ATP7A-related copper transport disorders: A systematic review and definition of the clinical subtypes.

In patients with ATP7A-related disorders, counseling is challenging due to clinical overlap between the entities, the absence of predictive biomarkers and a clear genotype-phenotype correlation. We performed a systematic literature review by querying the MEDLINE and Embase databases identifying 143 relevant papers. We recorded data on the phenotype and genotype in 162 individuals with a molecularly confirmed ATP7A-related disorder in order to identify differentiating clinical criteria, evaluate genotype-phenotype correlations and propose management guidelines. Early seizures are specific for classical Menkes disease (CMD), that is characterized by early-onset neurodegenerative disease with high mortality rates. Ataxia is an independent indicator for atypical Menkes disease, that shows better survival rates than CMD. Bony exostoses, radial head dislocations, herniations and dental abnormalities are specific for occipital horn syndrome (OHS) that may further present with developmental delay and connective tissue manifestations. Intracranial tortuosity and bladder diverticula, both with high risk of complications, are common among all subtypes. Low ceruloplasmin is a more sensitive and discriminating biomarker for ATP7A-related disorders than serum copper. Truncating mutations are frequently associated with CMD, in contrast with splice site and intronic mutations which are more prevalent in OHS.

Impact of covalent functionalization by diazonium chemistry on the electronic properties of graphene on SiC.

Plenty of strategies focused on covalent interaction have been developed to functionalize graphene's surface in order to employ it in a wide range of applications. Among them, the use of radical species including nitrene, carbene and aryl diazonium salts is regarded as a promising strategy to establish the covalent functionalization of graphene. In this work, we highlight the effect of diazonium chemistry on the electronic properties of graphene on SiC. On the basis of X-ray and synchrotron-based photoemission experiments, we were able to prove that 3,4,5-trimethoxybenzenediazonium (TMeOD) units, reduced and chemisorbed onto graphene using electrochemistry, preserve the electronic structure of the Dirac cone, through inducing a slightly additional n-type doping of graphene, as revealed by a downshift of the Dirac cone probed by angle-resolved photoemission experiments.

Highly controllable direct femtosecond laser writing of gold nanostructures on titanium dioxide surfaces.

A highly reproducible and controllable deposition procedure for gold nanostructures on a titanium dioxide (TiO2) surface using femtosecond laser light has been demonstrated. This is realized by precisely focusing onto the TiO2 surface in the presence of a pure gold ion solution. The deposition is demonstrated both in dot arrays and line structures. Thanks to the multi-photon excitation, we observe that the deposition area of the nanostructures can be confined to a degree far greater than the diffraction limited focal spot. Finally, we demonstrate that catalytic activity with visible light irradiation is enhanced, proving the applicability of our new deposition technique to the catalytic field.

Substrate Effects in the Supramolecular Assembly of 1,3,5-Benzene Tricarboxylic Acid on Graphite and Graphene.

The behavior of small molecules on a surface depends critically on both molecule-substrate and intermolecular interactions. We present here a detailed comparative investigation of 1,3,5-benzene tricarboxylic acid (trimesic acid, TMA) on two different surfaces: highly oriented pyrolytic graphite (HOPG) and single-layer graphene (SLG) grown on a polycrystalline Cu foil. On the basis of high-resolution scanning tunnelling microscopy (STM) images, we show that the epitaxy matrix for the hexagonal TMA chicken wire phase is identical on these two surfaces, and, using density functional theory (DFT) with a non-local van der Waals correlation contribution, we identify the most energetically favorable adsorption geometries. Simulated STM images based on these calculations suggest that the TMA lattice can stably adsorb on sites other than those identified to maximize binding interactions with the substrate. This is consistent with our net energy calculations that suggest that intermolecular interactions (TMA-TMA dimer bonding) are dominant over TMA-substrate interactions in stabilizing the system. STM images demonstrate the robustness of the TMA films on SLG, where the molecular network extends across the variable topography of the SLG substrates and remains intact after rinsing and drying the films. These results help to elucidate molecular behavior on SLG and suggest significant similarities between adsorption on HOPG and SLG.

Comparative in vitro performances of bare Nitinol surfaces.

Comparative fibrinogen adsorption and platelet morphology were evaluated on a wide array of well-characterized Nitinol surfaces (polished, chemically etched, boiled in water, electropolished in different electrolytes and heat treated). XPS, SEM, AFM, atomic adsorption spectroscopy and electrochemistry were employed to acquire information on surface chemistry, topography and Ni release. Obtained surfaces, of various topographies and crystallinity from mostly amorphous to nano-crystalline with Ni concentration from 1 to 8%, induced Ni release into biological medium in a subtoxic range (0-11 ng/ml/cm(2)). Fibrinogen adsorption to Nitinol surfaces ranged from that characteristic to pure Ni (130 ng/cm(2)) to pure Ti (300 ng/cm(2)). It was directly proportional to the Ti surface concentration and correlated with open circuit potential related to surface charge. Human platelet morphology varied from round to fully spread depending on surface treatment. Base layer of fully spread cells detected on all surfaces could be even and smooth with no propensity for thrombosis or sticky causing platelet aggregation and thrombus-like structures. Using appropriate surface treatments thrombogenicity of Nitinol can be manipulated to satisfy both the requirements for stents and defect closures.

Structural analysis of wheat wax (Triticum aestivum, c.v. 'Naturastar' L.): from the molecular level to three dimensional crystals.

In order to elucidate the self assembly process of plant epicuticular waxes, and the molecular arrangement within the crystals, re-crystallisation of wax platelets was studied on biological and non-biological surfaces. Wax platelets were extracted from the leaf blades of wheat (Triticum aestivum L., c.v. 'Naturastar', Poaceae). Waxes were analysed by gas chromatography (GC) and mass spectrometry (MS). Octacosan-1-ol was found to be the most abundant chemical component of the wax mixture (66 m%) and also the determining compound for the shape of the wax platelets. The electron diffraction pattern showed that both the wax mixture and pure octacosan-1-ol are crystalline. The re-crystallisation of the natural wax mixture and the pure octacosan-1-ol were studied by scanning tunnelling microscopy (STM), atomic force microscopy (AFM), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Crystallisation of wheat waxes and pure octacosano-1-ol on the non polar highly ordered pyrolytic graphite (HOPG) led to the formation of platelet structures similar to those found on the plant surface. In contrast, irregular wax morphologies and flat lying plates were formed on glass, silicon, salt crystals (NaCl) and mica surfaces. Movement of wheat wax through isolated Convallaria majalis cuticles led to typical wax platelets of wheat, arranged in the complex patterns typical for C. majalis. STM of pure octacosan-1-ol monolayers on HOPG showed that the arrangement of the molecules strictly followed the hexagonal structure of the substrate crystal. Re-crystallisation of wheat waxes on non-polar crystalline HOPG substrate showed that technical surfaces could be used to generate microstructured, biomimetic surfaces. AFM and SEM studies proved that a template effect of the substrate determined the orientation of the re-grown crystals. These effects of the structure and polarity of the substrate on the morphology of the epicuticular waxes are relevant for understanding interactions between biological as well as technical surfaces and waxes.

Dynamics in physisorbed monolayers of 5-alkoxy-isophthalic acid derivatives at the liquid/solid interface investigated by scanning tunneling microscopy

Monolayers of isophthalic acid derivatives at the liquid/solid interface have been studied with scanning tunneling microscopy (STM). We have investigated the dynamics related to the phenomenon of solvent co-deposition, which was previously observed by our research group when using octan-1-ol or undecan-1-ol as solvents for 5-alkoxy-isophthalic acid derivatives. This solvent co-deposition has now been visualized in real-time (two frames per second) for the first time. Dynamics of individual molecules were investigated in mixtures of semi-fluorinated molecules with video-STM. The specific contrast arising from fluorine atoms in STM images allows us to use this functionality as a probe to analyze the data obtained for the mixtures under investigation. Upon imaging the same region of a monolayer for a period of time we observed that non-fluorinated molecules progressively substitute the fluorinated molecules. These findings illustrate the metastable equilibrium that exists at the liquid/solid interface, between the physisorbed molecules and the supernatant solution.

Scanning tunneling microscopy: a unique tool in the study of chirality, dynamics, and reactivity in physisorbed organic monolayers.

Scanning tunneling microscopy (STM) is applied to study organic monolayers, physisorbed at the liquid-graphite interface. Due to the very local nature of the probing, the structure of these adlayers has been imaged with very high detail. The high resolution allowed us to investigate the effect of molecular chirality on the monolayer formation and provided a unique way to study chemical reactions at the liquid-graphite interface. Making use of a fast scanning mode, dynamic processes in these adlayers have been visualized.

Femtosecond Dynamics of Norrish Type-II Reactions: Nonconcerted Hydrogen-Transfer and Diradical Intermediacy.

Norrish type-II and McLafferty rearrangements, which both involve an intramolecular transfer of a gamma H atom, can be differentiated on the femtosecond time scale. The McLafferty rearrangement results in ion fragmentation of the parent ketone, whereas the Norrish type-II reaction leads to a diradical species, which then either cyclizes or fragments (see scheme). For Norrish type-II reactions, the reaction time for the transfer of the hydrogen atom is within 70 - 90 fs, and the lifetime of the diradical intermediate is in the range of 400 - 700 ps at the total energy studied.

Terrylenimides: New NIR Fluorescent Dyes.

Terrylenimides 3 and 4 represent a new class of blue colorants, exhibiting absorption maxima at 650 to 700 nm and fluorescence emissions in the NIR region (673 to 750 nm). The terrylenimides were synthesized by means of various organometallic coupling reactions, catalyzed by transition metal complexes (Ni(o) , Pd(o) ) and starting from the aromatic bromides, boronic acids, or organotin compounds. The terrylenimides have all the properties expected of excellent fluorescent dyes: high extinction coefficients, high fluorescence quantum yields, and very good thermal, chemical, and photochemical stabilities. Owing to its extended π system, 3 can reversibly accept four negative charges. By varying the substituents, 3 and 4 can be modified to serve either as soluble dyes or as insoluble pigments.