Replication of fly eyes by the conformal-evaporated-film-by-rotation technique.

We replicated a biological template, namely the eye of a fruit fly, at the micro- and nanoscales by implementing the conformal-evaporated-film-by-rotation (CEFR) technique, which allows the replication of even curved biotemplates. Chalcogenide glasses were used for replication due to their infrared optical properties, combined with good chemical and mechanical durability. Microscopy, together with optical characterization in the visible and near-infrared ranges, indicates high-fidelity replication of the original biotemplate. The CEFR technique could be useful for the development of highly efficient, biomimetic optical devices.

Mid-IR biosensor: detection and fingerprinting of pathogens on gold island functionalized chalcogenide films.

Antibody (human IgG, anti-E. coli O157:H7, and anti-Salmonella) complexes on the surface of IR-transparent Ge-containing chalcogenide glass films were formed via thiol chemistry on 20-nm-thick gold islands. As a first step, the protocol was validated by monitoring fluorescently tagged targets to validate binding. FT-IR spectroscopy confirmed that the coating of the films with 20-nm gold did not have a significant effect on the propagation and penetration of IR evanescent waves through the film. The films functionalized with anti-E. coli O157:H7 and anti-Salmonella antibodies were used to detect E. coli O157:H7 and S. enteriditis through label-free IR fingerprinting. Highly selective detection of bacterial targets was achieved at both the species (E. coli vs. S. enteriditis) and strain level (E. coli O157:H7 vs E. coli K12). A mid-infrared approach could thus be used as a biosensor as well as a molecular fingerprinting tool.

Surface characterizations of mono-, di-, and tri-aminosilane treated glass substrates.

The surface properties and structure of mono-, di-, and tri-aminosilane treated glass surfaces were investigated using surface analytical techniques including X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, atomic force microscopy (AFM), and streaming potential. An optimized dip-coating process was demonstrated to produce roughly silane monolayer coverage on the glass surface. The surface charge measurements indicated that aminosilanization converts the glass surface from negative to positive potentials at neutral pH values. Higher positive streaming potential was observed for tri-compared with mono- and di-aminosilane treated glass surfaces. For all aminosilane treated glass samples, the high-resolution N 1s XPS spectra indicated a preferential orientation of the protonated amino-groups towards the glass surface whereas the free amino groups were protruding outward. This study aimed to obtain uniform, reproducibly thin, strongly adhering, internally cross-linked, and high positively charged aminosilane-coated glass surfaces for the attachment of DNA fragments used in microarraying experiments.

[Family pediatricians and obstructive sleep disorders]. / Il pediatra di famiglia e i disturbi respiratori ostruttivi nel sonno.

UNLABELLED: BREATHING: Problems related to the Obstructive Sleep Disordered Breathing (OSDB) are so many: 1) a noso- graphic setting has still to be defined and this leads to contrasting results concerning the prevalence of the OSDB; 2) the absence of a single pathogenetic trigger which can explain the sudden increase of the number of cases of the OSDB since the 1980's; 3) a poor integration between clinical and diagnostic tests; 4) a not well defined role of the family pediatrician in approaching the OSDB. OBJECTIVES: From the above introduction we can deduce four objectives of the study: 1) verifying the prevalence of the OSDB; 2) studying if an early development of the adenotonsillar tissues can influence the on-set of the OSDB; 3) a better definition of the clinical diagnosis; 4) knowing what decisions the family pediatrician do take as concerns the diagnostic tests and therapy. MATERIAL AND METHOD: This study was carried out on questionnaires completed by 8 family pediatricians which consisted of two parts: the first section regarded the whole population interviewed (2.271 children) and the second more specific was reserved only to the 42 children classified as affected by the OSDB. These 42 children presented at least 3 of the following 4 features during sleep: (1) the parents are worried about the way their child breaths (2) snoring (3) apnea (4) paradoxical rib cage movement in inspiration. RESULTS: The prevalence of the OSDB was 1.8%. However considering how suggested by some authors even those children who snored and also presented oral respiration, the prevalence increased to 10.3%. These values are similar to the international results with a prevalence of 2-3% for the more severe forms defined as Obstructive Sleep Apnea Syndromes (OSAS) and of 8-11% considering all the forms of the OSDB. Grouping these patients according to their ages, it resulted that the highest incidence of the OSDB was in children between 3-5 years. This observation supports the hypothesis that at the base of the OSDB is an early development of the adenotonsillar tissues, thus in constrast which the classical course which identifies the peak of adenotonsillar hypertrophy between 4 and 6 years of age. The frequency of the single signs and symptoms in the various ages permits the improvement of the clinical diagnosis: in particular snoring, oral respiration and tonsillar hypertrophy are less frequent in the first three years of life, while in the older children the percentage of growth inhibition decreased and it becomes more difficult observing paradoxical rib cage movement in inspiration. Concerning the diagnostic tests, the family pediatrician asks only exceptionally specific test during sleep (5% of the patients). Concerning therapy, many were the indications for adenotonsillectomy even during the first three years of age (82% of the patients) proving that the family paediatrician has overcome the old attitude of not indicating operation in the first 4-5 years of age. CONCLUSION: The confirmed high prevalence of the OSDB, the possibility of further improving the clinical diagnosis, the good capacity of the family pediatrician concerns diagnosis and therapy are all factors which favour the direct management of most of the children with adenotonsillar hypertrophy by the family pediatrician. The diagnosis and therapeutic choice can find support in sleep tests when necessary. These tests have to be carried out in a specialized laboratory and the results be interpreted together with the clinical signs and symptoms. Patients who have to be managed by Pediatric sleep laboratory are: 1) children with OSDB due to organic and functional alterations on genetic basis; 2) children in whom adenotonsillectomy presents a high risk such as a severe respiratory insufficiency and the young age of the patient (less 12-18 months of life).

Surface heterogeneity and surface area from linear inverse gas chromatography. Application to glass fibers.

A new method of measuring surface heterogeneity of non-porous adsorbents by inverse gas chromatography (IGC) is developed. In contrast with the methods described in the literature which are based on nonlinear chromatography (thermodynamics of adsorption) this method is based on linear chromatography (kinetics of adsorption). The mass balance equation of linear chromatography with axial diffusion term and the Langmuir kinetic equation on an open (non-porous) heterogeneous surface are solved by the method of Laplace transforms. The expressions for four semi-invariants of an elution profile are obtained. These are linear combinations of the moments of the distribution of sites in residence time of adsorbed molecule with coefficients determined from elution profile of non-adsorbing gas. Four semi-invariants of elution profiles of benzene and methane on a column packed with E-glass fiber were determined experimentally at temperatures around 100 degrees C. The mean, the standard deviation of the normal distribution in adsorption energy as well as the sticking coefficient and pre-exponential factor of the Frenkel equation are determined for benzene on E-glass. A method of the specific surface determination from linear IGC is proposed.

Laser-based microscopic approaches: application to cell signaling in environmental lung disease.

Cell-imaging approaches using new laser-based technologies have a wide applicability to thefields of pathology and cell biology. Here, we present the application of several of these techniques, including confocal scanning laser microscopy (CSLM), laser scanning cytometry (LSC), and laser capture microdissection (LCM), to studies of cell signaling by environmental agents in lung disease. Using both cells in culture and lung tissue, we show that these technologies are powerful tools for understanding signal transduction cascades elicited by toxic agents, such as oxidants and asbestosfibers, and their relationship to the development of cell injury and proliferation, responses leading to lung disease and/or repair.

In vitro dissolution of Synthos ceramics in an acellular physiological environment.

"Synthos" (beta-tricalcium phosphate) implants in bone are resorbed and replaced with endogenous bone. This investigation was conducted to study by continuous flow and static system techniques, whether or not resorption of synthos occurs by passive dissolution at 37 degrees C. Calcium and phosphates were released in a time dependent manner from synthos in calcium and phosphate free Tris-Hcl buffer (pH 7.4). Scanning electron micrographs (SEM) of buffer exposed ceramics indicated breakdown of grain structure. In contrast, levels of human plasma calcium and phosphate were not altered by ceramics. Significant amounts of 32p were absorbed by the ceramics in the first hour and 45Ca in the second hour of exposure to plasma containing the radioactive isotopes. Exposure of ceramics to plasma did not alter the levels of plasm isotopes significantly for the remaining duration of the experiment. However, breakdown of grain structure was evident in SEM's of ceramics exposed to plasma. It appears that in an acellular physiological environment, dissolution of synthos is diffusion dependent and is limited to a localized surface exchange phenonmenon.

Analysis of bioglass fixation of hip prostheses.

The analysis of the bonding interface between hip prostheses and bone after functional use in animals was carried out. Scanning electron microscopy (SEM) with energy dispersive analysis (EDX), and Auger electron spectroscopy were used to evaluate the bonding interface. Various methods of postsacrifice sample preparation were used to evaluate the effect of such different methods on the analysis of the bonding interface. Comparison of the results with several rat tibia implant experiments is also presented.