Design and Synthesis of Some New Furan-Based Derivatives and Evaluation of In Vitro Cytotoxic Activity

New furan-based derivatives have been, designed, synthesized, and evaluated for their cytotoxic and tubulin polymerization inhibitory activities. DNA flow cytometric study of pyridine carbohydrazide 4 and N-phenyl triazinone 7 demonstrated G₂/M phase cell cycle disruptions. Accumulation of cells in the pre-G1 phase and positive annexin V/PI staining, which may be caused by degeneration or fragmentation of the genetic components, suggested that cell death occurs via an apoptotic cascade. Furthermore, compounds 4 and 7 had a strong pro-apoptotic impact through inducing the intrinsic mitochondrial mechanism of apoptosis. This mechanistic route was verified by an ELISA experiment that indicated a considerable rise in the levels of p53 and Bax and a drop in the level of Bcl-2 when compared with the control.     

Photo- and Electrochemical Dual-Responsive Iridium Probe for Saccharide Detection

Dual detection systems are of interest for rapid, accurate data collection in sensing systems and in vitro testing. We introduce an Ir^III complex with a boronic acid receptor site attached to the 2-phenylpyridine ligand as an ideal probe with photo- and electrochemical signals that is sensitive to monosaccharide binding in aqueous solution. The complex displays orange luminescence at 618 nm, which is reduced by 70 and 40 % upon binding of fructose and glucose, respectively. The electro-chemiluminescent signal of the complex also shows a direct response to monosaccharide binding. The Ir^III complex shows the same response upon incorporation into hydrogel matrices as in solution, thus demonstrating the potential of its integration into a device, as a nontoxic, simple-to-use tool to observe sugar binding over physiologically relevant pH ranges and saccharide concentrations. Moreover, the complex's luminescence is responsive to monosaccharide presence in cancer cells.     

Design,Synthesis, and In Vitro Cytotoxic Activity of Certain 2-[3-Phenyl-4-(pyrimidin-4-yl)-1H-pyrazol1-yl]acetamide Derivatives

Russian Journal of Organic Chemistry - With a view to finding new anticancer agents, different aryloxy groups were attached to C2 of the pyrimidine ring in...     

Synthesis,characterization and studies of new 3‐benzyl‐4H‐1,2,4‐triazole‐5‐thiol and thiazolo[3,2‐b][1,2,4]triazole‐5(6H)‐one heterocycles

3‐Benzyl‐4‐phenyl‐1,2,4‐triazole‐5‐thiol ( 1 ) was synthesized and used as starting material for preparation of 1,2,4‐triazole bearing substituted thiosemicarbazides moiety ( 4a‐d ) in high yields. The thiosemicarbazides 4a‐d were cyclized in basic medium to give two triazole rings linked by thiomethylene group ( 5a‐d ), while cyclization of thiosemicarbazides 4a‐d with chloroacetyl chloride in the presence of CHCl₃ and K₂CO₃ afforded the thiazolidinone derivatives 6a‐d . The reaction of thiosemicarbazides 4a‐c with phenacyl bromide in the presence of EtOH and fused CH₃COONa gave the corresponding thiazoline ring systems 7a‐c . Condensation of the 3‐benzyl‐1,2,4‐triazole‐5(1H)‐thiol ( 1 ) with chloroacetic acid and aromatic aldehydes ( 8a‐ g) in boiling acetic acid/acetic anhydride mixture in the presence of fused sodium acetate gave one single isomer only, which might be 9a‐g or 10a‐g . Upon application of Micheal addition reaction on compounds 9a‐e with cyclic secondary amines such as piperidine or morpholine the 2‐benzyl‐6‐(α‐amino‐aryl/methyl)‐1,3‐thiazolo[3,2‐ b][1,2,4]‐triazol‐5‐ols ( 11a‐j ) were obtained in good yields The structure of all new compounds were determined using both spectral and elemental analyses.     

Onset of the Jet Quenching Phenomenon

JETP Letters - The aim of this study is to set a baseline for the jet quenching measurements of the Quark Gluon Plasma formed in the large system size Nucleus-Nucleus (A-A) at top central...     

A novel multilevel coding technique for high speed optical fiber communication systems

This paper delineates a novel coding technique, a combination of coding and multiplexing technique, known as mapping multiplexing technique (MMT). A mapping algorithm is used to multiplex four channels, each of which running at 10 Gbit/s. Up to four bits per symbol at a symbol rate of 10 Gboud was successfully transmitted over a single wavelength. Compare to the conventional return to zero (RZ) and none-return to zero (NRZ)-time division multiplexing (TDM) more than 75% and 50% reduction in the spectral width are achieved, respectively. Calculated chromatic dispersion tolerance of ±130 ps/nm is achieved for the 40 Gbit/s MMT transmission system at the expense of ∼2 dB degradation in the receiver sensitivity (compared to NRZ) due to an increase in the number of levels and in the signal dependency of signal-spontaneous beat noise. In comparison with conventional 4-ary system, the proposed system depicts ∼6.5 dB improvement in terms of receiver sensitivity.     

Characterisation of defects in p-GaN by admittance spectroscopy

Mg-doped GaN films have been grown on (0 0 0 1) sapphire using metal organic vapour phase epitaxy. Use of different buffer layer strategies caused the threading dislocation density (TDD) in the GaN to be either approximately 2×10⁹ cm⁻² or 1×10¹⁰ cm⁻². Frequency-dependent capacitance and conductance measurements at temperatures up to 450 K have been used to study the electronic states associated with the Mg doping, and to determine how these are affected by the TDD. Admittance spectroscopy of the films finds a single impurity-related acceptor level with an activation energy of 160±10 meV for [Mg] of about 1×10¹⁹ cm⁻³, and 120±10 eV as the Mg precursor flux decreased. This level is thought to be associated with the Mg acceptor state. The TDD has no discernible effect on the trap detected by admittance spectroscopy. We compare these results with cathodoluminescence measurements reported in the literature, which reveal that most threading dislocations are non-radiative recombination centres, and discuss possible reasons why our admittance spectroscopy have not detected electrically active defects associated with threading dislocations.     

Synthesis and Characterization of Dihydrouracil Analogs Utilizing Biginelli Hybrids

Dihydrouracil presents a crucial intermediate in the catabolism of uracil. The vital importance of uracil and its nucleoside, uridine, encourages scientists to synthesize novel dihydrouracils. In this paper, we present an innovative, fast, and effective method for the synthesis of dihydrouracils. Hence, under mild conditions, 3-chloroperbenzoic acid was used to cleave the carbon–sulfur bond of the Biginelli hybrids 5,6-dihydropyrimidin-4(3H)-ones. This approach led to thirteen novel dihydrouracils synthesized in moderate-to-high yields (32–99%).