Evaluation of Nanomechanical Properties of Tomato Root by Atomic Force Microscopy.

Here, different tissue surfaces of tomato root were characterized employing atomic force microscopy on day 7 and day 21 of growth through Young's modulus and plasticity index. These parameters provide quantitative information regarding the mechanical behavior of the tomato root under fresh conditions in different locations of the cross-section of root [cell surface of the epidermis, parenchyma (Pa), and vascular bundles (Vb)]. The results show that the mechanical parameters depend on the indented region, tissue type, and growth time. Thereby, the stiffness increases in the cell surface of epidermal tissue with increasing growth time (from 9.19 ± 0.68 to 13.90 ± 1.68 MPa) and the cell surface of Pa tissue displays the opposite behavior (from 1.74 ± 0.49 to 0.48 ± 0.55); the stiffness of cell surfaces of Vb tissue changes from 10.60 ± 0.58 to 6.37 ± 0.53 MPa, all cases showed a statistical difference (p < 0.05). Viscoelastic behavior dominates the mechanical forces in the tomato root. The current study is a contribution to a better understanding of the cell mechanics behavior of different tomato root tissues during growth.

Study of the properties of ZnO:Zn thin films obtained from ZnO/Zn/ZnO structure deposited by DC sputtering.

A method to manage the resistivity of n-type ZnO films is presented. It involves the controlled diffusion of Zn at low temperature in N2 atmosphere into the ZnO/Zn/ZnO structure. The structures were made by DC sputtering technique. The diffusion periods were varied from 5 to 30 min. This process allow us to obtain ZnO films with excess of Zn (ZnO:Zn). The electrical characterization showed that the resistivity of the films can be varied from 0.01 to 100 omega-cm, the electron concentration from 10(19) to 10(17) cm(-3) and the carrier mobility from 10 to 40 cm2N-s. The films are nanocrystalline with preferred (002) orientation and crystal size that varies from 13 to 20 nm depending on the diffusion period. The films have a band gap of 3.18 eV and 70% of transmittance in the visible region, these properties were obtained from the transmittance measurements of low-resistivity films. Films have good structural, optical and electrical properties, and could be used in the manufacture of light emitting diodes.

Dataset of the synthesis parameters to deposit YSZ on stainless steel AISI 316L by sputtering technique.

The data presented in this article are related to the research previously published "improvement of adhesion and barrier properties of biomedical stainless steel by deposition of YSZ coatings using RF magnetron sputtering". It contains the structural, morphological, compositional and electrochemical characterization of bare AISI 316L substrate which was used as a substrate to coat with yttria-stabilized zirconia (YSZ). The chemical composition and topography analyses from X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and micrographs from atomic force microscopy (AFM) as well as the roughness value of the YSZ-sputtered coating on AISI 316L substrates are presented as complementary data of the article.

Physical and structural characterisation of zein and chitosan edible films using nanotechnology tools.

The use of composite edible films made from biopolymers has attracted interest as a way to reduce pollution and recycling problems; however, the relation between barrier, mechanical and structural properties of the films have been scarcely studied. The aim of this work was to evaluate composite zein-chitosan edible films by applying common nanotechnology tools and to relate the results to zein concentration and film structural changes. Rougher, more elastic, and less hard film structures with better water vapour barrier properties were obtained using larger zein concentrations. Raman spectroscopy exhibited unexpected interactions, as indicated by the disappearance of the thiol groups of cysteine in the zein films and the appearance of O=S=O and C-O-S groups in the blended materials in conjunction with the disappearance of zein ε-amino and -NH2 functional groups in the zein film samples, thereby confirming changes in the blended film structure. Zein concentration presented linear correlations with water vapour permeability (R=-0.978) and film roughness (R=0.929). The composite films presented better barrier and mechanical properties than single ingredient films. This information shows the benefit of using protein-polysaccharide blends to prepare edible films.