8 research outputs found
Solvent-Driven Supramolecular Wrapping of Self-Assembled Structures
Self‐assembly relies on the ability of smaller and discrete entities to spontaneously arrange into more organized systems by means of the structure‐encoded information. Herein, we show that the design of the media can play a role even more important than the chemical design. The media not only determines the self‐assembly pathway at a single‐component level, but in a very narrow solvent composition, a supramolecular homo‐aggregate can be non‐covalently wrapped by a second component that possesses a different crystal lattice. Such a process has been followed in real time by confocal microscopy thanks to the different emission colors of the aggregates formed by two isolated PtII complexes. This coating is reversible and controlled by the media composition. Single‐crystal X‐ray diffraction and molecular simulations based on coarse‐grained (CG) models allowed the understanding of the properties displayed by the different aggregates. Such findings could result in a new method to construct hierarchical supramolecular structures
Structural effects of trifluoromethylation and fluorination in gold(i) BIPHEP fluorothiolates
p-Backbonding and non-covalent interactions in the JohnPhos and polyfluorothiolate complexes of gold(i)
Beyond conventional physical examination in hepatology: POCUS
Point-of-care ultrasound (POCUS) refers to the use of ultrasound imaging through pocket-sized sonographic devices at the patient’s bedside, to make a diagnosis or direct a procedure and immediately answer a clinical question. Its goal is to broaden the physical examination, not to replace conventional ultrasound studies. POCUS has evolved as a complement to physical examination and has been adopted by different medical specialties, including hepatology. A narrative synthesis of the evidence on the applications of POCUS in hepatology was carried out, describing its usefulness in the diagnosis of cirrhosis of the liver, metabolic dysfunction-associated steatotic liver disease (MASLD), decompensated cirrhosis, and portal hypertension. The review also encompasses more recent applications in the hemodynamic evaluation of the critically ill patient with cirrhosis of the liver, patients with other liver diseases, as well as in the ultrasound guidance of procedures.POCUS could make up part of the daily clinical practice of gastroenterologists and hepatologists, simplifying the initial evaluation of patients and optimizing clinical management. Its accessibility, ease of use, and low adverse event profile make POCUS a useful tool for the properly trained physician in the adequate clinical setting. The aim of this review was to describe the available evidence on the usefulness of POCUS in the daily clinical practice of gastroenterologists and hepatologists. Resumen: La ecografía en el punto de atención (POCUS) se refiere a la utilización del ultrasonido (US) mediante dispositivos ultrasonográficos de bolsillo, al pie de la cama del paciente, con el objetivo de establecer un diagnóstico o dirigir un procedimiento y responder a una cuestión clínica de forma inmediata, su finalidad es ampliar la exploración física, no sustituir la evaluación ultrasonográfica convencional. POCUS ha evolucionado como un complemento del examen físico siendo adoptado por distintas especialidades médicas, incluyendo la hepatología. Se elaboró una síntesis de evidencia narrativa sobre las aplicaciones de POCUS en hepatología, describiendo la utilidad de POCUS en el diagnóstico de cirrosis hepática, enfermedad hepática esteatósica asociada a disfunción metabólica (MASLD, por sus siglas en inglés), cirrosis descompensada y el diagnóstico de hipertensión portal, así como las más recientes aplicaciones de POCUS en la evaluación hemodinámica del paciente con cirrosis hepática en estado crítico, otras enfermedades hepáticas y guía ultrasonográfica de procedimientos.POCUS podría formar parte de la práctica clínica diaria de gastroenterólogos y hepatólogos, simplificando la evaluación inicial de los pacientes y optimizando el manejo clínico. Su accesibilidad, facilidad de uso y bajo perfil de efectos adversos la hacen una herramienta útil para el médico propiamente entrenado en el escenario clínico adecuado, por lo que el objetivo de esta revisión fue describir la evidencia que existe sobre la utilidad de POCUS en la práctica clínica diaria de gastroenterólogos y hepatólogos
Structural Diversity and Argentophilic Interactions in Small Phosphine Silver(I) Thiolate Clusters
10 pags., 5 figs., 4 tabs.Silver(I) coordination compounds display an interesting geometrical diversity, the possibility of having distinct coordination numbers (typically from 2 to 4) and the capability of forming argentophilic (Ag⋅⋅⋅Ag) interactions. These properties complicate the accurate prediction of structures of silver complexes under certain experimental conditions. In this work, we show how subtle modifications in thiolate and phosphine ligands exert important effects on the nuclearity and geometry of phosphine caped clusters [Ag(SR)] (n=4, 6 and 8). We rationalize these effects in terms of the electronic environment of silver centers by analyzing the electronic density of the single-crystal X-ray structures via the Quantum Theory of Atoms in Molecules (QTAIM) and the Non-Covalent Interaction (NCI)-Index. Furthermore, we characterized attractive and repulsive argentophilic contacts by means of the Interacting Quantum Atoms (IQA) energy partition. Our results provide insights on the effects of ancillary ligands in controlling the structure of silver-thiolate clusters. Such control is relevant towards a bottom-up approach to the atomic precise construction of higher nuclearity clusters.We acknowledge fundingby DGAPA-UNAM project IN210818,andby CONACYT-Mexico through the postdoctoral grant 740732. We are also thankful for the instrumental support of the Unit for Industryand Research Support (USAII)at the School of Chemistry at UNAM, Mexico and for the computer time provided by DGTIC/UNAMproject LANCAD-DGTIC-UNAM-250.G.M.-A acknowledges the RSC-Chemists’CommunityFund suppor
Gypsophila bermejoi G. López: A possible case of speciation repressed by bioclimatic factors
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Genomic surveillance reveals dynamic shifts in the connectivity of COVID-19 epidemics
Summary:
The maturation of genomic surveillance in the past decade has enabled tracking of the emergence and spread of epidemics at an unprecedented level. During the COVID-19 pandemic, for example, genomic data revealed that local epidemics varied considerably in the frequency of SARS-CoV-2 lineage importation and persistence, likely due to a combination of COVID-19 restrictions and changing connectivity. Here, we show that local COVID-19 epidemics are driven by regional transmission, including across international boundaries, but can become increasingly connected to distant locations following the relaxation of public health interventions. By integrating genomic, mobility, and epidemiological data, we find abundant transmission occurring between both adjacent and distant locations, supported by dynamic mobility patterns. We find that changing connectivity significantly influences local COVID-19 incidence. Our findings demonstrate a complex meaning of ‘local’ when investigating connected epidemics and emphasize the importance of collaborative interventions for pandemic prevention and mitigation