Protective effect of melatonin and carnosine against radiation induced kidney injury

Journal of Radioanalytical and Nuclear Chemistry - We designed this study to determine possible protective roles of melatonin and carnosine on radiation. Wistar albino rats were divided to five...     

Photochemical reactions of M(CO)5THF (M = Cr, Mo, W) with thio Schiff bases

The hitherto unknown complexes, [M₂(CO)₆(μ-CO)(μ-L)], [M = Cr; 1, Mo; 2, W; 3] and [M₂(CO)₆(μ-CO)(μ-L′)], [M = Cr; 4, Mo; 5, W; 6] have been synthesized by the photochemical reactions of photogenerated intermediate, M(CO)₅THF (M = Cr, Mo, W) with thio Schiff base ligands, N,N′-bis(2-aminothiophenol)-1,4-bis(2-carboxaldehydephenoxy)butane (H ₂ L) and N,N′-bis(2-aminothiophenol)-1,7-bis(2-formylphenyl)-1,4,7-trioxaheptane (H ₂ L′). The complexes have been characterized by elemental analysis, LC-mass spectrometry, magnetic studies, FT-IR and ¹H NMR spectroscopy. The spectroscopic studies show that H ₂ L and H ₂ L′ ligands are converted to benzothiazole derivatives, L and L′ after UV irradiation and coordinated to the central metal as bridging ligands via the central azomethine nitrogen and sulphur atoms in 1–6.     

Synthesis and characterization of cannabimimetic aminoalkylindole based 5‐(4‐alkyl‐1‐naphthoylamino)‐1,3,4‐thiadiazole‐2‐sulfonamides

A novel series of cannabimimetic aminoalkylindole‐based sulfonamide derivatives was synthesized. These new compounds were synthesized by reacting acyl chlorides of naphthoic acids with deacetylated acetazolamide in the presence of N‐ethyl‐morpholine to give structures incorporating 1‐naphthoyl groups of cannabimimetic aminoalkylindoles and a five‐membered heteroring typical of antiglaucoma sulfa drugs. The synthesized compounds were characterized using standard techniques. Photoluminescence of these derivatives was also studied, where more electron‐donating groups on the aromatic ring at the para‐position caused an increase in the intensity of the main peaks and shifts to higher emission wavelengths. © 2011 Wiley Periodicals, Inc. Heteroatom Chem 22:707–714, 2011; View this article online at wileyonlinelibrary.com . DOI 10.1002/hc.20738     

Electrochemical Investigation of Gold Based Screen Printed Electrodes: An Application for a Seafood Toxin Detection

Although commercial screen-printed electrodes (SPEs) are used extensively for biosensor purposes nowadays, detailed studies on characterization are still limited. In this study, the surface of the gold-based screen-printed electrode (SPGE) was carefully modified with self-assembly-monolayer through an optimized immobilization procedure. The key physical and chemical properties with regeneration capacity of the developed biosensors were assessed by various characterization techniques. Then SPGE was used to determine its sensitivity, limit of detection (LOD) and limit of quantification (LOQ) for a toxin substance of domoic acid in seafood that has become more common and rising concern of marine wildlife and seawater pollution. LOD in phosphate buffered saline (PBS) and cell culture media were obtained as 2.93 ng mL⁻¹ and 4.28 ng mL⁻¹, respectively. The reduced sensitivity for antibody-based biosensors in the cell culture medium was probably due to interaction of nonspecific compounds with DA in the culture medium compared to the much less complex environment of PBS. In addition, the regeneration capacity has been found very limited due to inherent heterogeneity and low robustness. This study can be used for the main challenges with the design requirements of commercial SPE-based biosensors to provide a detailed perspective for further toxicity studies.     

Synthesis of new bio‐based hydrogels derived from bile acids by free‐radical photo‐polymerization

In this article, the study on the swelling and thermal behaviors of a new series of bile acid‐based polymeric hydrogels is reported. For this purpose, in the first step, the reduction of carboxyl acid groups of some common bile acids including cholic acid (CA), chenodeoxy cholic acid (CDCA), and lithocholic acid (LCA) to the corresponding alcohols by lithium aluminum hydride (LiAlH₄) in THF solution is performed. Then, hydroxyl functionalities of the obtained products are reacted with the acryloyl chloride in the presence of triethylamine (TEA). Finally, the cross‐linking reactions between acryloyl functionalized bile acids and methoxy poly(ethylene glycol) monomethacrylate (MPEGMA) are conducted by free‐radical photo‐polymerization technique at λ = 350 nm in the presence of 2,2‐Dimethoxy‐2‐phenylacetophenone (DMPA) as an initiator to achieve the desired bile acid‐based polymeric hydrogels. The resulting hydrogels and their intermediates are characterized by Fourier transform infrared (FT‐IR) and Proton nuclear magnetic resonance (¹H‐NMR) spectroscopies. The swelling and thermal behavior of the obtained hydrogels indicates that the hydrogel starting from cholic acid is more swellable and has enhanced thermostability compared to others. Thus, the results of this study offer beneficial insights to researchers working in particularly bio‐medical industry.     

Multicomponent formation route to a new class of oxygen-based 1,3-dipoles and the modular synthesis of furans

A new class of phosphorus-containing 1,3-dipoles can be generated by the multicomponent reaction of aldehydes, acid chlorides and the phosphonite PhP(catechyl). These 1,3-dipoles are formally cyclic tautomers of simple Wittig-type ylides, where the angle strain and moderate nucleophilicity in the catechyl-phosphonite favor their cyclization and also direct 1,3-dipolar cycloaddition to afford single regioisomers of substituted products. Coupling the generation of the dipoles with 1,3-dipolar cycloaddition offers a unique, modular route to furans from combinations of available aldehydes, acid chlorides and alkynes with independent control of all four substituents.

A new class of phosphorus-containing 1,3-dipoles has been developed, which, when coupled with cycloaddition, offers modular synthesis of furans with independent control of all four substituents.     

On the asymptotic optimality of the randomized linear program for network revenue management

For network revenue management problems, it is known that the bid prices computed through the so-called deterministic linear program are asymptotically optimal as the capacities on the flight legs and the expected numbers of product requests increase linearly with the same rate. In this paper, we show that the same asymptotic optimality result holds for the bid prices computed through the so-called randomized linear program. We computationally investigate how the performance of the randomized linear program changes with different problem parameters and with the number of samples. The hope is that our asymptotic optimality result and computational experiments will raise awareness for the randomized linear program, which has yet not been popular in the research community or industry.