44 research outputs found

    Eco-friendly synthesis of PbTiO3 nanoparticles and PbTiO3/carbon quantum dots binary nano-hybrids for enhanced photocatalytic performance under visible light

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    PbTiO3 nanoparticles, carbon quantum dots CQDs and their composite (i.e. PbTiO3/CQDs) were prepared and studied using XRD, FT-IR, VSM, TEM, BET, PL, FESEM, UV�Vis, and EDX. Designing highly-effective PbTiO3/CQDs binary nano-hybrids include several fascinating properties of visible light, biocompatibility, eco-friendly response and good durability. Various composites containing different amounts of CQDs were prepared, and the effects of catalysts on enhancing the photocatalytic activity of PbTiO3 nanoparticles in the resulting binary nano-hybrid have been investigated. Test experiments indicated that PbTiO3 nanoparticles could remove only 53 of Rh B, while PbTiO3/5CQDs binary nano-hybrids reached a removal maximum of 100. Further the removal of different dyes using the PbTiO3/CQDs binary nano-hybrids has been evaluated and the removal mechanism has also been discussed. © 2018 Elsevier B.V

    Evaluation and statistical optimization of a method for methylated cell-free fetal DNA extraction from maternal plasma

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    Purpose: Methylated cell-free fetal DNA (cffDNA) in maternal plasma can potentially be used as a biomarker for accurate noninvasive prenatal testing (NIPT) of fetal disorders. Recovery and purification of cffDNA are key steps for downstream applications. In this study, we aimed to developed and evaluated different aspects of an optimized method and compared its efficiency with common methods used for extraction of methylated cffDNA. Methods: Single factor experiments, Plackett-Burman (PB) design, and response surface methodology (RSM) were conducted for conventional Triton/Heat/Phenol (cTHP) method optimization. The total cell-free DNA (cfDNA) was extracted from pooled maternal plasma using the optimized method called the Triton/Heat/Phenol/Glycogen (THPG), cTHP method, a column-based kit, and a magnetic bead-based kit. In the next step, methylated cfDNA from the extracted total cfDNA was enriched using a methylated DNA immunoprecipitation (MeDIP) kit. Real-time quantitative polymerase chain reaction was performed on the RASSF1 gene and hyper region to determine the genomic equivalents per milliliter (GEq/ml) values of the methylated cfDNA and cffDNA, respectively. Results: The optimum values of the significant factors affecting cfDNA extraction from 200 μl of plasma were 3% SDS, 1% Triton X-100, 0.9 μg/μl glycogen, and 0.3 M sodium acetate. The GEq/ml values of methylated cffDNA extracted using the THPG method were significantly higher than for the tested extraction methods (p < 0.001). Conclusions: Our results indicate that the THPG method is more efficient than the other tested methods for extraction of low copy number methylated cffDNA from a small volume of maternal plasm

    FLP/FRT Recombination from Yeast: Application of a Two Gene Cassette Scheme as an Inducible System in Plants

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    Phytosensors are plants that are genetically engineered for sensing and reporting the presence of a specific contaminant, including agriculturally important biological agents. Phytosensors are constructed by transforming plants to contain specific biotic- or abiotic-inducible promoters fused to a reporter gene. When such transgenic plants encounter the target biotic or abiotic agent, the specific inducible promoter is triggered and subsequently drives the expression of the reporter gene, which produces a signal for detection. However, several systems lack robustness, rapid induction and promoter strength. Here, we tested the FLP/FRT recombination system in a construct containing a two gene cassette organization and examined its potential in transgenic Arabidopsis and tobacco plants using a β-glucuronidase (GUS) reporter. In this model system, a heat-shock inducible promoter was employed to control the expression of the FLP recombinase gene. Upon heat induction and subsequent active FLP-mediated excision event, the GUS gene was placed in close proximity to the 35S promoter resulting in an active GUS reporter expression. Our results demonstrate that the two gene cassette scheme of inducible FLP/FRT recombination system is functional in tobacco and Arabidopsis, providing additional insights into its possible application in phytosensing such as creating strong readout capabilities

    Novel utility-based optimal bit-loading algorithm for orthogonal frequency division multiple access wireless networks

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    In this study, the authors propose a novel channel and queue aware algorithm for allocating power and subcarrier to users in orthogonal frequency division multiple access (OFDMA) networks. The proposed algorithm utilises a utility function to simultaneously balance and improve the efficiency and fairness of radio resource allocation. In contrast to the conventional approaches in the literature, in which it is assumed that the OFDMA system is able to support a continuous set of bit rates, here, in the system model the authors consider the fact that in practical OFDMA systems only a limited set of bit rates are supported. Furthermore, the authors do not consider the full buffer assumption and note that in practice a user scheduled for transmission might not always have data to transmit. By formulating the radio resource allocation the authors then show optimal bit loading results in a greedy algorithm that employs both bit removal and bit filling procedures. The solutions are developed in the framework of a matroid theory. The authors then analyse the average system throughput and investigate the performance of the proposed algorithm through simulations. Comparisons to similar approaches are also conducted which indicates significant performance improvement

    Oral immunization of mice with Omp31-loaded N-trimethyl chitosan nanoparticles induces high protection against Brucella melitensis infection

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    Morteza Abkar,1 Mahdi Fasihi-Ramandi,2 Hamid Kooshki,3 Abbas Sahebghadam Lotfi4 1Nanomedicine and Nanobiology Research Center, Shiraz University of Medical Sciences, Shiraz, 2Molecular Biology Research Center, 3Nanobiotechnology Research Center, Baqiyatallah University of Medical Sciences, 4Department of Clinical Biochemistry, Faculty of Medicine, Tarbiat Modares University, Tehran, Iran Abstract: Brucellosis is a group of closely associated zoonotic bacterial illnesses caused by members of the genus Brucella. B. melitensis Omp31 is a promising candidate for a subunit vaccine against brucellosis. This study surveyed the immunogenicity of Omp31 alone and with incomplete Freund&rsquo;s adjuvant (Omp31-IFA) and N-trimethyl chitosan (TMC/Omp31) nanoparticles (NPs), as well as the effect of Omp31 immunization route on immunological responses and protection. After expression and purification, the recombinant Omp31 (rOmp31) was loaded onto TMC NPs by ionic gelation. The particle size, loading efficiency and in vitro release of the NPs were examined. Omp31-IFA was administered intraperitoneally, while TMC/Omp31 NPs were administered orally and intraperitoneally. According to the antibody subclasses and cytokine profile, intraperitoneal immunization by Omp31-IFA and TMC/Omp31 NPs induced T helper 1 (Th1) and Th1&ndash;Th2 immune responses, respectively. On the other hand, oral immunization with TMC/Omp31 NPs elicited a mixed Th1&ndash;Th17 immune response. Data obtained from the cell proliferation assay showed that vaccination with Omp31 stimulated a vigorous antigen-specific cell proliferative response, which could be further increased after oral immunization with TMC/Omp31 NPs. Vaccinated groups of mice when challenged with B. melitensis 16M were found to be significantly protected in the orally administered group in comparison with the intraperitoneally immunized mice. Results of this study indicated that the reason for high protection after oral vaccination can be via elicited Th17 response. Keywords: brucellosis, Th17, trimethyl chitosan, vaccine, nanoparticl

    The first record of Rickettsia hoogstraalii (Rickettsiales: Rickettsiaceae) from Argas persicus (Acari: Argasidae) in Iran

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    The rickettsiae (Rickettsiales: Rickettsiaceae) are obligate intracellular and Gram-negative bacteria. They depend on arthropod vectors as well as the mammalian hosts for survival in the nature. 327 soft tick specimens associated the aviary were collected in Khorramabad county of Lorestan province, western Iran. Ticks were identified as Argas persicus according to a taxonomical key. Then, 64 tick specimens were analyzed for the presence of rickettsial DNA. Out of 64 specimens, 6 of them were positive and totally three DNA sequences including a single sequence of each ompA, ompB and sca4 genes was obtained from A. persicus ticks. Rickettsia hoogstraalii was detected in Ar. persicus representing the first record of this species in Iran. Sca4 gene fragment was unable to specify rickettsial infection in Ar. persicus ticks according to BLAST analysis. © 2020 Systematic & Applied Acarology Society

    Effect of 8 weeks of aerobic training on serum level of visfatin and TNF-α in non-athletic young women

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    Background and Objective: There are controversial reports about the effect of training on serum level of visfatin and TNF-α Cytokine .This study was done to evaluate the effect of 8 weeks of aerobic training on serum level of visfatin and TNF-α in non-athletic young women. Methods: In this quasi-experimental study, thirty non-athletic healthy women were non-randomly based on the weight, height, BMI index and body fat percentage divided into two control and training groups. In the training group 8 weeks of aerobic exercise on a stationary bicycle 3 times a week was performed. Serum level of visfatin and TNF-α was measured using ELISA method, prior and at the end of 8th week of training while the subjects were fasted for 12-14 hours. Results: At the end of 8 weeks of aerobic exercise, serum level of visfatin and TNF-α significantly reduced in the training group in comparison with controls (P<0.05). Conclusion: Eight weeks of aerobic training reduces visfatin and TNF-α serum level in non-athletic healthy women
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