15 research outputs found
Stereochemistry‐Controlled Supramolecular Architectures of New Tetrahydroxy‐Functionalised Amphiphilic Carbocyanine Dyes
The syntheses of novel amphiphilic 5,5′,6,6‐tetrachlorobenzimidacarbocyanine (TBC) dye derivatives with aminopropanediol head groups, which only differ in stereochemistry (chiral enantiomers, meso form and conformer), are reported. For the achiral meso form, a new synthetic route towards asymmetric cyanine dyes was established. All compounds form J aggregates in water, the optical properties of which were characterised by means of spectroscopic methods. The supramolecular structure of the aggregates is investigated by means of cryo‐transmission electron microscopy, cryo‐electron tomography and AFM, revealing extended sheet‐like aggregates for chiral enantiomers and nanotubes for the mesomer, respectively, whereas the conformer forms predominately needle‐like crystals. The experiments demonstrate that the aggregation behaviour of compounds can be controlled solely by head group stereochemistry, which in the case of enantiomers enables the formation of extended hydrogen‐bond chains by the hydroxyl functionalities. In case of the achiral meso form, however, such chains turned out to be sterically excluded
Multivalent bacteria binding by flexible polycationic microsheets matching their surface charge density
Aiming at the overall negative surface charge of bacteria, a new strategy of antibacterial agents based on large polymer‐modified graphene oxide (GO) sheets is assessed. The presented flexible, polycationic sheets match the size and charge density of the Escherichia coli surface charge density (2 × 1014 cm−2). These matching parameters create an unspecific but very strong bacteria adsorber by multivalent, electrostatic attraction. Their interaction with bacteria is visualized via atomic force and confocal microscopy and shows that they effectively bind and wrap around E. coli cells, and thereby immobilize them. The incubation of Gram‐negative and ‐positive bacteria (E. coli and methicillin‐resistant Staphylococcus aureus , MRSA) with these polycationic sheets leads to the inhibition of proliferation and a reduction of the colony forming bacteria over time. This new type of antibacterial agent acts in a different mode of action than classical biocides and could potentially be employed in medicinal, technical, or agriculture applications. The presented microsheets and their unspecific binding of cell interfaces could further be employed as adsorber material for bacterial filtration or immobilization for imaging, analysis, or sensor technologies
Adaptive flexible sialylated nanogels as highly potent influenza A virus inhibitors
Flexible multivalent 3D nanosystems that can deform and adapt onto the virus surface via specific ligand–receptor multivalent interactions can efficiently block virus adhesion onto the cell. We here report on the synthesis of a 250 nm sized flexible sialylated nanogel that adapts onto the influenza A virus (IAV) surface via multivalent binding of its sialic acid (SA) residues with hemagglutinin spike proteins on the virus surface. We could demonstrate that the high flexibility of sialylated nanogel improves IAV inhibition by 400 times as compared to a rigid sialylated nanogel in the hemagglutination inhibition assay. The flexible sialylated nanogel efficiently inhibits the influenza A/X31 (H3N2) infection with IC50 values in low picomolar concentrations and also blocks the virus entry into MDCK‐II cells
Investigación en Matemáticas, Economía, Ciencias Sociales y Agronomía
Cada trabajo del libro incluye conclusiones para los interesados en las temáticas aludidas y en ellos nos enteramos de aspectos como los siguientes: - El mayor incremento del precio de los insumos como el maíz, sorgo y en menor medida desperdicio de pan, en relación con el menor crecimiento del precio del ganado en pie, dará como consecuencia un desabasto de carne bovina. - El agua es un recurso primordial en las zonas áridas y semiáridas de México, en tanto que su aporte limita la producción de la agricultura. En este estudio se observó que el precio real del agua es muy bajo en relación a otras zonas agrícolas del mundo. - Hoy en día en el país se consumen alrededor de 718 mil barriles diarios de gasolinas, un aproximado de 113.7 millones de litros, una cantidad tan grande que nuestro país se ve en la necesidad de importar cerca del 39 % de las gasolinas que consumimos. - Los jaliscienses radicados en Estados Unidos tienen una mayor capacidad de financiamiento del bienestar en la entidad, que el propio gobierno de ese estado. - México continuará basando sus finanzas públicas y su política de desarrollo económico en la extracción de combustibles fósiles (petróleo). Este modelo acelerará el deterioro y agotamiento de los recursos naturales. -La importancia de la agricultura orgánica radica en que retoma los tres ámbitos de la sustentabilidad; el ámbito ambiental, el económico y el social. - Es fundamental motivar la organización de los productores de haba para que ellos puedan captar una mayor proporción de los altos márgenes de precios que los consumidores están dispuestos a pagar. - Las condiciones del clima afectan a la producción agraria. Debido al fenómeno de cambio climático, es necesario contar con herramientas informáticas que proporcionen información climatológica para poder tomar medidas preventivas a favor de una mayor cantidad y calidad de producción. La herramienta de software permite la consulta del clima por localidades evitando la necesidad de contar con una estación meteorológica
Quantification of multivalent interactions between sialic acid and influenza a virus spike proteins by single-molecule force spectroscopy
Multivalent Flexible Nanogels Exhibit Broad-Spectrum Antiviral Activity by Blocking Virus Entry
The
entry process of viruses into host cells is complex and involves
stable but transient multivalent interactions with different cell
surface receptors. The initial contact of several viruses begins with
attachment to heparan sulfate (HS) proteoglycans on the cell surface,
which results in a cascade of events that end up with virus entry.
The development of antiviral agents based on multivalent interactions
to shield virus particles and block initial interactions with cellular
receptors has attracted attention in antiviral research. Here, we
designed nanogels with different degrees of flexibility based on dendritic
polyglycerol sulfate to mimic cellular HS. The designed nanogels are
nontoxic and broad-spectrum, can multivalently interact with viral
glycoproteins, shield virus surfaces, and efficiently block infection.
We also visualized virus–nanogel interactions as well as the
uptake of nanogels by the cells through clathrin-mediated endocytosis
using confocal microscopy. As many human viruses attach to the cells
through HS moieties, we introduce our flexible nanogels as robust
inhibitors for these viruses
Hyperbranched glycerol-based core-amphiphilic branched shell nanotransporters for dermal drug delivery
Medición,control y conocimiento de la presión arterial: Iniciativa Mayo Mes de la Medición Colombia 2017
La prevalencia de presión arterial es alta en esta población adulta joven,en la cual el desconocimiento de la condición de HTA estambién alta,y en aquellos que conocen su condición existe un porcentaje bajo de control de la HTA, resultados que de muestran la necesi-dad de implementar programas eficaces de detección de pacientes hipertensos y de establecer tratamientos estandarizados para mejorar el control de la HTA como una estrategia para la reducción de eventos cardiovasculares.The prevalence of blood pressure is high in this young adult population, in which ignorance of the HTA condition is also high, and in those who know their condition there is a low percentage of control of the HTA, results that show the need To implement effective programs for the detection of hypertensive patients and to establish standardized treatments to improve the control of HT as a strategy for the reduction of cardiovascular events.Introducción. -- Materiales y métodos. -- Resultados y Discusión000066948220131202747https://orcid.org/0000-0002-2328-7468https://scienti.minciencias.gov.co/gruplac/jsp/visualiza/[email protected]
Functionalized nanographene sheets with high antiviral activity through synergistic electrostatic and hydrophobic interactions
Memorias del primer Simposio Nacional de Ciencias Agronómicas
Primer simposio nacional de Ciencias Agronómicas: El renacer del espacio de discusión científica para el Agro colombiano