Estimation of water diffusivity parameters on grape dynamic drying

A computer program was developed, aiming at estimating water diffusivity parameters in a dynamic drying process with grapes, assessing the predictability of corresponding non-isothermal drying curves. It numerically solves Fick’s second law for a sphere, by explicit finite differences, in a shrinking system, with anisotropic properties and changing boundary conditions.     

A novel magneto‐impedance sensor model based on the zeros of Bessel functions

Nowadays, the design of magneto‐impedance (MI) sensors requires the development of lumped circuit models that can be simulated through equivalent impedance circuits relied on Bessel functions. A new impedance model based on Senani's equivalent using the zeros of Bessel functions is developed in this paper. The model allows to describe the impedance as a transfer function that can be easily synthesized by means of current conveyor circuits and passive elements. The mathematical representation was verified under simulation of transfer functions involving different number of poles and zeros. Moreover, the model has been verified using SPICE simulations and measurement results from a fabricated prototype demonstrating its scope and validity. Finally, a study of finite tracking errors of CCIIs used in the implementation of magneto‐impedance sensor has been realized. Copyright © 2014 John Wiley & Sons, Ltd.     

Herbivore Oral Secreted Bacteria Trigger Distinct Defense Responses in Preferred and Non-Preferred Host Plants

Insect symbiotic bacteria affect host physiology and mediate plant-insect interactions, yet there are few clear examples of symbiotic bacteria regulating defense responses in different host plants. We hypothesized that plants would induce distinct defense responses to herbivore- associated bacteria. We evaluated whether preferred hosts (horsenettle) or non-preferred hosts (tomato) respond similarly to oral secretions (OS) from the false potato beetle (FPB, Leptinotarsa juncta), and whether the induced defense triggered by OS was due to the presence of symbiotic bacteria in OS. Both horsenettle and tomato damaged by antibiotic (AB) treated larvae showed higher polyphenol oxidase (PPO) activity than those damaged by non-AB treated larvae. In addition, application of OS from AB treated larvae induced higher PPO activity compared with OS from non-AB treated larvae or water treatment. False potato beetles harbor bacteria that may provide abundant cues that can be recognized by plants and thus mediate corresponding defense responses. Among all tested bacterial isolates, the genera Pantoea, Acinetobacter, Enterobacter, and Serratia were found to suppress PPO activity in tomato, while only Pantoea sp. among these four isolates was observed to suppress PPO activity in horsenettle. The distinct PPO suppression caused by symbiotic bacteria in different plants was similar to the pattern of induced defense-related gene expression. Pantoea inoculated FPB suppressed JA-responsive genes and triggered a SA-responsive gene in both tomato and horsenettle. However, Enterobacter inoculated FPB eliminated JA-regulated gene expression and elevated SA-regulated gene expression in tomato, but did not show evident effects on the expression levels of horsenettle defense-related genes. These results indicate that suppression of plant defenses by the bacteria found in the oral secretions of herbivores may be a more widespread phenomenon than previously indicated.     

Non-Canonical Roles of Tau and Their Contribution to Synaptic Dysfunction

Tau plays a central role in a group of neurodegenerative disorders collectively named tauopathies. Despite the wide range of diverse symptoms at the onset and during the progression of the pathology, all tauopathies share two common hallmarks, namely the misfolding and aggregation of Tau protein and progressive synaptic dysfunctions. Tau aggregation correlates with cognitive decline and behavioural impairment. The mechanistic link between Tau misfolding and the synaptic dysfunction is still unknown, but this correlation is well established in the human brain and also in tauopathy mouse models. At the onset of the pathology, Tau undergoes post-translational modifications (PTMs) inducing the detachment from the cytoskeleton and its release in the cytoplasm as a soluble monomer. In this condition, the physiological enrichment in the axon is definitely disrupted, resulting in Tau relocalization in the cell soma and in dendrites. Subsequently, Tau aggregates into toxic oligomers and amyloidogenic forms that disrupt synaptic homeostasis and function, resulting in neuronal degeneration. The involvement of Tau in synaptic transmission alteration in tauopathies has been extensively reviewed. Here, we will focus on non-canonical Tau functions mediating synapse dysfunction.     

Complementary Functions of Plant AP Endonucleases and AP Lyases during DNA Repair of Abasic Sites Arising from C:G Base Pairs

Abasic (apurinic/apyrimidinic, AP) sites are ubiquitous DNA lesions arising from spontaneous base loss and excision of damaged bases. They may be processed either by AP endonucleases or AP lyases, but the relative roles of these two classes of enzymes are not well understood. We hypothesized that endonucleases and lyases may be differentially influenced by the sequence surrounding the AP site and/or the identity of the orphan base. To test this idea, we analysed the activity of plant and human AP endonucleases and AP lyases on DNA substrates containing an abasic site opposite either G or C in different sequence contexts. AP sites opposite G are common intermediates during the repair of deaminated cytosines, whereas AP sites opposite C frequently arise from oxidized guanines. We found that the major Arabidopsis AP endonuclease (ARP) exhibited a higher efficiency on AP sites opposite G. In contrast, the main plant AP lyase (FPG) showed a greater preference for AP sites opposite C. The major human AP endonuclease (APE1) preferred G as the orphan base, but only in some sequence contexts. We propose that plant AP endonucleases and AP lyases play complementary DNA repair functions on abasic sites arising at C:G pairs, neutralizing the potential mutagenic consequences of C deamination and G oxidation, respectively.     

Cell Death Mechanisms Induced by CLytA-DAAO Chimeric Enzyme in Human Tumor Cell Lines

The combination of the choline binding domain of the amidase N-acetylmuramoyl-L-alanine (CLytA)-D-amino acid oxidase (DAAO) (CLytA-DAAO) and D-Alanine induces cell death in several pancreatic and colorectal carcinoma and glioblastoma cell lines. In glioblastoma cell lines, CLytA-DAAO-induced cell death was inhibited by a pan-caspase inhibitor, suggesting a classical apoptotic cell death. Meanwhile, the cell death induced in pancreatic and colon carcinoma cell lines is some type of programmed necrosis. In this article, we studied the mechanisms that trigger CLytA-DAAO-induced cell death in pancreatic and colorectal carcinoma and glioblastoma cell lines and we acquire a further insight into the necrotic cell death induced in pancreatic and colorectal carcinoma cell lines. We have analyzed the intracellular calcium mobilization, mitochondrial membrane potential, PARP-1 participation and AIF translocation. Although the mitochondrial membrane depolarization plays a crucial role, our results suggest that CLytA-DAAO-induced cell death is context dependent. We have previously detected pancreatic and colorectal carcinoma cell lines (Hs766T and HT-29, respectively) that were resistant to CLytA-DAAO-induced cell death. In this study, we have examined the putative mechanism underlying the resistance in these cell lines, evaluating both detoxification mechanisms and the inflammatory and survival responses. Overall, our results provide a better understanding on the cell death mechanism induced by CLytA-DAAO, a promising therapy against cancer.     

Formulation of a Biodegradable Detergent for Cleaning Oily Residues Generated during Industrial Processes

The use of toxic petroleum-based heavy oils is common in industrial processes. The cleaning of machines, equipment, and other surface covered in these oils is achieved with expensive products that are often also toxic and harmful to both the health of workers and the environment. The present paper proposes the development of a sustainable biodetergent made from plant-based materials. Tests were performed to determine the properties of the biodetergent in terms of its surfactant and emulsifying capacities, stability, toxicity, and the removal of heavy oil from glass plates and metallic surfaces. The formulation was composed of a natural solvent (cottonseed oil), a plant-based surfactant agent (saponin), and two natural stabilizers (carboxymethylcellulose and glycerine). The formulation was stable, nontoxic, and highly efficient, removing 100% of the heavy oil from glass and metallic surfaces. This solution developed in this study could be used in diverse industries with the need to clean machines and parts encrusted with oil and grease as well as the cleaning of floors covered with petroleum-based residues. A preliminary analysis of the economic feasibility of using the detergent was carried out at a Brazilian power plant. Besides the reduction in environmental impact due to the use of a nontoxic, biodegradable product as well as the reduction in health risks to workers associated with toxic cleaning products, this new product can have a considerable impact on the market as an environmentally friendly solution.     

Synthesis,Molecular Modeling and Biological Evaluation of Metabolically Stable Analogues of the Endogenous Fatty Acid Amide Palmitoylethanolamide

Palmitoylethanolamide (PEA) belongs to the class of N-acylethanolamine and is an endogenous lipid potentially useful in a wide range of therapeutic areas; products containing PEA are licensed for use in humans as a nutraceutical, a food supplement, or food for medical purposes for its analgesic and anti-inflammatory properties demonstrating efficacy and tolerability. However, the exogenously administered PEA is rapidly inactivated; in this process, fatty acid amide hydrolase (FAAH) plays a key role both in hepatic metabolism and in intracellular degradation. So, the aim of the present study was the design and synthesis of PEA analogues that are more resistant to FAAH-mediated hydrolysis. A small library of PEA analogues was designed and tested by molecular docking and density functional theory calculations to find the more stable analogue. The computational investigation identified RePEA as the best candidate in terms of both synthetic accessibility and metabolic stability to FAAH-mediated hydrolysis. The selected compound was synthesized and assayed ex vivo to monitor FAAH-mediated hydrolysis and to confirm its anti-inflammatory properties. ¹H-NMR spectroscopy performed on membrane samples containing FAAH in integral membrane protein demonstrated that RePEA is not processed by FAAH, in contrast with PEA. Moreover, RePEA retains PEA’s ability to inhibit LPS-induced cytokine release in both murine N9 microglial cells and human PMA-THP-1 cells.