Preparation,characterization, and pharmacokinetics of the inclusion complex of genipin-β-cyclodextrin

Objective: The aim of this study was to prepare the inclusion complex of genipin (GP) and β-cyclodextrin (β-CD) with improved stability, solubility, and bioavailability and to study the pharmacokinetics of β-CD inclusion complex in mice. Methods: Lyophilization was employed in the preparation of the inclusion complex of GP–β-CD, whose formation was confirmed by infrared, ultraviolet, differential scanning calorimetry, X-ray diffraction, and phase solubility method. Comparative studies on the in vitro solubility and stability and in vivo evaluation of GP in mice were investigated. Liquid–liquid extraction was used for the isolation of GP in the assay of its concentration. After injection in the caudal vein at equal doses of the inclusion complex of free GP, the drug concentration in mice plasma at fixed time after administration was determined by high-performance liquid chromatography method. Results: The results demonstrated that GP–β-CD solid powders showed improved stability and solubility in aqueous solution, when comparing with free GP. The results of the in vivo study showed that the inclusion complex of GP–β-CD exhibited the dissimilar pharmacokinetics from that of free GP after intravenous administration. The inclusion complex of GP–β-CD displayed longer MRT_0–∞ and higher AUC_0–∞ than free GP did. Conclusions: The relative bioavailability of the inclusion complex of GP–β-CD to free GP was 305.3%, which demonstrated that GP formulations containing β-CD significantly increased the bioavailability.     

Study of the distribution of ²²⁶Ra in ground water near the uranium industry of Jharkhand, India

Ground water is the principal source of drinking water in the rural areas of India. With the aim of determining, the contribution of (226)Ra to natural background radiation through drinking water exposure pathway near an operating uranium mining industry at Jaduguda, Jharkhand state of eastern India, the (226)Ra activity concentrations were measured in potable ground water. The water analysed, both tube well and well water, was collected in areas near the uranium industry and away. The (226)Ra concentration was measured by emanometric technique. The (226)Ra level in ground water was ranging between minimum detection limit of 3.5 mBq l(-1) and a maximum of 208 mBq l(-1). The analysis of variance reveals that there is insignificant statistical variation in the median (226)Ra concentration up to a distance of >10 km from the mining complex. Variation in concentration of (226)Ra in sources is attributed to the local geochemistry and environmental factors. The (226)Ra concentration was significantly elevated in natural artesian wells in the vicinity of uranium mineralised hill and it varies from 53.4 to 754 mBq l(-1). The WHO [Guidelines for Drinking Water Quality. Third Edition, Vol. 1, Recommendation (2004)] guideline value of 1000 mBq l(-1) has not been exceeded in any of the sources investigated.     

How to monitor the modulus of elasticity of concrete,automatically since the earliest age?

Monitoring the evolution of an early age set of parameters on concrete is necessary to predict the early age behaviour of structures. The difficulty lies in the fact that this monitoring must be automatic because the concrete hardening process takes place over a long period after the casting. This paper presents a new methodology and an apparatus, specifically designed at IFSTTAR, to monitor the hardening process of a concrete. Mainly, the Young’s modulus can be monitored in compression. Measurements start soon after having cast the concrete and the sample temperature is completely controlled so that the concrete maturity is well mastered. The performances of this apparatus, obtained on an ordinary concrete, are compared to more classical measurements using an extensometer mounted on the sample just after the setting time and to ultrasonic measurements. In these cases, the temperatures were not controlled and results have to be expressed in equivalent time. A comparison with another method developed and used at ULB by using the same concrete, in the frame of a joined cooperation between our two laboratories is achieved. This test set up is based on the so called Temperature Stress Testing Machine (TSTM). This device has been specifically designed with a control of the concrete maturity by the use of a dummy specimen only submitted to free deformations (thermal, shrinkage). The TSTM allows compressive and tensile testing starting just after the setting time. In addition, concrete properties, such as compressive and tensile strength, have been characterized at early age. These values have been used for the design of the loading histories applied in the automatic tests. The heat released by the cement hydration has also been measured in order to express the results on a maturity scale.     

On the Correction of the Melting Curve of the Eutectic Co–C for the Effect of the Thermal Inertia of the Furnace

This paper considers the influence of the thermal inertia of the furnace on the shape of the melting curve of the eutectic Co–C. To this end, melting experiments have been performed in a uniform three-zone furnace, with an inherent substantial thermal inertia. The thermal inertia has been quantified by measuring the step-response of the furnace with the sample in its solid state, just below its melting temperature. From the analysis of the effect of the thermal inertia of the furnace, it turned out that during melting the temperature distribution within the furnace, surrounding the crucible, is bound to be in a non-stationary state. This provided the key to properly finalizing the correction to be applied. The shape of the corrected curve differs considerably from that of the curve, as measured, in that the former shows a flatter melting plateau, and a larger curvature on the way down to the solidus point. As regards the liquidus temperature \(T_{\mathrm{liq}}\)—of major interest in the characterization of the transition temperature of high-temperature fixed points—it is demonstrated that the thermal inertia of the furnace shows a kind of self-compensating mechanism. But the effects of the thermal inertia of the furnace on the parameters defining the Scheil fit, involved in the correction procedure, were considerable.     

Definition and measurement of the shear-lag parameter, β, as an index of the stress transfer efficiency in polymer composites

The shear-lag parameter, , employed in various problems of shear-lag analysis of composites is an unknown parameter which, in certain cases, is impossible to define. In this paper, a new methodology is proposed for the definition and subsequent experimental measurement of for various single-fibre model composites. It is argued that, if is defined as a fitting parameter for the solution of the shear-lag differential equation, then it can effectively serve as a stress-transfer efficiency index. The dependence of upon the conditions prevailing at the fibre–matrix interface will be demonstrated by measuring as a function of the fibre sizing in a carbon–epoxy composite system. © 1998 Chapman & Hall     

Electronic Structure of Technetium Metal,Calculated in the Approximation of the Xα-Discrete Variation Method

Electronic structure of the fragments (number of atoms from 6 to 93) of hexagonal close-packed and face-centered cubic structures of technetium metal was calculated in the approximation of the X-discrete variation nonempirical method. The results agree well with band calculations of both occupied and unoccupied electronic states in solid Tc as well as with the experimental data of conversion electron and optical spectroscopy. The quantum chemical model can be used for calculations of technetium-ruthenium binary phases which can be formed in the course of transmutation of technetium metal.     

Temperature dependence of the Anderson-Grüneisen parameter δ of Co,Ru, and Er

The third-order elastic (TOE) constants of cobalt, ruthenium, and erbium have been calculated as a function of temperature using the nearest neighbor central-force model of Srinivasan and Ramji Rao, taking into account the temperature variation of the second-order elastic (SOE) constants of the metal. The Anderson-Grüneisen (AG) parameter has been evaluated at different temperatures using the respective TOE constants at each temperature for the three metals. It is found that the AG parameter for these metals does not vary markedly with temperature.     

Distribution of crack extension force,the Ĵ-integral,along a through-crack-front of a plate

The -integral is an extension of the J-integral proposed by Rice. It represents the crack-extension force; i.e., the energy release rate per unit of a crack-tip translation in three-dimensional elastic-plastic materials. The distribution of the -integral along the crack-front in a plate subjected to a monotonic loading is determined by a three-dimensional elastic-plastic finite element method.The three-dimensional calculation elucidates that the -integral takes its maximum value at the mid-thickness of the plate and takes a smaller value near the plate surfaces. It is shown that the -integral at the mid-thickness takes an intermediate value between those obtained by two-dimensional plane-strain and plane-stress computations; and that for a compact specimen it agrees with the J-integral value determined from the computed load versus the load-line-displacement curve using the Merkle-Corten formula.

---

Résumé L'intégrale J est une extension de l'intégrale J proposée par Rice. Elle représente une force d'extension d'une fissure, à savoir le taux de relaxation de l'énergie par unité de translation de l'extrémité de la fissure dans des matériaux tridimensionnels élasto-plastiques. On détermine la distribution de l'intégrale J le long du front de fissuration dans une tôle soumise à charge croissante, à l'aide d'une méthode élastoplastique par éléments finis sur trois dimensions.Le calcul tridimensionnel permet d'établir que l'intégrale J revêt sa valeur maximale à mi-épaisseur de la tôle, et une valeur plus faible au voisinage des surfaces de la tôle.On montre que l'intégrale J à mi-épaisseur prend une valeur intermédiaire entre les valeurs ci-dessus, lorsqu'elle est déterminée par calculs à deux dimensions en état plan de déformation on en état plan de tension. On montre aussi que, dans le cas d'une éprouvette compacte, cette valeur est en accord avec la valeur de l'intégrale J établie à partir de la courbe calculée en fonction du déplacement sur la ligne de charge, à l'aide de la formule de Merkle-Corten.

     

A correlation of ΔK th-value with the exponent,m, in the equation of fatigue crack growth for various steels

Literature (mainly in Japan) relating to fatigue-crack-growth-data at R=0 in an air environment for a wide range of steels is reviewed with particular attention to the threshold stress intensity, K _th. The collected data are analyzed in terms of the exponent, m(the slope of the linear portion of the log(da/dN)-logD relationship) by taking account of microstructure, material strength, fracture toughness and specimen thickness. The mean rate of fatigue crack growth for ductile steels in the range from the intermediate growth rate to threshold level and the relevant threshold values at R=0, K _th0, can be represented asda/dN = 1.700 × 10^-4(K103.6)^m - 10^-6andK _th0 = 103.6(5.88 × 10^-3)^1/m,where (da/dN) and K are measured by the units of mm/cycle and kgf/mm^3/2, respectively. Contrary to this, in the case of extremely brittle steels with K _IC-value below 200 kgf/mm^3/2 (the fracture occurs by the intergranular separation), the relationships are given byda/dN = 2.893 × 10^-5(K/49.94)^m - 2.5 × 10^-7andK _th0 = 49.94(8.64 × 10^-3)^1/m.

---

Résumé La littérature, principalement japonaise, relative aux données sur la propagation des fissures de fatigue pour R=0 dans un environnement d'air et pour une large catégorie d'aciers fait l'objet d'une revue avec une attention particulière pour l'intensité de contrainte de seuil, K _th. Les données collectées sont analysées en terme de l'éxposant m (qui représente la pente de la portion linéaire de la relation log(da/dN)-log K, en tenant compte de la microstructure, de la résistance du matériau, de la ténacité à la rupture et de l'épaisseur de l'éprouvette. La vitesse moyenne de propagation d'une fissure de fatigue dans le cas des aciers ductiles dans la fourchette entre la vitesse intermédiaire de fissuration et le niveau critique, et les valeurs correspondantes de seuil à R=0, K _th0 peuvent être représentées par la relation:da/dN = 1.700 × 10^-4(K103.6)^m - 10^-6etK _th0 = 103.6(5.88 × 10^-3)^1/m,où (da/dN) et K sont mesurés en unités de mm/cycle et en kgf/mm^3/2 respectivement. En contraste, dans le cas d'aciers extrèmement fragiles avec des valeurs K _IC en dessous de 200 kgf/mm^3/2 (la rupture se produit par une séparation intergranulaire), ces relations sont données par:da/dN = 2.893 × 10^-5(K/49.94)^m - 2.5 × 10^-7etK _th0 = 49.94(8.64 × 10^-3)^1/m.

     

A comparison of the effects of γ-irradiation and ethylene oxide sterilization on the properties of compression moulded poly-d,l-lactide

Compression moulded specimens from two batches of poly-d,l-lactide, of different molecular weights, have been subjected to -radiation and to ethylene oxide (ETO) exposure to establish the effects of sterilizing procedures on potential orthopaedic implants. Materials were exposed to between zero and 10 Mrad, and up to three standard ETO cycles. Tensile properties, dynamic mechanical behaviour, fracture toughness and hydrolytic degradation rates were measured. Molecular weight change was determined by size exclusion chromatography and solution viscosity. Calculated radiochemical yields suggest that the primary effects of irradiation are random chain scission. A clear relationship between properties and molecular weight was established and is used to interpret the relative effects of the two sterilization procedures. With -irradiation scission processes cause a fall in molecular weight in both batches whereas ETO only significantly affected the lower molecular weight batch. It is thought that the ETO effects are determined by moisture diffusion rates which are molecular weight dependent, and therefore property changes with the higher molecular weight material are more limited.     

A review of some elements in the history of grain boundaries,centered on Georges Friedel,the coincident ‘site’ lattice and the twin index

I trace the origin of the inverse density of coincident lattice sites to Georges Friedel in 1904 (Études sur les groupements cristallins). Georges Friedel (1865–1933), son of the Chemist and Mineralogist Charles Friedel, called this parameter the twin (macle) index and defined it as the ratio of the total number of nodes of the primitive lattice to the number of coincident nodes restored by the twin operation. Friedel’s 1904 ‘multiple lattice’ is our Coincident Site Lattice. Georges Friedel introduced the Σ symbol in 1920 (Contribution à l’étude géométrique des macles) as the ratio of the volume of a (not necessarily primitive) multiple cell to the volume of the primitive cell. G. Friedel provides his reader with several formulae which, in the cubic case, give Σ = h ² + k ² + l ² (h, k and l being the indices of the twin plane) and a twin index I equal to Σ if Σ is odd, equal to Σ/2 if Σ is even. All these definitions and formulae are included in the 1926 version of his celebrated textbook ‘Leçons de Cristallographie’. Georges Friedel was also concerned with the ‘material lattice’ (the crystal structure) behind the mathematical lattice, but besides his contributions to the study of liquid crystals, Georges Friedel was mainly interested in Mineralogy and not in Metallurgy. This may explain why Walter Rosenhain apparently never knew of Friedel’s work and why Kronberg and Wilson had to re-discover the importance of the density of coincidence sites, at the atomistic level, in 1949 in copper. Georges Friedel’s grandson, Jacques Friedel, made the first numerical estimate of interface energies using interatomic potentials that same year but only published these results in 1953. Knowledge of these past events may help us to better understand the present theories and, hopefully, to develop our future understanding more efficiently.     

The effect of rapid solidification on the structure, decomposition behavior, electrical and mechanical properties of the Sn–Cd binary alloys

A group of rapidly solidified Sn–Cd alloys has been prepared by a melt-spinning technique. X-ray diffraction, microstructure, and differential thermal analysis have been carried out. Youngs modulus and internal friction have been measured, and the temperature dependence of resistivity has been evaluated. The results show a modification in both the microstructure and decomposition behavior. Also, an interesting connection between Youngs modulus and the axial ratio (c/a) of the unit cell of the -Sn was found in which Youngs modulus increases by increasing the axial ratio (c/a). It was found also that the internal friction increases on increasing the Cd concentration.     

Determination of the reduced matrix of the piezoelectric, dielectric, and elastic material constants for a piezoelectric material with C∞ symmetry

We present a procedure for determining the reduced piezoelectric, dielectric, and elastic coefficients for a C(∞) material, including losses, from a single disk sample. Measurements have been made on a Navy III lead zirconate titanate (PZT) ceramic sample and the reduced matrix of coefficients for this material is presented. In addition, we present the transform equations, in reduced matrix form, to other consistent material constant sets. We discuss the propagation of errors in going from one material data set to another and look at the limitations inherent in direct calculations of other useful coefficients from the data.     

Investigation of the Dynamics of Evaporation of Condensed Bodies on the Basis of the Law of Spectral‐Radiation Intensity of Particles

The fundamentals of radiation theory and the mechanism of evaporation of condensed bodies are presented. The distribution functions of particles of a body by energies and by the intensity of their transition from one energy level to another in the process of evaporation have been obtained based on the law of spectralradiation intensity of the body particles. The temperature dependence of the resulting vapor flow on the outer surface of a massive condensed body and a thin layer in equilibrium and nonequilibrium states, which, in the limit, transforms to the known Hertz–Knudsen formula, has been found.     

Characterization of the tableting properties of β-cyclodextrin and the effects of processing variables on inclusion complex formation,compactibility and dissolution

Abstract

The tableting properties of a number of commercially available β-cyclodextrins were characterized. Fluidity was insufficient for routine direct compression. Compactibility varied by source but was excellent. Lubrication requirements were minimal. An inclusion complex of β-cyclodextrin/Progesterone was formed and the tableting properties of the complex were compared to those of a physical mixture in both directly compressed and wet granulated products. Inclusion complexes spontaneously formed during wet granulation processing. Substantial differences in tableting properties were found as processing variables were changed. β-cyclodextrin exhibits considerable promise as a standard filler binder in tableting.     

Study on the evolution of the microstructure,phase composition,three-dimensional morphology,and hardness in the solution treatment of Mg−7.80Gd−2.43Y−0.38Zr alloy

The evolution of the microstructure, phase composition, three-dimensional morphology, and hardness of Mg−7.80Gd−2.43Y−0.38Zr (wt.%) alloys during solution treatment at 480 °C is investigated using scanning electron microscopy (SEM), electron probe micro-analyzer, nanoindentation, and x-ray tomography. The as-cast alloy consists of an α-Mg matrix phase and divorced eutectics, including the secondary and the supersaturated magnesium phases. The chemical composition of the secondary phase is similar to that of Mg_7.22(Gd, Y), and the nanoindentation hardness of the secondary phase is significantly higher than that of the α-Mg matrix phase, according to the energy-dispersive spectroscopic and nanoindentation analyses. The three-dimensional morphology and quantitative information, such as the number and volume fraction of the secondary phases during the solution treatment, are discussed in detail. A large number of small acicular secondary phases are found near the large secondary phase after solution treatment at 480 °C for 1 h, while the acicular phase disappears completely after 2 h. The secondary phase dissolves into the α-Mg matrix after solution treatment for 8 h, and the solution-treated alloy primarily consists of an α-Mg matrix phase and a cuboid-shaped phase, which was identified as (Gd,Y)H₂.