Spectrophotometric determination of ketoprofen in pharmaceutical preparations by means of charge transfer complex formation

A spectrophotometric determination of ketoprofen based upon oxime formation followed by charge transfer complexation with o-chloranil has been developed. Different variables affecting the complexation process have been studied. Beer's law is obeyed in the concentration range 10-80 microg/ml. The method has been successfully applied to the determination of ketoprofen in pure form and in pharmaceutical dosage forms in the presence of its impurities.     

Y2O2S∶Er3+，Yb3+的制备及Er3+离子在晶场中的能级分裂

采用沉淀法制备前驱体,通过不同温度合成了上转换发光材料Y2O2S∶Er3+,Yb3+,运用XRD,SEM和上转换发射光谱对其进行表征。结果表明,所合成的Y2O2S∶Er3+Yb3+属于六方晶系晶体,随着合成温度的升高,产物的粒径不断增大,上转换发射光强度逐渐增加。研究Y2O2S∶Er3+Yb3+的上转换发光过程,红光发射和绿光发射分别源于Er3+离子的4F9/2→4I15/2以及2H11/2→4I15/2,4S3/2→4I15/2能级跃迁。利用群论计算了晶场中Er3+离子的能级分裂数目。     

Zirconium silicotungstate matrix as a prospective sorbent material for the preparation of <Superscript>113</Superscript>Sn/<Superscript>113m</Superscript>In generator

The zirconium silicotungstate (ZrSiW) was studied as an effective sorbent material to be used in the ¹¹³Sn/^113mIn generator. The results elucidated that the distribution coefficient of ¹¹³Sn (3700 mL/g) is greater than ^113mIn (275 mL/g) from 0.1 M HCl acid solution to the ZrSiW material. The maximum sorption capacity of Sn (IV) was found to be 33 mg per gram ZrSiW (~?0.3 mmol/g). The elution yield of ^113mIn was found to be >?78?±?6.4% with an acceptable purity of radionuclidic and radiochemical (≥?99.99 and 96.8%, respectively). The rigorous separation of ^113mIn from the ¹²⁵Sb was carried out due to its long half-life (2.758 years) and beta emission that causes tissue damage. Zr, W and Si levels are below the permitted limit in the ^113mIn eluate.     

一类含测度的非强制拟线性椭圆方程解的存在性和不存在性

本文主要研究如下含非线性梯度项的非强制拟线性椭圆方程\begin{equation*}\left \{\begin{array}{rl}-\text{div}(\frac{|\nabla u|^{p-2}\nabla u}{(1+|u|)^{\theta(p-1)}})+\frac{|u|^{p-2}u|\nabla u|^{p}}{(1+|u|)^{\theta p}}=\mu,~&x\in\Omega,\\ u=0,~&x\in\partial\Omega,\end{array}\right.\end{equation*} 弱解的存在性和不存在性, 其中$\Omega\subseteq\mathbb{R}^N(N\geq3)$ 是有界光滑区域, $1相似文献   

Synthesis of Hexahydro-<Emphasis Type="Italic">1H</Emphasis>-pyrido[3,2-<Emphasis Type="Italic">c</Emphasis>]azepines as Hypotensive Agents of Expected Calcium-Channel Blocking Activity

Summary. Michael addition reaction of 3-(4-fluorophenylamino)-2-cyclohexenone and its 5,5-dimethyl derivative to the acrylonitrile derivatives afforded the novel hexahydroquinolines. The target hexahydro-1H-pyrido[3,2-c]azepine derivatives were obtained via ring enlargement of the corresponding hexahydroquinolines under Schmedt conditions. Some novel pyrido[3,2-c]azepines showed hypotensive activity in vivo on normotensive anaesthetized male adult albino rats and their effects on the ventricular contraction and auricular rate of isolated rabbit hearts using Langendorff’s method and nefidipine as a reference drug were studied. Compounds 29 and 36 which bear some structural similarities to nefidipine exhibited the highest hypotensive activity and negative inotropic as well as chronotropic activities.     

Specific capacitance of CoS encapsulated g-C3N4 core shell nanocomposite as extremely efficient counter electrode in quantum dots solar cells

Journal of Solid State Electrochemistry - In this context, the electrical conductivity and surface activity of cobalt sulphide (CoS) as counter electrode CE is improved by incorporating with...     

Low-frequency dilational elasticity of the nematic 4'-pentyl-4-biphenylcarbonitrile (5CB)/water interface

Axisymmetric oscillating pendant drop shape analysis has been used to study the interfacial rheology of the liquid crystal 4'-pentyl-4-biphenylcarbonitrile (5CB) in water with homeotropic anchoring. Nearly spherical 5CB droplets were subjected to low frequency (1-5 mHz) volume oscillations, and the increase in tension with surface dilation was used to calculate the complex modulus. The droplet interface response is completely elastic, with no relaxations occurring on the experimental time scale. This surprising result is attributed to droplet storage of elastic energy in the form of distorted orientational distributions within the bulk (Frank elasticity) and on the surface (anchoring elasticity).     

Low temperature measurements of electrical activity and Hall mobility of boron implanted silicon

This work investigates the electrical behaviour of boron implanted silicon at temperatures from 300k to 4.2k by means of Hall effect and sheet resistivity measurements. The ion energy is 100 Kev and the doses are 1×10¹², 2×10¹², 5×10¹², 1×10¹³, 2×10¹³, 5×10¹³, 1×10¹⁴, 2.5×10¹⁴, 5×10¹⁴, and 1×10¹⁵ ions/cm².The most accurate information about the electrical activity can be only found from measurements at low temperatures. Furthermore, a reverse annealing takes place in the annealing temperature range from 500 to 600 °C, and this range is found to be independent of the ion dose. It is also clear that the electrical activity depends strongly on the annealing temperatures, especially for annealing temperatures greater than 600 °C. For ion dose 1×10¹⁵ ions/cm² complete activity can be obtained by annealing up to 900 °C.

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Zusammenfassung Die vorliegende Arbeit beschreibt Untersuchungen über das elektrische Verhalten des Borimplantierten Siliziums mittels Hall Effekt- und Schicht-Widerstand-Messungen im Temperaturbereich von 300k bis 4.2k. Die Ionenenergie betrug dabei 100 Kev, und die Ionendosen waren 1×10¹², 2×10¹², 5×10¹², 1×10¹³, 2×10¹³, 5×10¹³, 1×10¹⁴, 2.5×10¹⁴, 5×10¹⁴, und 1×10¹⁵ Ionen/cm².Es wurde festgestellt, daß genauere Informationen über die Aktivierung der implantierten Dopanden nur aus Tieftemperatur-Messungen erhalten werden können. Weiterhin findet man ein negatives Ausheilen im Bereich von 500 bis 600 °C. Die Grenzen dieses negativen Ausheilbereiches sind von den Ionendosen unabhängig. Es ist eindeutig, daß die Aktivierung der Dopanden sehr stark von der Ausheiltemperatur abhängig ist, insbesondere für Ausheiltemperaturen größer als 600 °C. Für die Ionendosis 1×10¹⁵ Ionen/cm² kann bei einer Ausheiltemperatur von 900 °C eine vollständige Aktivierung erreicht werden.

     

Triblock copolymer Pluronic®F127 sustains insulin release and reduces initial burst of microspheres—in vitro and in vivo study

In many cases, initial release of drugs from microparticles is undesirable. In the present study, Pluronic^®F127, which shows thermosensitive characteristic, was used for controlling both the initial release and the sustained release of insulin from microspheres. Calcium-alginate insulin microspheres were prepared by emulsion technology and dispersed in a thermosensitive semisolid gel, the PF127. In vitro study demonstrated that PF127 could protect the activity of insulin in some extent and control the initial release and sustained release of insulin well. The results of in vivo hypoglycemic experiment carried out on diabetic rats also displayed a well correlation with in vitro release patterns. The results suggested that PF127 could sustain insulin release through a subcutaneous injection, and this material was available to deliver insulin aiming for prolonged and smooth hypoglycemic function.     

Spectrophotometric and atomic absorption determination of ramipril, enalapril maleate and fosinopril through ternary complex formation with molybdenum (V)-thiocyanate (Mo(V)-SCN)

Three different sensitive and accurate spectroscopic procedures were developed for the determination of three angiotensin-converting enzyme inhibitors, namely, ramipril, enalapril maleate and fosinopril. The first two spectrophotometric (extractive and non-extractive) procedures were based on ternary complex formation with molybdenum(V) thiocyanate. The formed complex can be determined by extraction with chloroform measured at lambdamax 517 nm Beer's law was obeyed in the concentration range from (10--90 microg ml(-1)) for ramipril and fosinopril and (4--36 microg ml(-1)) for enalapril maleate with molar absorptivity 1.2x10(4), 2x10(4) and 3.4x10(4) l mol(-1) cm(-1), respectively, or by direct measurement after addition of benzalkonium chloride as surfactant and measuring the formed ternary complex at lambdamax 545 nm with a linear relationship in the concentration range from (8-7-2 microg ml(-1)), (3--27 microg ml(-1)) and (8--72 microg ml(-1)) for ramipril, enalapril maleate and fosinopril with molar absorptivity 1.5x10(4), 5x10(4) and 2.1x10(4) l mol(-1) cm(-1), respectively. The third procedure is atomic absorption measurement through the quantitative determination of molybdenum content of the complex. These methods hold their accuracy and precision well when applied to the determination of ramipril, enalapril maleate and fosinopril in their dosage forms.