Introduction: In this study, we utilized the pulsed photoacoustic (PA) technique to analyze globular sedimentation in whole human blood, with a focus on distinguishing between healthy individuals and those with hemolytic anemia.
Methods: Blood samples were collected from both healthy individuals (women and men) and those with hemolytic anemia, and temporal and spectral parameters of PA signals were employed for analysis.
Results: Significant differences (p < 0.
Amyotrophic lateral sclerosis (ALS) is an adult-onset neurodegenerative disease that causes the degeneration of motor neurons in the motor cortex and spinal cord. Patients with ALS experience muscle weakness and atrophy in the limbs which eventually leads to paralysis and death. NAD is critical for energy metabolism, such as glycolysis and oxidative phosphorylation, but is also involved in non-metabolic cellular reactions.
View Article and Find Full Text PDFThree new cationic surfactants--cetyl-bis(2-dimethylaminoethyl)ether bromide (CBDEB), dodecyl-bis(2-dimethylaminoethyl)ether bromide (DBDEB), and -hexyl-bis(2-dimethylaminoethyl)ether bromide (HBDEB)-have been designed herein using a simple and tailorable synthesis route. CBDEB and DBDEB, the 16- and 12-carbon chain surfactants, demonstrate facile, rapid, and controllable aqueous syntheses of gold nanoparticles (AuNPs) as dual-action reducing and capping agents. The synthesis strategy, using only surfactant and HAuCl salt, and 4 min of heating at 80 °C, results in spherical AuNPs (average diameters of 13.
View Article and Find Full Text PDFPhotonic crystals (PCs) are nanomaterials with photonic properties made up of periodically modulated dielectric materials that reflect light between a wavelength range located in the photonic band gap. Colloidal PCs (C-PC) have been proposed for several applications such as optical platforms for the formation of physical, chemical, and biological sensors based on a chromatic response to an external stimulus. In this work, a robust protocol for the elaboration of photonic crystals based on SiO particle (SP) deposition using the vertical lifting method was studied.
View Article and Find Full Text PDFThis paper aims to implement a laser-induced ultrasound imaging reconstruction method based on the delay-and-sum beamforming through the synthetic aperture focusing technique (SAFT) for a circular scanning, performed with a tomograph that had one acoustic sensor and a system that rotates the sample around a fixed axis. The proposed method, called the Single-sensor Scanning Synthetic Aperture Focusing Technique, considers the size of the sensor and the detection procedure inside the SAFT's algebra. This image reconstruction method was evaluated numerically, using the Green function for the laser-induced ultrasound wave equation to generate a forward problem, and experimentally, using a solid object of polylactic acid, and a Sprague-Dawley rat heart located in a tissue-mimicking phantom.
View Article and Find Full Text PDFChem Commun (Camb)
November 2022
Tunable gold nanostars were synthesized through the reduction of gold salt by an aminosugar, -methyl-D-glucamine, in a seed-less route. The nanoparticle morphology and size were facilely tuned through adjustments in reaction pH and LED light-mediated synthesis. The materials demonstrated low inherent cytotoxicity and high potential for photothermal therapy.
View Article and Find Full Text PDFA label-free molecular imprinted polymer (MIP) sensor was fabricated for the detection of progesterone in aqueous solutions, by polymerization inside the void spaces of colloidal crystals, which gave them photonic properties. The prepolymerization mixture was prepared from acrylic acid as the functional monomer, ethylene glycol as the cross-linker agent, ethanol as solvent, and progesterone as the imprinted template. After polymerization, the colloidal crystal was removed by acid etching and the target eluted with a solvent.
View Article and Find Full Text PDFWe recently reported on fixed-path length laser-induced sound pinging (FPL-LISP) as a rapid photoacoustic technique employing an inexpensive benchtop tattoo-removal laser for reliably determining the speed of sound in low-volume fluids. In this contribution, we demonstrate the capacity of FPL-LISP to analyze representative commercial beverages for their natural or artificial sweetener contents. As a benchmark, the speed of sound was determined for solutions of sugars (glucose, fructose, sucrose), mock high fructose corn syrup (HFCS-55), and 12 household sweeteners (culinary sugars, syrups, honey, molasses) across the concentration range of 1-20% w/v in water, simulating the typical sweetener range found in commercial soft drinks.
View Article and Find Full Text PDFAims: Cardiomyocyte Ca2+ homoeostasis is altered with ageing and predisposes the heart to Ca2+ intolerance and arrhythmia. Transient receptor potential vanilloid 4 (TRPV4) is an osmotically activated cation channel with expression in cardiomyocytes of the aged heart. The objective of this study was to examine the role of TRPV4 in Ca2+ handling and arrhythmogenesis following ischaemia-reperfusion (I/R), a pathological scenario associated with osmotic stress.
View Article and Find Full Text PDFIEEE Trans Ultrason Ferroelectr Freq Control
July 2020
In this study, we present a quantitative photoacoustic (PA) method for performing absorption measurements on highly absorbing samples. Based on the thermoelastic mechanism, the relative changes in PA signal amplitude allowed the determination of absorption coefficients of materials in the 0.19-2500-cm range, with no prior knowledge of the material's optoacoustic properties required.
View Article and Find Full Text PDFNicotinamide adenine dinucleotide (NAD) plays a critical role in energy metabolism and bioenergetic homeostasis. Most NAD in mammalian cells is synthesized via the NAD salvage pathway, where nicotinamide phosphoribosyltransferase (NAMPT) is the rate-limiting enzyme, converting nicotinamide into nicotinamide mononucleotide (NMN). Using a Thy1-Nampt projection neuron conditional knockout (cKO) mouse, we studied the impact of NAMPT on synaptic vesicle cycling in the neuromuscular junction (NMJ), end-plate structure of NMJs and muscle contractility of semitendinosus muscles.
View Article and Find Full Text PDFNorepinephrine (NE) activates adrenergic receptors (ARs) in the hypothalamic paraventricular nucleus (PVN) to increase excitatory currents, depolarise neurones and, ultimately, augment neuro-sympathetic and endocrine output. Such cellular events are known to potentiate intracellular calcium ([Ca ] ); however, the role of NE with respect to modulating [Ca ] in PVN neurones and the mechanisms by which this may occur remain unclear. We evaluated the effects of NE on [Ca ] of acutely isolated PVN neurones using Fura-2 imaging.
View Article and Find Full Text PDFChronic hyperinsulinemia, , increases the resistance of peripheral tissues to insulin by desensitizing insulin signaling. Insulin, in a heterologous manner, can also cause IGF-1 resistance. The aim of the current study was to investigate whether insulin-mediated insulin and IGF-1 resistance develops in pancreatic -cells and whether this resistance results in -cell decompensation.
View Article and Find Full Text PDFIntracellular nicotinamide phosphoribosyltransferase (iNAMPT) is the rate-limiting enzyme of the mammalian NAD biosynthesis salvage pathway. Using inducible and conditional knockout (cKO) mice, we show that Nampt gene deletion in adult projection neurons leads to a progressive loss of body weight, hypothermia, motor neuron (MN) degeneration, motor function deficits, paralysis, and death. Nampt deletion causes mitochondrial dysfunction, muscle fiber type conversion, and atrophy, as well as defective synaptic function at neuromuscular junctions (NMJs).
View Article and Find Full Text PDFTropomyosin 1 (TPM1) is an essential sarcomeric component, stabilising the thin filament and facilitating actin's interaction with myosin. A number of sarcomeric proteins, such as alpha myosin heavy chain, play crucial roles in cardiac development. Mutations in these genes have been linked to congenital heart defects (CHDs), occurring in approximately 1 in 145 live births.
View Article and Find Full Text PDFIt is widely held that the melanosome is an exemplar of the absorption features of melanin-containing cells, which are assumed to be uniform in both size and optical characteristics. In recent years, however, it has become increasingly apparent that this is a strikingly poor assumption. Indeed, melanin extracted from natural sources and synthetic melanin both show wide variability in their degree of polymerization (molecular weight) and spectroscopic characteristics.
View Article and Find Full Text PDFReactive oxygen species (ROS) play a profound role in cardiorespiratory function under normal physiological conditions and disease states. ROS can influence neuronal activity by altering various ion channels and transporters. Within the nucleus tractus solitarii (nTS), a vital brainstem area for cardiorespiratory control, hydrogen peroxide (HO) induces sustained hyperexcitability following an initial depression of neuronal activity.
View Article and Find Full Text PDFMany diseases that result in dysfunction and dysmorphology of the heart originate in the embryo. However, the embryonic heart presents a challenging subject for study: especially challenging is its electrophysiology. Electrophysiological maturation of the embryonic heart without disturbing its physiological function requires the creation and deployment of novel technologies along with the use of classical techniques on a range of animal models.
View Article and Find Full Text PDFNanoparticle-assisted ultrasound generation by pulsed laser or photoacoustic (PA) techniques has been employed in the study of several tissues both in vivo and in vitro. Among the many applications of this technology, the detection of few cells in vitro is of particular interest. However, the toxicity induced by laser irradiation used for PA signal generation, whether in the absence or the presence of PA enhancers, within single isolated cells has not yet been investigated in detail.
View Article and Find Full Text PDFWe present a straightforward, environmentally-benign, one-pot photochemical route to generate alloyed AgAu bimetallic nanoparticle decorated aminoclays in water at room temperature. The protocol uses no reducing agent (e.g.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
February 2014
Inward remodeling is the most prevalent structural change found in the resistance arteries and arterioles of hypertensive individuals. Separate studies have shown that the inward remodeling process requires transglutaminase activation and the polymerization of actin. Therefore, we hypothesize that inward remodeling induced via endogenous transglutaminase activation requires and depends on actin cytoskeletal structures.
View Article and Find Full Text PDFExercise in general, and mechanical signals in particular, help ameliorate the neuromuscular symptoms of aging and possibly other neurodegenerative disorders by enhancing muscle function. To better understand the salutary mechanisms of such physical stimuli, we evaluated the potential for low intensity mechanical signals to promote enhanced muscle dynamics. The effects of daily brief periods of low intensity vibration (LIV) on neuromuscular functions and behavioral correlates were assessed in mice.
View Article and Find Full Text PDFWe report a simple, robust fluorescence biosensor for the ultra-sensitive detection of Clostridium botulinum Neurotoxin Type A (BoNT/A) in complex, real-world media. High intrinsic signal amplification was achieved through the combined use of ultra-bright, photostable dye-doped nanoparticle (DOSNP) tags and high surface area nanoporous organosilicate (NPO) thin films. DOSNP with 22 nm diameter were synthesized with more than 200 times equivalent free dye fluorescence and conjugated to antibodies with average degree of substitution of 90 dyes per antibody, representing an order of magnitude increase compared with conventional dye-labeled antibodies.
View Article and Find Full Text PDFWhen separating two species with similar densities but differing sedimentation velocities (because of differences in size), centrifugal elutriation is generally the method of choice. However, a major drawback to this approach is the requirement for specialized equipment. Here, we present a new method that achieves similar separations using standard benchtop centrifuges by loading the seperands as a layer on top of a dense buffer of a specified length, and running the benchtop centrifugation process for a calculated amount of time, thereby ensuring that all faster moving species are collected at the bottom, while all slower moving species remain in the buffer.
View Article and Find Full Text PDFWe report ultrabright, photostable, sub-25 nm nanoparticle agglomerates (suprananoparticles) assembled from a few hundred 3.3 ± 0.9 nm units, each hosting on average a single rhodamine 6G (Rh6G) dye molecule encased in a thin organosilicate cage.
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