Publications by authors named "Rafael Lira"

Introduction: Judo, a martial art created by Jigoro Kano in 1882, is a martial art promoting physical and spiritual development. Despite its "gentle way" philosophy, it poses a significant risk for cervical spine injuries, often resulting from throws and ground techniques.

Methods: This cross-sectional study analyzed cervical injuries among professional judo athletes from January to July 2024.

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Article Synopsis
  • Recent advancements in molecular reporters have renewed interest in studying membrane properties, focusing on new fluorescent probes with improved optical characteristics.
  • This study employs fluorescence lifetime imaging to analyze various fluorescent dyes' effectiveness in assessing synthetic and biological membrane properties, especially in response to different agents.
  • Findings indicate that some common dyes can perform comparably to specialized sensitive dyes, emphasizing the importance of selecting appropriate sensors based on their sensitivity and environmental responsiveness for biophysical experiments.
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Membrane fusion is a ubiquitous process associated with a multitude of biological events. Although it has long been appreciated that membrane mechanics plays an important role in membrane fusion, the molecular interplay between mechanics and fusion has remained elusive. For example, although different lipids modulate membrane mechanics differently, depending on their composition, molar ratio, and complex interactions, differing lipid compositions may lead to similar mechanical properties.

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Premise: The central Oaxaca Basin has a century-long history of agave cultivation and is hypothesized to be the region of origin of other cultivated crops. Widely cultivated for mezcal production, the perennial crop known as "espadín" is putatively derived from wild Agave angustifolia. Nevertheless, little is known about its genetic relationship to the wild A.

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Lateral phase heterogeneity in biomembranes can govern cellular functions and may serve as a platform for enrichment or depletion of membrane-anchored molecules. In this work, we address the question of how the process of membrane fusion is affected by the membrane phase state (fluid or gel) and by phase coexistence, as well as the effects of fusion-mediated incorporation of exogeneous lipids on phase separation. Our system is based on the fusion of cationic fluid large unilamellar vesicles (LUVs) composed of dioleoyl trimethylammonium propane (DOTAP) and dioleoyl phosphoethanolamine (DOPE) with neutral and anionic giant unilamellar vesicles (GUVs) composed of phosphatidylcholine and phosphatidylglycerol.

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Background: Genetic diversity is fundamental for the survival of species. In particular, in a climate change scenario, it is crucial that populations maintain genetic diversity so they can adapt to novel environmental conditions. Genetic diversity in wild agaves is usually high, with low genetic differentiation among populations, in part maintained by the agave pollinators such as the nectarivorous bats.

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Liposomes represent important drug carrier vehicles in biological systems. A fusogenic liposomal system composed of equimolar mixtures of the cationic lipid DOTAP and the phospholipid DOPE showed high fusion and delivery efficiencies with cells and lipid vesicles. However, aspects of the thermodynamics involving the interaction of these fusogenic liposomes and biomimetic systems remain unclear.

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Cell membranes are highly asymmetric and their stability against poration is crucial for survival. We investigated the influence of membrane asymmetry on electroporation of giant unilamellar vesicles with membranes doped with GM1, a ganglioside asymmetrically enriched in the outer leaflet of neuronal cell membranes. Compared with symmetric membranes, the lifetimes of micronsized pores are about an order of magnitude longer suggesting that pores are stabilized by GM1.

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A variety of artificial cells springs from the functionalization of liposomes with proteins. However, these models suffer from low durability without repair and replenishment mechanisms, which can be partly addressed by replacing the lipids with polymers. Yet natural membranes are also dynamically remodeled in multiple cellular processes.

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Resealing of membrane pores is crucial for cell survival. Membrane surface charge and medium composition are studied as defining regulators of membrane stability. Pores are generated by electric field or detergents.

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Quantum dots (QDs) have attracted considerable attention as fluorescent probes for life sciences. The advantages of using QDs in fluorescence-based studies include high brilliance, a narrow emission band allowing multicolor labeling, a chemically active surface for conjugation, and especially, high photostability. Despite these advantageous features, the size of the QDs prevents their free transport across the plasma membrane, limiting their use for specific labeling of intracellular structures.

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Background: Mexico is one of the most floristically rich countries in the world. Despite significant contributions made on the understanding of its unique flora, the knowledge on its diversity, geographic distribution and human uses, is still largely fragmented. Unfortunately, deforestation is heavily impacting this country and native tree species are under threat.

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Contemporary biological cells are sophisticated and highly compartmentalized. Compartmentalization is an essential principle of prebiotic life as well as a key feature in bottom-up synthetic biology research. In this review, the dynamic growth of compartments as an essential prerequisite for enabling self-reproduction as a fundamental life process is discussed.

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Cytochrome ubiquinol oxidase is a transmembrane protein, which oxidizes ubiquinone and reduces oxygen, while pumping protons. Apart from its combination with FF-ATPase to assemble a minimal ATP regeneration module, the utility of the proton pump can be extended to other applications in the context of synthetic cells such as transport, signaling, and control of enzymatic reactions. In parallel, polymers have been speculated to be phospholipid mimics with respect to their ability to self-assemble in compartments with increased stability.

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The rhizosphere provides several benefits to the plant host being a strong determinant for its health, growth and productivity. Nonetheless, the factors behind the assembly of the microbial communities associated with the rhizosphere such as the role of plant genotypes are not completely understood. In this study, we tested the role that intraspecific genetic variation has in rhizospheric microbial community assemblages, using genetically distinct wild cotton populations as a model of study.

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Background: The interest in mechanics of synthetic and biological vesicles has been continuously growing during the last decades. Liposomes serve as model systems for investigating fundamental membrane processes and properties. More recently, extracellular vesicles (EVs) have been investigated mechanically as well.

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One of the best conservation strategies for wild germplasm is conservation of genetic banks. The success of conservation relies heavily on the micropropagation or performance of the species of interest. In the context of global change, crop production challenges and climate change, we face a reality of intensified crop production strategies, including genetic engineering, which can negatively impact biodiversity conservation.

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1,6-Diphenyl-1,3,5-hexatriene (DPH) is one of the most commonly used fluorescent probes to study dynamical and structural properties of lipid bilayers and cellular membranes via measuring steady-state or time-resolved fluorescence anisotropy. In this study, we present a limitation in the use of DPH to predict the order of lipid acyl chains when the lipid bilayer is doped with itraconazole (ITZ), an antifungal drug. Our steady-state fluorescence anisotropy measurements showed a significant decrease in fluorescence anisotropy of DPH embedded in the ITZ-containing membrane, suggesting a substantial increase in membrane fluidity, which indirectly indicates a decrease in the order of the hydrocarbon chains.

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Liposomes are used in synthetic biology as cell-like compartments and their microfluidic production through double emulsions allows for efficient encapsulation of various components. However, residual oil in the membrane remains a critical bottleneck for creating pristine phospholipid bilayers. It has been discovered that osmotically driven shrinking leads to detachment of the oil drop.

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Polymer-based nanoparticles have an increasing presence in research due to their attractive properties, such as flexible surface functionality design and the ability to scale up production. Poly(ionic liquid) (PIL) nanoparticles of size below 50 nm are very unique in terms of their high charge density and internal onion-like morphology. The interaction between PIL nanoparticles and giant unilamellar vesicles (GUVs) of various surface charge densities is investigated.

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Membrane fusion is a ubiquitous process in biology and is a prerequisite for many intracellular delivery protocols relying on the use of liposomes as drug carriers. Here, we investigate in detail the process of membrane fusion and the role of opposite charges in a protein-free lipid system based on cationic liposomes (LUVs, large unilamellar vesicles) and anionic giant unilamellar vesicles (GUVs) composed of different palmitoyloleoylphosphatidylcholine (POPC)/palmitoyloleoylphosphatidylglycerol (POPG) molar ratios. By using a set of optical-microscopy- and microfluidics-based methods, we show that liposomes strongly dock to GUVs of pure POPC or low POPG fraction (up to 10 mol%) in a process mainly associated with hemifusion and membrane tension increase, commonly leading to GUV rupture.

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Agronomic management of plants is a powerful evolutionary force acting on their populations. The management of cultivated plants is carried out by the traditional process of human selection or plant breeding and, more recently, by the technologies used in genetic engineering (GE). Even though crop modification through GE is aimed at specific traits, it is possible that other non-target traits can be affected by genetic modification due to the complex regulatory processes of plant metabolism and development.

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Background: Identifying factors influencing plant management allows understanding how processes of domestication operate. Uncertain availability of resources is a main motivation for managing edible plants, but little is known about management motives of non-edible resources like medicinal and ceremonial plants. We hypothesized that uncertain availability of resources would be a general factor motivating their management, but other motives could operate simultaneously.

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Compartments for the spatially and temporally controlled assembly of biological processes are essential towards cellular life. Synthetic mimics of cellular compartments based on lipid-based protocells lack the mechanical and chemical stability to allow their manipulation into a complex and fully functional synthetic cell. Here, we present a high-throughput microfluidic method to generate stable, defined sized liposomes termed 'droplet-stabilized giant unilamellar vesicles (dsGUVs)'.

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