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Cytotoxicology is a branch of toxicology which studies the mechanism and effect of exogenous substances on the damage of life cells. It can be used in the evaluation of food safety toxicology and the toxic mechanism of harmful substances in food. Food processing and production in the detection of toxic and hazardous substances improved functional foods in the efficacy of active ingredients of research. There are several methods of cytotoxicology studied the different effects of exogenous substances on the cells, including cell activity and genetic effects, which resulting in changes of cell morphology and apoptosis detection. Many factors affect the safety of food, including pesticide residues, food additives, heavy metal materials, biological toxins. Cytotoxicology is a rapid, accurate and economic analysis method for food safety by studying the toxicity, toxic metabolism and toxic effect mechanism of harmful factors in food. It has the advantages of fast, accurate and economic and has a good effect in food safety field. In this paper, the application of cytotoxic technology in screening of the above-mentioned hazards is expounded. [ABSTRACT FROM AUTHOR]

An unbounded, space-invariant but time-varying medium conserves the wave number k of the wave but alters the frequency of the wave. Thus a switched medium acts like a frequency transformer, the frequencies of the newly created waves (output waves) are easily computed. The amplitudes of the output waves depend on the rise time Tr of the profiles of the parameters of the switched medium. [ABSTRACT FROM AUTHOR]

Both cis- and trans-regulatory mutations drive changes in gene expression that underpin plant phenotypic evolution. However, how and why these two major types of regulatory mutations arise in different genes and how gene expression is inherited and associated with these regulatory changes are unclear. Here, by studying allele-specific expression in F1 hybrids of pink-flowered sacred lotus (Nelumbo nucifera) and yellow-flowered American lotus (N. lutea), we reveal the relative contributions of cis- and trans-regulatory changes to interspecific expression rewiring underlying petal color change and how the expression is inherited in hybrids. Although cis-only variants influenced slightly more genes, trans-only variants had a stronger impact on expression differences between species. In F1 hybrids, genes under cis-only and trans-only regulatory effects showed a propensity toward additive and dominant inheritance, respectively, whereas transgressive inheritance was observed in genes carrying both cis- and trans-variants acting in opposite directions. By investigating anthocyanin and carotenoid coexpression networks in petals, we found that the same category of regulatory mutations, particularly trans-variants, tend to rewire hub genes in coexpression modules underpinning flower color differentiation between species; we identified 45 known genes with cis- and trans-regulatory variants significantly correlated with flower coloration, such as ANTHOCYANIN 5-AROMATIC ACYLTRANSFERASE (ACT), GLUTATHIONE S-TRANSFERASE F11 (GSTF11), and LYCOPENE 1-CYCLASE (LCYE). Notably, the relative abundance of genes in different categories of regulatory divergence was associated with the inferred magnitude of constraints like expression level and breadth. Overall, our study suggests distinct selective constraints and modes of gene expression inheritance among different regulatory mutations underlying lotus petal color divergence. [ABSTRACT FROM AUTHOR]

Objective: To investigate the biological role of miR-143 and miR-199a in mediating the progression of osteosarcoma (OS) by targeting cyclooxygenase (COX-2). Introduction: COX-2 plays a crucial role in the development and progression of OS. However, the specific regulatory mechanisms of COX-2 in OS are still not well understood. Methods: The expression levels of COX-2, miR-143 and miR-199a in OS tissues were detected using immunohistochemistry, qPCR, or western blot assays. The targeting relationship between miRNAs and COX-2 was determined. The effect of miRNA and COX-2 on OS cells was evaluated in vitro and in vivo. Results: COX-2 expression was upregulated while miR-143 and miR-199a were downregulated in OS tissues. miR-143 and miR-199a suppressed the proliferation, migration, and invasion of OS cells. The dual-luciferase reporter gene assay showed that COX-2 was a direct target of miR-143 and miR-199a. Genetic knockdown of COX-2 significantly suppressed cell proliferation, induced apoptosis, and inhibited migration and invasion of OS cells. The expression levels of COX-2 and PGE2 were decreased after the overexpression of miR-143 and miR-199a. Additionally, COX-2 silencing inhibited the tumorigenesis of OS and the synthesis of PGE2 in vivo. Conclusions: miR-143 and miR-199a/COX-2 axis modulates the proliferation, invasion, and migration in osteosarcoma. [ABSTRACT FROM AUTHOR]

We observe a dramatic enhancement in third harmonic generation (THG) when intense femtosecond laser pulses travel through CO2-laser-induced spark in air. By further investigating the dependence of the enhancement factor on the delay between the femtosecond laser pulse and CO2 laser pulse in various gases at different pressures, we reveal that the enhancement in THG results from the suppression of Gouy-phase-induced destructive interference, which can be attributed to a fast and a slow process. Our analyses show that the plasma generated in CO2 laser field plays the dominant role in the fast process whereas hydrodynamics of the gas heated by the CO2 laser contributes to the slow process. [ABSTRACT FROM AUTHOR]

1,4-Dihydropyridines are an important class of calcium channel blockers. However, difficulties in the preparation of nonsymmetric Hantzsch esters impede further development in this area. Benzylic C-H functionalization of Hantzsch pyridines is an efficient approach to nonsymmetric Hantzsch pyridines. We herein report a promoter-free benzylic C-H functionalization of pyridines, which allows preparation of a variety of pyridines unsymmetrically substituted in the 2/6-positions. A plausible mechanism is proposed for this reaction. This work provides a new way to prepare unsymmetrical pyridines and enriches the scope of C-H functionalization of aza-arenes. [ABSTRACT FROM AUTHOR]

Background: Diabetes is associated with an increased risk of cardiovascular disease and atherosclerosis. Increasing evidence shows that CD40–CD40L interaction plays a crucial role in the pathogenesis of atherosclerosis and coronary artery disease. The purpose of this study was to assess whether CD40 system expressions were disrupted in patients with diabetes. Methods: Sixteen normal controls and 72 patients including 20 with type 2 diabetes mellitus (DM), 15 with type 1 DM, 20 with coronary heart disease (CHD) and 17 CHD with coexisting DM were investigated. The expression of CD40 and CD40L on platelet was analyzed by indirect-immunofluorescence flow cytometry and serum-soluble CD40L level was determined by a commercially available ELISA. Serum of AGE was detected by fluorescence spectroscopy. Results: Type 1 DM, type 2 DM, CHD and CHD Patients with coexisting diabetes showed a significant increase of CD40 (81.8±11.7, 70.7±11.6, 68.5±10.2, 79.9±11.9 MIF, respectively) and CD40L (18.4±5.1, 13.9±4.1, 13.5±3.7, 16.7±4.7 MIF, respectively) coexpression on platelets as well as sCD40L (15.6±3.5, 14.1±3.3, 12.2±3.5, 13.5±3.6 ng/ml, respectively) compared with controls (p<0.01). A positive correlation was found between serum AGE levels in patients with DM and CD40–CD40L system. We also observed a significant correlation between hemoglobinA1c (HbA1c) concentration and CD40L on platelets (r=0.71, p<0.001) as well as sCD40L (r=0.69, p<0.001), but not for CD40 on platelets. Conclusions: Patients with diabetes show increased coexpression of CD40 system, especially CD40L, which may create a proinflammatory and prothrombotic milieu for aggravating the development of atherosclerosis. [Copyright &y& Elsevier]

The generation of laserlike narrow bandwidth emissions from nitrogen molecular ions (N+2) generated in intense near- and mid infrared femtosecond laser fields has aroused much interest because of the mysterious physics underlying such a phenomenon. Here, we perform a pump-probe measurement on the nonlinear interaction of rotational quantum wave packets of N+2 generated in midinfrared (e.g., at a wavelength centered at 1580 nm) femtosecond laser fields with an ultrashort probe pulse whose broad spectrum overlaps both P- and R-branch rotational transition lines between the electronic states N+2(B²Σ+u,v'=0) and N+2(X²Σ+g,v=0). The results indicate the occurrence of highly efficient near-resonant stimulated Raman scattering in the quantum wave packets of N+2 ions generated in strong laser fields in the midinfrared region, of which the underlying mechanism is different from that of the air lasers generated in atmospheric environment when pumping with 800 nm intense pulses. [ABSTRACT FROM AUTHOR]

Objective: The new glioma cell line SHG-139 was established and its phenotype, tumorigenicity, pathological characteristics, derived stem cells SHG139S were studied. Methods: Immunohistochemistry was used to assess expressions in the patient and mouse tumor tissues, SHG-139 and SHG-139S. Primary SHG-139 culture was performed, cell proliferation, cell cycle and genetic characteristics were assessed. MiRNA (Micro RNA) and LncRNA (Long non-coding RNA) microarray was performed. Results: We found that the glioma tissue was positive for A2B5 (Glial precursors ganglioside), GFAP (Glial fibril l ary acidic protein), S-100 (Acid calcium bingding protein), VEGF (Vascular endothelial growth factor), VEGFR (Vascular endothelial growth factor receptor) and negative for Ki-67 (Nuclcar-associated antigen). SHG-139 proliferated significantly within 24h; its total number of chromosomes was 68; ratios of SHG-139 and SHG-139S cells in G1 phase were highest. SHG-139 cells were positive for A2B5, GalC (Galactocerebrosides), GFAP, S-100 and Vimentin, while SHG-139S cells were positive for A2B5, Nestin, and NG2 (Neuron-glia antigen2), and negative for Vimentin and IDHR132H (Isocitrate dehydrogenase); cells rarely stained for CD133 (Cluster of differentiation 133). SHG-139 intracranial xenografts expressed GFAP, but no overt oligodendroglioma was observed. In SHG-139S xenografts, GFAP and S-100 were expressed, while CD133 was not detected; a few A2B5+ cells were found at tumor edges, and typical oligodendroglioma were obtained. In addition, SHG-139S xenograft tumors were more aggressive than those of SHG-139. Anti-mouse CD31 (Cluster of differentiation31) staining revealed murine vessels at the border between xenograft tumor and normal brain tissue; Anti-human CD34 (Cluster of differentiation34) staining was negative. Biochip technology of SHG139S showed several miRNA and lncRNA were differently expressed in SHG139and SHG139S. Conclusions: SHG-139 was an astroglioma cell line which yielded stem cells SHG-139S. SHG-139S cells constituted an A2B5+/CD133-GSC subgroup. [ABSTRACT FROM AUTHOR]