly upregulated in the cecal mucosa by the HC diet (P < 0.05). Our results indicate that an HC diet induces microbiota dysbiosis, metabolic disorders, and mucosal damage in the hindgut of goats
Negative effects of long-term feeding of high-grain diets to lactating goats on milk fat production and composition by regulating gene expression and DNA methylation in the mammary gland
Abstract Background It is well known that feeding a high concentrate (HC) diet to lactating ruminants likely induces subacute ruminal acidosis (SARA) and leads to a decrease in milk fat production. However, the effects of feeding a HC diet for long periods on milk fatty acids composition and the mechanism behind the decline of milk fat still remains poorly understood. The aim of this study was to investigate the impact of feeding a HC diet to lactating dairy goats on milk fat yield and fatty acids composition with an emphasis on the mechanisms underlying the milk fat depression. Seventeen mid-lactating dairy goats were randomly allocated to three groups. The control treatment was fed a low-concentrate diet (35% concentrate, n = 5, LC) and there were two high-concentrate treatments (65% concentrate, HC), one fed a high concentrate diet for a long period (19 wks, n = 7, HL); one fed a high concentrate diet for a short period of time (4 wk, n = 5, HS). Milk fat production and fatty acids profiles were measured. In order to investigate the mechanisms underlying the changes in milk fat production and composition, the gene expression involved in lipid metabolism and DNA methylation in the mammary gland were also analyzed. Results Milk production was increased by feeding the HC diet in the HS and HL groups compared with the LC diet (P < 0.01), while the percentage of milk fat was lower in the HL (P < 0.05) but not in the HS group. The total amount of saturated fatty acids (SFA) in the milk was not changed by feeding the HC diet, whereas the levels of unsaturated fatty acids (UFA) and monounsaturated fatty acids (MUFA) were markedly decreased in the HL group compared with the LC group (P < 0.05). Among these fatty acids, the concentrations of C15:0 (P < 0.01), C17:0 (P < 0.01), C17:1 (P < 0.01), C18:1n-9c (P < 0.05), C18:3n-3r (P < 0.01) and C20:0 (P < 0.01) were markedly lower in the HL group, and the concentrations of C20:0 (P < 0.05) and C18:3n-3r (P < 0.01) were lower in the HS group compared with the LC group. However, the concentrations of C18:2n-6c (P < 0.05) and C20:4n-6 (P < 0.05) in the milk fat were higher in the HS group. Real-time PCR results showed that the mRNA expression of the genes involved in milk fat production in the mammary gland was generally decreased in the HL and HS groups compared with the LC group. Among these genes, ACSL1, ACSS1 & 2, ACACA, FAS, SCD, FADS2, and SREBP1 were down-regulated in the mammary gland of the HL group (P < 0.05), and the expressions of ACSS2, ACACA, and FADS2 mRNA were markedly decreased in the HS goats compared with the LC group (P < 0.05). In contrast to the gene expression, the level of DNA methylation in the promoter regions of the ACACA and SCD genes was increased in the HL group compared with the LC group (P < 0.05). The levels of ACSL1 protein expression and FAS enzyme activity were also decreased in the mammary gland of the HL compared with the LC group (P < 0.05). Conclusions Long-term feeding of a HC diet to lactating goats induced milk fat depression and FAs profile shift with lower MUFAs but higher SFAs. A general down-regulation of the gene expression involved in the milk fat production and a higher DNA methylation in the mammary gland may contribute to the decrease in milk fat production in goats fed a HC diet for long time periods
Table_1_The influence of adolescents’ internet adaptation on internet addiction: the mediating role of internet cultural adaptation.XLSX
This study investigates how adolescents’ internet adaptation influences internet addiction, with a particular focus on the mediating role of internet cultural adaptation. Grounded in cross-cultural adaptation theory, the study proposes that internet cultural adaptation can mitigate the negative relationship between internet adaptation and internet addiction. Conducting a large-scale random survey among Chinese adolescents, and employing standardized measures for internet addiction, internet cultural adaptation, and internet adaptation, the study finds a significant negative correlation between internet adaptation and internet addiction. More crucially, internet cultural adaptation plays a pivotal mediating role, such that when adolescents have higher capabilities in adapting culturally to the internet, the negative relationship between their internet adaptation and addiction is effectively alleviated. These findings not only provide a new perspective in understanding adolescent internet addiction but also offer theoretical guidance for devising preventive measures. The study also discusses practical applications of the results, emphasizing the importance of enhancing adolescents’ internet cultural adaptation, and presents new strategies for preventing and mitigating issues of internet addiction.</p
Preparation of TiH1.924 nanodots by liquid-phase exfoliation for enhanced sonodynamic cancer therapy
Dynamic therapy is attracting attention for cancer treatment. Here, the authors report that metal hydride nanodots can be used for sonodynamic therapy, which can be further enhanced by photothermal heating to increase tissue oxygenation
Experimental study of the physical and mechanical properties of pervious concrete with recycled and gravel aggregate
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Optogenetic Control of Heart Rhythm by Selective Stimulation of Cardiomyocytes Derived from Pnmt+ Cells in Murine Heart.
In the present study, channelrhodopsin 2 (ChR2) was specifically introduced into murine cells expressing the Phenylethanolamine n-methyltransferase (Pnmt) gene, which encodes for the enzyme responsible for conversion of noradrenaline to adrenaline. The new murine model enabled the identification of a distinctive class of Pnmt-expressing neuroendocrine cells and their descendants (i.e. Pnmt+ cell derived cells) within the heart. Here, we show that Pnmt+ cells predominantly localized to the left side of the adult heart. Remarkably, many of the Pnmt+ cells in the left atrium and ventricle appeared to be working cardiomyocytes based on their morphological appearance and functional properties. These Pnmt+ cell derived cardiomyocytes (PdCMs) are similar to conventional myocytes in morphological, electrical and contractile properties. By stimulating PdCMs selectively with blue light, we were able to control cardiac rhythm in the whole heart, isolated tissue preparations and single cardiomyocytes. Our new murine model effectively demonstrates functional dissection of cardiomyocyte subpopulations using optogenetics, and opens new frontiers of exploration into their physiological roles in normal heart function as well as their potential application for selective cardiac repair and regeneration strategies