106,939 research outputs found
Constructing Kurgans: an Introduction
No full textIntroduzione al volume che raccoglie interventi della conferenza e sintesi dei dati
Omologati nuovi cloni di Müller Thurgau
No full textTestate nuove selezioni di Müller Thurgau confrontate con varietà di riferimento francesi e tedesche. Verificate le performance agronomiche e tecnologiche, con particolare attenzione agli aspetti vegeto-produttivi e alle differenze clonali nelle componenti aromatiche primarie di questo vitign
Aqueous Humor Biomarkers of Müller Cell Activation in Diabetic Eyes
No full textPurpose: To identify early biomarkers of retinal Müller cell activation in diabetic eyes with or without clinically detectable signs of diabetic retinopathy (DR).
Methods: This study was a cross-sectional comparative case series. The aqueous humor (AH) of 34 eyes was collected in 12 healthy controls, 11 diabetic patients without DR, and 11 diabetic patients with nonproliferative DR. Full ophthalmic examination and spectral-domain optical coherence tomography were performed in all eyes. Glial fibrillary acidic protein (GFAP), aquaporin 1 (AQP1), and aquaporin 4 (AQP4) were quantified in AH samples as biomarkers of Müller cell activity by ELISA. Statistical analysis was performed with ANOVA followed by Tukey-Kramer post hoc test.
Results: There was no significant difference in the age among the three groups. Mean concentration of GFAP, AQP1, and AQP4 significantly increased in diabetic eyes versus controls (P < 0.05, for each comparison). Glial fibrillary acidic protein and AQP1 showed an approximate 2-fold increase, whereas AQP4 showed an approximate 25-fold increase in diabetics with DR versus controls. In diabetics without DR, AQP4 showed an approximate 6-fold increase versus controls.
Conclusions: Glial fibrillary acidic protein, AQP1, and AQP4-biomarkers of Müller cell activity-are significantly increased in human eyes with diabetes, confirming that Müller cells are precociously affected by diabetes mellitus
Solostücke, Arien, Lieder und Konzerte.
No full textT.-p. in German and English. --- -- v. 2. Variationen und Polonaise / Bernhardt Knop ; Conzert mit dem Choral : Wachet auf, ruft uns die Stimme / C.G. Müller ; Conzertino / C. Henning ; Conzertino / C.F. Kaestner ; Conzertino [F major] / H. Neumann ; Concert-Militair / J. Kühn ; Fantasie / Bernh. Knoop ; Conzertino [B♭ major] / C.G. Müller ; Conzertino / G. Wichtl
Aqueous Humor Biomarkers of Müller Cell Activation in Diabetic Eyes.
No full textPURPOSE:
To identify early biomarkers of retinal Müller cell activation in diabetic eyes with or without clinically detectable signs of diabetic retinopathy (DR).
METHODS:
This study was a cross-sectional comparative case series. The aqueous humor (AH) of 34 eyes was collected in 12 healthy controls, 11 diabetic patients without DR, and 11 diabetic patients with nonproliferative DR. Full ophthalmic examination and spectral-domain optical coherence tomography were performed in all eyes. Glial fibrillary acidic protein (GFAP), aquaporin 1 (AQP1), and aquaporin 4 (AQP4) were quantified in AH samples as biomarkers of Müller cell activity by ELISA. Statistical analysis was performed with ANOVA followed by Tukey-Kramer post hoc test.
RESULTS:
There was no significant difference in the age among the three groups. Mean concentration of GFAP, AQP1, and AQP4 significantly increased in diabetic eyes versus controls (P < 0.05, for each comparison). Glial fibrillary acidic protein and AQP1 showed an approximate 2-fold increase, whereas AQP4 showed an approximate 25-fold increase in diabetics with DR versus controls. In diabetics without DR, AQP4 showed an approximate 6-fold increase versus controls.
CONCLUSIONS:
Glial fibrillary acidic protein, AQP1, and AQP4-biomarkers of Müller cell activity-are significantly increased in human eyes with diabetes, confirming that Müller cells are precociously affected by diabetes mellitus
Amphiphilic tetraethylene glycol methacrylate-perfluoroalkyl acrylate block and random copolymers: Synthesis and self-assembling in water solution
No full textAmphiphilic block and random copolymers with perfluoroalkyl segments can efficiently provide self-assembled polymeric nanostructures[1], including micelles, vesicles, and nanogels, in water and organic solvents, via the intermolecular association or intramolecular self-folding of the copolymer chains[2]. These nanomaterials may display anti-biofouling properties against proteins, cells and organisms[3]. Moreover, perfluoroalkyl polymers have several attractive features: the polymers are immiscible with both water and common organic solvents, yet have selective interactions with fluorinated compounds resulting in unique association and molecular recognition.
Focusing on these features we have synthesized block and random copolymers of tetraethylene glycol methyl ether methacrylate (PEGMA) and 2-(perfluorohexyl)ethyl acrylate (FA). Owing to the controlled ATRP reaction, the molecular weight, composition and sequence of the amphiphilic block and random copolymers could be tuned in a predictable way.
In this contribution copolymers with PEGMA:FA ratios 70:30 and 90:10 are reported. The philic/phobic balance directly affected the self-assembling behaviour in bulk and in solution. Above a critical concentration in water (0.5 g/L), the copolymer chains are characterized by a bimodal size distribution (Fig.1, left), comprised of nanometer and submicrometer structures. While the larger structures were due to self-assembled, intermolecular aggregates, the smaller ones were attributed to single, intramolecular folded chains. Moreover, we found a sharp thermal transition depending on the copolymer composition (Fig.1, right). Above the transition temperature, one almost monodisperse stable phase existed, with size increasing from ~500 nm to ~1500 nm with copolymer concentration from 0.5 g/L to 5 g/L. Heating and cooling cycles showed the complete reversibility of these copolymer systems. The narrow size distributions accomplished for both copolymers above the thermal transition are ascribed to the formation of intriguing thermoresponsive polymersomes with homogeneous size
Müller glial cell reactivation in Xenopus models of retinal degeneration
No full textA striking aspect of tissue regeneration is its uneven distribution among different animal classes, both in terms of modalities and efficiency. The retina does not escape the rule, exhibiting extraordinary self-repair properties in anamniote species but extremely limited ones in mammals. Among cellular sources prone to contribute to retinal regeneration are Müller glial cells, which in teleosts have been known for a decade to re-acquire a stem/progenitor state and regenerate retinal neurons following injury. As their regenerative potential was hitherto unexplored in amphibians, we tackled this issue using two Xenopus retinal injury paradigms we implemented: a mechanical needle poke injury and a transgenic model allowing for conditional photoreceptor cell ablation. These models revealed that Müller cells are indeed able to proliferate and replace lost cells following damage/degeneration in the retina. Interestingly, the extent of cell cycle re-entry appears dependent on the age of the animal, with a refractory period in early tadpole stages. Our findings pave the way for future studies aimed at identifying the molecular cues that either sustain or constrain the recruitment of Müller glia, an issue of utmost importance to set up therapeutic strategies for eye regenerative medicine
Helmut Schmidt, the ‘Renewal’ of European Social Democracy and the Roots of Neoliberal Globalization
No full textThe chapter focuses on the approach of the Federal Republic of Germany Chancellor Helmut Schmidt to the international economic crisis of the 1970s. During his years in power (1974-1982), Schmidt took part in the newborn G6 (later G7) ‘club’ which promoted the deregulation of the international economy and more generally the adoption of a ‘neoliberal’ course. The chapter shows how Schmidt had been an active promoter of a more ‘laissez-faire’ oriented approach, which he deemed as a necessary alternative to the no longer productive Keynesian recipes. Besides, Schmidt estimated that only a renewed Transatlantic solidarity under US leadership could stand the challenge brought by the ‘South’ of the world and by its requests of a new and fairer economic order. Thus, moving away from the traditional tenets of social democracy, Schmidt’s approach ended up promoting a new ‘bipartisan consensus’ towards the reborn neoliberal doctrine
Tuning ultrafast electron injection dynamics at organic-graphene/metal interfaces
No full textThe properties of novel and prospective 2D materials are dramatically influenced by the interaction with a substrate. For example, the electronic hybridization of silicene states on Ag(111) or graphene ones on Ni(111) disrupts the Dirac fermions of the freestanding layers. This calls for efficient approaches to tune the interaction strength at the interface. Here we focus on the case of graphene functionalized by organic molecules and grown on Ni(111) and on the interfacial charge transfer dynamics. This is investigated by X-ray resonant photoemission spectroscopy, that is able to measure electron transfer rates occurring within few femtoseconds, and by a theoretical framework based on density-functional theory [1,2].
We use 4,4’-bipyridine as the prototypical molecule for these explorations as the energy level alignment of core-excited molecular orbitals allows ultrafast injection (τ=4fs) of electrons from the substrate to the molecule adsorbed on epitaxial graphene/Ni(111), which is characterized by a strong hybridization between C and metal states. We demonstrate that this interface can be decoupled by the addition of a second layer of graphene, where the one in contact with the metal acts as a buffer layer and the one in contact with the molecule is less hybridized with Ni underneath. As a result, the ultrafast injection of electrons from the substrate to the molecule is ∼4 times slower on weakly coupled bilayer graphene than on epitaxial graphene. Through our experiments and calculations, we can attribute this to a difference in the density of states close to the Fermi level between graphene and bilayer graphene. We therefore show how graphene coupling with the substrate influences charge transfer dynamics between organic molecules and graphene interfaces.
[1] G. Fratesi, C. Motta, M. I. Trioni, G. P. Brivio, and D. Sánchez-Portal, J. Phys. Chem. C 118, 8775 (2014)
[2] D. Cvetko, G. Fratesi, G. Kladnik, A. Cossaro, G.P. Brivio, L. Venkataraman, and A. Morgante, Phys. Chem. Chem. Phys. 18, 22140 (2016)
[3] A. Ravikumar, G. Kladnik, M. Müller, A. Cossaro, G. Bavdek, L. Patera, D. Sánchez-Portal, L. Venkataraman, A. Morgante, G. P. Brivio, D. Cvetko, and G. Fratesi, Nanoscale 10, 8014 (2018)
Ivan I. Schmalhausen (1884–1963)
No full textIvan I. Schmalhausen (1884–1963) was a Ukrainian geneticist and zoologist
nowadays recognized as a central figure in the development of the modern
evolutionary synthesis. He studied with Alexey Nikolaevich Severtsov, a leading
biologist and the founder of the Russian school of evolutionary morphology, who
made relevant contributions in the field of comparative anatomy. Following
Severtsov’s teaching, Schmalhausen became an expert in evolutionary morphology of animals and directed his attention towards experimental zoology.
Author of over 150 scientific papers on the study of patterns of growth,
correlation, and evolutionary theories, his most important book, Factors of
Evolution, was published in Russia in 1947 and translated into English in 1949
with a foreword by Theodosius Dobzhansky.
At the core of Schmalhausen’s scientific production is the theory of the
organism as a whole and the notion of stabilizing selection, which places his
work next to that of the British biologist Conrad Waddington. Schmalhausen has
been the recipient of several scientific awards and appointed member of both the
Ukrainian Academy of Sciences (1922) and the Academy of Sciences of the
USSR (1935)
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