Development and evaluation of a novel nucleic acid sequence-based amplification method using one specific primer and one degenerate primer for simultaneous detection of Salmonella Enteritidis and Salmonella Typhimurium

Salmonella Enteritidis and Salmonella Typhimurium are the most widespread causes of salmonellosis and gastrointestinal diseases worldwide. Thus, their simple and sensitive detection is significantly important in biosafety and point-of-care diagnostics. In that regard, although present nucleic acid-based attempts are mainly focused on the detection methods encompassing all Salmonella enterica members in a single reaction, serotypes other than S. Enteritidis and S. Typhimurium are clinically and epidemiologically rare to humans. Therefore, regarding high ribosomal RNA (rRNA) copy numbers in a cell, isothermal nucleic acid sequence-based amplification (NASBA) technique was employed for simple, sensitive and simultaneous detection of the bacteria. However, due to high sequence homology among 16S rRNA genes and consequently, very few specific regions, we developed a novel NASBA method called “single specific primer-NASBA or SSP-NASBA” in which the specificity of the antisense primer is sufficient to perform a specific NASBA reaction. Accordingly, we designed highly specific NASBA antisense and degenerate sense primers for a segment of 16S rRNA variable region by universal sequence alignment to simultaneously detect S. Enteritidis and S. Typhimurium. Meanwhile, the approach was successfully evaluated for various Salmonella as well as closely related non-Salmonella serovars. Specific and simultaneous detection of both bacteria was achieved with the designed primer set in a single reaction environment with a detection limit of less than 10 CFUs mL⁻¹. The developed NASBA assay should facilitate the overall process and provide a simple, fast, specific and sensitive approach for molecular diagnostics of pathogens under various circumstances, e.g. outbreaks.     

Three-Component Reaction of Triphenylphosphine,Dialkyl Acetylenedicarboxylate,and 2-Aminothiazole or 2-Aminobenzothiazole in the Presence of Arylglyoxals: An Efficient One-Pot Synthesis of Highly Functionalized Pyrroles

A new and efficient one-pot synthesis of polysubstituted pyrrole derivatives by three-component reaction of dialkyl acetylenedicarboxylates, triphenylphosphine, 2-aminothiazole or 2-aminobenzothiazole in the presence of arylglyoxals is described. The reactions were performed in dichloromethane at room temperature and neutral conditions and afforded good yields of products.     

An interesting route using electron-beam lithography and photolithography to pattern submicron interdigitated electrodes array for sensing applications

Journal of the Iranian Chemical Society - Increasing the interest in the silicon-based devices resulted in developing new methods and techniques to achieve advanced and more reliable designs and...     

Semi‐Interpenetrated Hydrogels‐Microfibers Electroactive Assemblies for Release and Real‐Time Monitoring of Drugs

Simultaneous drug release and monitoring using a single polymeric platform represents a significant advance in the utilization of biomaterials for therapeutic use. Tracking drug release by real‐time electrochemical detection using the same platform is a simple way to guide the dosage of the drug, improve the desired therapeutic effect, and reduce the adverse side effects. The platform developed in this work takes advantage of the flexibility and loading capacity of hydrogels, the mechanical strength of microfibers, and the capacity of conducting polymers to detect the redox properties of drugs. The engineered platform is prepared by assembling two spin‐coated layers of poly‐γ‐glutamic acid hydrogel, loaded with poly(3,4‐ethylenedioxythiophene) (PEDOT) microparticles, and separated by a electrospun layer of poly‐ε‐caprolactone microfibers. Loaded PEDOT microparticles are used as reaction nuclei for the polymerization of poly(hydroxymethyl‐3,4‐ethylenedioxythiophene) (PHMeDOT), that semi‐interpenetrate the whole three layered system while forming a dense network of electrical conduction paths. After demonstrating its properties, the platform is loaded with levofloxacin and its release monitored externally by UV–vis spectroscopy and in situ by using the PHMeDOT network. In situ real‐time electrochemical monitoring of the drug release from the engineered platform holds great promise for the development of multi‐functional devices for advanced biomedical applications.     

Electrochemical and theoretical study of novel functional porous graphene aerogel-supported Sm2O3 nanoparticles for supercapacitor applications

Journal of Solid State Electrochemistry - A graphene aerogel cross-linked by p-phenylenediamine (PPDA) composite with Sm2O3 nanoparticles (AP.Sm) was synthesized as a novel nanocomposite via a...     

Electrochemical Energy Storage Electrodes via Citrus Fruits Derived Carbon: A Minireview

This review investigates the synthesis and electrochemical performance of the electrode of the electrochemical energy storage (EES) devices obtained from peels and scraps of the citrus fruits. The EES devices include batteries, supercapacitors, and hybrid systems that have considerable value and various applications. The electrode is considered as the most important part of all EES devices. Tremendous efforts have been done to enhance the electrochemical energy storage electrode (EESE). The citrus fruits abundance leads to a decrease in their price and makes possible to use them as ingredients to fabricate EESE. Also, the electrochemical analyses determined that citrus fruits have considerable potential to use as the EESE. Using citrus fruits peels and scraps as biomass substances to prepare EESE leads to the electrodes which have low cost, environmentally friendly and appropriate electrochemical applications.     

Preparation of carbon nanotube-containing hybrid composites from epoxy,novolac, and epoxidized novolac resins using sol–gel method

Journal of Thermal Analysis and Calorimetry - Three different hybrid composites were prepared from tetraethyl orthosilicate oligomer-modified epoxy resin (MER),...     

Production of cationic 198Au3+ and nonionic 198Au0 for radionuclide therapy applications via the natAu(n,γ)198Au reaction

¹⁹⁸Au (??_max?=?0.96?MeV (98.6?%), ??_max?=?0.412?MeV (95.5?%) and T _1/2 ?=?2.7?days) is a radionuclide with very appealing characteristics. ¹⁹⁸Au has been widely used to treat the uterus, bladder, cervix, prostate, melanoma, breast, skin and other cancers. In the present study, cationic ¹⁹⁸Au⁺³ and nonionic ¹⁹⁸Au⁰ are prepared following thermal neutron irradiation of commercially available natural gold compounds in Tehran Research Reactor via the ^natAu(n,??)¹⁹⁸Au reaction. The prospects in the production of pure ¹⁹⁸Au⁰ and ¹⁹⁸Au⁺³ for radionuclide therapy are discussed and effect of reduction on the activity of radioactive gold is evaluated. Au⁰ particles were synthesized via NaBH₄ reduction of aqueous solutions of hydrogen tetrachloroaurate trihydrate. Then two quartz tubes were charged with cationic ¹⁹⁸Au³⁺ and nonionic ¹⁹⁸Au⁰. After irradiation by thermal neutrons, the samples were analyzed for a period of 1?month by liquid scintillation counter and high purity germanium detector. As a result, ^natAu³⁺ reduction process had no significant effect on the activity of the ¹⁹⁸Au sample. In conclusions, natural gold thermal neutron activation cross section is reasonably high for medical application.     

Novel and facile methods for the synthesis of DTPA-mono-amide: a new completely revised strategy in radiopharmaceutical chemistry

DTPA is a very strong metal chelator widely utilized in radiopharmaceutical chemistry for conjugation of chemicals which do not have enough potency for direct metalo-labeling and also to manage toxic radioactive materials such as plutonium, americium, and curium. It is difficult to conjugate DTPA to an amine group in a singular direction and such reactions usually also coincidently produce a mixture of DTPA-bis-amides and DTPA-mono-amide resulting in considerable insufficiencies/difficulties in synthesis and especially yield/separation procedures. In this paper, novel methods for the exclusive synthesis of DTPA-mono-amide have been established which extensively reduce the difficulties otherwise encountered and increase the reaction’s yield considering the green chemistry approaches. This is expected to be of interest to radiopharmaceutical researchers interested in the DTPA (Radio)-metallic-conjugate. Overall, this paper provides a framework to achieve a higher degree of propriety from DTPA as a chelator to conjugate to the chemical compounds.     

Synthesis of water dispersible boron core silica shell (B@SiO<Subscript>2</Subscript>) nanoparticles

Water dispersible boron nanoparticles have great potential as materials for boron neutron capture therapy of cancer and magnetic resonance imaging, if they are prepared on a large scale with uniform size and shape and hydrophilic modifiable surface. We report the first method to prepare spherical, monodisperse, water dispersible boron core silica shell nanoparticles (B@SiO₂ NPs) suitable for aforementioned biomedical applications. In this method, 40 nm elemental boron nanoparticles, easily prepared by mechanical milling and carrying 10-undecenoic acid surface ligands, are hydrosilylated using triethoxysilane, followed by base-catalyzed hydrolysis of tetraethoxysilane, which forms a 10-nm silica shell around the boron core. This simple two-step process converts irregularly shaped hydrophobic boron particles into the spherically shaped uniform nanoparticles. The B@SiO₂ NPs are dispersible in water and the silica shell surface can be modified with primary amines that allow for the attachment of a fluorophore and, potentially, of targeting moieties.

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