Regge poles in the collective model of the nuclear giant multipole resonances

Giant nuclear resonance states, of higher multipolarity than dipole, have recently been observed in hadron and electron scattering. They may possibly be described by the collective Goldhaber-Teller model as extended to the higher multipolarity case, and as generalized to include spin-isospin vibrations and spin waves. Based on such a model, we show that the multipole resonances, together with the conventional dipole resonances, can be generated by the motion of a few basic Regge poles through the complex angular momentum plane. This viewpoint unifies all the resonances with a given spin-isospin character but arbitrary value of the multipolarity, and suggests the existence of the higher-multipole resonances as a consequence of the existence of the dipole resonance. We also analyze these Regge poles in terms of collective surface waves (“creeping waves”) circumnavigating the nucleus, and we determine their phase velocities and attenuations. Finally, the giant resonances them selves are explained as a resonant reinforcement of phase-matched surface waves.     

Anionic polymerization. IV. Effect of crown ethers on alkylsodium initiator

The polymerization of butadiene and copolymerization of butadiene-styrene with alkylsodium catalyst modified by crown ethers in hydrocarbon solvent has been investigated. This catalyst system produced polybutadiene of high viscosity (2.0–5.0) and high vinyl content (80%) in high conversion (75–95%). These results are in contrast to those obtained with aliphatic ether-modified alkylsodium polymerization which typically gives products of low molecular weight and at low conversion. The copolymerization of butadiene-styrene with alkylsodium catalyst modified by crown ethers gave a copolymer which did not contain block styrene. Although the copolymer did not contain block styrene, there was an unusually high level of incorporation of styrene in the copolymer at low conversion. This behavior is quite different from either modified organolithium or unmodified organosodium initiators, in which the styrene is uniformly and randomly incorporated along the chain.     

Sensitization of Mn with CdS nanoparticles via electrochemical deposition technique for photocurrent enhancement of nanomaterial’s-sensitized photoelectrochemical cells

A photoconversion efficiency of 2.12% was obtained under visible light illumination by nanostructure-sensitized photoelectrochemical cells using Mn/CdS as sensitizer loaded on TiO₂ nanotube arrays (NTAs) (Mn/CdS/TiO₂). Sensitization of Mn on CdS nanoparticles pre-loaded on TiO₂ NTAs was carried out by a two-step electrodeposition method. Compared with unsensitized TiO₂ NTAs, the photocurrent had increased from 0.03 to 4.12 for Mn/CdS/TiO₂ prepared at 1 min. The effects of deposited Mn on the physical, chemical, and photoelectrochemical properties of the CdS/TiO₂ NTAs nanostructure were investigated by using UV–visible diffuse reflectance spectroscopy, X-ray diffractometry, and field-emission scanning electron microscopy coupled with energy dispersive X-ray spectroscopy. The photoelectrochemical analysis was examined in a three-electrode system under a halogen illumination by using the prepared film as the photo-anode.     

Simultaneous Determination of Pyridoxine, Meclizine and Buclizine in Dosage Formulations and Human Serum by RP-LC

Rapid liquid chromatographic procedures for analytical quality control of pharmaceutical preparations and human serum containing antihistamine drugs, meclizine and buclizine alone or in combination with pyridoxine are proposed, using acetonitrile:water (80:20) as a mobile phase (pH adjusted to 2.6), methylparaben as internal standard and UV detection was made at 230 nm. The results obtained showed a good agreement with the declared content. The method shows good linearity in the range of 30–10,000 ng mL^?1 for pyridoxine and 25–10,000 ng mL^?1 for meclizine and buclizine serum concentrations with a correlation coefficient 0.9999 (inter- and intra-day CV < 3.91%). The recovery was >97.8%. The proposed method may be used for the quantitative analysis of meclizine and buclizine alone or in combination with pyridoxine from raw materials, in bulk drugs, dosage formulations and in serum.     

Numerical simulation of forced convective power law nanofluid through circular annulus sector

Journal of Thermal Analysis and Calorimetry - In this article, we have studied effect of two types of solid nanoparticles (i.e., TiO $$_{2}$$ and Cu) on the forced convective power law fluid flow...     

Application of chemometric approach for development and validation of high performance liquid chromatography method for estimation of ropinirole hydrochloride

A systematic Quality by Design approach was employed for developing an isocratic reversed‐phase liquid chromatographic technique for the estimation of ropinirole hydrochloride in bulk drug and pharmaceutical formulations. LiChrospher RP 18‐5 Endcapped column (25 cm × 4.6 mm id) at ambient temperature (25 ± 2°C) was used for the chromatographic separation of the drug. The screening of factors influencing chromatographic separation of the active pharmaceutical ingredient was performed employing fractional factorial design to identify the influential factors. Optimization of the selected factors was carried out using central composite design for selecting the optimum chomatographic conditions. The mobile phase employed was constituted of Solvent A/Solvent B (65:35 v/v) (Solvent A [methanol/0.05 M ammonium acetate buffer, pH 7, 80:20 v/v] and Solvent B [high performance liquid chromatography grade water]) and used at 0.6 mL/min flow rate, while UV detection was performed at 250 nm. Linearity was achieved in the drug concentration range 5–100 µg/mL (R² = 0.9998) with limits of detection and quantification of 1.02 and 3.09 µg/mL, respectively. Method validation was performed as per ICH guidelines followed by forced degradation studies, which indicated good specificity of the developed method for detecting ropinirole hydrochloride and its possible degradation products in the bulk drug and pharmaceutical formulations.     

Chemical,Nutrient and Physicochemical Properties of Brown Seaweed,Sargassum polycystum C. Agardh (Phaeophyceae) Collected from Port Dickson,Peninsular Malaysia

Recent increased interest in seaweed is motivated by attention generated in their bioactive components that have potential applications in the functional food and nutraceutical industries. In the present study, nutritional composition, metabolite profiles, phytochemical screening and physicochemical properties of freeze-dried brown seaweed, Sargassum polycystum were evaluated. Results showed that the S. polycystum had protein content of 8.65 ± 1.06%, lipid of 3.42 ± 0.01%, carbohydrate of 36.55 ± 1.09% and total dietary fibre content of 2.75 ± 0.58% on dry weight basis. The mineral content of S. polycystum including Na, K, Ca, Mg Fe, Se and Mn were 8876.45 ± 0.47, 1711.05 ± 0.07, 1079.75 ± 0.30, 213.85 ± 0.02, 277.6 ± 0.12, 4.70 ± 0.00 and 4.45 ± 0.00 mg 100/g DW, respectively. Total carotenoid, chlorophyll a and b content in S. polycystum were detected at 45.28 ± 1.77, 141.98 ± 1.18 and 111.29 µg/g respectively. The total amino acid content was 74.90 ± 1.45%. The study revealed various secondary metabolites and major constituents of S. polycystum fibre to include fucose, mannose, galactose, xylose and rhamnose. The metabolites extracted from the seaweeds comprised n-hexadecanoic acid, 1,2-benzenedicarboxylic acid, mono(2-ethylhexyl) ester, benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy- methyl ester, 1-dodecanol, 3,7,11-trimethyl-, which were the most abundant. The physicochemical properties of S. polycystum such as water-holding and swelling capacity were comparable to several commercial fibre-rich products. In conclusion, results of this study indicate that S. polycystum is a potential candidate as functional food sources for human consumption and its cultivation needs to be encouraged.     

Synthesis of Pyrano,Pyrido, Oxazino,and Spiro Pyrazole Derivatives and Their Antimicrobial Activity

Russian Journal of Organic Chemistry - Condensation of 5-methyl-2-phenyl-1,2-dihydro-3H-pyrazol-3-one with 4-hydroxybenzaldhyde in alcoholic sodium hydroxide yielded...     

Development and validation of a rapid and sensitive UPLC–MS/MS assay for simultaneous quantification of paclitaxel and cyclopamine in mouse whole blood and tissue samples

The prominent stromal compartment surrounds pancreatic ductal adenocarcinoma and protects the tumor cells from chemo‐ or radiotherapy. We hypothesized that our nano formulation carrying cyclopamine (CPA, stroma modulator) and paclitaxel (PTX, antitumor agent) could increase the permeation of PTX through the stromal compartment and improve the intratumoral delivery of PTX. In the present study a sensitive, reliable UPLC–MS/MS method was developed and validated to quantify PTX and CPA simultaneously in mouse whole blood, pancreas, liver and spleen samples. Docetaxel was used as the internal standard. The method demonstrated a linear range of 0.5–2000 ng/mL for whole blood and tissue homogenates for both PTX and CPA. The accuracy and precision of the assay were all within ±15%. Matrix effects for both analytes were within 15%. Recoveries from whole blood, liver, spleen and pancreas homogenates were 92.7–105.2% for PTX and 72.8–99.7% for CPA. The stability was within ±15% in all test biomatrices. The validated method met the acceptance criteria according to US Food and Drug Administration regulatory guidelines. The method was successfully applied to support a pharmacokinetic and biodistribution study for PTX and CPA in mice biomatrices.     

The Involvement of l-Arginine-Nitric Oxide-cGMP-ATP-Sensitive K+ Channel Pathway in Antinociception of BBHC,a Novel Diarylpentanoid Analogue,in Mice Model

The present study focuses on the possible involvement of l-arginine-nitric oxide-cGMP-ATP-sensitive K⁺ channel pathway in the antinociceptive activity of a novel diarylpentanoid analogue, 2-benzoyl-6-(3-bromo-4-hydroxybenzylidene)cyclohexen-1-ol (BBHC) via a chemical nociceptive model in mice. The antinociceptive action of BBHC (1 mg/kg, i.p.) was attenuated by the intraperitoneal pre-treatment of l-arginine (a nitric oxide synthase precursor) and glibenclamide (an ATP-sensitive K⁺ channel blocker) in acetic acid-induced abdominal constriction tests. Interestingly, BBHC’s antinociception was significantly enhanced by the i.p. pre-treatment of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a selective inhibitor of soluble guanylyl cyclase (p < 0.05). Altogether, these findings suggest that the systemic administration of BBHC is able to establish a significant antinociceptive effect in a mice model of chemically induced pain. BBHC’s antinociception is shown to be mediated by the involvement of l-arginine-nitric oxide-cGMP-ATP-sensitive K⁺ channel pathway, without any potential sedative or muscle relaxant concerns.