Bimetallic nanoparticles as a novel chemiresistor coating

Here, we describe the chemiresistive sensing of some volatile organic compounds with a novel film of chemically synthesized Au–Pt bimetallic nanoparticles (NPs) stabilized with 11-mercaptoundecanoic acid. The chemiresistive sensing properties were measured over a concentration range of 1.4–250 mg L^?1 for methanol, ethanol, ethyl acetate and acetone vapours and the responses were compared with Au and Pt monometallic nanoparticles. It is observed that the sensitivity of bimetallic nanoparticles is increased about 60 % in exposure to methanol and ethanol vapours, but there are no changes in the sensitivity to the other tested vapours. In addition, the detection limit is improved about 80–100 % for all tested vapours in bimetallic nanoparticles compared to AuNPs and 20–30 % compared to PtNPs.     

Cu/SiO2：A recyclable catalyst for the synthesis of octahydroquinazolinone

A simple and one-pot method for the synthesis of octahydroquinazolinone is reported.Cu/SiO₂ in refluxing ethanol catalyzes this three-component condensation reaction to afford the corresponding quinazolinones in good yields.     

Nanostructured Screen Printed Graphite Electrode for the Development of a Novel Electrochemical Genosensor

The aim of this work is the preparation of DNA‐sensing architectures based on gold nanoparticles (AuNPs) in conjunction with an enzyme‐amplified detection to improve the analytical properties of genosensor. In order to assess the utility of study as DNA‐sensing devices, a thiolated DNA capture probe sequence was immobilized on the gold nanoparticle modified surface. After labeling of the biotinylated hybrid with a streptavidin‐alkaline phosphatase conjugate, the electrochemical detection of the enzymatic product was performed on the surface of a disposable electrode. Two different enzymatic substrates to detect the hybridization event were studied. In the first case, the enzyme catalyzed the hydrolysis of α‐naphthyl phosphate; the product is electroactive and has been detected by means of differential pulse voltammetry (DPV). In the second one, the enzyme catalyzed the precipitation of an insoluble and insulating product on the sensing interface. In this case, the electrochemical transduction of the hybridization process was performed by electrochemical impedance spectroscopy (EIS).     

Reactions of Hydrazonoyl Halides 41: 1 Synthesis of 1,2,4-Triazoles, 2,3-Dihydro-1,3,4-thiadiazoles,and Triazolo[4, 3-a]pyrimidines

Triazoles, thiadiazoles, and triazolo[4, 3-a]pyrimidines were synthesized via reaction of hydrazonoyl halides with each of 3-methyl-4-(methylthiothioxomethyl)-2-pyrazolin-5-one, 3-methyl-4-[methylthio(phenylamino)methyl]-2-pyrazolin-5-one, and pyrimidine-2-thiones. Structures of the newly synthesized compounds were elucidated on the basis of elemental analysis, spectral data, and alternative-methods synthesis whenever possible.     

One Pot Synthesis of Some New Heteroylselenoglycolic Acids and Their Biological Activity

Abstract

A convenient one pot three-stage synthesis was used for obtaining new heteroylselenoglycolic and di-heteroylselenoglycolic acids by nucleophilic substitution reaction of the starting compounds pyridineselenol, pyridazineselenol, and quinolineselenol with α-chloro- or α,α-dichloroacetic acids for 1-h stirring. The newly synthesized compounds were screened biologically for anti-microbial and anti-oxidant activities. The structure of all new compounds was confirmed by ¹H NMR, ¹³C NMR, Mass, and IR spectroscopy and elemental analyses.     

Design,Docking, and Synthesis of Some New Pyrazoline and Pyranopyrazole Derivatives as Anti‐inflammatory Agents

Design and synthesis of some novel pyrazoline and pyranopyrazole derivatives as potential anti‐inflammatory agents are described. Most of the compounds were tested for their anti‐inflammatory (in vitro and in vivo) and ulcerogenic activities. In all tested compounds, it was found that pyrazolines, 2a , and pyrazolopyrano[2,3‐d]pyrimidine 9 are the potent anti‐inflammatory and selective cyclooxygenase‐2 (COX‐2) inhibitor. All compounds are mainly in the safe level. Docking study of 2a and 9 revealed higher affinity for binding with the active site of COX‐2 enzyme like SC‐558, a selective COX‐2 inhibitor.     

Synthesis,characterization and pharmacological investigations of some novel heterocyclic derivatives incorporating pyrene and sugar moieties

A series of substituted pyrene derivatives 2–15 incorporated heterocyclic and sugar moieties were synthesized and evaluated as antiviral activities using 1-acetylpyrene as a starting material. The structure assignment of the new compounds was based on chemical and spectroscopic evidence. The detailed synthesis, spectroscopic data and pharmacological activities of the synthesized compounds were reported.     

Fe(NO3)3 as an efficient catalyst for regio- and stereo-controlled ring expansion of 1,2-diaroyl-3-arylaziridines

Several 1,2-diaroyl-3-arylaziridines were previously prepared conveniently and used in the preparation of 5-benzoyl-2,4-diaryl oxazolines in the presence of NaI. In this work, synthesis of some trans-4-benzoyl-2,5-diaryl oxazolines by a regio- and stereo-controlled reaction in the presence of Iron (III) nitrate at room temperature is reported. A plausible mechanism has been proposed for ring expansion of N-acyl aziridines to oxazolines.     

A microfluidic bioreactor for increased active retrovirus output

Retroviruses are one of the most commonly used vectors in ongoing gene therapy clinical trials. To evaluate and advance virus production on the microscale platform, we have created a novel microfluidic bioreactor for continuous retrovirus production. We investigated the growth kinetics of a retroviral packaging cell line in microfluidic bioreactors for several compartment sizes, and packaging cells perfused in the microdevices showed similar growth kinetics to those cultured in conventional static conditions. To evaluate the efficiency of retrovirus production, virus titers from the microdevices were compared to those obtained from static tissue culture. When retrovirus production and collection were maintained at 37 degrees C, virus production levels were comparable for the microdevices and static tissue culture conditions. However, immediate cold storage downstream of the packaging cells in the microdevices resulted in 1.4- to 3.7-fold greater active virus production levels with the microdevices compared to the conventional static conditions over a 5 day period. Lastly, the use of microfluidics for virus production provides a continuous supply of virus supernatant for immediate infection of target cells or for preservation and storage. Such devices will be valuable for the optimization of production and evaluation of retroviruses and other viral vectors for gene therapy applications.     

Study of optical properties of highly oriented nanocrystalline V2O5·nH2O films doped with K ions

Optical transmission and reflection measurements of highly oriented nanocrystalline K_xV₂O₅·nH₂O films (0 ≤ x < 0.01) were studied. The optical constants such as, refractive index, the extinction coefficient, absorption coefficient, optical band gap have been calculated. The optical spectra of all samples exhibited two distinct regions of optical gap, E_op1 suggesting a direct allowed transition with optical gap ranging from 0.37 up to 0.42 eV and E_op2 suggesting a direct forbidden transition with optical gap ranging from 2.02 up to 2.23 eV. This indicates that K_xV₂O₅·nH₂O films have more than one type of conduction mechanism.