EFFECT OF ANNEALING TEMPERATURE ON THE OPTICAL AND STRUCTURAL PROPERTIES OF DIP-COATED Al2O3 THIN FILMS PREPARED BY SOL–GEL ROUTE

Thin films of Al2O3 were prepared by the sol–gel process. Dip-coating technique was used for deposition of the Al2O3 thin films onto glass substrates. Optical and structural properties of the films were investigated with respect to the annealing temperature (100–500°C). The structure of these films was determined by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was performed for the analysis of surface morphology. For determination of the optical constants of Al2O3 thin films, UV-Visible spectrophotometry measurements were carried out. Annealing temperature affects the structural and optical properties of the Al2O3 thin films. The refractive index and extinction coefficient of the films at 550 nm wavelength increase from 1.56 to 1.66, and from 3.41 × 10-5 to 5.54 × 10-5, respectively while optical band gap and thickness of the films decrease from 4.15 eV to 4.11 eV, and 360 nm to 260 nm, respectively, by increasing annealing temperature from 100°C to 500°C.Aluminum oxide, sol–gel, thin films, optical constants

In-silico design, expression, and purification of novel chimeric Escherichia coli O157:H7 OmpA fused to LTB protein in Escherichia coli.

E. coli O157:H7, one of the major EHEC serotypes, is capable of developing bloody diarrhea, hemorrhagic colitis (HC), and fatal hemolytic uremic syndrome (HUS) and is accompanied by high annual economic loss worldwide. Due to the increased risk of HC and HUS development following antibiotic therapy, the prevention of infections caused by this pathogen is considered to be one of the most effective ways of avoiding the consequences of this infection. The main aim of the present study was to design, express, and purify a novel chimeric protein to develope human vaccine candidate against E. coli O157:H7 containing loop 2-4 of E. coli O157:H7, outer membrane protein A (OmpA), and B subunit of E. coli heat labile enterotoxin (LTB) which are connected by a flexible peptide linker. Several online databases and bioinformatics software were utilized to choose the peptide linker among 537 analyzed linkers, design the chimeric protein, and optimize the codon of the relative gene encoding this protein. Subsequently, the recombinant gene encoding OmpA-LTB was synthesized and cloned into pET-24a (+) expression vector and transferred to E. coli BL21(DE3) cells. The expression of OmpA-LTB chimeric protein was then carried out by induction of cultured E. coli Bl21 (DE3) cells with 1mM isopropyl-β-D-thiogalactopyranoside (IPTG). The purification of OmpA-LTB was then performed by nickel affinity chromatography. Expression and purification were analyzed by sodium dodecyl sulphate poly acrylamide gel electrophoresis. Moreover, the identity of the expressed protein was analyzed by western blotting. SDS-PAGE and western immunoblotting confirmed the successful expression of a 27 KDa recombinant protein after 24 hours at 37°C post-IPTG induction. OmpA-LTB was then successfully purified, using nickel affinity chromatography under denaturing conditions. The yield of purification was 12 mg per liter of culture media. Ultimately, we constructed the successful design and efficient expression and purification of OmpA-LTB divalent under the above-mentioned conditions

Lethality Assay of Radiopharmaceutical bis-Thiosemicarbazones Using Brine Shrimp (Artemia salina) Test: Toxicity of bis-thiosemicarbazones

In the present study, aqueous solutions of some copper-complexing ligands were screened for their cytotoxicity using brine shrimp lethality test. Among the ligands tested, diacetyl-bis(N4- methylthiosemicarbazones) (ATSM) proved to be the most safe and non-toxic compound (2% lethality at 10 ppm), while pyruvaldehyde Bis(N4-methyl)thiosemicarbazone (PTSM) was shown to possess low toxicity (7% lethality at 10 ppm) and glyoxal-bis-thiosemicarbazone (GTS) proved to be a toxic compound even at 1 ppm (20% lethality). An interesting structure-toxicity relationship was observed for the ligands based on their water solubility leading to more toxicity which can be related to polysaccharide crustae of the shrimps. Considering the 1-10 ppm to be the maximum possible concentration of the ligands in the finalpharmaceutical samples, the safety of these ligands are ATSM>PTSM>GTS

Evaluation of [ 67 Ga]Citrate in The Detection of Various Microorganism Infections in Animal Models

ABSTRACT Introduction: Gallium-67 citrate has been known as a good infection agent in nuclear medicine for decades. In this work the value of 67 Ga-citrate has been investigated in infected animal models using SPECT imaging at optimized/standardized conditions. Methods: The bacterial (Staphylococcus aureus; S.a. and Escherichia coli; E.c.) and fungal (Candidae albicans; C.a.) species from standard sources were cultured according to the standard procedures and wild-type NMRI rats were inoculated by the injection of 5x10 7 microorganisms (MO) into their thighs and animals incubated for infection site formation for 2 and 3 days followed by iv injection of freshly prepare

<i>In silico</i> design of a novel chimeric <i>shigella</i> IpaB fused to C terminal of <i>clostridium perfringens</i> enterotoxin as a vaccine candidate

<p>This study aimed to design a novel chimeric protein <i>in silico</i> to serve as a serotype-independent vaccine candidate against <i>Shigella</i>. The chimera contains amino acid residues 240–460 of <i>Shigella</i> invasion plasmid antigen B (IpaB) and the C-terminus of <i>Clostridium perfringens</i> enterotoxin (C-CPE). Amino acid sequences of 537 peptide linkers were obtained from two protein linker databases. 3D structures of IpaB-CPE_290–319, IpaB-CPE_184–319, IpaB-CPE_194–319 and 537 newly designed IpaB-linker-CPE_290–319 constructs with varying linker regions were predicted. These predicted 3D structures were merged with the 3D structures of native IpaB_240–460, CPE_194–319, CPE_184–319 and CPE_290–319 to select the structure most similar to native IpaB and C-CPE. Several <i>in silico</i> tools were used to determine the suitability of the selected IpaB-C-CPE structure as a vaccine candidate. None of the 537 linkers was capable of preserving the native structure of CPE_290–319 within the IpaB-linker-CPE_290–319 structure. <i>In silico</i> analysis determined that the IpaB-CPE_194–319 3D structure was the most similar to the 3D structure of the respective native CPE domain and that it was a stable chimeric protein exposing multiple B-cell epitopes. IpaB-CPE_194–319 was designed for its capability to bind to human intestinal epithelial and M cells and to accumulate on these cells. The predicted B-cell epitopes are likely to be capable of inducing a mucosal antibody response in the human intestine against <i>Shigella</i> IpaB. This study also showed that the higher binding affinities of CPE_184–319 and CPE_194–319 to claudin molecules than those of CPE_290–319 is the result of preserving the 3D structures of CPE_184–319 and CPE_194–319 when they are linked to the C-termini of other proteins.</p