Contents: Production and Applications of Chitin and Chitosan Krill as a promising raw material for the production of chitin in Europe - Containerized plant for producing chitin - Preparation and characterization of chitosan from Mucorales - Chitosan from Absidia orchidis - Scaling up of lactic acid fermentation of prawn wastes in packed-bed column reactor for chitin recovery - Preparation of chitin by acetic acid fermentation - Inter-source reproducibility of the chitin deacetylation process - Comparative analysis of chitosans from insects and crustacea - Effect of the rate of deacetylation on the physico-chemical properties of cuttlefish chitosan - Deacetylation of chitin by fungal enzymes - Production of partially degraded chitosan with desired molecular weight - Chitin-containing materials Mycoton for wounds treatment - Biological activity of selected forms of chitosan - Application of chitosan on the preservation quality of cut flowers - Preparation and characterization of chitosan films: application in cell cultures - Transport phenomena in chitin gels - Symplex membranes of chitosan and sulphoethylcellulose - Preparation and use of chitosan-Ca pectinate pellets - Bioseparation of protein from cheese whey by using chitosan coagulation and ultrafiltration membranes - Preparation of silk fibroin/chitosan fiber - Preparation of paper sheets containing microcrystalline chitosan - Applications of chitosan in textile printing - Permanent modification of fibrous materials with biopolymers - Ion exchanger from chitosan - Chitosan in waste water treatment - The immobilization of tyrosinase on chitin and chitosan and its possible use in wastewater treatment - Utilization of modified chitosan in aqueous system treatment Biomaterials Chemical and preclinical studies on 6-oxychitin - Diverse biological effects of fungal chitin-glucan complex - Effect of concentration of neutralizing agent on chitosan membrane properties - Preliminary investigation of the compatibility of a chitosan-based peritoneal dialysis solution - Influence of chitosan on the growth of several cellular lines - A new chitosan containing phosphonic group with chelating properties - Biocompatibility of chitin materials using cell culture method Oral Administration of Chitosan Recent results in the oral administration of chitosan - Reduction of absorption of dietary lipids and cholesterol by chitosan, its derivatives and special formulations - Chitosan in weight reduction: results from a large scale consumer study - Conformation of chitosan ascorbic acid salt - Trimethylated chitosans as safe absorption enhancers for transmucosal delivery of peptide drugs - Chitosan derivates as intestinal penetration enhancers of the peptide drug buserelin in vivo and in vitro - Chitosan microparticles for oral vaccination: optimization and characterization - Effect of chitosan in enhancing drug delivery across buccal mucosa - Influence of chitosans on permeability of human intestinal epithelial (Caco-2) cells: The effect of molecular weight, degree of deacetylation and exposure time - Oral polymeric N-acetyl-D-glucosamine as potential treatment for patients with osteoarthritis - Clinicoimmunological efficiency of the chitin-containing drug Mycoton in complex treatment of a chronic hepatitis - Interactions of chitin, chitosan, N-laurylchitosan, and N-dimethylaminopropyl chitosan with olive oil - The chitin-containing preparation Mycoton in a pediatric gastroenterology case - Antifungal activity and release behaviour of cross-linked chitosan films incorporated with chlorhexidine gluconate - Release of N-acetyl-D-glucosamine from chitosan in saliva - Physical and Physicochemical Properties Recent approach of metal binding by chitosan and derivatives - As(V) sorption on molybdate-impregnated chitosan gel beads (MICB) - Influence of medium pH on the biosorption of heavy metals by chitin-containing sorbent Mycoton - Comparative studies on molecular chain parameters of polyelectrolyte chains: the stiffness parameter B and temperature coefficient of intrinsic viscosity of chitosans and poly(diallyldimethylammonium chloride) - Crystalline behavior of chitosan - The relationship between the crystallinity and degree of deacetylation of chitin from crab shell - Reversible water-swellable chitin gel: modulation of swellability - Syneresis aspects of chitosan based gel systems - In situ chitosan gelation using the enzyme tyrosinase - Preparation and characterization of controlling pore size chitosan membranes - Fabrication of porous chitin matrices - Changes of polydispersity and limited molecular weight of ultrasonic treated chitosan - A statistical evaluation of IR spectroscopic methods to determine the degree of acetylation of ?-chitin and chitosan - Products of alkaline hydrolysis of dibutyrylchitin: chemical composition and DSC investigation - Chitosan emulsification properties Chemistry of Chitin and Chitosan Chemically modified chitinous materials: preparation and properties - Progress on the modification of chitosan - The graft copolymerization of chitosan with methyl acrylate using an organohalide-manganese carbonyl coinitiator system - Grafting of 4-vinylpyridine, maleic acid and maleic anhydride onto chitin and chitosan - Peptide synthesis on chitosan/chitin - Graft copolymerization of methyl methacrylate onto mercapto-chitin - Thermal depolymerization of chitosan salts - Radiolysis and sonolysis of chitosan - two convenient techniques for a controlled reduction of molecular weight - Thermal and UV degradation of chitosan - Heat-induced physicochemical changes in highly deacetylated chitosan - Chitosan fiber and its chemical N-modification at the fiber state for use as functional materials - Preparation of a fiber reactive chitosan derivative with enhanced microbial activity - Chromatographic separation of rare earths with complexane types of chemically modified chitosan - The effects of detergents on chitosan - Chitosan-alginate PEC films prepared from chitosan of different molecular weights - Enzymology of Chitin and Chitosan Biosynthesis and Degradation Enzymes of chitin metabolism for the design of antifungals - Enzymatic degradation of chitin by microorganisms - Kinetic behaviours of chitinase isozymes - An acidic chitinase from gizzards of broiler (Gallus gallus L.) - On the contribution of conserved acidic residues to catalytic activity of chitinase B from Serratia marcescens - Detection, isolation and preliminary characterisation of a new hyperthermophilic chitinase from the anaerobic archaebacterium Thermococcus chitonophagus - Biochemical and genetic engineering studies on chitinase A from Serratia marcescens - Induction of chitinase production by Serratia marcescens, using a synthetic N-acetylglucosamine derivative - Libraries of chito-oligosaccharides of mixed acetylation patterns and their interactions with chitinases - Approaches towards the design of new chitinase inhibitors - Allosamidin inhibits the fragmentation and autolysis of Penicillium chrysogenum - cDNA encoding chitinase in the midge, Chironomus tentans - Extraction and purification of chitosanase from Bacillus cereus - Substrate binding mechanism of chitosanase from Streptomyces sp. N174 - Chitosanase-catalyzed hydrolysis of 4-methylumbelliferyl ?-chitotrioside - A rust fungus turns chitin into chitosan upon plant tissue colonization to evade recognition by the host - Antibiotic kanosamine is an inhibitor of chitin biosynthesis in fungi - PCR amplification of chitin deacetylase genes - Amplification of antifungal effect of GlcN-6-P synthase and chitin synthase inhibitors - ?-N-Acetylhexosaminidases: two enzyme families, two mechanisms - Purification and characterisation of chitin deacetylase from Absidia orchidis - Effect of aluminium ion on hydrolysis reaction of carboxymethyl- and dihydroxypropyl-chitin with lysozyme - Structure and function relatioship of human N-acetyl-D-glucosamine 2-epimerase (renin binding protein) - Identification of active site residue(s)

Deuteration effects on the vibronic structure of the emission and excitation spectra of triangular [4]phenylene (D3h[4]phenylene) were studied using laser-excited Shpolskii spectroscopy (LESS) in an octane matrix at 4.2 K. For correct assignment of the vibrational modes, the experimental results were compared with calculated frequencies (B3LYP/6-31G*). CH vibrations were identified by their characteristic isotopic shifts in the spectra of deuterated triangular [4]phenylenes. Two CC stretching modes, at 100 cm–1 and 1176 cm–1, suitable as probes for bond strength changes in the excited state, were identified. The isotope effect on the internal conversion rates of triangular [4]phenylene was evaluated from measurements of temperature dependent lifetime. Isotope dependency and the magnitude of the internal conversion rates indicate that internal conversion in triangular [4]phenylene is most likely induced by CH vibrations. The results obtained by LESS and lifetime measurements were compared with PM3 PECI calculations of the excited state structure. The theoretical results and the relation between ground and excited state vibration energies of the 1176 cm–1 probe vibration indicate a reduction of bond alternation of the central cyclohexatriene ring in the excited state.

In the present study, photophysical properties of [N]phenylenes were studied by means of stationary and time-resolved absorption and fluorescence spectroscopy (in THF at room temperature). For biphenylene (1) and linear [3]phenylene (2a), internal conversion (IC) with quantum yields ΦIC > 0.99 is by far the dominant mechanism of S1 state deactivation. Angular [3]phenylene (3a), the zig-zag [4]- and [5]phenylenes (3b), (3c), and the triangular [4]phenylene (4) show fluorescence emission with fluorescence quantum yieds and lifetimes between ΦF = 0.07 for (3a) and 0.21 for (3c) and τF = 20 ns for (3a) and 81 ns for (4). Also, compounds (3) and (4) exhibit triplet formation upon photoexcitation with quantum yields as high as ΦISC = 0.45 for (3c). The strong differences in the fluorescence properties and in the triplet fromation efficiencies between (1) and (2a) on one hand and (3) and (4) on the other are related to the remarkable variation of the internal conversion (IC) rate constants kIC. A tentative classification of (1) and (2a) as “fast IC compounds”, with kIC > 109 s-1, and of (3) and (4) as “slow IC compounds”, with kIC ≈ 107 s-1, is suggested. This classification cannot simply be related to Hückel’s rule-type concepts of aromaticity, because the group of “fast IC compounds” consists of “antiaromatic” (1) and “aromatic” (2a), and the group of “slow IC compounds” consists of “antiaromatic” (3b), (4) and “aromatic” (3a), (3c). The IC in the [N]phenylenes is discussed within the framework of the so-called energy gap law established for non-radiative processes in benzenoid hydrocarbons.

The salivary glands of the blowfly were injected with luminescent oxygen-sensitive microbeads. The changes in oxygen content within individual gland tubules during hormone-induced secretory activity were quantified. The measurements are based on an upgraded phase-modulation technique, where the phase shift of the sensor phosphorescence is determined independently from concentration and background signals. We show that the combination of a lock-in amplifier with a fluorescence microscope results in a convenient setup to measure oxygen concentrations within living animal tissues at the cellular level.

Quantum dots (QDs) are common as luminescing markers for imaging in biological applications because their optical properties seem to be inert against their surrounding solvent. This, together with broad and strong absorption bands and intense, sharp tuneable luminescence bands, makes them interesting candidates for methods utilizing Forster Resonance Energy Transfer (FRET), e. g. for sensitive homogeneous fluoroimmunoassays (FIA). In this work we demonstrate energy transfer from Eu3+-trisbipyridin (Eu-TBP) donors to CdSe-ZnS-QD acceptors in solutions with and without serum. The QDs are commercially available CdSe-ZnS core-shell particles emitting at 655 nm (QD655). The FRET system was achieved by the binding of the streptavidin conjugated donors with the biotin conjugated acceptors. After excitation of Eu-TBP and as result of the energy transfer, the luminescence of the QD655 acceptors also showed lengthened decay times like the donors. The energy transfer efficiency, as calculated from the decay times of the bound and the unbound components, amounted to 37%. The Forster-radius, estimated from the absorption and emission bands, was ca. 77Å. The effective binding ratio, which not only depends on the ratio of binding pairs but also on unspecific binding, was obtained from the donor emission dependent on the concentration. As serum promotes unspecific binding, the overall FRET efficiency of the assay was reduced. We conclude that QDs are good substitutes for acceptors in FRET if combined with slow decay donors like Europium. The investigation of the influence of the serum provides guidance towards improving binding properties of QD assays.

A technique has been developed to measure absolute intracellular oxygen concentrations in green plants. Oxygen-sensitive phosphorescent microbeads were injected into the cells and an optical multifrequency phase-modulation technique was used to discriminate the sensor signal from the strong autofluorescence of the plant tissue. The method was established using photosynthesis-competent cells of the giant algae Chara corallina L., and was validated by application to various cell types of other plant species.

The fluorescence properties and the fluorescence quenching by Tb3+ of substituted benzoic acid were investigated in solution at different pH. The substituted benzoic acids were used as simple model compounds for chromophores present in humic substances (HS). It is shown that the fluorescence properties of the model compounds resemble fluorescence of HS quite well. A major factor determining the fluorescence of model compounds are proton transfer reactions in the electronically excited state. It is intriguing that the fluorescence of the model compounds was almost not quenched by Tb3+ while the HS fluorescence was decreased very effectively. From our results we concluded that proton transfer reactions as well as conformational reorientation processes play an important role in the fluorescence of HS. The luminescence of bound Tb3+ was sensitized by an energy transfer step upon excitation of the model compounds and of HS, respectively. For HS the observed sensitization was dependent on its origin indicating differences 1) in the connection between chromophores and binding sites and 2) in the energy levels of the chromophore triplet states. Hence, the observed sensitization of the Tb3+ luminescence could be useful to characterize structural differences of HS in solution. Interlanthanide energy transfer between Tb3+ and Nd3+ was used to determine the average distance R between both ions using the well-known formalism of luminescence resonance energy transfer. R was dependent on the origin of the HS reflecting the difference in structure. The value of Rmin seemed to be a unique feature of the HS. It was further found that upon variation of the pH R also changed. This demonstrates that the measurement of interlanthanide energy transfer can be used as a direct method to monitor conformational changes in HS.

Contents: Introduction Experimental Techniques: The LIF demonstrator unit - The LIF demonstrator unit - The mobile LIF spectrometer OPTIMOS - Investigated petroleum products and soil samples Results and Discussion: Photophysical properties of the petroleum products LIF spectroscopic investigations of oil-spiked samples LIF spectroscopic investigations of real-world soils Conclusions

Die Anwendung zweier ähnlicher fasergekoppelte Diodenlaser-Spektrometer-Systeme werden vorgestellt. Basis sind handelsübliche DFB-Laserdioden der optischen Kommunikationstechnik. Der faseroptische Aufbau, das Detektionsverfahren (2f Wellenlängenmodulations-Spektroskopie mit Balanced Receiver), Rauschverhalten und Detektionslimit werden diskutiert. Zur in-situ Plasma-Diagnostik von CO- und CO2-Konzentrationen in industriellen CO2-Lasern der Materialbearbeitung wurde eine Wellenlänge von 1582 nm verwendet. Bei einem Gasdruck von 100 hPa und einer Absorptionsweglänge von 14,9 cm wurden mit einer Laserdiode simultan CO- und CO2-Konzentrationen von 0% bis 11% im Gasgefäß bei laufender Hochfrequenzgasentladung des CO2-Lasers zeitaufgelöst gemessen. Vorgestellt und diskutiert werden Aufbau und Eigenschaften des Spektrometers sowie die Ergebnisse der dynamischen Gasanalysen, die zu einer Verbesserung der Katalysator-Technik im CO2-Laser beigetragen haben.Mit isotopenaufgelöster CO- und CO2-Spektroskopie können biologische Gasaustauschprozesse, z.B. in Gasen aus dem Erdboden untersucht werden. Hierzu wurde ein fasergekoppeltes feldtaugliches Diodenlaser-Spektrometer bei Wellenlängen um 1605 nm zur Messungder Isotopologe 12C16O, 13C16O, 12C18O und 12C16O2, 13C16O2, 12C18O16O aufgebaut. Die Messung erfolgt extraktiv in Langwegzellen mit unterschiedlichen Absorptionsweglängen von 100.9 m und 29.9 m. Es werden Kalibrationsmessungen zur Linearität und zur Präzision der Bestimmung der Isotopenverhältnisse sowie Wiederholungsmessungen zur Stabilität vorgestellt. Nachweisgrenzen von wenigen ppm konnten für die CO- und CO2-Isotopologen erhalten werden.

Steady-state and time-resolved fluorescence methods were applied to investigate the fluorescence properties of humic substances of different origins. Using standard 2D emission and total luminescence spectra, fluorescence maxima, the width of the fluorescence band and a relative fluorescence quantum efficiency were determined. Different trends for fulvic acids and humic acids were observed indicating differences in the heterogeneity of the sample fractions. The complexity of the fluorescence decay of humic substances is discussed and compared to simple model compounds. The effect of oxidation of humic substances on their fluorescence properties is discussed as well.