Preparation and stability of cosmetic formulations with an anti-aging peptide

Wrinkling of the skin is the most obvious sign of deterioration of the human body with age. This process involves a number of genetic, constitutional, hormonal, nutritional, and environmental factors, in addition to the influence of frequently repeated facial movements during laughing, smoking, etc. This article reviews the physiological basis and mechanism of action of the active cosmetic ingredient acetyl hexapeptide-8 (Argireline®). We prepared two formulations: an emulsion with an external aqueous phase for normal to dry skin, and a gel for oily skin. Laboratory analyses, rheology tests and in vitro release assays were used to evaluate the stability of these formulations for cosmetic treatment.     

Determination of thermal conductivity, specific heat and thermal diffusivity of albacore (Thunnus alalunga)

Summary Thermal conductivity values of dried and raw albacore muscle were determined by means of a thermal conductivity probe. A microcalorimetric method and differential scanning calorimetry were used to obtain specific heat values of dried and raw muscle and of dried muscle, respectively, at several temperatures between 20 °C and 150 °C. Thermal diffusivity was calculated during precooking of headed and eviscerated albacore and during heat treatment of cylindrical cans filled with edible parts of precooked albacore. The experimental temperature curves were adjusted to those obtained from an analytical solution of the heat transmission equation assuming cylindrical geometry, conduction mechanism and constant thermal properties of the material. From experimental thermal conductivity, specific heat and density values, thermal diffusivity values of 1.43 x 10^–7 m²/s with perpendicular heat flux to fibers and 1.65 x 10^–7 m²/s with parallel heat flux were calculated for raw albacore. The values of apparent thermal diffusivity were found 1.51 x 10^–7 m²/s and 1.29 x 10^–7 m²/s during precooking and heat treatment of cans, respectively.

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Bestimmung der Wärmeleitfähigkeit, der spezifischen Wärme und der Wärmediffusion in Thunfisch (Thunnus alalunga)

Zusammenfassung Die Wärmeleifähigkeit von getrocknetem und frischem Thunfisch wurde durch eingehende Untersuchungen bestimmt. Hierfür wurde eine mikorcalorimetrische Methode sowie die Differentialabtast-Calorimetrie angewandt, um damit die Werte für die spezifische Wärme des getrockneten und des frischen Muskels bei Temperaturen zwischen 20 °C und 150 °C zu bestimmen. Die Wärmediffusion wurde während des Vorkochens des ausgeweideten Thunfisches (aber mit Kopt) und während der Erhitzung der in Dosen abgefüllten eßbaren Teile des vorgekochten Thunfisches berechnet. Die experimentell erhaltenen Temperaturkurven wurden mit dene aus der analytischen Lösung der Wärmeübertragungsgleichung erhaltenen (bei Annahme einer cylindrischen Geometrie), des Leitfähigkeitsmechanismus und den konstanten thermischen Eigenschaften des Materials abgestimmt. Aus den experimentell gefundenen Werten wurde eine Wärmediffusion von 1,65·10^–7 m²/s bei parallelem Wärmefluß für rohen Thunfisch gemessen, während beim Vorkochen bzw. bei Erhitzung von Dosen diese Werte bei 1,51·10^–7 m²/s bzw. 1,29·10^–7 m²/s lagen.

     

Determination of ternary solutions concentration in liquid–liquid extraction by the use of attenuated total reflectance‐Fourier transform infrared spectroscopy and multivariate data analysis

A simple and rapid Fourier transform infrared‐attenuated total reflectance (FTIR‐ATR) spectroscopic chemometric method was developed to determine the concentration of solute and solvent in the raffinate layer in a liquid–liquid extraction (LLE) process using partial least squares (PLS) regression. Five type I extraction systems were used with different solute–solvent affinity. The developed model (correlation coefficient from 0.91 to 0.99) was validated with known concentration samples, and in all cases the difference was not larger than 0.5%w. The LLE for the five extraction systems was carried out in a three‐stage crosscurrent extraction process, quantifying the solute and solvent with the chemometric model developed. The results were used to calculate the stage and overall stage efficiencies for the five systems. This method showed to be fast and precise for the quantification of ternary systems in LLE.     

Enhanced quality and safety during on-board chilled storage of fish species captured in the Grand Sole North Atlantic fishing bank

The Grand Sole North Atlantic fishing bank is exploited by several European countries, although time lapsed between catch and destiny arrival can attain 15 days. In the present work, the use of slurry ice (SI) system was investigated for the on-board storage of chilled fish and carried out in parallel to traditional flake icing (FI). Three species (hake, Merluccius merluccius; angler, Lophius piscatorius; ray, Raja clavata) widely present in the mentioned bank were studied. A lower (p < 0.05) microbial (aerobes, psychrotrophes, proteolytics) development was observed in fishes subjected to SI system than in their counterpart specimens stored under FI. This correlated with lower (p < 0.05) productions of trimethylamine (hake and angler) and total volatile bases (ray) and extended shelf-life for fish species kept under SI conditions. In summary, on-board employment of SI can provide higher quality and safety products to consumer and allow increased commercial values while unloading and sale.     

Direct adhesion force measurements between E. coli and human uroepithelial cells in cranberry juice cocktail

Scope: Atomic force microscopy (AFM) was used to directly measure the nanoscale adhesion forces between P‐fimbriated Escherichia coli (E. coli) and human uroepithelial cells exposed to cranberry juice, in order to reveal the molecular mechanisms by which cranberry juice cocktail (CJC) affects bacterial adhesion. Methods and results: Bacterial cell probes were created by attaching P‐fimbriated E. coli HB101pDC1 or non‐fimbriated E. coli HB101 to AFM tips, and the cellular probes were used to directly measure the adhesion forces between E. coli and uroepithelial cells in solutions containing: 0, 2.5, 5, 10, and 27 wt% CJC. Macroscale attachment of E. coli to uroepithelial cells was measured and correlated to nanoscale adhesion force measurements. The adhesion forces between E. coli HB101pDC1 and uroepithelial cells were dose‐dependent, and decreased from 9.32±2.37 nN in the absence of CJC to 0.75±0.19 nN in 27 wt% CJC. Adhesion forces between E. coli HB101 and uroepithelial cells were low in buffer (0.74±0.18 nN), and did not change significantly in CJC (0.78±0.18 nN in 27 wt% CJC; P=0.794). Conclusion: Our study shows that CJC significantly decreases nanoscale adhesion forces between P‐fimbriated E. coli and uroepithelial cells.     

Checking the reliability of socket based communication software

Locating potential execution errors in software is gaining more attention due to the economical and social impact of software crashes. For this reason, many software engineers are now in need of automatic debugging tools in their development environments. Fortunately, the work on formal method technologies during the past 25 years has produced a number of techniques and tools that can make the debugging task almost automatic, using standard computer equipment and with a reasonable response time. In particular, verification techniques like model-checking that were traditionally employed for formal specifications of the software can now be directly employed for real source code. Due to the maturity of model-checking technology, its application to real software is now a promising and realistic approach to increase software quality. There are already some successful examples of tools for this purpose that mainly work with self-contained programs (programs with no system-calls). However, verifying software that uses external functionality provided by the operating system via API s is currently a challenging trend. In this paper, we propose a method for using the tool spin to verify C software systems that use services provided by the operating system thorough a given API. Our approach consists in building a model of the underlying operating system to be joined with the original C code in order to obtain the input for the model checker spin. The whole modeling process is transparent for the C programmer, because it is performed automatically and without special syntactic constraints in the input C code. Regarding verification, we consider optimization techniques suitable for this application domain, and we guarantee that the system only reports potential (non-spurious) errors. We present the applicability of our approach focusing on the verification of distributed software systems that use the API Socket and the network protocol stack TCP/IP for communications. In order to ensure correctness, we define and use a formal semantics of the API to conduct the construction of correct models.     

Investigation of the energy transfer mechanism in OLEDs based on a new terbium β-diketonate complex

This study is focused on the contribution of radiative and non-radiative processes to the electroluminescence emission of OLEDs based on a new terbium(III) complex: {Tris(acetylacetonate)[1,2,5]thiadiazole[3,4-f][1,10]phenanthroline}terbium(III) or [Tb(ACAC)₃TDZP]. The effects of the energy transfer mechanism are discussed based on photoluminescence and electroluminescence measurements. The terbium complex showed an intense photoluminescence with high color purity in the green region, characteristics of the Tb(III) ion narrow line transitions. However, when used in a double-layer OLED its electroluminescence showed an orange broad band emission which can be attributed to the electrophosphorescence of the ligands and to an inefficient energy transfer from the organic ligand to the Tb(III) ion. Alternatively, devices with a Tb(III) complex acting as a dopant (7.6%) in a matrix of CBP used as the active layer showed an improvement in the energy transfer process, resulting in the appearance of the characteristic emission lines of the Tb(III) ion.     

Analysis of fish and squid myofibrillar proteins by capillary sodium dodecyl sulfate gel electrophoresis: actin and myosin quantification

 A capillary electrophoretic method for the separation and quantification of fish and squid myofibrillar proteins was developed. The method uses sodium dodecyl sulfate and β-mercaptoethanol for solubilization and analysis of myofibrillar protein subunits. The separation of the different polypeptides is achieved by the sieving effect of the gel inside the capillary. A calibration curve for myosin heavy chain and actin UV absorbance quantification of these proteins was developed. Received: 2 November 1999 / Revised version: 16 February 2000