Confocal Raman microscopy (CRM) of biofilms enables one to determine the distribution of different microorganisms and other substances inside physiological intact microbial communities. These biofilms are of outstanding interest for biological wastewater treatment. In contrast to invasive techniques, such as fluorescent in situ hybridization (FISH), we were able to identify anaerobically ammonium-oxidising (anammox) bacteria without pretreatment processes of the samples just by its Raman vibrational signature. The presented results provide new insights into the complex interactions of different organisms in microbial communities without interfering with them.
SynopsisCaffeine is an effective slimming agent used for topical administration or in cosmetic products. The formulation must be such that caffeine reaches the adipocytes in the hypodermis. Biodegradable caffeine-loaded microspheres were evaluated for the transport of caffeine to its site of action for 24 h and upto 72 h. The mean diameter of the microspheres was 2.8 lm and their caffeine loading was 2.3 mg g -1 of particles. The permeation of caffeine from microspheres applied in aqueous suspension or from solution was evaluated through in vitro diffusion measurements with static Franz cells (n = 6) over 24 h or 72 h. The first experiments carried out on full-thickness skin without hypodermis showed that after 24 h the total amount of caffeine was twice as high from microspheres as from aqueous solution (22.6% vs. 9.99%). The results suggested that microspheres could easily penetrate through the skin and accumulate in the receptor compartment, ensuring continuous caffeine release. When the hypodermis was retained, microsphere penetration was only slightly decreased. After 72 hours of exposure the receptor fluid contained 15.3% free caffeine and 27.8% encapsulated fraction. The hypodermis hindered solution permeation, and therefore the free caffeine content was lower. Permeation of microspheres was not stopped by the presence of hypodermis.
SynopsisOptoacoustics is a new method to study the optical properties of human skin in vivo. We measured the absorption spectra of human skin in a study in twenty subjects belonging to skin phototypes I-IV. Absorption coefficients were determined in the range from 290 nm to 341 nm (3 nm steps) on the inner and outer side of the forearm and the ball of the thumb. Comparison of these new data with known action spectra of photobiologic effects and natural solar irradiation spectra indicates that the small wavelength range from ca. 300 nm to 320 nm may be responsible for significant detrimental and beneficial effects. Consequently, the skin is very sensitive to changes in irradiation in this spectral region.
SynopsisIn Asia, lighter skin is a desirable feature considered to be a symbol of beauty and femininity, and
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