Two-dimensional graphitic carbon nitride (g-C3N4) nanosheets and their derivatives for diagnosis and detection applications

The early diagnosis of certain fatal diseases is vital for preventing severe consequences and contributes to a more effective treatment. Despite numerous conventional methods to realize this goal, employing nanobiosensors is a novel approach that provides a fast and precise detection. Recently, nanomaterials have been widely applied as biosensors with distinctive features. Graphite phase carbon nitride (g-C3N4) is a two-dimensional (2D) carbon-based nanostructure that has received attention in biosensing. Biocompatibility, biodegradability, semiconductivity, high photoluminescence yield, low-cost synthesis, easy production process, antimicrobial activity, and high stability are prominent properties that have rendered g-C3N4 a promising candidate to be used in electrochemical, optical, and other kinds of biosensors. This review presents the g-C3N4 unique features, synthesis methods, and g-C3N4-based nanomaterials. In addition, recent relevant studies on using g-C3N4 in biosensors in regard to improving treatment pathways are reviewed

Evaluation of Immunogenicity of Cocktail DNA Vaccine Containing Plasmids Encoding Complete GRA5, SAG1, and ROP2 Antigens of Toxoplasma gondii in BALB/C Mice

Background: Severe and fatal complications of toxoplasmosis urge development of effective vaccines against the disease. The current study was performed to evalu­ate cocktail DNA vaccine containing plasmids encoding GRA5, SAG1, and ROP2 genes of Toxoplasma gondii in BALB/c mice in Tarbiat Modares University in 2012. Methods: The plasmids containing complete GRA5, SAG1, and ROP2 genes were mass extracted and then the recombinant plasmids were administered via intramuscu­lar injections according to immunized mice three times with three-week intervals. Then splenocytes were cultured, and proliferation as well as cytokine as­says were carried out. The other mice in each group were inoculated by the parasite and mortality of the mice was evaluated on a daily basis. Results: The results of cytokine assay for INF-γ were higher in the mice that re­ceived the cocktail DNA containing recombinant plasmids. Evaluation of prolifera­tion of splenocytes using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazo­lium bromide) assay indicated induction of cellular response. Measurement of total IgG and the isotypes of IgG1 and IgG2a showed that the cocktail DNA stimulated IgG and IgG2a production in comparison with the control groups (P<0.05). Furthermore, the survival rate of mice in the groups that received the cocktail DNA was significantly higher than that in the control groups (P<0.05). Conclusion: Administration of the cocktail DNA vaccine led to production of higher levels of IFN-γ, confirmed by secretion of IgG2a, and the immune response was shifted toward Th1. Thus, the cocktail DNA containing the recombinant plas­mids can be an appropriate candidate for immunization against toxoplasmosis

Antimicrobial Susceptibility Pattern and Prevalence of Extended-Spectrum beta-Lactamase Genotypes among Clinical Isolates of Acinetobacter baumanii in Tabriz, North-West of Iran

Background: Multidrug resistant (MDR) Acinetobacter baumanii strains have emerged as novel nosocomial pathogens threatening patients' lives, especially in intensive-care units (ICU). Various types of extended-spectrum beta-lactamases (ESBLs) are involved in conferring resistance to beta-lactam antibiotics, making their genotypic characterization an essential prerequisite to take proper preventative measures

Evolution of thermal and nonthermal radio continuum emission on kpc scales–Predictions for SKA

Resolved maps of the thermal and nonthermal radio continuum (RC) emission of distant galaxies are a powerful tool for understanding the role of the interstellar medium (ISM) in the evolution of galaxies. We simulate the RC surface brightness of present-day star forming galaxies in the past at $0.15<z<3$ considering two cases of radio size evolution: (1)~no evolution, and (2)~same evolution as in the optical. We aim to investigate the a)~structure of the thermal and nonthermal emission on kpc scales, b)~evolution of the thermal fraction and synchrotron spectrum at mid-radio frequencies ($\simeq$1-10\,GHz), and c)~capability of the proposed SKA1-MID reference surveys in detecting the RC emitting structures. The synchrotron spectrum flattens with $z$ causing curvature in the observed mid-radio SEDs of galaxies at higher $z$. The spectral index reported in recent observational studies agrees better with the no size evolution scenario. In this case, the mean thermal fraction observed at 1.4\,GHz increases with redshift by more than 30\% from $z=0.15$ to $z=2$ because of the drop of the synchrotron emission at higher rest-frame~frequencies. More massive galaxies have lower thermal fractions and experience a faster flattening of the nonthermal spectrum. The proposed SKA1-MID band~2 reference survey, unveils the ISM in M51- and NGC6946-like galaxies (with ${\rm M_{\star}}\simeq10^{10}\,{\rm M}_{\odot}$) up to $z=3$. This survey detects lower-mass galaxies like M33 (${\rm M_{\star}}\simeq10^{9}\,{\rm M}_{\odot}$) only at low redshifts $z\lesssim 0.5$. For a proper separation of the RC emitting processes at the peak of star formation, it is vital to include band~1 into the SKA1-MID reference surveys.Comment: accepted for publication in MNRAS journa

Mitigation of aflatoxin M1 in milk by the magnetized Fe₃O₄ lactic acid bacteria cells: a response surface methodology (RSM) study

The current work aimed to optimise aflatoxin M1 (AFM1) removal from milk by magnetic inactivated lactic acid bacteria (LAB) adsorbent using response surface methodology (RSM). In this research, the ability of 5 strains of LAB was evaluated for AFM1 removal. Lactobacillus rhamnosus, which indicated the highest adsorption efficiency compared to other strains (p 3O4 particles for the generation of magnetic inactivated LAB adsorbent, which was further characterised by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and vibrating sample magnetometer. The results indicated that L. rhamnosus cells were successfully functionalised and modified by Fe3O4 particles. A central composite design (CCD) was applied to investigate the effect of variables including time (5–125 min), temperature (3–23°C), initial AFM1 concentration (0.1–2.1 μg L-1), and fat (0–3.6%) on AFM1 removal from milk using synthesised adsorbent. According to the RSM model, the optimal adsorption conditions for the second-order model were observed at 73.60 min, the temperature of 17.82°C, AFM1 concentration of 1.598 µg L−1, and fat content of 0.9% leading to the maximum removal efficiency of 56.92%. Hence, the magnetic inactivated LAB adsorbent synthesised using this approach can be an efficient easy-to-separate adsorbent in removing AFM1 from milk. The main functional groups involved in AFM1 removal were carboxyl, amide, and hydroxyl/amino groups. Moreover, the synthesised adsorbent had superparamagnetic behaviour and could be rapidly separated from aqueous solutions. In conclusion, the current study presented a novel method for the efficient adsorption of AFM1 to improve the safety figures of milk.</p