Velasquezstorm4781

They also highlight the promising complementarity of this approach with more traditional biomonitoring frameworks and routine reports of air quality provided by environmental agencies.Although fumigants can effectively control soil-borne diseases they are typically harmful to beneficial microorganisms unless methods are developed to encourage their survival after fumigation. The soil fumigant 1,3-dichloropropene (1,3-D) is widely used because of its effective management of pathogenic nematodes and weeds. After fumigation with 1,3-D, Bacillus subtilis and Trichoderma harzianum fertilizer (either singularly or together) or humic acid were added to soil that had been used to produce tomatoes under continuous production for >20 years. We evaluated changes to the soil's physicochemical properties and enzyme activity in response to these fertilizer treatments, and the effects of these changes on beneficial bacteria. Fertilizer applied after fumigation increased the content of ammonium nitrogen, nitrate nitrogen, available phosphorus, available potassium and organic matter, and it promoted an increase in pH and electrical conductivity. The activity of urease, sucrase and catalase enzymes in the soil increased after fumigation. Taxonomic identification of bacteria using genetic analysis techniques showed that fertilizer applied after fumigation increased the abundance of Actinobacteria and the relative abundance of the biological control genera Sphingomona, Pseudomonas, Bacillus and Lysobacter. The abundance of these beneficial bacteria increased significantly when B. subtilis and T. harzianum were applied together. These results showed that fertilizer applied after fumigation can increase the abundance of beneficial microorganisms in the soil within a short period of time, which improved the soil's fertility, ecological balance and potentially crop quality and yield.Bioactive materials should maintain their properties during implantation and for long time in contact with physiological fluids and tissues. In the present research, five different bioactive materials (a bioactive glass and four different chemically treated bioactive titanium surfaces) have been studied and compared in terms of mechanical stability of the surface bioactive layer-substrate interface, their long term bioactivity, the type of hydroxyapatite matured and the stability of the hydroxyapatite-surface bioactive layer interface. Numerous physical and chemical analyses (such as Raman spectroscopy, macro and micro scratch tests, soaking in SBF, Field Emission Scanning Electron Microscopy equipped with Energy Dispersive Spectroscopy (SEM-EDS), zeta potential measurements and Fourier Transformed Infra-Red spectroscopy (FTIR) with chemical imaging) were used. Scratch measurements evidenced differences among the metallic surfaces concerning the mechanical stability of the surface bioactive layer-substrate interface. All the surfaces, despite of different kinetics of bioactivity, are covered by a bone like carbonate-hydroxyapatite with B-type substitution after 28 days of soaking in SBF. However, the stability of the apatite layer is not the same for all the materials dissolution occurs at pH around 4 (close to inflammation condition) in a more pronounced way for the surfaces with faster bioactivity together with detachment of the surface bioactive layer. A protocol of characterization is here suggested to predict the implant-bone interface stability.Polymeric nanoparticulate systems allow the encapsulation of bio-active substances, giving them protection against external agents and increasing the drug's bioavailability. The use of biocompatible and biodegradable polymers usually guarantees the harmless character of the formulation, and a controlled drug release is also assured. A relatively easy procedure to obtain polymeric formulations of bioactive agents is ionotropic gelation, which allows the synthesis of chitosan (CS) - sodium tri-polyphosphate nanoparticles (NPs) loading encapsulated proteins. In this work, Bovine serum albumin (BSA) model protein and a recombinant porcine alpha interferon variant were used to obtain nanoparticulate formulations. The internalization of the encapsulated material by cells was studied using a BSA-fluorescein system; the fluorescent conjugate was observable inside the cells after 20 h of incubation. The therapeutic CS-alpha interferon formulation showed a maximum of protein released in vitro at around 90 h. CP 43 concentration This system was found to be safe in a cytotoxicity assay, while biological activity experiments in vitro showed antiviral protection of cells in the presence of encapsulated porcine alpha interferon. In vivo experiments in pigs revealed a significant and sustained antiviral response through overexpression of the antiviral markers OAS2 and PKR. This proves the preservation of porcine alpha interferon biological activity, and also that a lasting response was obtained. This procedure is an effective and safe method to formulate drugs in nanoparticulate systems, representing a significant contribution to the search for more effective drug delivery strategies.The ability to decellularize and recellularize the corneas deemed unsuitable for transplantation may increase the number of available grafts. Decellularized corneas (DCs) may provide a natural microenvironment for cell adhesion and differentiation. Despite this, no study to date has evaluated their efficacy as a substrate for the induction of stem cell differentiation into corneal cells. The present study aimed to compare the efficiency of NaCl and NaCl plus nucleases methods to decellularize whole human corneas, and to investigate the effect of epithelial basement membrane (EBM) of whole DCs on the ability of human embryonic stem cells (hESCs) to differentiate into corneal epithelial-like cells when cultured in animal serum-free differentiation medium. As laminin is the major component of EBM, we also investigated its effect on hESCs differentiation. The decellularization efficiency and integrity of the extracellular matrix (ECM) obtained were investigated by histology, electron microscopy, DNA quantification, immunofluorescence, and nuclear staining. The ability of hESCs to differentiate into corneal epithelial-like cells when seeded on the EBM of DCs or laminin-coated wells was evaluated by immunofluorescence and RT-qPCR analyses. NaCl treatment alone, without nucleases, was insufficient to remove cellular components, while NaCl plus nucleases treatment resulted in efficient decellularization and preservation of the ECM. Unlike cells induced to differentiate on laminin, hESCs differentiated on DCs expressed high levels of corneal epithelial-specific markers, keratin 3 and keratin 12. It was demonstrated for the first time that the decellularized matrices had a positive effect on the differentiation of hESCs towards corneal epithelial-like cells. Such a strategy supports the potential applications of human DCs and hESCs in corneal epithelium tissue engineering.Tumor metastasis to brain is the main clinical manifestation of patients with advanced breast cancer, leading to poor survival prognosis. In order to detect the early incidence of brain metastasis, it is urgent to develop hypersensitive contrast agents for multimode imaging. In this study, PEG-phospholipids coated, a phage play derived peptide, BRBP1 peptide modified ultra-small iron oxide nanoparticles were prepared for targeted NIRF and MR imaging of breast cancer brain metastasis. The nanoparticles showed 10 nm core-shell, high relaxivity values and photon emission efficiency in vitro. The nanoparticles offered a T2 contrast imaging effect and near-infrared fluorescent signal enhancement. Compared with control peptide modified nanoparticles, the MR/NIRF imaging signal of BRBP1-modified nanoparticles in tumor tissue was significantly enhanced, which should be induced by the targeting ability of BRBP1 peptide. These results indicated that BRBP1-SPIO@mPEG (DiR) nanoparticles could be applied as an effective targeted delivery system for diagnosis of breast cancer brain metastasis.A nanocomposite based on bacterial cellulose (BC) containing montmorillonite (MMT) modified with silver (BC-MMT-Ag) was developed to be used as potential scaffold for wound healing. Montmorillonite was suspended in silver nitrate solution to incorporate silver in the matrix by ion exchange. The derivative silver clay suspension was used to modify bacterial cellulose membranes by ex situ technique. The BC nanocomposite was analyzed by thermal analysis, scanning electron microscopy, Fourier transform infrared and electron dispersion spectroscopies, X-ray diffraction, and rehydration capacity. The antimicrobial activity of the silver montmorillonite-bacterial cellulose nanocomposite was challenged in cultures of Gram(+) Staphylococcus aureus and Gram(-) Pseudomonas aeruginosa, and showed inhibition of growth in agar plates and biofilm formation as revealed by live-dead assay. Cytotoxicity of BC nanocomposites containing 1% to 25% of MMT-Ag showed good in vitro biocompatibility with L929 fibroblast cells.Biopolymer scaffold is expected to generate electrical stimulation, aiming to mimic an electrical microenvironment to promote cell growth. In this work, graphene and barium titanate (BT) was introduced into selective laser sintered poly-l-lactic acid (PLLA) scaffold. BT as one piezoelectric ceramic was used as the piezoelectric source, whereas graphene served as superior conductive filler. Significantly, the incorporated graphene enhanced the electrical conductivity and thereby increased the electric field strength applied on BT nanoparticles during poling. In this case, more electric domain within BT rearranged along the poling field direction, thus promoting the piezoelectric response of the composites. Results showed that the PLLA/BT/graphene scaffold exhibited relatively high output voltage of 1.4 V and current of 10 nA. Cells tests proved that these electrical signals considerably promoted cell proliferation and differentiation. Moreover, the scaffold exhibited improved mechanical properties due to the rigid particle enhancement effect and increased crystallinity.

To synthesize and characterize brushite particles in the presence of acidic monomers (acrylic acid/AA, citric acid/CA, and methacryloyloxyethyl phosphate/MOEP) and evaluate the effect of these particles on degree of conversion (DC), flexural strength/modulus (FS/FM) and ion release of experimental composites.

Particles were synthesized by co-precipitation with monomers added to the phosphate precursor solution and characterized for monomer content, size and morphology. Composites containing 20vol% brushite and 40vol% reinforcing glass were tested for DC, FS and FM (after 24h and 60 d in water), and 60-day ion release. Data were subjected to ANOVA/Tukey tests (DC) or Kruskal-Wallis/Dunn tests (FS and FM, alpha 5%).

The presence of acidic monomers affected particle morphology. Monomer content on the particles was low (0.1-1.4% by mass). Composites presented similar DC. For FS/24h, only the composite containing DCPD_AA was statistically similar to the composite containing 60vol% of reinforcing glass (withog all brushite-containing composites. Ion release was sustained for 60 days and it was not affected by particle morphology.