Background: Outcomes from cardiopulmonary resuscitation (CPR) following sudden cardiac arrest are suboptimal. Postresuscitation targeted temperature management has been shown to have benefit in subjects with sudden cardiac arrest due to ventricular fibrillation, but there are few data for outcomes from sudden cardiac arrest due to pulseless electrical activity. In addition, intra-CPR cooling is more effective than postresuscitation cooling.
View Article and Find Full Text PDFWorldwide, population aging and unhealthy lifestyles have increased the incidence of high-risk health conditions such as cardiovascular diseases, sleep apnea, and other conditions. Recently, to facilitate early identification and diagnosis, efforts have been made in the research and development of new wearable devices to make them smaller, more comfortable, more accurate, and increasingly compatible with artificial intelligence technologies. These efforts can pave the way to the longer and continuous health monitoring of different biosignals, including the real-time detection of diseases, thus providing more timely and accurate predictions of health events that can drastically improve the healthcare management of patients.
View Article and Find Full Text PDFRecent advancements in smart, wearable technologies have allowed the detection of various medical conditions. In particular, continuous collection and real-time analysis of electrocardiogram data have enabled the early identification of pathologic cardiac rhythms. Various algorithms to assess cardiac rhythms have been developed, but these utilize excessive computational power.
View Article and Find Full Text PDFBackground: On-demand preexposure prophylaxis may reduce one's risk of HIV acquisition; however, it is unclear if individuals with a very low frequency of HIV exposures are conferred adequate protection. We evaluated a novel approach dubbed HIV postexposure prophylaxis-in-pocket ("PIP"), for individuals with a low frequency of high-risk HIV exposures.
Setting: Two HIV clinics in Toronto, Canada, managing HIV prevention cases.
To develop an understanding of the nature of complex, spatiotemporal interactions between cells and the extracellular matrix (ECM), artificial ECMs formed from hydrogels with a particular spectrum of properties are being developed at a rapid pace. We report the microfluidic generation of small, monodisperse composite agarose-gelatin hydrogel modules (microgel particles) that can be used for cell encapsulation and can serve as instructive cellular microenvironments. The agarose component of the microgels gelled under reduced temperature, while gelatin modified with phenolic hydroxyl groups underwent peroxidase-catalyzed gelation.
View Article and Find Full Text PDFMicrofluidics (MFs) offers a promising method for the preparation of polymer microgels with exquisite control over their dimensions, shapes and morphologies. A challenging task in this process is the generation of droplets (precursors for microgels) from highly viscous polymer solutions. Spatial separation of MF emulsification and gelation of the precursor droplets on chip can address this challenge.
View Article and Find Full Text PDFIn this Concept article, recent advances in microfluidic platforms for the generation of cell-laden hydrogel particles (microgels) are reported. Advances in the continuous microfluidic encapsulation of cells in droplets and microgels are critically reviewed, and currently used methods for the encapsulation of cells in polymer microgels are discussed. An outlook on current applications and future directions in this field of research are also presented.
View Article and Find Full Text PDFWe demonstrate continuous flow acid-base titration reactions as an educational microfluidic platform for undergraduate and graduate analytical chemistry courses. A series of equations were developed for controlling and predicting the results of acid-base neutralisation reactions conducted in a microfluidic format, including the combinations of (i) a strong base and a strong acid, (ii) a strong base and a weak acid, and (iii) a strong base and a multiprotic acid. Microfluidic titrations yielded excellent repeatability.
View Article and Find Full Text PDFWe report the development of a versatile microfluidic (MF) reactor with multiple analytical probes, which can be used for (i) quantitative characterisation of molecular vibrational signatures of reactants or products, (ii) the localised real-time monitoring of temperature and (iii) site-specific measurements of pH of the reaction system. The analytical probes utilised for in situ reaction analysis include an ATR-FTIR probe, a temperature probe, and a pH probe. We demonstrate the applications of the MF reactor with integrated probes for the parallel monitoring of multiple variables in acid/base neutralisation reaction, of changes in buffer pH, temperature, and vibrational absorption bands, and for monitoring the kinetics of the reaction between CO(2) and a buffer system with therapeutic applications.
View Article and Find Full Text PDFThis communication describes a novel strategy for the continuous microfluidic generation of highly monodispersed particle-coated microbubbles using temperature-dependent dissolution of carbon dioxide.
View Article and Find Full Text PDFWe report a microfluidic (MF) approach to studies of temperature mediated carbon dioxide (CO(2)) transfer between the gas and the liquid phases. Micrometre-diameter CO(2) bubbles with a narrow size distribution were generated in an aqueous or organic liquid and subsequently were subjected to temperature changes in the downstream channel. In response to the cooling-heating-cooling cycle the bubbles underwent corresponding contraction-expansion-contraction transitions, which we term 'bubble breathing'.
View Article and Find Full Text PDFCo-culture strategies are foundational in cell biology. These systems, which serve as mimics of in vivo tissue niches, are typically poorly defined in terms of cell ratios, local cues and supportive cell-cell interactions. In the stem cell niche, the ability to screen cell-cell interactions and identify local supportive microenvironments has a broad range of applications in transplantation, tissue engineering and wound healing.
View Article and Find Full Text PDFFurther progress in the applications of self-assembled nanostructures critically depends on developing a fundamental understanding of the relation between the properties of nanoparticle ensembles and their time-dependent structural characteristics. Following dynamic generation of hot-spots in the self-assembled chains of gold nanorods, we established a direct correlation between ensemble-averaged surface-enhanced Raman scattering and extinction properties of the chains. Experimental results were supported with comprehensive finite-difference time-domain simulations.
View Article and Find Full Text PDFElasticity of cellular microenvironments strongly influences cell motility, phagocytosis, growth and differentiation. Currently, the relationship between the cell behaviour and matrix stiffness is being studied for cells seeded on planar substrates, however in three-dimensional (3D) microenvironments cells may experience mechanical signalling that is distinct from that on a two-dimensional matrix. We report a microfluidic approach for high-throughput generation of 3D microenvironments with different elasticity for studies of cell fate.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2010
A microfluidic route to producing small (<10 µm) bubbles with a narrow size distribution and long-time (at least, up to one month) stability is reported. The bubbles are encapsulated with a protein-polysaccharide shell. The strategy includes the following events, occurring in sequence: (i) a microfluidic generation of bubbles from a mixture of CO(2) and a minute amount of gases with low solubility in water, in an aqueous solution of lysozyme and sodium alginate; (ii) the dissolution of CO(2) leading to the shrinkage of bubbles and a local increase in acidity of the medium; (iii) the deposition of lysozyme at the gas-water interface triggered by the local decrease in pH; (iv) the deposition of alginate onto the lysozyme shell, due to the electrostatically driven complexation of alginate with lysozyme.
View Article and Find Full Text PDFIn this tutorial review we discuss recent advances in the application of microfluidics for the generation of microgels from synthetic and biological polymers. We summarize advantages and drawbacks of the current methods used in microfluidic synthesis and assembly of polymer microgels. Continuous microfluidic encapsulation of cells is discussed as an exemplary application of the microgels.
View Article and Find Full Text PDFWe report a microfluidic approach to generating capsules of biopolymer hydrogels. Droplets of an aqueous solution of a biopolymer were emulsified in an organic phase comprising a cross-linking agent. Polymer gelation was achieved in situ (on a microfluidic chip) by diffusion-controlled ionic cross-linking of the biopolymer, following the transfer of the cross-linking agent from the continuous phase to the droplets.
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