سال:1396 | دوره: | شماره: |تعداد مقالات:7

Due to the spread of infectious diseases, the existence of a rapid and sensitivedetection method is necessary today. Polymerase chain reaction-enzyme linkedimmunosorbent assay (PCR-ELISA) is a simple manner for detection of microorganism.For example, bacteria, viruses, fungi and others based on nucleic acidsequence. A large number of samples can be screened by this technique simultaneously,so it is not time consuming and is a quick manner. The high sensitivity andspecificity of PCR-ELISA make it a powerful technique by simple laboratoryfacilities. As a result it can be an excellent substituted manner for analysis anddetection in different various fields.

Contamination of soil with persistent organic contaminants has been of great concerndue to their long-term effects in the environment. Polycyclic aromatic hydrocarbons(PAHs) are a well-known group of organic contaminants characterized bytheir resistance to biodegradation and high hydrophobicity. Mobilization and migrationof PAH compounds in hydrocarbon-contaminated site may endangergroundwater resources. The main objective of this study was to investigate theinfluence of pulverized biochar on immobilization and release characteristics ofmodel PAHs. Column leaching test was used to simulate leaching of PAH compoundsfrom contaminated solid phase towards aqueous phase. Results showedstrong sorption of both studied PAHs i.e. phenanthrene and pyrene to soil particles,however, at the end of the experiment 5.32% and 0.99% of the initial solid phasecontent of, respectively, phenanthrene and pyrene released into water in unamendedsoil. Application of pulverized biochar could finally reduce mobilization and cumulativerelease of the above-mentioned PAH compounds significantly. Similar trendwas also obtained for sum 16 US EPA PAHs. Variation of pH during the leachingprocess and its contribution to mobilization and release of selected PAH compounds,which has scarcely studied previously, were also addressed. Results indicatedthat pulverized biochar as a cost-effective alternative to other carbon-richamendments e.g. activated carbon can be effectively employed for site remediationpurposes to reduce mobilization of PAHs in soil.

Muslims fast every day from down to sunset during the holy month of Ramadan.The possible side effect of Ramadan fasting on general health has been widelystudied, but oral health may also alter due to one month fast affecting some of thesalivary secondary metabolites. The aim of present research was identifying theinfluence of fasting on saliva of healthy individuals. The subjects were selectedfrom non-smoker male employees of one factory in Rasht. 35 healthy male (aged30-50 years), who fasted the whole Ramadan entered. Their unstimulated salivasamples were collected before, during and at the end of Ramadan. Concentration ofsalivary uric acid, the activity of alkaline phosphatase (ALP) and aspartate aminotransferase(AST) were then measured using spectrophotometric methods accordingto procedure given for serum. The results showed a significant reduction in theconcentration of salivary uric acid and AST, while the activity of ALP was significantlyincreased. It was concluded that some of salivary biochemical markers undergovarious fluctuations in response to fasting. However, more studies with alarger population and various biochemicals are required to certainly comment onthe matter.

Treatments employed for the consolidation of monumental stones made of limestonedue to incompatibility from the substrate and cement used for consolidation,plugging of pores induced by the new cement, leading to the acceleration of stonealteration. Microbial precipitation with a layer of calcium carbonate generated bybacteria might offer a solution to this dilemma because the layer would not blockthe natural pore structure, thus permitting free passage of soluble salts through thestone. In this study, an attempt has been made to provide an overview of the microbialinduced carbonate precipitation as promising technology for bioremediation ofsuch structures. At the first, the active microorganisms in the conservation of stonemonuments transferred to the laboratory using the swap dipped in nutrient broth ata historic cemetery. After incubation and growth of colonies, Gram-positive bacilliwere detected. Then pure single colonies were transferred to blood agar mediumand incubated at 37°C. the single colonies were transferred to the surface of sterilizelimestone pieces and incubated but no result was obtained. Therefore, in thenext phase bacilli bacteria-rich broth media was used. The control experimentswere conducted in accordance with the conditions mentioned without bacterialinoculation. The calcification process caused by the inoculated bacteria on the historicalstone samples was demonstrated using the scanning electron photomicrographs.Microbially induced calcium carbonate precipitation (MICP) technology toeco–friendly, self-healing and highly durable nature of these bio-binders, for conservationpurposes has been found suitable. But still there has been much to explorein order to bring this environmentally safe, cost effective and convenient technologyfrom lab to field scales.

Enterohemorrhagic Escherichia coli (EHEC) strains are foodborne pathogens withimportance in public health. The lack of effective clinical treatment, sequelae afterinfection and mortality rate in humans confirms the essential need for prophylacticand vaccines approaches. EspA, Tir, HcpA and Stx2 are major virulence factors foradherence and toxicity of EHEC, so an appropriate tetravalent immunogen consistof toxin subunit and crucial colonization factors was selected and constructed. Bioinformaticanalyses of recombinant construction such as sequences choosing andoptimizing, mRNA folding, physicochemical property in 2D and 3D structures,besides other immunoinformatics data like B-cell and T-cell epitopes and allergenicityof chimera were some reported according to the reliable servers. In silicoassessment of the chimeric proteins demonstrated the desired model has a propermRNA features, besides acceptable stability and solubility. This model is close tonative proteins topologically, and all domains were found to have a high antigeniccompetency and surface accessibility. These results can be beneficial for the developmentof a chimeric immunogen against adherence and toxicity of EHEC in ananimal model application.

An amperometric glucose biosensor was developed based on synergistic contributionsof prussian blue (PB) and a bucky gel (BG) consisting of carbon nanotubes(CNTs) and ionic liquid (IL). The PB nanoparticles were first deposited onto thesurface of a BG modified glassy carbon (GC) electrode (BG/GC). Then, the Ni2+ions were electrochemically inserted into the PB lattice to improve its stability atphysiological pH. Afterwards, Glucose oxidase (GOx) was immobilized on theBG/GC electrode using a cross-linking method. Amperometric measurements ofglucose were performed at −0.05 V vs. Ag/AgCl in 0.05 M phosphate buffer solutionat pH 7.4. The glucose biosensor exhibited a sensitivity of 45.03 μA/(mM.cm2)with a detection limit of 5×10-7 M. The amperometric response was linear in therange of 5×10-7 to 8.3×10−4 M.

In historical cases, mass disasters, missing person’s identification and ancient DNAinvestigations, bone and teeth samples are often the best and the only biologicalmaterial available for DNA typing. This is because of the physical and chemicalnature of the protein-mineral matrix of bone which is relatively resistant to theadverse environmental effects and biological attacks. Most bone extraction protocolsused in the forensic laboratories involve an incubation period of bone powderin extraction buffer for proteinase digestion, followed by the collection of the supernatant,and the elimination of large quantities of undigested bone powder. Herewe demonstrate an extremely effective protocol for recovery of DNA. This is performedin a method that retains and concentrates all the reagent volume for completeDNA recovery. For our study, we selected challenging bone samples of skeletonremains of the martyred individuals in Iraq’s imposed war on I.R. Iran (1980-1988). The bones that were extracted with our new protocol showed that this newprotocol significantly enhances the quantity of DNA that can be used for amplificationfrom degraded skeletal remains. At the same time we tested in parallel thesamples by using of QIAamp DNA Investigator Kit and attained the best results byusing new protocol. In fact, our new DNA extraction method is based on previousstandard methods such as Chelex and salting out. We have used this technique tosuccessfully recover authentic DNA Typing from extremely challenging samplesthat failed repeatedly using the standard protocols. However, the amount of recoveredDNA was very small but it was possible to extract genomic DNA from thesechallenging bone samples. The results indicated that our procedure for DNA extractionalthough yielded little amount of genomic DNA; however, it was pure DNAthat can be used for further analysis such as PCR amplification and DNA profiling.Since the new procedure is fast and needed less time than previously standard procedures,we have named it FDEB (Fast DNA Extraction of Bone).