Preparation and curing behaviour of microencapsulated curing agents for cold-mixed epoxy asphalt.

This study aimed to improve control over the curing behaviour of cold-mixed epoxy asphalt by using a microencapsulated curing agent (2-PZ@PC). Prepared through solvent evaporation, the 2-PZ@PC microcapsules had 2-phenylimidazole as the core material and polycarbonate as the shell material. The research examined the impact of core-shell mass ratio on microcapsule morphology and composition. Various equations, including the kinetics equation, Kissinger equation, Flynn-Wall-Ozawa, and Crane equations, were employed to assess the sustained release effect of 2-PZ@PC microcapsules on epoxy resin curing behaviour. Fluorescence microscopy and viscosity experiments were used to observe the release state of microcapsules and confirm the retardation phenomenon during construction. Optimal 2-PZ@PC microcapsules displayed a smooth spherical morphology and a maximum encapsulation rate of 32 wt% at a 1:1 core-shell ratio. The microencapsulated curing agent effectively regulated cold-mixed epoxy asphalt's curing behaviour, enhancing retention time control and application reliability.

Investigation of the soft carbon microstructure in silicon/carbon anodes for superior lithium storage.

It is essential to consider the controllable microstructure of soft carbon and its enhancement effect on the electrochemical performance of silicon (Si) active materials. In this study, a series of Si@mesocarbon microbead (Si@MCMB) composites were prepared using mesophase pitch as the soft carbon source to coat nano-Si. The results showed that the ordered carbon layer stacking of soft carbon increased slightly with increasing heat treatment temperature in the range of 800-1400 °C. The Si@MCMB composites at higher temperature had a turbostratic carbon layer texture with rich porosity and smaller specific surface area, and had good cycle stability and high rate performance. These results highlighted that the co-existing structure of turbostratic carbon arrays with abundant porosity from soft carbon, provided the electron/ion transfer channels, underwent Si alloy volume change and enhanced the mechanical stability. Importantly, the relationship between the capacity retention rate of the Si@MCMB anodes and the microstructural characteristics (carbon layer and porosity) of soft carbon was established, which provided effective guidance for the design of high-performance silicon/carbon (Si/C) anode materials.

Role of the cystathionine ß-synthase/H2S system in liver cancer cells and the inhibitory effect of quinolone-indolone conjugate QIC2 on the system.

Hydrogen sulfide (H2S), the third gasotransmitter, plays important roles in cancer biological processes. As endogenous H2S exerts pro-cancer functions, inhibition of its production in cancer cells may provide a new cancer treatment strategy and be achieved via regulation of the function of cystathionine ß-synthase (CBS), one of the main metabolic enzymes synthesizing H2S. This enzyme plays important roles in the development and progression of colon and ovarian cancer, primarily regulating mitochondrial bioenergetics and accelerating cell cycle progression. In the present study, we firstly investigated the role of the CBS/H2S system in human hepatoma cells, and then the inhibitory effect of a quinolone-indolone conjugate QIC2 on this system. When CBS was overexpressed in human hepatoma HepG2 and SMMC-7721 cells, inhibition of endogenous CBS/H2S significantly reduced their viability and growth rate, as well as the proliferation of SMMC-7721 cells. Meanwhile, CBS knockdown caused multiple effects, including apoptosis of SMMC-7721 cells, an increase in the Bcl-2-associated X protein (Bax)/B cell lymphoma/leukemia (Bcl-2) ratio, activation of caspase-3 and polyADP-ribose polymerase (PARP), when compared with the scramble siRNA (Sc siRNA)-transfected groups. Heme oxygenase-1 (HO-1; a microsomal enzyme) expression was significantly decreased while the reactive oxygen species (ROS) level was increased in the CBS siRNA-transfected SMMC-7721 cells. QIC2 significantly reduced SMMC-7721 cell viability in a dose-dependent manner and showed a lower toxicity in human normal liver HL-7702 cells relative to the positive controls sunitinib and doxorubicin (DOX). The compound also inhibited cell proliferation and induced cell apoptosis in SMMC-7721 cells. Further analysis indicated that QIC2 downregulated the CBS/H2S system, decreased both HO-1 protein and glutathione (GSH) levels while increased the ROS level and activated the caspase-3 cascade. Collectively, our results demonstrated that the CBS/H2S system plays important roles in human hepatoma cells and QIC2 significantly inhibited cell growth via downregulation of the system.

FFJ-3 inhibits PKM2 protein expression via the PI3K/Akt signaling pathway and activates the mitochondrial apoptosis signaling pathway in human cancer cells.

Pyruvate kinase isoenzyme M2 (PKM2) has previously been identified as a tumor biomarker and potential therapeutic target for the treatment of cancer. In the present study, FFJ-3, a structurally modified version of mollugin, an extract of the Traditional Chinese herbal medicine Rubia tinctorum (madder) was used in order to determine the anticancer activity of the compound and investigate the potential mechanisms underlying this effect in human cancer cells. The results of the present study revealed that FFJ-3 inhibited the survival of HepG2 human hepatoma cells, MCF-7 human breast cancer cells and A549 human lung adenocarcinoma cells using the MTT assay. In addition, FFJ-3 arrested cell cycle progression at G2/M and G1 in HepG2 and A549 cells, respectively. Further analyses demonstrated that FFJ-3 attenuated the expression of PKM2 protein via the inhibition of the phosphoinositide 3-kinase (PI3K)/Akt serine/threonine kinase (Akt) signaling pathway. Furthermore, treatment of all three cell types with FFJ-3 significantly increased apoptosis and decreased the mitochondrial membrane potential compared with the untreated control group. In addition, FFJ-3 treatment increased the ratio of B-cell lymphoma-2 (Bcl-2)/Bcl-2 associated X and activated the caspase-3 cascade. In conclusion, the inhibition of the PI3K/Akt signaling pathway and activation of the caspase-3 cascade by FFJ-3 were primarily responsible for the inhibition of cell proliferation and induction of apoptosis in MCF-7, HepG2 and A549 cells. The results of the present study suggest a potential therapeutic role for FFJ-3 in the treatment of human cancer.

Induction of apoptosis by FFJ-5, a novel naphthoquinone compound, occurs via downregulation of PKM2 in A549 and HepG2 cells.

Pyruvate kinase isoenzyme M2 (PKM2) has previously been identified as a tumor biomarker and as a potential target for cancer therapy. In this study, F§FJ-5, a characterized naphthoquinone modifier of mollugin, was synthesized in order to investigate its anticancer activity and the potential mechanisms. It was observed that FFJ-5 inhibited the cell growth of human lung adenocarcinoma cells A549 and human hepatoma cells HepG2 by MTT assays. FFJ-5 arrested cell cycle at the G2/M phase. Further analyses demonstrated that FFJ-5 attenuated the expression of PKM2 and reduced the production of adenosine triphosphate (ATP). Reduced expression and activity of epidermal growth factor receptor (EGFR) and Akt were observed in A549 and HepG2 cells exposed to FFJ-5. FFJ-5 exposure also resulted in cell apoptosis, in association with decreased intracellular pH level and mitochondrial membrane potential. In addition, FFJ-5 activated the caspase-3 cascade. In conclusion, FFJ-5 inhibited cancer cell growth via the blocking the EGFR-Akt-PKM2 pathway or through the synergistic action of EGFR, Akt and PKM2 proteins, alongside a decrease in ATP production. In addition, FFJ-5 induced cancer cell apoptosis by decreasing the intracellular pH level and the mitochondrial apoptosis pathway. The present results suggest a potential role of FFJ-5 on the therapy of human cancer.

Screening of α-Tocopherol Transfer Protein Sensitive Genes in Human Hepatoma Cells (HepG2).

α-Tocopherol transfer protein (α-TTP) is a ~32 kDa protein expressed mainly in hepatocytes. The major function of the protein is to bind specifically to α-tocopherol and, together, the complex transfers from late lysosomes to the cell membrane. A previous study indicated that some factors might be required in the transferring process. However, there is little information available about the potential transferring factors. In addition, there remains much to learn about other physiological processes which α-TTP might participate in. Thus, in this study a human α-TTP eukaryotic expression vector was successfully constructed and expressed in human hepatoma cells (HepG2). The sensitive genes related to α-TTP were then screened by microarray technology. Results showed that expression of the vector in HepG2 cells led to the identification of 323 genes showing differential expression. The differentially expressed transcripts were divided into four main categories, including (1) cell inflammation; (2) cell cycle and cell apoptosis; (3) cell signaling and gene regulation; and (4) cellular movement. A few cellular movement related transcripts were selected and verified by quantitative real-time PCR. Expressions of some were significantly increased in α-TTP-expressed group, which indicated that these factors were likely to play a role in the transferring process.

Transcriptome analysis of the Tan sheep testes: Differential expression of antioxidant enzyme-related genes and proteins in response to dietary vitamin E supplementation.

Gene-chip technology was employed to study the effect of dietary vitamin E on gene expression in sheep testes based on our previous research. Thirty-five male Tan sheep (20-30 days after weaning) with similar body weight were randomly allocated into five groups and supplemented 0, 20, 100, 200 and 2,000 IU sheep(-1)day(-1) vitamin E (treatments denoted as E0, E20, E100, E200, and E2000, respectively) for 120 days. At the end of the study the sheep were slaughtered and the testis samples were immediately collected and stored in liquid nitrogen. Differences in gene expression between different treated groups were identified. Based on GO enrichment analysis and the KEGG database to evaluate the gene expression data we found that vitamin E might affect genes in the testes by modulating the oxidation level, by affecting the expression of various receptors and transcription factors in biological pathways, and by regulating the expression of metabolism-associated genes. The effect of vitamin E supplementation on the expression of oxidative enzyme-related genes was detected by quantitative real-time PCR (qRT-PCR) and Western blot. The results show that dietary vitamin E, at various doses, can significantly increase (P<0.05) the mRNA and protein expression of Glutathione peroxidase 3 and Glutathione S-transferase alpha 1. In addition, the results of qRT-PCR of the antioxidant enzyme genes were consistent with those obtained using the gene chip microarray analysis. In summary, the dietary vitamin E treatment altered the expression of a number of genes in sheep testes. The increase in the mRNA and protein levels of antioxidant enzyme genes, coupled with the elevation in the activity of the antioxidant enzymes were primarily responsible for the improved reproductive performance promoted by dietary vitamin E.

Antioxidant effects of liquorice (Glycyrrhiza uralensis) extract during aging of longissimus thoracis muscle in Tan sheep.

The study was conducted to investigate the potential of liquorice extract (LE) from Glycyrrhiza uralensis as a dietary supplement for sheep to improve antioxidant capacity of meat. Fifty Tan sheep were randomly allocated to five groups with LE supplementation at levels of 0, 1000, 2000, 3000 and 4000 mg/kg feed. After 120 days, the longissimus thoracis muscle was sampled and conditioned for 0, 2, 4, 6 and 8 days at 4 °C. The results revealed that LE scavenged free radical in a dose-response manner in vitro. Supplementation with LE in animal diet increased (P<0.05) antioxidant content and radical scavenging activity while it decreased (P<0.05) reactive oxygen species (ROS) and thiobarbituric acid reactive substance (TBARS) levels of meat. Dietary LE supplementation can improve antioxidant capacity of meat, and the optimum dosage range of LE supplementation appeared to be 3000 to 4000 mg/kg feed.

Regulation of sheep α-TTP by dietary vitamin E and preparation of monoclonal antibody for sheep α-TTP.

α-Tocopherol transfer protein (α-TTP) is a cytosolic protein that plays an important role in regulating concentrations of plasma α-tocopherol (the most bio-active form of vitamin E). Despite the central roles that α-TTP plays in maintaining vitamin E adequacy, we have only recently proved the existence of the α-TTP gene in sheep and, for the first time, cloned its full-length cDNA. However, the study of sheep α-TTP is still in its infancy. In the present study, thirty-five local male lambs of Tan sheep with similar initial body weight were randomly divided into five groups and fed with diets supplemented with 0 (control group), 20, 100, 200, 2000IU·sheep(-1)·d(-1) vitamin E for 120 days. At the end of the experiment, the plasma and liver vitamin E contents were analyzed first and then α-TTP mRNA and protein expression levels were determined by quantitative real-time PCR (qRT-PCR) and Western-blot analysis, respectively. In addition, as no sheep α-TTP antibody was available, a specific monoclonal antibody (McAb) against the ovine α-TTP protein was prepared. The effect of vitamin E supplementation was confirmed by the significant changes in the concentrations of vitamin E in the plasma and liver. As shown by qRT-PCR and Western-blot analysis, dietary vitamin E does not affect sheep α-TTP gene expression, except for high levels of vitamin E supplementation, which significantly increased expression at the protein level. Importantly, the specific sheep anti-α-TTP McAb we generated could provide optimal recognition in ELISA, Western-blot and immunohistochemistry assays, which will be a powerful tool in future studies of the biological functions of sheep α-TTP.

Dietary vitamin E affects α-TTP mRNA levels in different tissues of the Tan sheep.

The α-tocopherol transfer protein (α-TTP) is a ~32kDa cytosolic protein that plays an important role in the efficient circulation of plasma α-tocopherol in the body, a factor with great relevance in reproduction. The α-TTP gene has been studied in a number of tissues; however, its expression and function in some ovine tissues remain unclear. A previous study from our laboratory has demonstrated α-TTP expression in sheep liver. In the present study we determined whether α-TTP is expressed in non-liver tissues and investigated the effects of dietary vitamin E on the α-TTP mRNA levels. Thirty-five male Tan sheep with similar body weight were randomly allocated into five groups and supplemented 0, 20, 100, 200 and 2000IUsheep(-1)day(-1) vitamin E, for four months, respectively. At the end of the study, the animals were slaughtered and tissue samples from the heart, spleen, lung, kidney, longissimus dorsi muscle and gluteus muscle were immediately collected. We found that the α-TTP gene is expressed in sheep tissues other than the liver. Moreover, dietary vitamin E levels had influenced the expression levels of α-TTP gene in these tissues in a tissue-specific way. The technique of immunohistochemistry was used to detect α-TTP in tissues of the heart, spleen, lung, and kidney and we found that α-TTP was mainly located in the cytoplasm while no α-TTP immunoreactivity was detected in the cytoplasm of longissimus dorsi and gluteus muscle samples. Importantly, our findings lay the foundation for additional experiments focusing on the absorption and metabolism of vitamin E in tissues other than the liver.

Molecular cloning and characterization of the sheep α-TTP gene and its expression in response to different vitamin E status.

The α-tocopherol transfer protein (α-TTP) is a ~32 kDa protein that exhibits a marked ligand specificity and selectively recognizes of α-tocopherol, which is the most active form of vitamin E. The α-TTP gene has been cloned and its physiological functions have been studied in numbers of species, however, the understanding of sheep α-TTP is still in his infancy. In this study, the full-length cDNA of sheep α-TTP gene was cloned from sheep liver by using of rapid amplification of complementary DNA ends (RACE). As a result, the sheep α-TTP gene was 1098 bp in nucleotide which contained 23 bp 5'-untranslated region (UTR), 226 bp 3'-UTR and 849 bp open reading frame (ORF) that encoded a basic protein of 282 amino acids. Further bioinformatic analysis indicated that the sheep α-TTP gene had a high homologous of both nucleotide and amino acid sequences compared with that of other species and had a Sec14p-like lipid-binding domain which called the CRAL-TRIO domain. Moreover, the expression of sheep α-TTP mRNA and protein in response to different vitamin E supplemented levels were observed according to quantitative real-time PCR (qRT-PCR) and Western blotting analysis. The results showed that dietary vitamin E levels did not affect α-TTP mRNA expression significantly while the low vitamin E supplemented level groups of sheep had significantly higher α-TTP protein compared to high-vitamin E groups.