A comprehensive model for solid-state polymerization of poly(ethylene terephthalate) was developed from analyzing the similarities and the differences between solid-state and melt polymerization. Considering the end groups diffusion limitation and the modification of concentrations of end groups and byproducts in the amorphous phase, a system of mass transfer and balance equations suitable for the solid-state polymerization of PET were obtained, based on simplifying the reaction kinetics of melt polymerization of PET. The degradation and other side reactions neglected in the earlier models for the solid-state polymerization of PET were included in the model. This simulation gave a quantitative prediction in the effect of temperature, particle size, starting molecular weight, and ratio of end groups on the degree of polymerization of products during the solid-state polymerization of poly(ethylene terephthalate). These simulation results were in agreement with experiments.

Trichoderma harzianum strain SQR-T037 is a biocontrol agent that has been shown to enhance the uptake of nutrients (macro- and microelements) by plants in fields. The objective of this study was to investigate the contribution of SQR-T037 to P and microelement (Fe, Mn, Cu and Zn) nutrition in tomato plants grown in soil and in hydroponic conditions. Inoculation with SQR-T037 significantly improved the biomass and nutrient uptake of tomato seedlings grown in a nutrient-limiting soil. So we investigated the capability of SQR-T037 to solubilise sparingly soluble minerals in vitro via four known mechanisms: acidification by organic acids, chelation by siderophores, redox by ferric reductase and hydrolysis by phytase. SQR-T037 was able to solubilise phytate, Fe2O3, CuO, and metallic Zn but not Ca3(PO4)2 or MnO2. Organic acids, including lactic acid, citric acid, tartaric acid and succinic acid, were detected by HPLC and LC/MS in two Trichoderma cultures. Additionally, we inoculated tomato seedlings with SQR-T037 using a hydroponic system with specific nutrient deficiencies (i.e., nutrient solutions deficient in P, Fe, Cu or Zn and supplemented with their corresponding solid minerals) to better study the effects of Trichoderma inoculation on plant growth and nutrition. Inoculated seedlings grown in Cu-deficient hydroponic conditions exhibited increases in dry plant biomass (92%) and Cu uptake (42%) relative to control plants. However, we did not observe a significant effect on seedling biomass in plants grown in the Fe- and Zn-deficient hydroponic conditions; by contrast, the biomass decreased by 82% in the P-deficient hydroponic condition. Thus, we demonstrated that Trichoderma SQR-T037 competed for P (phytate) and Zn with tomato seedlings by suppressing root development, releasing phytase and/or chelating minerals. The results of this study suggest that the induction of increased or suppressed plant growth occurs through the direct effect of T. harzianum on root development, in combination with indirect mechanisms, such as mineral solubilisation (including solubilisation via acidification, redox, chelation and hydrolysis).

Cardiac fibrosis is one of the major components of the healing mechanism following any injury of the heart and as such may contribute to both systolic and diastolic dysfunction in a range of pathophysiologic conditions. Canonically, it can occur as part of the remodeling process that occurs following myocardial infarction or that follows as a response to pressure overload. Integrins are cell surface receptors which act in both cellular adhesion and signaling. Most importantly, in the context of the continuously contracting myocardium, they are recognized as mechanotransducers. They have been implicated in the development of fibrosis in several organs, including the heart. This review will focus on the involvement of integrins and integrin-related proteins, in cardiac fibrosis, outlining the roles of these proteins in the fibrotic responses in specific cardiac pathologies, discuss some of the common end effectors (Angiotensin II, transforming growth factor beta 1 and mechanical stress) through which integrins function and finally discuss how manipulation of this set of proteins may lead to new treatments which could prove useful to alter the deleterious effects of cardiac fibrosis.

Background: Talin is an integrin-actin linker essential for integrin activation.Results: Talin1 has distinct developmental and postnatal expression in heart versus Talin2. Cardiac-myocyte specific Talin1 deletion alters physiological and molecular responses of the myocardium to stress.Conclusion: Talin1 has a unique mechanotransductive role in the cardiomyocyte.Significance: Reduction of talin1 in cardiomyocytes may have beneficial effects in the stressed myocardium.

Half-sandwich metal-based anticancer complexes suffer from uncertain targets and mechanisms of action. Herein we report the observation of the images of half-sandwich iridium and ruthenium complexes in cells detected by confocal microscopy. The confocal microscopy images showed that the cyclopentadienyl iridium complex 1 mainly accumulated in nuclei in A549 lung cancer cells, whereas the arene ruthenium complex 3 is located in mitochondria and lysosomes, mostly in mitochondria, although both complexes entered A549 cells mainly through energy-dependent active transport. The nuclear morphological changes caused by Ir complex 1 were also detected by confocal microscopy. Ir complex 1 is more potent than cisplatin toward A549 and HeLa cells. DNA binding studies involved interaction with the nucleobases 9-ethylguanine, 9-methyladenine, ctDNA, and plasmid DNA. The determination of bovine serum albumin binding was also performed. Hydrolysis, stability, nucleobase binding, and catalytic NAD + / NADH hydride transfer tests for complexes 1 and 3 were also carried out. Both complexes activated depolarization of mitochondrial membrane potential and intracellular ROS overproduction and induced cell apoptosis. Complex 3 arrested the cell cycle at the G 0 /G 1 phase by inactivation of CDK 4/cyclin D1. This work paves the way to track and monitor half-sandwich metal complexes in cells, shines a light on understanding their mechanism of action, and indicates their potential application as theranostic agents.

Poly(ether sulfone) (PES) nanofibers were prepared by the gas-jet/electrospinning of its solutions in N,N-dimethylformamide (DMF). The gas used in this gasjet/electrospinning process was nitrogen. The morphology of the PES nanofibers was investigated with scanning electron microscopy. The process parameters studied in this work included the concentration of the polymer solution, the applied voltage, the tip-collector distance (TCD), the inner diameter of the needle, and the gas flow rate. It was found from experimental results that the average diameter of the electrospun PES fibers depended strongly on these process parameters. A decrease in the polymer concentration in the spinning solutions resulted in the formation of nanofibers with a smaller diameter. The use of an 18 wt % polymer solution yielded PES nanofibers with an average diameter of about 80 nm. However, a morphology of mixed bead fibers was formed when the concentration of PES in DMF was below 20 wt % during gas-jet/electrospinning. Uniform PES nanofibers with an average diameter of about 200 nm were prepared by this electrospinning with the following optimal process parameters: the concentration of PES in DMF was 25 wt %, the applied voltage was 28.8 kV, the gas flow was 10.0 L/min, the inner diameter of the needle was 0.24 mm, the TCD was 20 cm, and the flow rate was 6.0 mL/h.

How mechanical signals are transmitted in the cardiac myocyte is poorly understood. In this study, we produced a tamoxifen-inducible mouse model in which β1 integrin could be reduced specifically in the adult cardiomyocyte, so that the function of this integrin could be assessed in the postnatal and mechanically stressed heart. The expression of β1 integrin was reduced to 35% of control levels, but function remained normal at baseline. With aortic constriction, the knockout mice survived but had a blunted hypertrophic response. Integrin knockout myocytes, in contrast to controls, showed reduced integrin-linked kinase expression both at baseline and after hemodynamic stress; focal adhesion kinase expression was reduced after stress. Alterations in multiple signaling pathways were detected in the integrin knockout group after acute and chronic hemodynamic stress. Most remarkably, when we challenged the knockout mice with short-term loading, the robust responses of several kinases (extracellular signal-regulated kinase 1/2, p38, and Akt) evident in control mice were essentially abolished in the knockout mice. We also found that reduction of myocyte β1 integrin expression modified adrenergic-mediated signaling through extracellular signal-regulated kinase, p38, and Akt. Reduction of β1 integrin expression in the mature cardiac myocyte leads to a varied response compared with when this protein is reduced during either the embryonic or perinatal period. These results show that β1 integrin expression is required for proper mechanotransductive and adrenergic responses of the adult heart.

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