Entropy squeezing of multi-photon field interacting with a single Cooper-pair box

We investigate the entropy squeezing and entanglement of the Cooper-pair box interacting with multi-photon cavity field. The field is prepared initially in the coherent state, while the Cooper-pair box is assumed to start from a mixed state. We find that the number of photons and the detuning parameters play an important role in the entropy squeezing and entanglement. We observe that the entropy squeezing can be used as a good indicator of the entanglement. This study opens promising perspectives for creating remote quantum information processing networks.     

Modeling and device parameter design to improve reset time in binary-oxide memristors

A simulation-based analysis is conducted to study the set and reset times of TiO₂-based memristor device. This analysis uses nonlinear device model that captures the effects of large electric field inside memristor devices. Previous studies report strong asymmetry between reset and set times with reset time being several orders of magnitude higher than set time. The aim of this work was to investigate the effect of the device length and oxygen vacancies profile on the switching time. Our results show that a device model with a length of 10 nm and accurate parameters can result in more realistic device characteristics. Also, oxygen vacancies profile can be tuned to improve the reset time. MATLAB is used to simulate a 10-nm device, and the initial vacancy profile is chosen to look like inverted parabola. The results show reduced ratio between reset and set times from several orders of magnitude presented in the literature to not more than 1.5×. Thus, the proposed oxygen vacancies profile and quantitative results derived from it can be used to suggest a physical memristor device. In addition, the tuned parameters and model that matches actual device behavior can be factored in memristor fabrication.     

A new CZE method for profiling human serum albumin and its related forms to assess the quality of biopharmaceuticals

We present a new CZE method, which uses a polyethylene oxide-coated capillary to separate native HSA from more than five of its structural variants. These variants include oxidized, truncated, and cysteinylated forms of HSA which can all be found in biopharmaceutical products. Both CE and MS confirmed the high degree of heterogeneity of HSA preparations. Recovery studies demonstrated that adsorption of HSA on the capillary was significantly reduced under the conditions we developed, which led to a satisfactory repeatability (RSD for migration times and relative peak areas were less than 0.2 and 7.0%, respectively). Assignment of the main peaks was attempted using in vitro degraded/stressed HSA. We used our method to test batch-to-batch comparability and detected slight quantitative differences in the proportion of native HSA in batches produced from different fractionation methods.     

Synthesis of new 2-pyridinone and thiazole derivatives containing coumarin moiety

Coumarin has shown considerable therapeutic potency because of its versatile biological prosperities. Also, pyridines have been adopted in medicinal chemistry as potent ring. Moreover, several investigations reported the potency of thiazole-containing compounds. So, during this research, new functionalized 2-pyridinone and thiazole derivatives bearing coumarin moiety were aimed to synthesize. Many trials to obtain the 6-amino-2-oxo-pyridine-3,5-dicarbonitriles through the condensation of cyanoacetohydrazone of 3-acetyl coumarin with 2-(arylidene)malononitriles were carried out using different reaction conditions. In all cases, the reaction gave none of the corresponding 2-pyridinone derivatives except the reaction with 2-(benzylidene)-malononitrile afforded product in few yield. Moreover, the reaction of another cyanoacetanilide with the 2-(arylidene)-malononitrile afforded the unexpected arylidene derivatives rather than the expected pyridin-2-one derivatives. Finally, new thiazoles bearing coumarin moiety were synthesized using 3-acetylcoumarin N-(2,4-dimethoxyphenyl)-thiosemicarbazone. Cyclization of thiosemicarbazone derivative with ethyl 2-chloroacetate, chloroacetone or phenacyl bromide afforded in high yields the corresponding derivatives of thiazolidin-4-one, 4-methylthiazole or 4-phenylthiazole, respectively.     

High Molecular Weight Poly(ethylenimine)‐Based Water‐Soluble Lipopolymer for Transfection of Cancer Cells

Over the past decade, search for novel materials for nucleic acid delivery has prompted a special interest in polymeric nanoparticles (NPs). In this study, the biological applicability of a water‐soluble cationic lipopolymer (WSLP) obtained by the modification of high molecular weight branched poly(ethylenimine) (PEI) with cholesteryl chloroformate is characterized and assessed for better cellular membrane permeability. To test the delivery efficiency of the produced lipopolymer, plasmid DNA (pDNA) encoding the enhanced green fluorescent protein and WSLP are mixed at different charge ratios. WSLP and WSLP/pDNA complexes are characterized by dynamic and static light scattering, particle charge detection, scanning electron microscopy, and transmission electron microscopy. The pDNA loading of WSLP is also verified by agarose gel electrophoresis. Cytotoxicity of PEI, WSLP, and of WSLP/pDNA is evaluated on human A549 and HeLa cells. A remarkable dependence of the toxicity on the dose, cholesterylation, and charge ratio is detected. Transfection is monitored by flow cytometry and by fluorescence microscopy. Importantly, cholesterylation decreases the toxicity of the polymer, while promoting high transfection efficiency in both cell lines. This work indicates a possible optimization mode of the high molecular weight PEI‐based WSLP rendering it a promising candidate for gene delivery.     

Anodic Polarographic Determination of Nilvadipine in Dosage Forms and Spiked Human Urine

 The anodic polarographic behaviour of nilvadipine was studied by using direct-current (DC), polarography and differential-pulse polarography (DPP). Nilvadipine, being a dihydropyridine derivative, exhibits well-defined anodic waves over the whole pH range of the Britton-Robinson buffers (BRb). In BRb of pH = 4, the diffusion-current constant was 6.45 ± 0.07 μA · mM⁻¹. The current-concentration plots are rectilinear over the ranges 1.6–12.8 and 0.2–12.8 μg/ml for DC polarography and DPP, respectively, with minimum detectability of 0.05 μg/ml (1.3 × 10⁻⁷ M) in case of the latter technique. The proposed method was successfully applied for determination of the drug in commercial capsules containing the drug, the percentage recoveries being in good agreement with the label claim. Furthermore, the method was applied for the determination of the drug in spiked human urine, the percentage recovery being 96.84 ± 2.83. Received January 25, 2001 Revision June 18, 2001     

Validated Voltammetric Method for the Simultaneous Determination of Anti‐diabetic Drugs,Linagliptin and Empagliflozin in Bulk,Pharmaceutical Dosage Forms and Biological Fluids

A cobalt oxide nanoparticles (Co₃O₄NPs) and multi walled carbon nanotubes (MWCNTs) modified carbon paste electrodes were used to study the electrochemical behavior of linagliptin and empagliflozin in Britton Robinson buffer solution of pH 8.0 using cyclic and square wave voltammetry. The above mentioned modified electrodes showed highly sensitive sensing and gave an excellent anodic response for both drugs. The peak current varied linearly over the concentration ranges: 3.98×10^?5–1.53×10^?3 mol L^?1 (18.82–723.00 μg/mL) and 7.94×10^?6–1.07×10^?4 mol L^?1 (3.65–48.25 μg/mL) with determination coefficients of 0.9999 and 0.9998 for linagliptin and empagliflozin, respectively. The recoveries and relative standard deviations were found in the following ranges: 98.80 %–102.00 % and 0.23 %–1.90 % for linagliptin and 98.30 %–101.80 % and 0.11 %–1.86 % for empagliflozin. The detection and quantification limits were 1.13×10^?5 and 3.76×10^?5 mol L^?1 (5.34and17.77 μg/mL) for linagliptin, 1.71×10^?6and 5.68×10^?6 mol L^?1 (0.77 and 2.56 μg/mL) for empagliflozin. The proposed sensors have been successfully applied for the determination of the drugs in bulk, pharmaceutical formulations and biological fluids.     

Solvent‐free mixed micellar mobile phases: An advanced green chemistry approach for reversed‐phase HPLC determination of some antihypertensive drugs

Minimizing the amount of organic solvents without loss in chromatographic performance has been an important step toward greening analytical methodologies. Mobile‐phase composition is the key for maintaining separation efficiency in liquid chromatography while decreasing the procedure hazardousness. If sodium dodecyl sulfate is mixed with Brij‐35 in the mobile phase, they could be used as a green alternative for using organic modifiers. In this research, the effect of changing the relative amounts of both surfactants was studied on the chromatographic performance and separation efficiency of ten antihypertensive drugs belonging to different categories. The use of surfactants has many advantages including low cost and toxicity, safe environmental disposal, unique selectivity besides high solubilization capabilities. The optimum separation was maintained using a mobile phase (0.01 M Brij‐35, 0.08 M sodium dodecyl sulfate and 0.01 M sodium dihydrogen phosphate/pH 5) on reversed‐phase C18 core–shell column at flow rate 1.5 mL/min and temperature 30°C. The method was successfully applied for the determination of the drugs in various marketed dosage forms. International Conference of Harmonization guidelines were followed to validate the developed method. Additionally, the method was verified on the Green Analytical Procedure Index in regards to the greenness and found to be an excellent green alternative method.     

New furochromone derivatives as promising in-vitro anti-proliferative agents toward HepG-2 and MCF-7 cell lines with molecular docking studies

Based on the considerable features of the multicomponent reactions (MCRs) in the field of organic and medicinal chemistry, the present work was designed to synthesize a new series of imidazole, pyridine, and pyrimidine derivatives using MCRs to obtain new anti-proliferative agent beside exploration of their interaction mechanism by molecular docking technique. MCRs of furochromone carbaldehyde 1 , benzoin, and ammonium acetate afforded the corresponding 2,4,5-trisubstituted imidazole 2 . However, MCRs of 1 with benzoin, amine derivatives, and ammonium acetate yielded the corresponding 1,2,4,5-tetrasubstituted imidazole 3a,b . In addition, pyridine 4a,b-5a,b and pyrimidine derivatives 6a,d were synthesized via condensation of 1 with different carbonyl compounds and ammonium acetate or benzyl urea, respectively. The in-vitro anti-Proliferative activities of the new furochromone derivatives were screened toward MCF-7 and HepG-2 cancer cell lines as well as the normal cell line (human normal melanocyte, HFB4) in comparison to the known anticancer drugs: 5-fluorouracil and doxorubicin using MTT assay. Compounds 5a and 5b revealed effective anti-proliferative activity against MCF-7 cell lines with IC ₅₀ 18 and 22 μg/mL, respectively, compared to 5-fluorouracil (IC ₅₀ of 13 μg/mL). However, compounds 6a-d exhibited potent activity against HepG-2 cancer cell lines of IC ₅₀ ranging from 18 to 20 μg/mL compared to doxorubicin (IC ₅₀ of 14 μg/mL). Moreover, the binding mode of the most active furochromones 5a,b and 6a-d inside the active site of the epidermal growth factor receptor (EGFR) kinase enzyme (PDB ID: 5CAV) were studied using molecular docking technique. Compounds 6b,c showed excellent docking results compared to the known EGFR inhibitors ( 4ZQ ).