Chronomics, human time estimation, and aging

Franz Halberg, Robert B Sothern, Germaine Cornélissen, Jerzy Czaplicki1Halberg Chronobiology Center, University of Minnesota, Minneapolis, MN, USA; 1Institut de Pharmacologie et de Biologie Structurale CNRS, Université Paul Sabatier, Toulouse, FranceBackground: Circadian rhythm stage affects many outcomes, including those of mental aging.Methods: Estimations of 1 minute ∼5 times/day for a year, 25 years apart, by a healthy male biomedical scientist (RBS), are analyzed by the extended cosinor.Results: Cycles of a half-week, a week, ∼30 days, a half-year and a year, in self-assessed 1-minute estimation by RBS between 25 and 60 years of age in health, are mapped for the first time, compared and opposite effects are found. For RBS at 60 vs at 25 years of age, it takes less time in the morning around 10:30 (P < 0.001), but not in the evening around 19:30 (P = 0.956), to estimate 1 minute.Discussion: During the intervening decades, the time of estimating 1 minute differed greatly, dependent on circadian stage, being a linear decrease in the morning and increase in the evening, the latter modulated by a ∼33.6-year cycle.Conclusion: Circadian and infradian rhythm mapping is essential for a scrutiny of effects of aging. A ∼30-day and a circannual component apparent at 25 years of age are not found later; cycles longer than a year are detected. Rhythm stages await tests as markers for timing therapy in disease.Keywords: circadian rhythm, mental function, time estimatio

Arabinogalactan proteins improve plant regeneration in barley (Hordeum vulgare L.) anther culture

Androgenesis-based methods of doubled haploid (DH) production show considerable variation in efficiency in different barley genotypes. Arabinogalactan proteins (AGPs) have been shown to play a key role in several developmental processes, including embryogenesis, in different plant species. In this study we investigated the effect of exogenous AGPs from gum arabic on androgenesis and the regeneration efficiency in barley anther culture. Supplementation of the induction medium with 10 mg l^{-1} gum arabic increased the total plant regeneration rate up to 2.8 times; when exposure to GA was extended to also include the pretreatment step, the regeneration rate was up to 6.6-times higher than in control. The effect of gum arabic was reversed by the Yariv reagent, an AGPs antagonist. This suggests a direct involvement of AGPs in androgenic development from barely microspores. Addition of gum arabic reduced cell mortality, increased the frequency of mitotic divisions of microspores and the number of multicellular structures (MCSs) when compared to control. The positive effect of gum arabic also included reduction in time required for the androgenic induction and substantially improved the quality of formed embryos. Observations made in this study imply a complex role of AGPs during androgenic development and confirmed the usefulness of gum arabic in production of barley androgenic plants

Backward phase-matched second-harmonic generation from stacked metasurfaces

We demonstrate phase-matched second-harmonic generation (SHG) from three-dimensional metamaterials consisting of stacked metasurfaces. To achieve phase matching, we utilize a novel mechanism based on phase engineering of the metasurfaces at the interacting wavelengths, facilitating phase-matched SHG in the unconventional backward direction. By stacking up to five metasurfaces, we obtain the expected factor of 25 enhancement in SHG efficiency. Our results motivate further investigations to achieve higher conversion efficiencies also with more complex wavefronts.Comment: 5 pages, 3 figures, supplementary materia

Caténanes, votaxanes et ADN fonctionnalisés pour des applications en optique non linéaire

The concept of interlocked molecules is known from sixties and up to now catenanes and rotaxanes of up to 4 components were synthesized and still the number of components in-crease. These are relatively small molecules when in nature large catenanes are present in DNA molecules. Catenanes and rotaxanes are mechanically interlocked molecules composed of moving parts, held together, where one (or more of them) can move and/or positioning with respect to the other. This unique architecture makes them very interesting as possible candidates for molecular machine-type applications in the field of nonlinear optics particularly in photonics, optoelectronics and optical data storage. In this work we report the results of our studies of nonlinear optical properties of some selected catenanes and rotaxanes. The nonlinear properties were studied by different techniques. The results show important electronic contribution to the third order nonlinear susceptibility confirmed by theoretical calculations at the molecular level. Also, we report the results of nonlinear optical properties of functionalized DNA. The results show high enhancement of nonlinearity when the modified DNA was used. At the same time the best results were observed in holography experiments when DNA-CTMA was used as a matrix for doping of disperse red 1.La synthèse de caténanes et rotaxanes remonte aux années 60. Aujourd'hui la plupart de ces molécules enchevêtrées, synthétisées comportent jusqu'à 4 éléments et ce nombre continu de croître. Toutefois, ces molécules restent relativement petites, comparées `a celles trouvées dans la nature tels que les caténanes présents dans l'ADN. Les caténanes et rotaxanes sont des molécules mécaniquement assemblées, composées de pièces mobiles, liées, ou non (ou plus d'elles), pouvant se mouvoir et/ou se déplacer par rapport aux autres. Cette architecture unique les rend très intéressants et fait d'eux des candidats potentiels pour les machines moléculaires, ainsi que pour des applications dans le domaine de l'optique non linéaire, en particulier dans la photonique, l'optoélectronique et le stockage de données optique. Dans ce travail, nous exposons les résultats de nos recherches portant sur les propriétés optiques non-linéaires de quelques caténanes et rotaxanes. Ces propriétés non-linéaires ont été abordées par différentes techniques. Les résultats montrent une importante contribution électronique dans la susceptibilité non-linéaire de troisième ordre confirmée par des calculs théoriques au niveau moléculaire. Nous exposons également les résultats des propriétés optiques non linéaires de l'ADN fonctionnalisé. Ces résultats montrent une recrudescence des non linéarités quand l'ADN modifiée est utilisé. Par ailleurs, on a observé les meilleurs résultats dans des expériences d'holographie quand l'ADN-CTMA est utilisé comme matrice pour le dopage du disperse red 1

Some selected functionalized catenanes, rotaxanes and the DNA for nonlinear optical applications

La synthèse de caténanes et rotaxanes remonte aux années 60. Aujourd'hui la plupart de ces molécules enchevêtrées, synthétisées comportent jusqu'à 4 éléments et ce nombre continu de croître. Toutefois, ces molécules restent relativement petites, comparées a celles trouvées dans la nature tels que les caténanes présents dans l'ADN. Les caténanes et rotaxanes sont des molécules mécaniquement assemblées, composées de pièces mobiles, liées, ou non (ou plus d'elles), pouvant se mouvoir et/ou se déplacer par rapport aux autres. Cette architecture unique les rend très intéressants et fait d'eux des candidats potentiels pour les machines moléculaires, ainsi que pour des applications dans le domaine de l'optique non linéaire, en particulier dans la photonique, l'optoélectronique et le stockage de données optique. Dans ce travail, nous exposons les résultats de nos recherches portant sur les propriétés optiques non-linéaires de quelques caténanes et rotaxanes. Ces propriétés non-linéaires ont été abordées par différentes techniques. Les résultats montrent une importante contribution électronique dans la susceptibilité non-linéaire de troisième ordre confirmée par des calculs théoriques au niveau moléculaire. Nous exposons également les résultats des propriétés optiques non linéaires de l'ADN fonctionnalisé. Ces résultats montrent une recrudescence des non linéarités quand l'ADN modifiée est utilisé. Par ailleurs, on a observé les meilleurs résultats dans des expériences d'holographie quand l'ADN-CTMA est utilisé comme matrice pour le dopage du disperse red 1.The concept of interlocked molecules is known from sixties and up to now catenanes and rotaxanes of up to 4 components were synthesized and still the number of components in-crease. These are relatively small molecules when in nature large catenanes are present in DNA molecules. Catenanes and rotaxanes are mechanically interlocked molecules composed of moving parts, held together, where one (or more of them) can move and/or positioning with respect to the other. This unique architecture makes them very interesting as possible candidates for molecular machine-type applications in the field of nonlinear optics particularly in photonics, optoelectronics and optical data storage. In this work we report the results of our studies of nonlinear optical properties of some selected catenanes and rotaxanes. The nonlinear properties were studied by different techniques. The results show important electronic contribution to the third order nonlinear susceptibility confirmed by theoretical calculations at the molecular level. Also, we report the results of nonlinear optical properties of functionalized DNA. The results show high enhancement of nonlinearity when the modified DNA was used. At the same time the best results were observed in holography experiments when DNA-CTMA was used as a matrix for doping of disperse red 1.ANGERS-BU Lettres et Sciences (490072106) / SudocSudocFranceF

Nonlinear plasmonic metasurfaces

Nonlinear plasmonic metasurfaces have recently attracted considerable interest, due to their potential for enabling nanoscale nonlinear optics. Here, we review the current progress in this topic while paying special attention to existing challenges. In order to limit our scope, we concentrate on nonlinear metasurfaces utilizing inter-particle and lattice effects and focus on metasurfaces operating close to visible and near-infrared frequencies. We will also critically discuss the short and longer term prospects of nonlinear metasurfaces to start rivalling traditional nonlinear materials in applications.submittedVersionPeer reviewe

Some selected and functionalised organometallic molecules for NLO applications

Date du colloque&nbsp;: 06/2009International audienceOrganometallics nano complexes are important targets for the construction of advanced materials, the investigation of electron-transfer processes and of novel devices for non-linear optical (NLO) applications. In this work the diagnostic and characterisation of novel molecular organics nano complexes thin films functionalized for NLO applications will be discussed. On other hand a rich study of the formation of surface-relief gratings (SRGs), using a picosecond pulsed laser at 532 nm, resulted in instantaneous inscription will be presented.</p

Third harmonic generation via dendrimers of four generations

Date du colloque&nbsp;: 12/2009International audienceWe report on third harmonic generation of E-O active dendrimers dispersed in polycarbonate matrix. Four kinds of polyester type dendrimers G0, G1, G2 and G3 containing azobenzene in the core used as third order nonlinear optical active chromophores were prepared as guest-host type system based on polycarbonate matrix spin-coated on a glass substrate. Third harmonic generation was measured while exciting the samples with fundamental wavelength 1.064 ¿m. Non-linear third-order susceptibility ¿(3) for different generations of dendrimers was evaluated.</p