Histological diagnosis in aspiration curettage]

Gentamicin sulfate was given to rabbits for four weeks in two dosage regimens, either 4 or 8 mg/kg subcutaneously twice a day. Two of the seven animals in each group regained nearly normal renal function after a transient rise in the level of serum creatinine, but the remainder developed severe renal failure leading to the death of all but one of these rabbits. None of the animals showed significant hyperglycemia, buy glycosuria appeared in all and was significantly correlated with the extent of renal damage. These findings demonstrate gentamicin-induced derangement of proximal tubular function and thus amplify the previously demonstrated histologic changes due to the drug. When the drug was administered twice daily, there was marked nephrotoxicity in rabbits given dosages of gentamicin only slightly higher than those employed clinically.     

Capillary electrophoresis as analytical method for active ingredient determination in cosmetic matrices

Capillary electrophoresis (CE) has emerged as an important technique applied to analytical chemistry and quality control. In the cosmetic field ascorbic acid is important for soothing, bleaching and for its scavenger activity. Ascorbic acid is responsible for great number of physiological oxidations in electron transfer reactions. Many natural substances have a functional activity which is very difficult to preserve or even to prolong with the requested and expected treatment. This paper reports the study of capillary electrophoresis for the characterization of ascorbic acid as the active ingredient in a new delivery system that is able to preserve stability and to prolong release of ascorbic acid according to the concentration needs of a cosmetic formulation.     

Determination of Ozone In Water By The Indigo Method: A Submitted Standard Method

The indigo method for the determination of ozone as formulated for the new Swiss Standard Methods for Drinking Water Analysis is presented with an international list of suppliers of indigo trisulfonate. Such a new selective and simple method will be needed in many countries because current methods for ozone analysis are generally non-selective when applied on real drinking waters or wastewaters.

Ozone rapidly and stoichiometrically decolorizes indigo trisulfonate in acidic solution. The decrease in absorbance at 600 nm is linear with ozone residual and is 0.42±0.01 cm^-1 per mg/L (Δ = 20,000 L Mol^-1cm^-1 at 600 nm when compared to the uv absorption of pure ozone of = 2900 L Mol^-1cm^-1 at 258 nm). The limits of detection are 2 µg/L for an instrumental and 10 µg/L for a visual field method.     

Rate constants of reactions of ozone with organic and inorganic compounds in water—II: Dissociating organic compounds

Rate constants of reactions of ozone with non-ionized solutes, such as aliphatic alcohols, olefins, chlorosubstituted ethylenes, substituted benzenes and carbohydrates, have been determined from the absolute rates with which ozone reacts in the presence of various concentrations of these compounds in water. They have been tested by comparison with the relative rates by which pairs of these solutes are transformed by ozone. Different experimental methods have been developed to determine such rate constants in the range from 10⁻² to 10⁵ M⁻¹ s⁻¹. Interferences between the direct reactions of ozone and reactions due to its preliminary decomposition to secondary oxidants could be eliminated. The kinetics of all the reactions studied are first order with respect to ozone and solute concentration. The rate constants of many types of organic compounds in water are of the same order of magnitude as in organic solvents. Substituted benzenes, however, react in water about 100 times faster. They obey a linear free energy relationship with p = −3.1 when based on δ_p⁺ values. Comparisons of rate constants with chemical structures of the reacting groups show that all reactions of ozone are highly selective and electrophilic. The kinetic data allow explanation of the chemical effects of ozone observed in water treatment practice.     

The flow of phosphorus in food production and consumption -- Linköping, Sweden, 1870-2000

Phosphorus is an important substance for agricultural production of food. Being a limited resource, it is of great interest for regional, as well as global food security. At the same time it presents a pollution problem for the aquatic environment in Sweden since it contributes to eutrophication of surface waters and the Baltic Sea. This study analyses the flow of phosphorus based on consumption and production of food for an average inhabitant of a Swedish city, Link?ping, from 1870 until 2000. The study shows the changes in flows within the system of production and consumption of food, as well as between the different processes in this system, such as agriculture, food processing, consumption and waste handling, and output flows to the environment. The main changes in this system over time are a) the increasing flow of phosphorus reaching the consumer and hence the waste handling system, b) the increase in the flow of products from animal production, which mainly causes the increase in (a), and most notably c) the increased input of chemical fertilizer.     

Quantification of structural and material failure mechanisms across different length scales: from instability to brittle-ductile transitions

Structures may fail due to a myriad of different causes. Often, distinction is made between structural and material failure, that means a structure can fail, while the material is still intact (this is the case in so-called stability loss), or the material fails, which, as consequence, may lead to structural failure. The material behavior may turn out difficult to be mathematically guessed at the macro-level. On the other hand, a lot may be known about the chemistry or the microstructure of the material of interest. Herein, we aim at categorizing different scenarios which in the end provoke structural failure, discussing various cases investigated during the last five years, at the Institute for Mechanics of Materials and Structures of Vienna University of Technology: A well-chosen eigenvalue problem shows considerable potential for categorizing stability loss. We then turn to complex composite materials with a hierarchical organization, where a single constituent dominates the overall quasi-brittle failure of the material, such as lignin in wood and wood products, or the cement–water reaction products (shortly called hydrates) in cement-based materials. The picture changes if the first inelastically behaving constituent is related to ductile load carrying, then the loads within the microstructure are re-distributed before the overall material fails: this turns out to be the case in bone. Finally, due to highly confined multiaxial stress states, the elastic portion of the overall energy invested into the material may become negligible—and then yield design analysis employed on material volumes gives an idea of the highly ductile behavior of complex confined materials, such as asphalt. What integrates all the reported cases is the high capacity of mature mathematical and mechanical formulations to reveal the intricate, yet decipherable nature of the (continuum) mechanics of materials and structures.     

Retracted and replaced: Enabling technologies for the ‘always best connected’ concept

The following article from Wireless Communications and Mobile Computing ‘Enabling technologies for the “always best connected” concept’ by N. Passas, S. Paskalis, A. Kaloxylos, F. Bader, R. Narcisi, E. Tsontsis, A. S. Jahan and H. Aghvami published online on 23 August 2004 in Wiley InterScience ( www.interscience.wiley.com ) and in print on 2 March 2005 in Wireless Communications and Mobile Computing Volume 5 Issue 2 pp 175–191 has been retracted and replaced by agreement between the authors, the journal editors and John Wiley & Sons, Ltd. The article has been retracted due to the omission of the following contributing authors: M. O'Droma and I. Ganchev who are included as contributing authors in the replacement article. (DOI: 10.1002/wcm.392 )