Increasing Dimensionality in Self-Assembly: Toward Two-Dimensional Supramolecular Polymers.

Different approaches to achieve 2D supramolecular polymers, as an alternative to the covalent bottom-up approaches reported for the preparation of 2D materials, are reviewed. The significance of the operation of weak non-covalent forces to induce a lateral growth of a number of self-assembling units is collected. The examples of both thermodynamically and kinetically controlled formation of 2D supramolecular polymers showed in this review demonstrate the utility of this strategy to achieve new 2D materials with biased morphologies (nanosheets, scrolls, porous surfaces) and showing elegant applications like chiral recognition, enantioselective uptake or asymmetric organic transformations. Furthermore, elaborated techniques like seeded or living supramolecular polymerizations have been demonstrated to give rise to complex 2D nanostructures.

Whole-Exome Sequencing of 21 Families: Candidate Genes for Early-Onset High Myopia.

High myopia is the most severe and pathological form of myopia. It occurs when the spherical refractive error exceeds -6.00 spherical diopters (SDs) or the axial length (AL) of the eye is greater than 26 mm. This article focuses on early-onset high myopia, an increasingly common condition that affects children under 10 years of age and can lead to other serious ocular pathologies. Through the genetic analysis of 21 families with early-onset high myopia, this study seeks to contribute to a better understanding of the role of genetics in this disease and to propose candidate genes. Whole-exome sequencing studies with a panel of genes known to be involved in the pathology were performed in families with inconclusive results: 3% of the variants found were classified as pathogenic, 6% were likely pathogenic and the remaining 91% were variants of uncertain significance. Most of the families in this study were found to have alterations in several of the proposed genes. This suggests a polygenic inheritance of the pathology due to the cumulative effect of the alterations. Further studies are needed to validate and confirm the role of these alterations in the development of early-onset high myopia and its polygenic inheritance.

How can we improve the quality of health care in hospital attendance of medically complex children? / ¿Cómo podemos mejorar la calidad de la atención hospitalaria de los pacientes crónicos complejos en pediatría?

Hospital care of medically complex children (MCC) is increasing, although its real prevalence in Spain is unknown. OBJECTIVE: to analyze hospital admissions and outpatient follow-up of MCC in order to identify strategies to improve the quality of care of MCC. PATIENTS AND METHOD: An analytical, observational, and retrospective study was carried out. We included MCC who were admitted to Pediatric Hospitalization in the last 5 years, in a tertiary hospital without a specific unit for MCC. Clinical data related to their underlying pathology, outpatient visits, and hospital admissions were collected. A multivariate study was carried out to describe risk factors of the need for technological support and to predict prolonged admissions and the hospital consultation rate. RESULTS: 99 MCC (55.6% males) aged 3.9 (2-8) years were included. 41.4% of MCC required technological support at home and presented the highest number of comorbidities, hospital admissions, and care by different specialists (p < 0.01). Older MCC (p < 0.01) with underlying digestive disease (p < 0.04) and respiratory comorbidity (p < 0.04) presented a longer mean hospital stays. Younger patients with more admissions, longer average stay, and a lack of follow-up by the link nurse were associated with a greater number of annual consultations (p < 0.05). CONCLUSIONS: MCC require a high number of annual consultations and have long hospital stays. The creation of specialized consultations for MCC, multidisciplinary care, and the participation of the link nurse are strategies to improve the quality of care for MCC in hospitals without specific MCC units.

Whole-Exome Sequencing of 24 Spanish Families: Candidate Genes for Non-Syndromic Pediatric Keratoconus.

Keratoconus is a corneal dystrophy that is one of the main causes of corneal transplantation and for which there is currently no effective treatment for all patients. The presentation of this disease in pediatric age is associated with rapid progression, a worse prognosis and, in 15-20% of cases, the need for corneal transplantation. It is a multifactorial disease with genetic variability, which makes its genetic study difficult. Discovering new therapeutic targets is necessary to improve the quality of life of patients. In this manuscript, we present the results of whole-exome sequencing (WES) of 24 pediatric families diagnosed at the University Hospital La Paz (HULP) in Madrid. The results show an oligogenic inheritance of the disease. Genes involved in the structure, function, cell adhesion, development and repair pathways of the cornea are proposed as candidate genes for the disease. Further studies are needed to confirm the involvement of the candidate genes described in this article in the development of pediatric keratoconus.

Whole Exome Sequencing of 20 Spanish Families: Candidate Genes for Non-Syndromic Pediatric Cataracts.

Non-syndromic pediatric cataracts are defined as opacification of the crystalline lens that occurs during the first years of life without affecting other organs. Given that this disease is one of the most frequent causes of reversible blindness in childhood, the main objective of this study was to propose new responsible gene candidates that would allow a more targeted genetic approach and expand our genetic knowledge about the disease. We present a whole exome sequencing (WES) study of 20 Spanish families with non-syndromic pediatric cataracts and a previous negative result on an ophthalmology next-generation sequencing panel. After ophthalmological evaluation and collection of peripheral blood samples from these families, WES was performed. We were able to reach a genetic diagnosis in 10% of the families analyzed and found genes that could cause pediatric cataracts in 35% of the cohort. Of the variants found, 18.2% were classified as pathogenic, 9% as likely pathogenic, and 72.8% as variants of uncertain significance. However, we did not find conclusive results in 55% of the families studied, which suggests further studies are needed. The results of this WES study allow us to propose LONP1, ACACA, TRPM1, CLIC5, HSPE1, ODF1, PIKFYVE, and CHMP4A as potential candidates to further investigate for their role in pediatric cataracts, and AQP5 and locus 2q37 as causal genes.

Protein-directed crystalline 2D fullerene assemblies.

Water soluble 2D crystalline monolayers of fullerenes grow on planar assemblies of engineered consensus tetratricopeptide repeat proteins. Designed fullerene-coordinating tyrosine clamps on the protein introduce specific fullerene binding sites, which facilitate fullerene nucleation. Through reciprocal interactions between the components, the hybrid material assembles into two-dimensional 2 nm thick structures with crystalline order, that conduct photo-generated charges. Thus, the protein-fullerene hybrid material is a demonstration of the developments toward functional materials with protein-based precision control of functional elements.

Fine-tuning the assemblies of carbon nanodots and porphyrins.

We present charge-transfer assemblies of electron accepting, pressure-synthesized carbon nanodots (pCNDs) and an electron donating porphyrin. Amidine derivatization of the porphyrin allows for hydrogen bonding interactions with the carboxyl groups on the surface of pCNDs, which drive the formation of the assembly. Upon photoexcitation, this electron donor-acceptor supramolecular construct features ultrafast charge separation, and subsequent charge recombination in 27 ps.

Tuning Optoelectronic and Chiroptic Properties of Peptide-Based Materials by Controlling the Pathway Complexity.

Supramolecular chemistry has evolved from the traditional focus on thermodynamic on-pathways to the complex study of kinetic off-pathways, which are strongly dependent on environmental conditions. Moreover, the control over pathway complexity allows nanostructures to be obtained that are inaccessible through spontaneous thermodynamic processes. Herein, we present a family of peptide-based π-extended tetrathiafulvalene (exTTF) molecules that show two self-assembly pathways leading to two distinct J-aggregates, namely metastable (M) and thermodynamic (T), with different spectroscopic, chiroptical, and electrochemical behavior. Moreover, cryo-transmission electron microscopy (cryo-TEM) reveals a different morphology for both aggregates and a direct observation of the morphological transformations from tapes to twisted ribbons.

Supramolecular Electronic Interactions in Porphyrin-SWCNT Hybrids through Amidinium-Carboxylate Connectivity.

New supramolecular (metal)porphyrin/SWCNT hybrids have been synthesized through a combination of hydrogen bond and electrostatic interactions. Our experimental findings reveal through different techniques (XPS, TGA, UV-vis, Raman, and TEM) an efficient n-doping of the SWCNT from the electron donor (metal)porphyrin through the efficient and strong amidinium-carboxylate connectivity.

Mesoscopic helical architectures via self-assembly of porphyrin-based discotic systems.

Mesoscopic super-helices with preferred helicity have been serendipitously formed from the self-assembly of electroactive extended core discotic molecules. The investigation at dilute concentrations reveals intramolecular hydrogen-bonding and π-π stacking interactions as the driving force of the chiral self-assembly at different length scales.

Determining the Attenuation Factor in Molecular Wires Featuring Covalent and Noncovalent Tectons.

Hybrid covalent/supramolecular porphyrin-fullerene structures were synthesized as highly efficient molecular wires with a remarkably low attenuation factor (ß=0.07±0.01 Å-1 ). Hydrogen-bonding interactions and p-phenylene oligomers of different lengths are responsible for efficient electron transfer in the molecular wires.

Repeat protein scaffolds: ordering photo- and electroactive molecules in solution and solid state.

The precise control over the organization of photoactive components at the nanoscale is one of the main challenges for the generation of new and sophisticated macroscopically ordered materials with enhanced properties. In this work we present a novel bioinspired approach using protein-based building blocks for the arrangement of photo- and electroactive porphyrin derivatives. We used a designed repeat protein scaffold with demonstrated unique features that allow for the control of their structure, functionality, and assembly. Our designed domains act as exact biomolecular templates to organize porphyrin molecules at the required distance. The hybrid conjugates retain the structure and assembly properties of the protein scaffold and display the spectroscopic features of orderly aggregated porphyrins along the protein structure. Finally, we achieved a solid ordered bio-organic hybrid thin film with anisotropic photoconductivity.

Supramolecular One-Dimensional n/p-Nanofibers.

Currently, there is a broad interest in the control over creating ordered electroactive nanostructures, in which electron donors and acceptors are organized at similar length scales. In this article, a simple and efficient procedure is reported en-route towards the construction of 1D arrays of crystalline pristine C60 and phenyl-C61-butyric acid methyl ester (PCBM) coated onto supramolecular fibers based on exTTF-pentapeptides. The resulting n/p-nanohybrids have been fully characterized by a variety of spectroscopic (FTIR, UV-Vis, circular dichroism, Raman and transient absorption), microscopic (AFM, TEM, and SEM), and powder diffraction (X-ray) techniques. Our experimental findings document the tendency of electroactive exTTF-fibers to induce the crystallization of C60 and PCBM, on one hand, and to afford 1D n/p-nanohybrids, on the other hand. Furthermore, photogenerated radical ion pairs, formed upon visible light irradiation of the n/p-nanohybrids, feature lifetimes on the range of 0.9-1.2 ns.

Supramolecular pentapeptide-based fullerene nanofibers: effect of molecular chirality.

The supramolecular organization of new fullerene derivatives endowed with peptides as biomolecular templates affords ordered nanofibers of several micrometres length based on hydrogen bonds and π-π interactions.

Electron-deficient fullerenes in triple-channel photosystems.

Fullerenes of increasing electron deficiency are designed, synthesized and evaluated in multicomponent surface architectures to ultimately build gradients in LUMO levels with nine components over 350 meV down to -4.22 eV.

Highly ordered n/p-co-assembled materials with remarkable charge mobilities.

Controlling self-organization and morphology of chemical architectures is an essential challenge in the search for higher energy-conversion efficiencies in a variety of optoelectronic devices. Here, we report a highly ordered donor/acceptor functional material, which has been obtained using the principle of ionic self-assembly. Initially, an electron donor π-extended tetrathiafulvalene and an electron-acceptor perylene-bisimide were self-organized separately obtaining n- and p-nanofibers at the same scale. These complementary n- and p-nanofibers are endowed with ionic groups with opposite charges on their surfaces. The synergic interactions establish periodic alignments between both nanofibers resulting in a material with alternately segregated donor/acceptor nanodomains. Photoconductivity measurements show values for these n/p-co-assembled materials up to 0.8 cm(2) V(-1) s(-1), confirming the effectiveness in the design of these heterojunction structures. This easy methodology offers great possibilities to achieve highly ordered n/p-materials for potential applications in different areas such as optoelectonics and photovoltaics.

Controlling the crystalline three-dimensional order in bulk materials by single-wall carbon nanotubes.

The construction of ordered single-wall carbon nanotube soft-materials at the nanoscale is currently an important challenge in science. Here we use single-wall carbon nanotubes as a tool to gain control over the crystalline ordering of three-dimensional bulk materials composed of suitably functionalized molecular building blocks. We prepare p-type nanofibres from tripeptide and pentapeptide-containing small molecules, which are covalently connected to both carboxylic and electron-donating 9,10-di(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene termini. Adding small amounts of single-wall carbon nanotubes to the so-prepared p-nanofibres together with the externally controlled self assembly by charge screening by means of Ca(2+) results in new and stable single-wall carbon nanotube-based supramolecular gels featuring remarkably long-range internal order.

A collection of fullerenes for synthetic access toward oriented charge-transfer cascades in triple-channel photosystems.

The development of synthetic methods to build complex functional systems is a central and current challenge in organic chemistry. This goal is important because supramolecular architectures of highest sophistication account for function in nature, and synthetic organic chemistry, contrary to high standards with small molecules, fails to deliver functional systems of similar complexity. In this report, we introduce a collection of fullerenes that is compatible with the construction of multicomponent charge-transfer cascades and can be placed in triple-channel architectures next to stacks of oligothiophenes and naphthalenediimides. For the creation of this collection, modern fullerene chemistry-methanofullerenes and 1,4-diarylfullerenes-is combined with classical Nierengarten-Diederich-Bingel approaches.

Concave versus planar geometries for the hierarchical organization of mesoscopic 3D helical fibers.

Chromophore-peptide systems: a study on a series of pentapeptides covalently connected to planar π systems (1 a and 1 b) or to a curved π system (1 c) showed the influence of the concave shape on the efficient chiral transmission at nano- and mesoscales. Control over the hierarchical growth by H bonding, π-π, and solvophobic interactions made possible the efficient generation of electroactive 3D helical fibers.