Effects of Cyanobacterial Lipopolysaccharides from Microcystis on Glutathione-Based Detoxification Pathways in the Zebrafish (Danio rerio) Embryo

Cyanobacteria (“blue-green algae”) are recognized producers of a diverse array of toxic secondary metabolites. Of these, the lipopolysaccharides (LPS), produced by all cyanobacteria, remain to be well investigated. In the current study, we specifically employed the zebrafish (Danio rerio) embryo to investigate the effects of LPS from geographically diverse strains of the widespread cyanobacterial genus, Microcystis, on several detoxifying enzymes/pathways, including glutathione-S-transferase (GST), glutathione peroxidase (GPx)/glutathione reductase (GR), superoxide dismutase (SOD), and catalase (CAT), and compared observed effects to those of heterotrophic bacterial (i.e., E. coli) LPS. In agreement with previous studies, cyanobacterial LPS significantly reduced GST in embryos exposed to LPS in all treatments. In contrast, GPx moderately increased in embryos exposed to LPS, with no effect on reciprocal GR activity. Interestingly, total glutathione levels were elevated in embryos exposed to Microcystis LPS, but the relative levels of reduced and oxidized glutathione (i.e., GSH/GSSG) were, likewise, elevated suggesting that oxidative stress is not involved in the observed effects as typical of heterotrophic bacterial LPS in mammalian systems. In further support of this, no effect was observed with respect to CAT or SOD activity. These findings demonstrate that Microcystis LPS affects glutathione-based detoxification pathways in the zebrafish embryo, and more generally, that this model is well suited for investigating the apparent toxicophore of cyanobacterial LPS, including possible differences in structure-activity relationships between heterotrophic and cyanobacterial LPS, and teleost fish versus mammalian systems

Pengujian Media Tanam Kompos Dan Residu Sampah Rumah Tangga Terhadap Basa Tukar, Ktk, Kb Dan Produksi Tanaman Sawi (Brassica Juncea L. Czern) Di Lahan Pekarangan Kec. Sunggal

The Study to evaluate the effect compost of household waste as growing media and the residual ofhousehold waste pit on the availability of KTK, KB and the production of mustard (Brassica junceaL. Czern) corp in yard. This research was conducted in the compost yard in Desa Sei SemayangKecamatan Sunggal Kabupaten Deli Serdang and in the laboratory of Agricultural Faculty ofUniversity of North Sumatra. The design of this research were non-factorial random design which isconsisting of 9 treatments with 3 replications. The treatment are M1 (100% soil), M2 (75% soil +25% compost), M3 (50% soil + 50% compost), M4 (25% soil + 75% compost), M5 (75% soil +25% residues of the household waste pit), M6 (50% soil + 50% residues of the household wastepit), M7 (25% soil + 75% residues of the household waste pit), M8 (50% compost+ 50% residues ofthe household waste pit), M9 (100% residues of the household waste pit). The result is that researchas household waste compost and residues of the household waste pit and the combination of both,very significantly increased the K-dd, Base Saturation of the soil as well as the production of thewet weight mustard plant and not significant to Ca, Mg and Na contensts

Preparation of Oxide Solid Solutions by Thermal Decomposition of Tutton\u27s Salts, (NH4)2M(SO4)2∙6H2O (M=Mn, Zn, Fe)

A recent study of the themnal decomposition of Tutton\u27s salts, (NH4hM(S0412\u27 6H20, in which M represents a mixture of two to six transition elements, showed that when the salts are decomposed in an argon atmosphere the final products of decomposition are solid solutions of metal (2+) oxides but when decomposed in air the resulting solid solutions are metal (2 +) and (3 +) oxides.! Thermal decomposition of Tutton\u27s salts containing a definite ratio of metals in the structure may, therefore, be a route for the synthesis of a homogeneous, uncontaminated reactive powder useful for the preparation of homogeneous magnetic ceramics

Study of Tutton\u27s Salts (NH4)M(SO4)2 · 6H2O with Mixed Metal Ions in the Structure

Tutton\u27s salts, (NH4hM(S04h\u27 6H20, in which M represents one, two or three different metal ions in the structure have been obtained previously. Because of similar properties of the transition . elements we started to study the system (NH4hS04-H20-MS04 (M= Mn, Fe, Co, Ni, Cu, Zn or mixtures of these elements) and we isolated the crystals (NH4hM(S04)2. 6H20 where M represents mixtures of Ni, Zn; Co, Ni, Zn; Co, Ni, Cu, Zn; Fe, Co, Ni, Cu, Zn; Mn, Fe, Co, Ni, Cu, Zn. The products were characterized by chemical analysis. X-ray powder photographs of the products confirmed that they have structures similar to those of other Tutton\u27s salts. The thermal decomposition of the salts was studied in air and in an argon atmosphere and the final products were identified by X-ray powder photographs

Comparing faceted and smoothed tool surface descriptions in sheet metal forming simulation

This study deals with different tool surface description methods used in the finite element analysis of sheet metal forming processes. The description of arbitrarily-shaped tool surfaces using the traditional linear finite elements is compared with two distinct smooth surface description approaches: (i) Bézier patches obtained from the ComputerAided Design model and (ii) smoothing the finite element mesh using Nagata patches. The contact search algorithm is presented for each approach, exploiting its special features in order to ensure an accurate and efficient contact detection. The influence of the tool modelling accuracy on the numerical results is analysed using two sheet forming examples, the unconstrained cylindrical bending and the reverse deep drawing of a cylindrical cup. Smoothing the contact surfaces with Nagata patches allows creating more accurate tool models, both in terms of shape and normal vectors, when compared with the conventional linear finite element mesh. The computational efficiency is evaluated in this study through the total number of increments and the required CPU time. The mesh refinement in the faceted description approach is not effective in terms of computational efficiency due to large discontinuities in the normal vector field across facets, even when adopting fine meshes.The authors gratefully acknowledge the financial support of the Portuguese Foundation for Science and Technology (FCT) via the projects PTDC/EME-TME/118420/2010 and PEst-C/EME/ UI0285/2013 and by FEDER funds through the program COMPETE – Programa Operacional Factores de Competitividade, under the project CENTRO-07-0224-FEDER-002001 (MT4MOBI). The first author is also grateful to the FCT for the PhD grant SFRH/BD/69140/2010.info:eu-repo/semantics/publishedVersio

Injectable gellan gum-based nanoparticles-loaded system for the local delivery of vancomycin in osteomyelitis treatment

Infection spreading in the skeletal system leading to osteomyelitis can be prevented by the prolonged administration of antibiotics in high doses. However systemic antibiotherapy, besides its inconvenience and often low efficacy, provokes numerous side effects. Thus, we formulated a new injectable nanoparticle-loaded system for the local delivery of vancomycin (Vanc) applied in a minimally-invasive way. Vanc was encapsulated in poly(Llactide- co-glycolide) nanoparticles (NPs) by double-emulsification. The size (258 ± 11 nm), polydispersity index (0.240 ± 0.003) and surface potential (-25.9 ± 0.2 mV) of NPs were determined by dynamic light scattering and capillary electrophoresis measurements. They have a spherical morphology and a smooth topography as observed using atomic force microscopy. Vanc loading and encapsulation efficiencies were 8.8 ± 0.1 and 55.2 ± 0.5 %, respectively, based on fluorescence spectroscopy assays. In order to ensure injectability, NPs were suspended in gellan gum and cross-linked with $Ca^{2+}$; also a portion of dissolved antibiotic was added to the system. The resulting system was found to be injectable (extrusion force 11.3 ± 1.1 N), reassembled its structure after breaking as shown by rheology tests and ensured required burst release followed by sustained Vanc delivery. The system was cytocompatible with osteoblast-like MG-63 cells (no significant impact on cells’ viability was detected). Growth of Staphylococcus spp. reference strains and also those isolated from osteomyelitic joints was inhibited in contact with the injectable system. As a result we obtained a biocompatible system displaying ease of application (low extrusion force), self-healing ability after disruption, adjustable drug release and antimicrobial properties