Longevity interventions modulate mechanotransduction and extracellular matrix homeostasis in C. elegans.

Dysfunctional extracellular matrices (ECM) contribute to aging and disease. Repairing dysfunctional ECM could potentially prevent age-related pathologies. Interventions promoting longevity also impact ECM gene expression. However, the role of ECM composition changes in healthy aging remains unclear. Here we perform proteomics and in-vivo monitoring to systematically investigate ECM composition (matreotype) during aging in C. elegans revealing three distinct collagen dynamics. Longevity interventions slow age-related collagen stiffening and prolong the expression of collagens that are turned over. These prolonged collagen dynamics are mediated by a mechanical feedback loop of hemidesmosome-containing structures that span from the exoskeletal ECM through the hypodermis, basement membrane ECM, to the muscles, coupling mechanical forces to adjust ECM gene expression and longevity via the transcriptional co-activator YAP-1 across tissues. Our results provide in-vivo evidence that coordinated ECM remodeling through mechanotransduction is required and sufficient to promote longevity, offering potential avenues for interventions targeting ECM dynamics.

Persistent radical anions in the series of peri-arylenes: broadband light absorption until far in the NIR and purely organic magnetism.

ABSTRACT: Stable radicals in organic conjugated molecules are of great interest due to their magnetic signals and broad optical absorptions. In this paper, we report on naphthalene, benzoperylene, perylene, terrylene, and quaterrylene carboximides, reduced under controlled conditions, where stable metal-free solid salts of radical anions could be obtained forming darkly colored solutions with line-rich UV/Vis/NIR spectra and exhibiting special magnetic properties. The most bathochromic shift of the absorption maxima extend from 760 until 1700 nm. Persistent paramagnetic properties of the solids were observed and temperature-dependent susceptibilities are measured.

Characterization of the photocurrents generated by the laser of atomic force microscopes.

The conductive atomic force microscope (CAFM) has become an essential tool for the nanoscale electronic characterization of many materials and devices. When studying photoactive samples, the laser used by the CAFM to detect the deflection of the cantilever can generate photocurrents that perturb the current signals collected, leading to unreliable characterization. In metal-coated semiconductor samples, this problem is further aggravated, and large currents above the nanometer range can be observed even without the application of any bias. Here we present the first characterization of the photocurrents introduced by the laser of the CAFM, and we quantify the amount of light arriving to the surface of the sample. The mechanisms for current collection when placing the CAFM tip on metal-coated photoactive samples are also analyzed in-depth. Finally, we successfully avoided the laser-induced perturbations using a two pass technique: the first scan collects the topography (laser ON) and the second collects the current (laser OFF). We also demonstrate that CAFMs without a laser (using a tuning fork for detecting the deflection of the tip) do not have this problem.

Substitution of aromatics by amines at room temperature with negative energy of activation: amino peri-arylenes as metal-free components for dye-sensitized solar cells.

Substitution reactions of the chemically and photochemically unusually stable perylenetetracarboxylic bisimides proceed with neat amines even below room temperature where negative effective energies of activation were found. Analogous reactions proceed with naphthalenecarboximides as the lower homologues and terrylene and quaterrylene carboximides as the higher homologues. Bathochromically absorbing dyes with a novel pattern of substitution were obtained suitable as efficient metal-free light-absorbers for dye-sensitized solar cells.

Chromophores arranged as "magnetic meta atoms": building blocks for molecular metamaterials.

Benzoperylenetriscarboximides were parallel arranged by stiff spacers where exciton interactions could be controlled by their distance. The most bathochromic electronic transition of the chromophores essentially exhibits only an electric component where an orthogonal magnetic component was established by the distance-controlled interaction of chromophores. Such arrangements were discussed as building blocks for molecular metamaterials.

Controlling UV/vis absorption and Stokes shifts in highly fluorescent chromophores by molecular dynamics in targeted construction of dyads.

Perylenedicarboximides were interlinked in their free peri-position to form dyads where the UV/vis absorptivity was amplified by exciton effects and the strong fluorescence bathochromically shifted by molecular dynamics. Applications of this type of dye with such increased Stokes shifts were discussed.

Axially chiral bichromophoric fluorescent dyes.

A new life for Kurt Mislow's authentic amines: Diaminobiphenyls were applied as the framework materials for the synthesis of axially chiral bichromophoric systems with strong CD and CPL effects.

Cs(10)Ta(29.27)o(78).

Single crystals of caesium tantalate(V), Cs(10)Ta(29.27)O(78), were obtained as a serendipitous product in a welded tantalum ampoule by a blank reaction of CsBr and bis-muth subnitrate [Bi(5)O(OH)(9)(NO(3))(4)] with the container material. The crystal structure of the title compound is made up of a three-dimensional framework constituted by two types of layers, viz. (Ta(6)O(15))(n) and (Ta(3)O(9))(n), parallel to (001), which are linked together by TaO(6) octa-hedra (3m. symmetry) along [001]. This framework has cavities where three independent Cs(+) ions (3m. and m2 symmetry, respectively) are located. The compound reveals a Ta deficiency at one trigonal prismatic coordinated site (m2 symmetry). The composition of the title compound was verified by energy-dispersive X-ray analysis of single crystals.

Selective imaging of saturated and unsaturated lipids by wide-field CARS-microscopy.

Wide-field Coherent Anti-Stokes Raman Scattering (CARS) microscopy is employed to identify saturated and unsaturated fatty acids in micro-emulsions and cells, using the ratio between the strong -C-H CARS signal at 2850 cm(-1) and the weak signal of the =C-H vibration around 3015 cm(-1) for distinction. Quantitative CARS imaging at the =C-H resonance is challenging, since it yields only a low CARS signal, and small differences on the order of 5% in the concentration of polyunsaturated fatty lipids have to be detected. For this purpose we draw advantage of the high signal-to-noise ratio of wide-field CARS microscopy that is achieved by an excitation geometry involving a "sheet-of-light"-type illumination.