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Biomacromolecules Mar 2022Cellulose fibrils are the structural backbone of plants and, if carefully liberated from biomass, a promising building block for a bio-based society. The mechanism of...
Cellulose fibrils are the structural backbone of plants and, if carefully liberated from biomass, a promising building block for a bio-based society. The mechanism of the mechanical release─fibrillation─is not yet understood, which hinders efficient production with the required reliable quality. One promising process for fine fibrillation and total fibrillation of cellulose is cavitation. In this study, we investigate the cavitation treatment of dissolving, enzymatically pretreated, and derivatized (TEMPO oxidized and carboxymethylated) cellulose fiber pulp by hydrodynamic and acoustic (i.e., sonication) cavitation. The derivatized fibers exhibited significant damage from the cavitation treatment, and sonication efficiently fibrillated the fibers into nanocellulose with an elementary fibril thickness. The breakage of cellulose fibers and fibrils depends on the number of cavitation treatment events. In assessing the damage to the fiber, we presume that microstreaming in the vicinity of imploding cavities breaks the fiber into fibrils, most likely by bending. A simple model showed the correlation between the fibrillation of the carboxymethylated cellulose (CMCe) fibers, the sonication power and time, and the relative size of the active zone below the sonication horn.
Topics: Biomass; Carbohydrates; Cellulose; Oxidation-Reduction; Sonication
PubMed: 35099936
DOI: 10.1021/acs.biomac.1c01309 -
Progress in Biophysics and Molecular... 2007This paper is based on material presented at the start of a Health Protection Agency meeting on ultrasound and infrasound. In answering the question 'what is... (Review)
Review
This paper is based on material presented at the start of a Health Protection Agency meeting on ultrasound and infrasound. In answering the question 'what is ultrasound?', it shows that the simple description of a wave which transports mechanical energy through the local vibration of particles at frequencies of 20 kHz or more, with no net transport of the particles themselves, can in every respect be misleading or even incorrect. To explain the complexities responsible for this, the description of ultrasound is first built up from the fundamental properties of these local particle vibrations. This progresses through an exposition of the characteristics of linear waves, in order to explain the propensity for, and properties of, the nonlinear propagation which occurs in many practical ultrasonic fields. Given the Health Protection environment which framed the original presentation, explanation and examples are given of how these complexities affect issues of practical importance. These issues include the measurement and description of fields and exposures, and the ability of ultrasound to affect tissue (through microstreaming, streaming, cavitation, heating, etc.). It is noted that there are two very distinct regimes, in terms of wave characteristics and potential for bioeffect. The first concerns the use of ultrasound in liquids/solids, for measurement or material processing. For biomedical applications (where these two processes are termed diagnosis and therapy, respectively), the issue of hazard has been studied in depth, although this has not been done to such a degree for industrial uses of ultrasound in liquids/solids (sonar, non-destructive testing, ultrasonic processing etc.). However, in the second regime, that of the use of ultrasound in air, although the waves in question tend to be of much lower intensities than those used in liquids/solids, there is a greater mismatch between the extent to which hazard has been studied, and the growth in commercial applications for airborne ultrasound.
Topics: Biophysical Phenomena; Biophysics; Humans; Models, Theoretical; Radiation Injuries; Sonication; Ultrasonic Therapy; Ultrasonics
PubMed: 17045633
DOI: 10.1016/j.pbiomolbio.2006.07.026 -
Ultrasonics Sonochemistry Nov 2022Spherical SiO nanoparticles (SSNs) have been inventively synthesized using the Stöber method with sonication at medium-high frequencies (80, 120, and 500 kHz), aiming...
Spherical SiO nanoparticles (SSNs) have been inventively synthesized using the Stöber method with sonication at medium-high frequencies (80, 120, and 500 kHz), aiming to control SSN size and shorten reaction time. Compared to the conventional method, such sonication allowed the Stöber reaction complete in 20-60 min with a low molar ratio of NHOH/tetraethyl orthosilicate (0.84). The hydrodynamic diameters of 63-117 nm of SSNs were obtained under sonication with 80, 120, and 500 kHz of ultrasonic frequencies. Moreover, the SSNs obtained were smaller at 120 kHz than at 80 kHz in a multi-frequencies ultrasonic reactor, and the SSN size decreased with increasing ultrasonic power at 20 °C, designating the sonochemical unique character, namely, the SSN-size control is associated with the number of microbubbles originated by sonication. With another 500 kHz ultrasonic bath, the optimal system temperature for producing smaller SSNs was proven to be 20 °C. Also, the SSN size decreased with increasing ultrasonic power. The smallest SSNs (63 nm, hydrodynamic diameter by QELS, or 21 nm by FESEM) were obtained by sonication at 207 W for 20 min at 20 °C. Furthermore, the SSN size increased slightly with increasing sonication time and volume, favoring the scale-up of SSNs preparation. The mechanisms of controlling the SSN size were further discussed by the radical's role and effects of ammonia and ethanol concentration.
Topics: Sonication; Silicon Dioxide; Microbubbles; Nanoparticles; Temperature
PubMed: 36182836
DOI: 10.1016/j.ultsonch.2022.106181 -
IEEE Transactions on Bio-medical... Nov 2022Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest brainstem tumor in children. Focused ultrasound combined with microbubble-mediated BBB opening... (Comparative Study)
Comparative Study
OBJECTIVE
Diffuse intrinsic pontine glioma (DIPG) is the most common and deadliest brainstem tumor in children. Focused ultrasound combined with microbubble-mediated BBB opening (FUS-BBBO) is a promising technique for overcoming the frequently intact blood-brain barrier (BBB) in DIPG to enhance therapeutic drug delivery to the brainstem. Since DIPG is highly diffusive, large-volume FUS-BBBO is needed to cover the entire tumor region. The objective of this study was to determine the optimal treatment strategy to achieve efficient and homogeneous large-volume BBBO at the brainstem for the delivery of an immune checkpoint inhibitor, anti-PD-L1 antibody (aPD-L1).
METHODS
Two critical parameters for large-volume FUS-BBBO, multi-point sonication pattern (interleaved vs. serial) and microbubble injection method (bolus vs. infusion), were evaluated by treating mice with four combinations of these two parameters. 2D Passive cavitation imaging (PCI) was performed for monitoring the large-volume sonication.
RESULTS
Interleaved sonication combined with bolus injection of microbubbles resulted in 1.29 to 2.06 folds higher efficiency than other strategies as evaluated by Evans blue extravasation. The average coefficient of variation of the Evans blue delivery was 0.66 for interleaved sonication with bolus injection, compared to 0.68-0.88 for all other strategies. Similar trend was also observed in the quantified total cavitation dose and coefficient of variance of the cavitation dose. This strategy was then applied to deliver fluorescently labeled aPD-L1 which was quantified using fluorescence imaging. A strong segmented linear correlation (R = 0.81) was found between the total cavitation dose and the total fluorescence intensity of aPD-L1 delivered at different sonication pressures (0.15 MPa, 0.30 MPa, and 0.45 MPa).
SIGNIFICANCE
Findings from this study suggest that efficient and homogeneous large-volume FUS-BBBO can be achieved by interleaved sonication combined with bolus injection of microbubbles, and the efficiency and homogeneity can be monitored by PCI.
Topics: Animals; Mice; Blood-Brain Barrier; Drug Delivery Systems; Evans Blue; Immune Checkpoint Inhibitors; Microbubbles; Sonication
PubMed: 35476579
DOI: 10.1109/TBME.2022.3170832 -
Acta Orthopaedica Feb 2017
Topics: Canada; Editorial Policies; Fracture Healing; Humans; Periodicals as Topic; Sonication; Tibial Fractures
PubMed: 27998203
DOI: 10.1080/17453674.2016.1269273 -
Molecules (Basel, Switzerland) Feb 2023Carbonyl olefinations are among the most important organic syntheses that form C=C bonds, as they usually have high yields and in addition offer excellent... (Review)
Review
Carbonyl olefinations are among the most important organic syntheses that form C=C bonds, as they usually have high yields and in addition offer excellent stereoselectivity. Due to these advantages, carbonyl olefinations have important pharmaceutical and industrial applications. These reactions contain an additional step of an α-functionalized carbanion to an aldehyde or ketone to produce alkenes, but syntheses performed using metal carbene complexes are also known. The Wittig reaction is an example of carbonyl olefination, one of the best ways to synthesize alkenes. This involves the chemical reaction between an aldehyde or ketone with a so-called Wittig reagent, for instance phosphonium ylide. Triphenylphosphine-derived ylides and trialkylphosphine-derived ylides are the most common phosphorous compounds used as Wittig reagents. The Wittig reaction is commonly involved in the synthesis of novel anti-cancer and anti-viral compounds. In recent decades, the use of ultrasound on the Wittig reaction (and on different modified Wittig syntheses, such as the Wittig-Horner reaction or the aza-Wittig method) has been studied as a green synthesis. In addition to the advantage of green synthesis, the use of ultrasounds in general also improved the yield and reduced the reaction time. All of these chemical syntheses conducted under ultrasound will be described further in the present review.
Topics: Molecular Structure; Sonication; Alkenes; Aldehydes
PubMed: 36838946
DOI: 10.3390/molecules28041958 -
Molecules (Basel, Switzerland) Dec 2022Sonication is recognized as a potential food processing method to improve the functional properties of fruit juice. This study evaluated the effects of different...
Sonication is recognized as a potential food processing method to improve the functional properties of fruit juice. This study evaluated the effects of different sonication durations (20, 40, and 60 min) and thermal pasteurization on the nutritional, antioxidant, and microbial properties of noni juice. Fresh noni juice served as the control. The main organic acids detected were malic (57.54−89.31 mg/100 mL) and ascorbic (17.15−31.55 mg/100 mL) acids. Compared with the fresh sample, the concentrations of these compounds were significantly improved (p < 0.05) in the 60 min sonicated sample but reduced (p < 0.05) in the pasteurized sample. Moreover, sonication for 60 min resulted in increments of scopoletin, rutin, and vanillic acid compared to the fresh sample. The antioxidant activity of the juice sample was improved in the sample sonicated for 60 min. Irrespective of juice processing method, the level of microbial counts in noni juice was within the satisfactory level over the 8 weeks of refrigerated (4 °C) storage. This study highlights the feasibility of using ultrasound processing to enhance the quality of noni juice on the industrial scale.
Topics: Antioxidants; Morinda; Fruit; Pasteurization; Sonication
PubMed: 36615507
DOI: 10.3390/molecules28010313 -
Progress in Biophysics and Molecular... 2007Ultrasound is defined as sound of a frequency that is too high for the human ear to detect--i.e. it is inaudible. Nevertheless this "silent sound" has a large range of... (Review)
Review
Ultrasound is defined as sound of a frequency that is too high for the human ear to detect--i.e. it is inaudible. Nevertheless this "silent sound" has a large range of applications in science, medicine and industry. The study of the effects of ultrasound on materials--known as sonochemistry--is one of the broadest and most exciting areas in current research. In this review some recent developments with major potential are identified from the fields environmental protection and materials processing. Environmental protection can refer to methods of preventing pollution or to the removal of existing pollution. Here we will look at examples drawn from the latter in which ultrasound has been used for the purification of water (chemical and biological), the decontamination of the atmosphere and soil remediation i.e. the classic three domains of water, air and land. In terms of materials processing two examples have been chosen, the treatment of sewage sludge and the control of crystallisation. In both of these cases it is predominantly the mechanical effects of acoustic cavitation, which produce the enhanced digestion, and dewatering of sludge and provide for the control in crystallisation processes.
Topics: Bioreactors; Conservation of Natural Resources; Industry; Sonication; Ultrasonography; Waste Management
PubMed: 16928393
DOI: 10.1016/j.pbiomolbio.2006.07.007 -
Annual Review of Biomedical Engineering Jul 2021Specialized features of vasculature in the central nervous system greatly limit therapeutic treatment options for many neuropathologies. Focused ultrasound, in... (Review)
Review
Specialized features of vasculature in the central nervous system greatly limit therapeutic treatment options for many neuropathologies. Focused ultrasound, in combination with circulating microbubbles, can be used to transiently and noninvasively increase cerebrovascular permeability with a high level of spatial precision. For minutes to hours following sonication, drugs can be administered systemically to extravasate in the targeted brain regions and exert a therapeutic effect, after which permeability returns to baseline levels. With the wide range of therapeutic agents that can be delivered using this approach and the growing clinical need, focused ultrasound and microbubble (FUS+MB) exposure in the brain has entered human testing to assess safety. This review outlines the use of FUS+MB-mediated cerebrovascular permeability enhancement as a drug delivery technique, details several technical and biological considerations of this approach, summarizes results from the clinical trials conducted to date, and discusses the future direction of the field.
Topics: Blood-Brain Barrier; Brain; Drug Delivery Systems; Humans; Microbubbles; Sonication
PubMed: 33752471
DOI: 10.1146/annurev-bioeng-062117-121238 -
SLAS Technology Apr 2023A sample preparation step involving dissociation of tissues into their component cells is often required to conduct analysis of nucleic acids and other constituents from...
A sample preparation step involving dissociation of tissues into their component cells is often required to conduct analysis of nucleic acids and other constituents from tissue samples. Frequently, the extracellular matrix and cell-cell adhesions are disrupted via treatment with a chemical dissociating reagent or various mechanical forces. In this work, a new, high-throughput, multiplexed method of dissociating tissues and cellular aggregates into single cells using ultrasound frequency bath sonication is explored and characterized. Different operating parameters are evaluated, and a treatment protocol with potential for uniform, high-throughput tissue dissociation is compared to the existing best chemical and orbital plate shaking protocol. Metrics such as percent dissociation, cellular recovery, average aggregate size, proportion of various aggregate sizes, membrane circularity, and cellular viability are subsequently assessed and found to be favorable. In optimized conditions, 53 ± 8% of 1 mm biopsy cores are dissociated within 30 min using sonication alone, surpassing leading high-throughput orbital plate shaking techniques five-fold. Chemical digestion is also 2 times more effective when complexed with sonication rather than orbital plate shaking. RNA content, quality, and expression are found to be superior to the standard protocol in terms of transcriptional preservation.
Topics: Sonication; Cell Survival
PubMed: 36642327
DOI: 10.1016/j.slast.2023.01.001