Achromatic nanostructured gradient index microlenses.

We present a development of microlenses achromatically corrected in near-infrared spectral windows. We show that the standard fiber drawing technology can be successfully applied to the development achromatic gradient index microlenses by means of internal nanostructurization. These gradient index microlenses can achieve similar performance to standard aspheric doublets, while utilizing a simpler, singlet element geometry with flat surfaces. A nanostructured lens with a parabolic profile was designed using a combination of the simulated annealing method and the effective medium approximation theory. Measurements on the fabricated lenses show that the microlenses have a nearly wavelength-independent focal plane at a distance of about 35 µm from the lens facet over the wavelength range of 600-1550 nm. The successful design and fabrication of achromatic flat-parallel rod microlenses opens new perspectives for micro-imaging systems and wavelength-independent coupling into optical fibers.

Assessment of incretins in oral glucose and lipid tolerance tests may be indicative in the diagnosis of metabolic syndrome aggravation.

Incretins stimulated by oral meals are claimed to be protective for the pancreatic beta cells, to increase insulin secretion, to inhibit glucagon release, slow gastric emptying (glucagon-like peptide-1) and suppress appetite. Recently it has however been suggested that glucagon-like peptide-1 (GLP-1) is putative early biomarker of metabolic consequences of the obesity associated proinflammatory state. The study was aimed to compare the release of incretins and some of early markers of inflammation at the fasting and postprandial period induced by functional oral glucose as well as lipid load in healthy controls and patients with metabolic syndrome (MS) to see if functional tests may be helpful in searching for the inflammatory status of patients. Fifty patients with MS and 20 healthy volunteers (C) participated in this study. The 3-hour oral glucose (OGTT) and the 8-hour oral lipid (OLTT) tolerance tests were performed. At fasting leptin and adiponectin, as well as every 30 minutes of OGTT and every 2 hours of OLTT blood concentration of GLP-1, glucose-dependent insulinotropic polypeptide (GIP), glucose, insulin, triglycerides, free fatty acids, glutathione peroxidase, interleukin-6, sE-selectin, monocyte chemoattractant protein-1 (MCP1) and visfatin were measured. At fasting and during both OGTT and OLTT the level of incretins did not differ between the MS and the C group. Both glucose and lipids reach food activated incretins secretion. Glucose was the main GLP-1 release activator, while the lipid load activated evidently GIP secretion. A significantly larger AUC-GIP after the lipid-rich meal over the carbohydrate meal was observed, while statistically bigger value of AUC-GLP-1 was noticed in OGTT than in OLTT (P < 0.001) within each of the investigated groups. In patients with the highest fasting plasma GIP concentration (3(rd) tertile), IL-6, MCP-1, sE-selectin and visfatin blood levels were increased and correlated with glutathione peroxydase, leptin/adiponectin ratio, higher visfatin and interleukin-6 levels. The fat containing meals stimulate the long-lasting release of incretins, mainly GIP, parallel to the increase of the markers of low grade inflammation associating obesity in metabolic syndrome. The possibility of use of the postprandial (OLTT) GIP release measurement for the low grade inflammation progress in MS patients is suggested.

Nanoscale structures and dynamics of a boundary liquid layer.

Our long term scientific interest is the understanding of the interface properties of flowing liquids on a microscopic level. Various mechanisms have been introduced to explain the origin of slip at a solid-liquid interface like the formation of a thin depletion layer or a molecular ordering of the liquid near the interface. Reflectometry (using x-rays or neutrons) is a powerful technique to probe structures in this surface region. However, to date much less attention has been paid to the dynamical properties. In the first part of this paper we show that a different ordering of water exists next to a hydrophobic substrate in comparison to a hydrophilic interface. Furthermore, we find that shear has no effect on the depletion layer on hydrophobic substrates, while no depletion layer exists for hydrophilic surfaces. The second part of the paper addresses the dynamical properties of the boundary layer, and we present a new method which enables the observation of the diffusion dynamics of polymers next to a solid substrate. As a proof of concept, the dynamics of micelles next to the interface has been explored using grazing incidence neutron spin-echo spectroscopy. We were able to verify that investigation of the dynamics of the sample is feasible with this grazing incidence technique and we present data taken near the critical angle of total reflection. It appears that the diffusive motion of micelles at the hydrophobic (repulsive) interface is faster than at a hydrophilic interface or in the bulk. Furthermore, neutron spin-echo spectroscopy was extended to a first evaluation of the Doppler shift which occurs under flow.

Mitral and aortic valve replacement in a patient with ectodermal anhydrotic dysplasia. A case report.

Ectodermal anhydrotic dysplasia is a rare, usually X-linked recessive malformation of ectodermal tissues and organs. The case of a 17-year-old boy with ectodermal anhydrotic dysplasia and concomitant combined mitral valve disease and aortic insufficiency is described. The surgical risk was considered to be high due to severe atrophia of the laryngo-pharyngeal mucosa complicating endotracheal intubation and the possibility of postoperative temperature control disturbances. Double valve replacement was performed late in the autumn, after laryngo-pharyngeal pharmacological treatment preparing for endotracheal intubation. The peri-operative course was managed without any complication related to the hereditary malformation. Our experience suggests that patients suffering from ectodermal anhydrotic dysplasia may undergo open heart surgery after appropriate preparation. Potential postoperative problems related to the hypohydrosis and impaired spontaneous temperature control could be prevented in our patient.