Thinking Outside the Blue Box: Induced Fit within a Unique Self-Assembled Polycationic Cyclophane

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Journal of the American Chemical Society.[Abstract] We present herein the development of a new polycationic molecular receptor, inspired by the ubiquitous cyclobis(paraquat-p-phenylene)cyclophane (“blue box”). Our analogue, the “white box”, has been easily self-assembled on a preparative scale in water, using a template-assisted process by acyl hydrazone bonding of complementary bis(pyridinium)xylylene tweezers, followed by kinetic trapping of the empty receptor. The obtained macrocycle was found to display a marked pH responsiveness in water, because of an abnormal acidity of the amide protons within its structure. Consequently, and because of the concurrence of rotational isomerism under acidic conditions (fixed at higher pH values), the compound was found to display a dual behavior as a conformationally locked/flexible molecular host, being able to recognize appropriate aromatic substrates, in a lock and key or induced fit fashion, by a conjunction of π–π, C–H···π, and, crucially, the hydrophobic effect.This research was supported by the Ministerio de Economía y Competitividad (MINECO FEDER, Grant CTQ2016-75629-P

Corinth terraces re-visited: Improved paleoshoreline determination using Pleiades-DEMs

International audienceThe newest generation of satellites have greatly improved the capabilities of optical imagery over the last decade. Ground resolution has increased by one order of magnitude (to sub-metric pixel images), and improved sensors allow images to be located with an absolute accuracy of within a few meters. Better-resolved images facilitate refined tectonic studies of faults, basins, terraces, and other geomorphic features as it provides the opportunity to extract detailed topographic information. We have developed high-resolution digital elevation models (DEMs) in eight locations in Greece from tri-stereo satellite images acquired by the new Pleiades platform of CNES. With 0.5m resolution, these DEMs are state-of-the-art in comparison to previous DEMs made from satellite imagery. In this study we explore the potential of one of these DEMs, in the eastern Gulf of Corinth, for the analysis of a flight of marine terraces

A convenient synthesis of new 6-substituted purinylcarbanucleosides on cyclopenta[b]thiophene

The 12th International Electronic Conference on Synthetic Organic Chemistry session Bioorganic Chemistry and Natural ProductsThe first members of a new family of heterocarbobicyclic nucleoside analogues have been synthesized from the cis/trans mixture of (4-amino-5,6-dihydro-4H-cyclopenta[b]thiophen-6-yl)methanols cis/trans-7. The separation of cis and trans intermediates during preparation of the 6-chloropurine derivatives allowed separate preparation of the purine heterocarbanucleosides cis-10 and trans-11, from which cis-(12-14) and trans-(16-18) were obtained by replacement of the 6-chloro substituent with amino, hydroxy and cyclopropylamino groups. Additionally, the 6-phenyl-purinyl analogues cis-15 and trans-19 were prepared from cis-10 and trans-11 using Suzuki-Miyaura methodologyThe authors thank the Xunta de Galicia for financial support under project PGIDIT02BTF20305P

Desarrollo y validación experimental de una metodología para estudiar la propagación de grietas por fatiga en metales

La presencia y propagación de grietas en estructuras y componentes es un reto para sectores industriales como el oil&gas, energía eólica o nuclear. El presente estudio resume la investigación realizada para desarrollar y validar un procedimiento basado en el método de los Elementos Finitos capaz de simular la propagación de grietas tridimensionales. La investigación comprende una parte experimental donde se ha caracterizado la velocidad de propagación de fisuras frente a fatiga del acero grado R5, utilizado en cadenas de fondeo offshore. Para ello se ha determinado la Ley de Paris del material mediante el ensayo de una probeta de flexión en tres puntos. Asimismo, se ha realizado un estudio estadístico para estimar la incertidumbre en la velocidad de propagación de la grieta. Los resultados experimentales han sido empleados como inputs del modelo numérico desarrollado en ANSYS APDL. Este algoritmo permite evaluar numéricamente los parámetros de la mecánica de la fractura en el frente de fisura durante su crecimiento. Esta información alimenta un algoritmo iterativo que proporciona el avance del frente de fisura. Finalmente, se ha realizado un estudio de sensibilidad para evaluar el efecto del tamaño del mallado en los resultados.The existence and propagation of cracks in structures and components is a challenge for industrial sectors such as oil & gas, wind or nuclear. The present study summarizes the research carried out to develop and validate a procedure, based on the finite element method, able to simulate the propagation of three-dimensional cracks. This research comprises an experimental part where the fatigue crack propagation rate of the grade R5 steel, widely used in offshore mooring chains, has been characterized. For this purpose, the Paris Law of the material has been determined by testing a three point bending specimen. Furthermore, a statistical study to estimate the uncertainty in the crack propagation rate was carried out. The experimental results have been used as inputs for the numerical model developed in ANSYS APDL. This algorithm allows numerical evaluating the fracture mechanics parameters in the crack front during its growth. This information feedbacks an iterative algorithm that provides the crack front growth. Finally, a sensitivity study was carried out to evaluate the effect of the meshing size on the results

Aqueous Three-Component Self-Assembly of a Pseudo[1]rotaxane Using Hydrazone Bonds

[Abstract] We present herein the synthesis of a new polycationic pseudo[1]rotaxane, self-assembled in excellent yield through hydrazone bonds in aqueous media of three different aldehyde and hydrazine building blocks. A thermodynamically controlled process has been studied sequentially by analyzing the [1 + 1] reaction of a bisaldehyde and a trishydrazine leading to the macrocyclic part of the system, the ability of this species to act as a molecular receptor, the conversion of a hydrazine-pending cyclophane into the pseudo[1]rotaxane and, lastly, the one-pot [1 + 1 + 1] condensation process. The latter was found to smoothly produce the target molecule through an integrative social self-sorting process, a species that was found to behave in water as a discrete self-inclusion complex below 2.5 mM concentration and to form supramolecular aggregates in the 2.5–70 mM range. Furthermore, we demonstrate how the abnormal kinetic stability of the hydrazone bonds on the macrocycle annulus can be advantageously used for the conversion of the obtained pseudo[1]rotaxane into other exo-functionalized macrocyclic species.The authors are thankful for the funding received from the MCIN/AEI/10.13039/501100011033 and ERDF “A way of making Europe” (CTQ2016-75629-P, CTQ2017-89166-R and PID2019-105272GB-I00), the Consellería de Cultura, Educación e Universidade, Xunta de Galicia (ED431C 2018/39, ED431C 2022/39 and 508/2020), and the European Research Council (ERC) under the European Union’s Horizon 2020 Research and Innovation Programme (Grant Agreement No. 851179). P.C. and A.B.-G. thank the Consellería de Cultura, Educación e Universidade, Xunta de Galicia for their PhD and postdoctoral fellowships (ED481A-2020/019 and ED481B-2021-099, respectively). M.D.-A. thanks the Fundación Gil Dávila and the Ministerio de Universidades (FPU21/06302) for his PhD fellowships. E.P. thanks the MCIN/AEI/10.13039/501100011033 and ESF “Investing in your future” for her Ramón y Cajal contract (RYC2019-027199-I)Xunta de Galicia; ED431C 2018/39Xunta de Galicia; ED431C 2022/39Xunta de Galicia; 508/2020Xunta de Galicia; ED481A-2020/019Xunta de Galicia; ED481B-2021-09

Relación entre las concentraciones de polen aéreo de Artemisia, Chenopodiaceae, Plantago y Taraxacum y la prevalencia de polinosis en estudiantes universitarios de León

XV lnternational A.P.L.E. Symposium of Palynolog

Recycling of Waste Toner Powder as Adsorbent to Remove Aqueous Heavy Metals

[EN] The removal of Cd2+, Zn2+ and Ni2+ from metal solutions onto waste toner power (WTP) was investigated. The influence of parameters such as pH, contact time, initial metal concentration and adsorbent dosage was studied in batch adsorption experiments. Batch equilibrium experiments showed that the highest removal efficiency for Zn2+ and Cd2+ occurs at pH 7, while pH 5 is the most suitable for Ni2+ removal. The amount of metal removed (mg/g) improved when increasing the initial concentration, and sorption of heavy metals reached equilibrium in 24 h. Metals’ uptake increased with increasing adsorbent dosage. The adsorption isotherms of Zn2+, Cd2+ and Ni2+ onto WTP fit the Langmuir better than the Freundlich model with correlation coefficient R2 values ranging from 0.998 to 0.968 and 0.989 to 0.881, respectively. The data showed that the maximum adsorption capacity of heavy metals, amax, ranged from 2.42 to 1.61 mg/g, from 6.22 to 2.01 mg/g and from 3.49 to 2.56 mg/g for Ni2+, Zn2+ and Cd2+, respectively, with the three WTPs used in this study. This adsorbent can potentially be used to remove metal ions from wastewater.SIThis work has been partially supported by RECYCLIA and by projects MCI-20-PID2019- 106939GB-I00 financed by the STATE AGENCY FOR RESEARCH (MINECO)

“Skills for pills”: The dialectical-behavioural therapy skills training reduces polypharmacy in borderline personality disorder

Objective: Polypharmacy and overprescription of off-label medications are common in patients with borderline personality disorder (BPD). The aim of the present naturalistic study was to explore whether the skills training module of dialectical-behavioural therapy (DBT) can reduce polypharmacy in these patients in routine clinical practice. Methods: Retrospective, observational study of 377 patients with a primary diagnosis of BPD consecutively admitted to the BPD outpatient unit from 2010 through 2020. All patients were invited to participate in the DBT skills training module (DBT-ST). DBT-ST participants (n = 182) were compared with a control group who did not participate in DBT-ST (n = 195). Pre-post intervention changes in medication load and use of antidepressants, benzodiazepines, mood stabilizers, and antipsychotics were evaluated. Results: At baseline, most patients (84.4%) were taking at least one medication and 46.9% were on polypharmacy. Compared to controls, patients in the DBT-ST group presented a significant reduction in the number of medications (2.67–1.95 vs. 2.16–2.19; p < 0.001), medication load (4.25–3.05 vs. 3.45–3.48; p < 0.001), use of benzodiazepines (54.4%–27.5% vs. 40%–40.5%; p < 0.001), mood stabilizers (43.4%–33% vs. 36.4%–39.5%; p < 0.001), and antipsychotics (36.3%–29.1% vs. 34.4%–36.9%; p < 0.001). Conclusions: These findings suggest that patients with BPD can benefit from the DBT-ST module, which may reduce the medication load, particularly of sedatives. The results suggest that DBT-ST may be useful to treat overmedication in patients with BPD and could help to promote “deprescription” in clinical practice.This study was supported by Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). The authors would like to thank Bradley Londres for professional English language editing

Strain-balanced type-II superlattices for efficient multi-junction solar cells

Multi-junction solar cells made by assembling semiconductor materials with different bandgap energies have hold the record conversion efficiencies for many years and are currently approaching 50%. Theoretical efficiency limits make use of optimum designs with the right lattice constant-bandgap energy combination, which requires a 1.0–1.15 eV material lattice-matched to GaAs/Ge. Nevertheless, the lack of suitable semiconductor materials is hindering the achievement of the predicted efficiencies, since the only candidates were up to now complex quaternary and quinary alloys with inherent epitaxial growth problems that degrade carrier dynamics. Here we show how the use of strain-balanced GaAsSb/GaAsN superlattices might solve this problem. We demonstrate that the spatial separation of Sb and N atoms avoids the ubiquitous growth problems and improves crystal quality. Moreover, these new structures allow for additional control of the effective bandgap through the period thickness and provide a type-II band alignment with long carrier lifetimes. All this leads to a strong enhancement of the external quantum efficiency under photovoltaic conditions with respect to bulk layers of equivalent thickness. Our results show that GaAsSb/GaAsN superlattices with short periods are the ideal (pseudo)material to be integrated in new GaAs/Ge-based multi-junction solar cells that could approach the theoretical efficiency limit