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Hydrogels are made of a 3D network of crosslinked hydrophilic polymers that can absorb and retain large amounts of water and still remain insoluble ([1]) . Using different chemical and [...]

Gelatin sensitized with tot'hema and eosin (compounds used in medical therapy) appears to be an excellent material for microlens fabrication. Lenses are produced by irradiation with a 532 nm laser beam. Aspheric concave lenses are formed rapidly with low power radiation. The lens profile is analyzed, as well as imaging properties. Physics of lens formation is also proposed. All material constituents are nonpoisonous, resulting in an environmentally safe, low toxicity material. OCIS codes: 220.4000, 080.3630, 160.5470, 160.4670, 160.4760.

This work introduces a new and nondestructive methodology for the collection and chemical identification of latent fingermarks. The main challenges of this work were (a) to find an appropriate medium to lift fingermarks from various surfaces and (b) to develop an analytical approach for the identification of small quantities of sample while avoiding spectroscopic interference from the lifting media. Two different lifting media were evaluated and analyzed by ATR-FT-IR spectroscopic imaging, which affords inherent chemical specificity with rapid acquisition of data. This is the first time that chemical images of latent fingermarks collected with gel lifters from different surfaces have been obtained. Spatially resolved chemical images from different depths within the same sample were obtained using ATR-FT-IR imaging with a variable angle ATR accessory to minimize interference from the substrate. The possibility of obtaining, through the developed methodology, three-dimensional depth profiles of surface contaminants collected with the lifting gel shows great potential for the investigation of samples for forensic interest.

Byline: M. Moldao-Martins (1), S. M. Beirao-da-Costa (1), M. L. Beirao-da-Costa (1) Keywords: 'Bravo de Esmolfe' apple; Edible coatings; Texture; Colour Weight loss Abstract: Apples (Malus domestica Borkh cv Bravo de Esmolfe) were coated with a polysaccharide-based or a protein-based coating. Alginate and gelatine coatings at different concentrations, plasticized with glycerol and carboxymethylcellulose (CMC) plus sucroesters coatings plasticized with mono/diglycerides were tested. The effects of those coatings on the storage stability were followed by measurements of peel and pulp firmness, external L* a* and b* colour values, solid soluble content and weight loss during storage at 20 degC for three months. The 2 wt% alginate and 5 wt% gelatine coatings significantly reduced weight loss, thus maintaining fruit firmness and thereby preserving fruit freshness. The effects of those coatings also include the improvement of appearance and imparted an attractive natural-looking sheen to the fruit. Author Affiliation: (1) Microbiological and Agriculture Industries Center/DAIAT/Instituto Superior de Agronomia, Tapada da Ajuda, 1349 017, Lisbon, Portugal Article History: Received Date: 20/03/2003 Online Date: 16/08/2003

Paleogenetic investigations of ancient DNA extracted from fossil material is for many reasons susceptible to falsification by the presence of more recent contamination from several sources. Gelatine-based bone glue that has been used extensively for nearly two centuries by curators to preserve hard tissues contributes nonauthentic DNA to paleontological material. This fact has been frequently neglected and is barely mentioned in the literature. Now paleogeneticists, curators, and conservators are faced with the problem that treatment of samples with adhesives and consolidants for conservatory purposes has seldom been recorded. Here, we show that racemization of amino acids, and in particular serine, is an excellent indicator for the treatment of paleontological samples with glue. KEY WORDS amino acid; paleogenetics; racemization; skeletal remains

Silver halide sensitized gelatin (SHSG) holograms are similar to holograms recorded in dichromated gelatin (DCG), the main recording material for holographic optical elements (HOEs). The drawback of DCG is its low energetic sensitivity and limited spectral response. Silver halide materials can be processed in such a way that the final hologram will have properties like a DCG hologram. Recently this technique has become more interesting since the introduction of new ultra-fine-grain silver halide (AgHal) emulsions. In particular, high spatial-frequency fringes associated with HOEs of the reflection type are difficult to construct when SHSG processing methods are employed. Therefore an optimized processing technique for reflection HOEs recorded in the new AgHal materials is introduced. Diffraction efficiencies over 90% can be obtained repeatably for reflection diffraction gratings. Understanding the importance of a selective hardening process has made it possible to obtain results similar to conventional DCG processing. The main advantage of the SHSG process is that high-sensitivity recording can be performed with laser wavelengths anywhere within the visible spectrum. This simplifies the manufacturing of high-quality, large-format HOEs, also including high-quality display holograms of the reflection type in both monochrome and full color. OCIS codes: 090.2890, 090.2900, 230.1950, 040.5190, 350.5130, 050.7330.

Gelatin films were prepared

The non-antifungal, biocompatible peptide fragments from denatured type I collagen (gelatin) restrict the adherence of Candida albicans yeast cells to extracellular matrix glycoproteins. This helps in preventing diseases due to albicans. A 100% decrease in fungal adherence to type I collagen is obtained by the use of a gelatin peptide with 47 amino acids.

We present a method for increasing the bandwidth of reflection holograms in dichromated gelatin. The recording plate has two dichromated-gelatin layers of different hardness so that their shrinkage at the end of processing is different. We use this method for doubling the bandwidth of holographic mirrors that are designed for solar UV energy concentration. We also study the superposition of two double-layer holograms, which results in UV holographic mirrors with a bandwidth of 60 nm.

The hydrophilic protein-like egg albumin gelatin is already successfully used in various fields such as pharmaceuticals and environmental analysis but can also be useful as a binding and stabilization agent. Silver(I) and gold(III) ions are among the metals that can be stabilized through gelatin binding and the produced silver and gold sol solutions have a long shelf-life and can still be analyzed using surface-enhanced Raman Scattering. Therefore, gelatin may have therapeutic benefits as well as its other chemistry applications.

The use of soft gelatin capsules of food ingredients in food products in the United Kingdom has failed to reach its potential level despite the large number of associated benefits. Encapsulation offers portion control, biodegradability and disposability, improved appearance, longer shelf-life and edibility. Capsules preserve the aroma, flavour and freshness of the ingredients. Consumers surveyed responded positively to the use of food capsules, with products such as encapsulated chicken stock well-received for providing a lump-free ingredient distribution and rapid dissolution time.

The different effects on the shelf life of fresh meat by the use of gelatin coating, which is supposed to extend the shelf life, are presented.

Tissue engineering is the field of biomedicine that helps to restore or replace organs and tissues that are damaged, affected by disease, suffering from injury or congenital anomaly. It can [...]

An experiment showing the effect of mixing copper with gold is presented. For the purpose, jelly and gelatin are used as the ingredients instead of copper and gold.

Technology push and marketing pull, the 'Find a need and fill it' concept, and their interplay are discussed in relation to product development involving cranberries, eggs, yogurt and veal. In each of these products some new developments have been made based both on technological advances and on the needs consumers perceive, largely related to health issues.

The properties of light reflection, refraction and total internal reflection can be explored through an experiment that uses gelatin to serve as a lens, prism or light guide. Students in introductory physics courses can cut various shapes from sheets of gelatin and form optical components. Colored gelatin can also used to makes lenses that double as filters.

The authors provide techniques for constructing optical equipment with gelatin using molds. Mold construction techniques, procedures, and use of such elements to measure refraction are described.