59 research outputs found

    Zinc- and Copper-Doped Mesoporous Borate Bioactive Glasses: Promising Additives for Potential Use in Skin Wound Healing Applications

    Get PDF
    In this study, zinc (Zn)- and copper (Cu)-doped 13-93B3 borate mesoporous bioactive glasses (MBGs) were successfully synthesized using nitrate precursors in the presence of Pluronic P123. We benefited from computational approaches for predicting and confirming the experimental findings. The changes in the dynamic surface tension (SFT) of simulated body fluid (SBF) were investigated using the Du Noüy ring method to shed light on the mineralization process of hydroxyapatite (HAp) on the glass surface. The obtained MBGs were in a glassy state before incubation in SBF. The formation of an apatite-like layer on the SBF-incubated borate glasses was investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The incorporation of Zn and Cu into the basic composition of 13-93B3 glass led to changes in the glass transition temperature (Tg) (773 to 556 °C), particle size (373 to 64 nm), zeta potential (−12 to −26 mV), and specific surface area (SBET) (54 to 123 m2/g). Based on the K-means algorithm and chi-square automatic interaction detection (CHAID) tree, we found that the SFT of SBF is an important factor for the prediction and confirmation of the HAp mineralization process on the glasses. Furthermore, we proposed a simple calculation, based on SFT variation, to quantify the bioactivity of MBGs. The doped and dopant-free borate MBGs could enhance the proliferation of mouse fibroblast L929 cells at a concentration of 0.5 mg/mL. These glasses also induced very low hemolysis (<5%), confirming good compatibility with red blood cells. The results of the antibacterial test revealed that all the samples could significantly decrease the viability of Pseudomonas aeruginosa. In summary, we showed that Cu-/Zn-doped borate MBGs can be fabricated using a cost-effective method and also show promise for wound healing/skin tissue engineering applications, as especially supported by the cell test with fibroblasts, good compatibility with blood, and antibacterial properties

    Fabrication and characterization of cobalt- and copper-doped mesoporous borate bioactive glasses for potential applications in tissue engineering

    Get PDF
    Developing novel compositions of bioactive glasses (BGs) is key for accelerating tissue repair and regeneration. In this work, we developed a series of cobalt (Co)- and copper (Cu)-doped mesoporous bioactive glasses (MBGs) based on borate 13-93B3 composition using nitrate precursors. We took benefit from data science algorithms to predict and assess the physico-chemical and biological properties of the samples. The results showed that the presence of the dopants (Co and Cu) in the MBGs could change the glass transition temperature (Tg) (from 773 to 539 °C), the zeta potential (from -12 to -43 mV), and surface area (from 54 to 194 m2/g). However, the presence of 2.5 mol% of dopants in the composition led to just a slight decrease in their bioactivity. In vitro biocompatibility assays confirmed that all the glass samples were biocompatible. Furthermore, the doped MBGs exhibited potent antibacterial activity against both Gram-positive and Gram-negative bacteria. In addition, these glasses could induce the mobility of human umbilical vein endothelial cells (HUVECs) and enhance new blood vessel formation in ovo. According to the obtained data, it can be stated that this type of doped borate MBGs held great promise in tissue engineering applications

    Efficient inhibition of human immunodeficiency virus replication using novel modified microRNA-30a targeting 3'-untranslated region transcripts

    Get PDF
    RNA interference (RNAi)-based gene therapy is currently considered to be a combinatorial anti-human immunodeficiency virus-1 (HIV-1) therapy. Although arti­ficial polycistronic microRNAs (miRs) can reduce HIV-1 escape mutant variants, this approach may increase the risk of side effects. The present study aimed to optimize the efficiency of anti-HIV RNAi gene therapy in order to reduce the cell toxicity induced by multi-short hairpin RNA expression. An artificial miR-30a-3'-untranslated region (miR-3'-UTR) obtained from a single RNA polymerase II was used to simultaneously target all viral transcripts. The results of the present study demonstrated that HIV-1 replication was signifi­cantly inhibited in the cells with the miR-3'-UTR construct, suggesting that miR-3'-UTR may serve as a promising tool for RNAi-based gene therapy in the treatment of HIV-1. © 2016, Spandidos Publications. All Rights Reserved

    Short communication. Impact of the amino acid proline on the cold hardiness of honey bee, Apis mellifera L.

    Get PDF
    Like many insects, honey bee can increase its cold tolerance through freeze avoidance, using antifreeze proteins (AFPs) to lower its supercooling point (SCP). Proline is the most dominant amino acid in honey bee hemolymph, which can be obtained by the insect through feeding. In the current study the antifreeze activity of this amino acid was evaluated on worker honey bees, immediately before the start of cold season. The experiment was established on four treatments including three different concentrations of proline (1%, 3% and 4.35%) diluted in 1:1 water sucrose syrup, and the syrup without proline (control). Newly emerged worker honey bees were fed on the mentioned diets for 2 weeks, under cage condition, and then 20 bees from each treatment (cage) were selected randomly for determination of cold hardiness inside a cooling bath. Using a CHY data logger, equipped with a K100 sensor attached to the bee’s gaster, the SCP, the amount of released heat and the rate of this release as measures of insect cold hardiness were recorded. Proline significantly reduced honey bees’ SCP. The lowest point, -7.67±0.2646°C, was observed in the concentration of 1% proline. The amount of released heat and the rate of this release were not significantly different across the treatments

    Dual-Band Transceiver High Impedance Coil Array for Ultra-high Field Magnetic Resonance Imaging

    No full text
    A novel approach for designing an element of an arrayed radio frequency coil for ultrahigh field magnetic resonance imaging (UHF MRI) is presented. The purpose of this approach is to achieve the dual-band transceiver regime in a compact array of magnetic antennas. Our work qualitatively develops the concept of the so-called high-impedance coil (HIC), combined with the adequate interfacing circuitry, which offers the decoupling of the HICs in the array due to the very high self-impedance compared to the mutual impedance. This concept has not been previously thought applicable to dual-band transceiver arrays. We show that, by slightly modifying only the cable shield, we achieve a dual-band transceiver high-impedance coil (dual-band TRHIC). The needed modification implies two asymmetric gaps granting two useful eigenmodes to the cable loop. The resonant excitation of these modes will allow the magnetic resonant scanning of both hydrogen and Phosphorus in the 7 T dc magnetic field. To verify our ideas, we simulated and measured a single TRHIC in both transmitting and receiving regimes and similarly studied two linear arrays made of two and three proposed TRHICs. The method of asymmetric gaps, in our opinion, allows one to engineer the targeted multifrequency operation of arrayed TRHICs decoupled at these frequencies.Peer reviewe

    Energy indices in irrigated wheat production under conservation and conventional tillage and planting methods

    No full text
    Introduction: Conservation tillage system was recommended for soil erosion control in North America for the first time 60 years ago (Wang et al., 2006). Using this tillage system including minimum and zero tillage has been rapidly developed in recent years. Thearea covered by zero tillage in 2006 was 95 million ha all over the world (Dumanski et al., 2006). In addition to saving soil and water resources, conservation tillage system reduces energy consumption and improves energy indices by combining different tillage and planting operations. Results of research conducted in Fars province shows that conservation tillage saves fuel consumption for 77% compared to the conventional system (Afzalinia et al., 2009). Conservation tillage also reduces energy consumption from 23.6 to 42.8% in comparison to the conventional tillage (Rusu, 2005). Since energy indices would be affected by reduced input energies in conservation tillage, this research was conducted to evaluate the effect of different tillage and planting methods on energy inputs and energy indices in irrigated wheat production in Eghlid region. Materials and Methods: This research was performed to evaluate and compare the energy indices in irrigated wheat production under different tillage and planting methods. The study was conducted in the form of a randomized complete block experimental design with five treatments and three replications in Eghlid region. The treatments were included, conventional tillage and seed broadcasting (A), conventional tillage and planting with Machine Barzegar grain drill (B), reduced tillage and seeding with Roto-seeder (C), direct seeding with Jairan Sanaat grain drill (D), and direct seeding with Sfoggia direct drill (E). Experimental plots with 10 by 50 m dimensions were used in this study. Loss crop residues were taken out of the experimental plots and standing crop residues were retained in the plots. In the conventional tillage method, primary tillage was performed using a moldboard plow and secondary tillage operation was done using a disk harrow and land leveler. Seed bed was prepared in the reduced tillage method using a tine and disc cultivator which was able to complete the primary and secondary tillage operations simultaneously. Wheat seed was directly planted using direct planter without any seed bed preparation in the zero tillage method. Surface irrigation method was used to irrigate the plots and 11970 m3/ha water was consumed in each treatment. Input energies including direct energy (diesel and electricity) and indirect energy (water, labor, seed, fertilizer, chemicals, and machinery) were measured and calculated. Output energies (energy of grain and straw) were measured in each treatment and the share of each input energy, energy ratio, net energy gain, and energy productivity were determined and compared. Collected data were analyzed using SAS software and Duncan’s multiple range tests was used to compare the treatments means. Results and Discussion: Results showed that tillage and planting methods had a significant effect on fuel and machinery energies; while, the total input energy, crop grain yield, and crop biologic yield were not affected by the tillage and planting methods (Table 4). Fertilizers and chemicals had the highest contribution in input energy of all treatments. Results also indicated that reduced tillage and seeding with Roto-seeder had the highest energy ratio (1.46) and the lowest energy ratio (1.40) was related to the conventional tillage methods (Fig.1). The highest net energy gain (47653 MJ) was obtained from the reduced tillage and seeding with Roto-seeder; while, the lowest amount of net energy gain (41388 MJ) was related to the conventional tillage and planting with Machine Barzegar grain drill (Fig.3). Results also showed that the reduced tillage and seeding with Roto-seeder had the highest energy productivity (0.115 kg MJ-1) and the conventional tillage treatments had the lowest energy productivity of 0.110 kg MJ-1 (Fig.4). Conclusions: Results of this study showed that conservation tillage treatments (minimum and zero tillage) reduced total energy consumption (input energy) by decreasing fuel consumption and mechanical energy (energy of machinery) compared to the conventional tillage. Therefore, conservation tillage treatments had the higher energy ratio, net energy gain, and energy productivity compared to the conventional treatments. For this reason, conventional tillage and planting methods could be replaced with conservation tillage systems in Eghlid region. Meanwhile, in order to obtain more accurate results in energy indices comparison, differences in water consumption in various tillage and planting methods should be also considered
    corecore