Unique laser coding technology to fight falsified medicines.

Based on WHO statistics, counterfeit medicines represent 10% of the global drug trade. According to Directive 2011/62/EU as regards the prevention of falsified medicines from entering into the legal supply chain, a unique identification should be put on each box of drugs to be able to track and trace them. The objective of this study is to develop a technology to mark an individual traceability code directly on the surface of the tablet. By using this technique, anyone with a camera-enabled phone and a suitable application installed should be able to authenticate these drugs. By marking the medicine's surface, patients could be protected from fake drugs. The aim of the present work was to study how different types of lasers affect the film coating of the tablet during the laser marking intervention. To sum up, the present findings may contribute to efficient and reliable laser marking solutions in the unique identification procedure. Based on our measurement results, it can be stated that the excimer UV laser is clearly the most suitable marking instrument for anti-counterfeiting coding on solid coated tablet form as this caused the least amount of chemical degradation of the polymer film.

Comparison of cerebrocortical microvascular effects of different hypoxic-ischemic insults in piglets: a laser-speckle imaging study.

The newborn pig is a widely accepted large animal model of hypoxic/ischemic (H/I) encephalopathy (HIE) of the term neonate appropriate for translational research. The methodology of the induction of H/I stress shows extensive variability of the literature, and little is known how these affect study outcome. The purpose of the present study was to determine the cerebrocortical microvascular effects of different H/I insults used in current HIE piglet models. For the semiquantitative study of cerebrocortical blood flow, we developed a methodological innovation: an operating microscope was converted into a custom-designed laser-speckle imager. Anesthetized, air-ventilated newborn pigs (n=7) were fitted with a closed cranial window. Speckle image series (2 ms, 1 Hz) were collected during baseline conditions, during transient bilateral carotid artery occlusion (BCAO), hypoxic (FiO(2)=0.1) hypoxia, hypoxia + BCAO, and asphyxia induced by suspending ventilation. Laser-speckle contrast analysis was performed off-line over parenchymal and arteriolar regions of interests, and pial arteriolar diameters were also determined for detailed analysis of cortical perfusion changes. Under normoxic conditions, transient BCAO did not affect parenchymal perfusion or pial arteriolar diameters. Hypoxia induced marked cortical hyperemia in 5 out of 7 piglets, with simultaneous increases in pial arteriolar diameters and arteriolar flow velocity, however, BCAO could not even affect these hypoxia-induced perfusion changes. In contrast to hypoxia or hypoxia + BCAO, asphyxia inevitably led also to severe cerebrocortical ischemia. In summary, acute reversible BCAO does not reduce cerebrocortical blood flow in the piglet, and thus it likely does not exacerbate the effect of hypoxic ventilation. Asphyxia elicits not only severe hypoxia, but also severe brain ischemia. These microcirculatory effects must be taken into consideration when assessing results obtained in the various HIE piglet models.

Immobilization of urease by laser techniques: synthesis and application to urea biosensors.

Urease thin films have been immobilized using matrix-assisted pulsed laser evaporation for biosensor applications in clinical diagnostics. The targets exposed to laser radiation were made of frozen composites that had been manufactured by dissolving urease in distilled water. An UV KrF* (lambda = 248 nm, tauFWHM congruent with 30 ns, nu = 10 Hz) excimer source was used for the multipulse laser irradiation of the targets that were cooled down to solidification using Peltier elements. The incident laser fluence was set at 0.4 J/cm2. The surface morphology and chemical bonding states of the laser immobilized urease thin films were investigated by atomic force microscopy and Fourier transform infrared spectroscopy. The enzymatic activity and kinetics of the immobilized urease were assayed by the Worthington method, which monitors urea hydrolysis by coupling ammonia production to a glutamate dehydrogenase reaction. Decreased absorbance was found at 340 nm and correlated with the enzymatic activity of urease.