No abstract

Hydroxyapatite (HAp) coatings were prepared on Ti6Al4V substrate by electrodeposition method from electrolyte solution containing Ca(NO3)2, NH4H2PO4 and NaNO3. The results show that the HAp coatings were single phase crystals of HAp. Scanning electron microscope (SEM) images present that HAp/Ti6Al4V have flake shapes which arrange to form like-coral agglomerates. In vitro test of the Ti6Al4V and HAp/Ti6Al4V in simulated body fluid (SBF) solution was investigated with different immersion times. pH of SBF solution decreased and the mass of materials increased. SEM images prove the formation of apatite on the surface of Ti6Al4V and HAp/Ti6Al4V. The corrosion current density during immersion time of substrate is always higher than the one of HAp/Ti6Al4V because the deposited HAp can protect well for the substrate.

No abstract

The deposition of TiN on stainless steel substrates may improve the stability and compatibility of this material with bone, which may be advantageously exploited for the elaboration of advanced pros- thetic devices. In this work, TiN-coated 316LSS (by way of DC magnetron sputtering) was used as a starting material for investigating the electrochemical post-deposition of hydroxyapatite (HAp) which has a composition close to that of bone. Electrodeposition was carried out starting from an aqueous medium containing solubilized Ca(NO3)2 and NH4H2PO4 in the presence of H2O2. We report the influence of experimental conditions on the morphology of the obtained HAp coating on TiN/316LSS. The effect of applied potential, temperature, H2O2 concentration, pH and duration of reaction were thoroughly discussed on the basis of X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and Energy Dispersive X-ray Spectroscopy (EDX) results. This method appears advantageous for producing HAp-coated implant materials.

No abstract

Pesticide residue in food, especially in vegetables, is one of the important parameters to assess food safety. This study evaluates the pesticide use in vegetables from two provinces in Central Vietnamand and present data on pesticides detected in vegetables sampled from the sites. The potential health risk associated with the contamination of four commonly used pesticides in different vegetables is also discussed. Both household surveys and monitoring campaigns were conducted. The survey showed that improper pesticide application, storage, and waste disposal prevailed at the study sites. Only 20% of the respondent were aware of pesticide toxicity. As a result, pesticides were detected in 81% out of 290 vegetable samples collected at harvesting time. Up to 23% of samples had pesticide residues above the Maximum Residue Limit values. The highest total pesticide concentration quantified in vegetables in Thua Thien Hue was 11.9 mg/kg (green onions), and in Quang Binh was 38.6 mg/kg (mustard greens). Median residue levels of individual pesticides in vegetables ranged from 0.007 to 0.037 mg/kg. Among the ten target pesticides, cypermethrin, difenoconazole, and fenobucarb were detected at the highest frequencies (72%, 41%, and 37%, respectively). Pesticide residues varied between seasons at both study provinces. Pesticide contamination in the wet season was significantly higher than in the dry season. This study also discovered a potential health risk associated with fipronil residues in vegetables in Thua Thien Hue province. The paper provides recommendations for mitigation measures (both technological and social) in reducing potential health risks linked to pesticide use in vegetables in the region.

We report on the fabrication and the electrochemical behavior of TiN film on the 316L stainless steel (316LSS) material in simulated body fluid (SBF) solution for implant application. The characterization results indicate that the coated TiN is completely crystalline with (111) crystal orientation. Electrochemical results of 316LSS and TiN/316LSS material after 21 days of immersion in SBF show that the durability of the TiN/316LSS is much higher than that of 316LSS, which registers a very low corrosion current density (about tens of nA cm(-2)). The formation of hydroxyapatite on the surface of the TiN/316LSS is also confirmed by SEM, EDX, X-ray and IR spectroscopy.

Pesticide dissipation on foods like vegetables, fruits, and cereals is one of the most concerning aspects in pesticide toxicology as it involves risks to human health and food safety. In light if this, a laboratory-scale study was conducted for two separate systems, green onions (Allium fistulosum) and mustard greens (Brassica juncea),in order to identify the dissipation of fipronil and cypermethrin, two commonly used insecticides, under a tropical climate. After the pesticide application, vegetable samples from these microcosms were collected each day for 7 days to measure fipronil and cypermethrin (n=3) residues. The analytical method was validated and showed repeatability and trueness. The decay equations fit well to first-order kinetics with a correlation coefficient of R2>0.93 and p<0.0005. The calculated half-life values of fipronil were 2.9 d for green onions and 3.2 d for mustard greens while those of cypermethrin were, respectively, 4.5 d and 3.2 d. To meet the maximum residue levels (MRL) of fipronil (0.02 mg/kg) and cypermethrin (0.7 mg/kg) on vegetables, the estimated pre-harvest intervals should be updated to 23 d and 7.5 d, respectively.