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1.
Small ; : e2400756, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38709225

RESUMEN

The direct application of liquid marbles in electromagnetic wave (EMW) absorption is challenging due to their poor stability, susceptibility to gravitational collapse, and shaping difficulties. To address this issue, a novel strategy is proposed to incorporate liquid marble microstructures (NaCl/nano-SiO2) encapsulated in organic phases (Octadecane) into the rubber-matrix (SEBS) using the ultrasound-assisted emulsion blending method. The resulting NaCl/SiO2/Octadecane microstructures anchored to SEBS offer a substantial solid-liquid interface consisting of NaCl solution and SiO2. When subjected to an alternating electromagnetic (EM) field, the water molecules and polysorbate within SiO2 exhibit heightened responsiveness to the EM field, and the movement of Na+ and Cl- within these microstructures leads to their accumulation at the solid-liquid interface, creating an asymmetric ion distribution. This phenomenon facilitates enhanced interfacial polarization, thereby contributing to the material's EMW absorption properties. Notably, the latex with 16 wt% SEBS (E-3), exhibiting a surface morphology similar to human cell tissues, achieves complete absorption of X-band (fE = 4.20 GHz, RLmin = -33.87 dB). Moreover, the latex demonstrates light density (0.78 g cm-3) and environmental stability. This study not only highlights the predominant loss mechanism in rubber-based wave-absorbing materials but also provides valuable insights into the design of multifunctional wave-absorbing materials.

2.
Waste Manag Res ; 42(1): 74-80, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37102342

RESUMEN

Since the majority of valuable components in spent lithium-ion batteries, such as lithium, exists in the electrode materials, common studies focused on the treatment of the cathode materials, which ignored the harm of residual electrolyte. The cavitation and thermal effects produced by ultrasonic can not only be used for the separation of electrode materials, but also have a wide range of applications in the field of sewage pollutant degradation. This work used ultrasonic to treat simulated electrolyte (propylene carbonate (PC)) solution of spent lithium-ion batteries, explored the effect of ultrasonic power, the addition amount of H2O2 solution (30 wt%) and reaction temperature on the degradation of electrolyte, and analysed the ultrasonic degradation reaction from the perspective of reaction kinetics. And the synchronous experiment of cathode material separation and electrolyte degradation was conducted under the optimal conditions. The results showed that the highest degradation efficiency of PC in the electrolyte was 83.08% under the condition of ultrasonic power of 900 W, the addition of H2O2 solution (30 wt%) of 10.2 mL, reaction temperature of 120°C and reaction time of 120 minutes, and the separation efficiency was 100%. This work reduced the environmental and health risks in the cathode material separation process and was conducive to the green development of spent lithium-ion battery recycling technology.


Asunto(s)
Litio , Ultrasonido , Peróxido de Hidrógeno , Reciclaje/métodos , Suministros de Energía Eléctrica , Electrodos
3.
Angew Chem Int Ed Engl ; 63(28): e202405372, 2024 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-38659283

RESUMEN

Rational modulation of surface reconstruction in the oxygen evolution reaction (OER) utilizing defect engineering to form efficient catalytic activity centers is a topical interest in the field of catalysis. The introduction of point defects has been demonstrated to be an effective strategy to regulate the electronic configuration of electrocatalysts, but the influence of more complex planar defects (e.g., twins and stacking faults), on their intrinsic activity is still not fully understood. This study harnesses ultrasonic cavitation for rapid and controlled introduction of different types of defects in the FeCoNi/FeAl2O4 hybrid coating, optimizing OER catalytic activity. Theoretical calculations and experiments demonstrate that the different defects optimize the coordination environment and facilitate the activation of surface reconstruction into true catalytic activity centers at lower potentials. Moreover, it demonstrates exceptional durability, maintaining stable oxygen production at a high current density of 300 mA cm-2 for over 120 hours. This work not only presents a novel pathway for designing advanced electrocatalysts but also deepens our understanding of defect-engineered catalytic mechanisms, showcasing the potential for rapid and efficient enhancement of electrocatalytic performance.

4.
J Environ Manage ; 310: 114710, 2022 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-35220096

RESUMEN

A study on the intensification of ozone mass transfer in rotational flow field and UC-RF coupled-field was conducted. Two important operational parameters namely liquid flow rate and ultrasonic power, were optimized with regard to the ozone mass transfer efficiency. Results showed that the mass transfer coefficient (KLa) increased with liquid flow rate (up to 14 L min-1) and ultrasonic power (up to 1000 W). The maximum KLa value (1.0258 min-1) was obtained with the UC-RF coupled-field. Moreover, the reinforcement of mass transfer efficiency was promoted by the rotational flow field and UC-RF coupled-field due to the increase in the ozone-liquid contact area, intensification of turbulence, acceleration of interface renewal, and extension of residence time. Ozone microbubbles rose in the reactor in a spiral manner. In addition, the microbubbles produced in the rotational flow field served as cavitation nucleus that helped to generate the cavitation effect. The effective degradation of di-butyl phthalate (DBP) confirmed that its removal was improved by the ozone-liquid mass transfer and the promotion of hydroxyl radicals (·OH) production. The synergistic effect of DBP degradation via ultrasound-enhanced ozonation was significant.


Asunto(s)
Ozono , Contaminantes Químicos del Agua , Dibutil Ftalato , Radical Hidroxilo , Microburbujas , Ultrasonido
5.
J Environ Manage ; 303: 114200, 2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-34896859

RESUMEN

Reactive dyes, which are commonly used in the textile industry, are toxic and carcinogenic for the ecosystem and human health. The objective of this study was to investigate the removal of Reactive Blue 19 (RB19) from aqueous solution and synthetic textile industry wastewater using nanoscale zero-valent aluminum (nZVAl), ultrasonic bath (US-40 kHz), and combined US/nZVAl through the consideration of varying experimental parameters such as pH, nZVAl dosage, contact time, and initial RB19 dye concentration. The acidic pH value was an effective parameter to degrade RB19. As the nZVAl dosage and contact time increased, the degradation of RB19 dye from aqueous solution and synthetic textile industry wastewater increased using combined US/nZVAl process. A similar result was obtained for RB19 removal with combined US/nZVAl using 0.10 g dosage at 30 min, whereas it was obtained with nZVAl alone using 0.20 g dosage at 60 min. The sono-degradation process activated the nZVAl surface depending on US cavitation effect and shock waves, and increased RB19 dye uptake capacity with a shorter contact time and lower nZVAl dosage. Increasing the initial dye concentration decreased the removal efficiency for RB19. According to the obtained reusability results, nZVAl particles could be reused for four and two consecutive cycles of combined US/nZVAl and nZVAl alone, respectively.


Asunto(s)
Industria Textil , Contaminantes Químicos del Agua , Aluminio , Antraquinonas , Colorantes , Ecosistema , Humanos , Aguas Residuales , Contaminantes Químicos del Agua/análisis
6.
Angew Chem Int Ed Engl ; 61(5): e202113506, 2022 01 26.
Artículo en Inglés | MEDLINE | ID: mdl-34761489

RESUMEN

The clinical prospect of sonodynamic therapy (SDT) has not been fully realized due to the scarcity of efficient sonosensitizers. Herein, we designed phthalocyanine-artesunate conjugates (e.g. ZnPcT4 A), which could generate up to ca. 10-fold more reactive oxygen species (ROS) than the known sonosensitizer protoporphyrin IX. Meanwhile, an interesting and significant finding of aggregation-enhanced sonodynamic activity (AESA) was observed for the first time. ZnPcT4 A showed about 60-fold higher sonodynamic ROS generation in the aggregated form than in the disaggregated form in aqueous solutions. That could be attributed to the boosted ultrasonic cavitation of nanostructures. The level of the AESA effect depended on the aggregation ability of sonosensitizer molecules and the particle size of their aggregates. Moreover, biological studies demonstrated that ZnPcT4 A had high anticancer activities and biosafety. This study thus opens up a new avenue the development of efficient organic sonosensitizers.


Asunto(s)
Isoindoles
7.
J Ultrasound Med ; 38(7): 1855-1864, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30548874

RESUMEN

OBJECTIVES: Contrast-enhanced diagnostic ultrasound (US) has a potential to induce localized biological effects. The potential for contrast-enhanced diagnostic US bioeffects in liver were researched, with guidance from a report by Yang et al (Ultrasonics 2012; 52:1065-1071). METHODS: Contact and standoff scanning was performed for 10 minutes with a diagnostic US phased array at 1.6 MHz during bolus injection or infusion of a contrast agent at a high dose. The impact of the imaging on rat liver was investigated by measuring enzyme release, microvascular leakage, and staining of injured hepatocytes. RESULTS: The results showed liver enzyme release at 30 minutes, indicating liver injury, and elevated extraction of Evans blue dye, indicating microvascular leakage. In addition, Evans blue and trypan blue vital-staining methods revealed scattered stained cells within the US scan plane. For the Evans blue method, fluorescent cell counts in frozen sections were greatest for standoff exposure with contrast infusion. The count decreased strongly with depth for bolus injection, which was probably reflective of the high attenuation noted for this agent delivery method. CONCLUSIONS: The results qualitatively confirmed the report by Yang et al and additionally showed hepatocyte vital staining. Research is needed to determine the threshold for the effects and the contrast agent dose response.


Asunto(s)
Medios de Contraste/efectos adversos , Hepatocitos/efectos de los fármacos , Ultrasonografía , Animales , Azul de Evans , Masculino , Ratas , Ratas Sprague-Dawley
8.
Khirurgiia (Mosk) ; (7): 63-70, 2019.
Artículo en Ruso | MEDLINE | ID: mdl-31355817

RESUMEN

AIM: Structural and functional analysis of cells from purulent-necrotic wounds in patients with diabetic foot syndrome undergoing ultrasonic treatment with 0.2% Lavasept solution. MATERIAL AND METHODS: It is presented morphological/ultrastructural analysis of wound specimens in 90 (DFS) patients aged 27-80 years with diabetic foot syndrome and purulent-necrotic complications who were hospitalized in the department of wounds and wound infections of the Vishnevsky Institute of Surgery in 2013-2016. Main group consisted of 75 patients, control group - 15 patients. Mean age was 58.4±8.2 years. All patients had diabetes mellitus type II for previous 13±4.5 years. Severity of foot tissue damage was assessed according to Wagner classification (F. Wagner, 1981). 46 (51.1%) patients had Wagner III-IV, 44 (48.9%) patients - Wagner II. Complex treatment included radical surgical management of purulent lesion, surgical revascularization for critical limb ischemia and foot reconstruction at the final stage. Additional measures were complete unloading of the foot, correction of carbohydrate metabolism and concomitant diseases. Topical treatment between surgical stages included dressing with 1.0% betadine solution (once a day). Ultrasonic cavitation was additionally applied in the main group. Electron microscopic examination of specimens was used before treatment, after 3-5 and 7-10 days in order to assess effectiveness of ultrasound cavitation for purulent-necrotic complications of DFS. RESULTS: Ultrasound cavitation with 0.2% Lavasept solution effectively cleans wounds from microbial and cellular detritus, destroys cellular membranes of biofilm-forming microorganisms, prevents their redo development and reinfection of the wound. Effective management of the wounds accelerates reparative processes that allows to perform foot reconstruction early.


Asunto(s)
Antiinfecciosos Locales/administración & dosificación , Biguanidas/administración & dosificación , Pie Diabético/cirugía , Necrosis/cirugía , Procedimientos Quirúrgicos Ultrasónicos , Administración Tópica , Adulto , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/complicaciones , Pie Diabético/tratamiento farmacológico , Pie Diabético/patología , Humanos , Persona de Mediana Edad , Necrosis/tratamiento farmacológico , Necrosis/patología , Soluciones/administración & dosificación
9.
Artículo en Ruso | MEDLINE | ID: mdl-28884736

RESUMEN

The incidence of chronic endometritis remains rather high despite considerable progress in reproductive medicine including the advent of the new methods for assisted reproduction; the pregnancy rate after the treatment of this condition is still unacceptably low. It implies the necessity of the careful preparation of endometrium for the implantation of the embryo especially in women with a history of unsuccessful outcomes of the IVF treatment. It calls for the development of the efficient therapeutic modalities for the management of chronic endometritis and restoration of the normal reproductive function; their introduction into the therapeutic algorithm remains equally relevant. The characteristic features of chronic endometritis include blood circulatory disorders in the vessels of the uterus and in the pelvic vascular basin, changes of local immunity in the endometrium concomitant with the activation of cellular and humoral responses of inflammation in the form of enhanced leukocyte infiltration and increased production of cytokines. The long duration of such a process results in the development of fibrosis that, in its turn, leads to chronic tissue hypoxia, potentiation of inflammation, and disruption of decidualization that hampers successful implantation. The article shows the possibility of using low-intensity ultrasound for the treatment and rehabilitation of the patients presenting with chronic endometritis. The data concerning the primary biophysical processes developing in the tissues under the influence of ultrasound are discussed. The therapeutic effects and their underlying mechanisms and described. The physiotherapeutic treatment considerably improved vascular hemodynamics in the pelvic basin and produced trophotropic, defibrosing, and anti-inflammatory effects. The clinical data giving evidence of the high effectiveness of the application of intrauterine ultrasound cavitation provide a basis for the recommendation to include this physical factor in the existing algorithms for the pre-gravid preparation of the women presenting with disorders of the reproductive function and chronic endometritis.


Asunto(s)
Endometriosis/terapia , Terapia por Ultrasonido/métodos , Enfermedad Crónica , Endometriosis/rehabilitación , Endometrio/irrigación sanguínea , Endometrio/efectos de los fármacos , Endometrio/efectos de la radiación , Femenino , Humanos , Microcirculación/efectos de los fármacos , Microcirculación/efectos de la radiación , Fonoforesis , Polirribonucleótidos/administración & dosificación , Polirribonucleótidos/uso terapéutico , Resultado del Tratamiento , Ondas Ultrasónicas
10.
J Ultrasound Med ; 35(2): 373-80, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26764276

RESUMEN

OBJECTIVES: Glomerular capillary hemorrhage can be induced by ultrasonic cavitation during contrast-enhanced diagnostic ultrasound (US) exposure, an important nonthermal US bioeffect. Recent studies of pulmonary US exposure have shown that thresholds for another nonthermal bioeffect of US, pulmonary capillary hemorrhage, is strongly influenced by whether xylazine is included in the specific anesthetic technique. The objective of this study was to determine the influence of xylazine on contrast-enhanced diagnostic US-induced glomerular capillary hemorrhage. METHODS: In this study, anesthesia with ketamine only was compared to ketamine plus xylazine for induction of glomerular capillary hemorrhage in rats by 1.6-MHz intermittent diagnostic US with a microsphere contrast agent (similar to Definity; Lantheus Medical Imaging, Inc, North Billerica, MA). Glomerular capillary hemorrhage was measured as a percentage of glomeruli with hemorrhage found in histologic sections for groups of rats scanned at different peak rarefactional pressure amplitudes. RESULTS: There was a significant difference between the magnitude of the glomerular capillary hemorrhage between the anesthetics at 2.3 MPa, with 45.6% hemorrhage for ketamine only, increasing to 63.2% hemorrhage for ketamine plus xylazine (P < .001). However, the thresholds for the two anesthetic methods were virtually identical at 1.0 MPa, based on linear regression of the exposure response data. CONCLUSIONS: Thresholds for contrast-enhanced diagnostic US-induced injury of the microvasculature appear to be minimally affected by anesthetic methods.


Asunto(s)
Anestesia/métodos , Anestésicos Disociativos , Capilares , Medios de Contraste/efectos adversos , Hemorragia/inducido químicamente , Ketamina , Glomérulos Renales/irrigación sanguínea , Ultrasonografía/efectos adversos , Xilazina , Animales , Ratas
11.
Nano Lett ; 15(1): 442-9, 2015 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-25495006

RESUMEN

We present an experimental investigation of the mechanical stability of silica nanoparticle-based coatings as a function of the size of the nanoparticles. The coatings are built following a layer-by-layer procedure, alternating positive and negative surface charges. The mechanical stability of the multilayers is studied in water, on the basis of an ultrasonic cavitation test. The resistance of the coating to cavitation is found to remarkably increase with decreasing the size of the nanoparticles, indicating an increase of the cohesive energy density. The relative contribution of van der Waals and electrical double-layer interactions to the stability of the multilayer is discussed toward their size dependence.

12.
Ultrason Sonochem ; 108: 106982, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38981340

RESUMEN

SBS (styrene-butadiene-styrene block copolymer) is currently the most widely used asphalt modifier, and SBS modified asphalt is usually prepared by high-speed shearing. This paper combines the cavitation effect of ultrasonic to assist in the preparation of SBS modified asphalt, and conducts numerical simulation and rheological properties research on the cavitation bubbles in the molten SBS modified asphalt fluid. The cavitation bubbles in the modified asphalt fluid will expand and contract as the pressure changes inside and outside the bubbles. When the cavitation bubble is compressed to the minimum and the pressure inside the bubble reaches 1.94 × 105Pa, the direction of the velocity vector near the cavitation bubble will change with the expansion and compression of the bubble. The expansion-contraction process of a single cavitation bubble can release 6.41 × 10-7J of energy, thus breaking the long bonds in asphalt and generating a large number of free radicals react with the unsaturated C = C bonds in the SBS molecules. According to the preparation process of modified asphalt, the influence of ultrasonic wave on rheological property of modified asphalt was studied through experiments. The results show that ultrasonic treatment can enhance the elasticity of asphalt and improve the temperature sensitivity of asphalt. With the increase of ultrasonic treatment time, the anti-rutting deformation ability of SBS modified asphalt is greatly improved. At the same temperature, the recovery rate of asphalt also increases with the increase of ultrasonic treatment time, and the non-recoverable compliance (Jnr) decreases Combined with the numerical simulation of cavitation bubbles, the ultrasonic process is added to asphalt production, which is of great significance for the green production of modified asphalt and the improvement of the rheological properties of modified asphalt.

13.
Sci Rep ; 14(1): 16956, 2024 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-39043923

RESUMEN

In the field of power ultrasonic vibration processing, the thin liquid layer nestled between the tool head and the material serves as a hotbed for cavitation shock wave emissions that significantly affect the material's surface. The precise manipulation of these emissions presents a formidable challenge, stemming from a historical deficit in the quantitative analysis of both the ultrasonic enhancement effect and the shock wave intensity within this niche environment. Our study addresses this gap by innovatively modifying the Gilmore-Akulichev equation, laying the groundwork for a sophisticated bubble dynamics model and a pioneering shock wave propagation model tailored to the thin liquid layer domain. Firstly, our study investigated the ultrasound enhancement effect under various parameters of thin liquid layers, revealing an amplification of ultrasound pressure in the thin liquid layer area by up to 7.47 times. The mathematical model was solved using the sixth-order Runge-Kutta method to examine shock wave velocity and pressure under different conditions. our study identified that geometric parameters of the tool head, thin liquid layer thickness, ultrasonic frequency, and initial bubble radius all significantly influenced shock wave emission. At an ultrasonic frequency of 60 kHz, the shock wave pressure at the measurement point exhibited a brief decrease from 182.6 to 179.5 MPa during an increase. Furthermore, rapid attenuation of the shock wave was found within the range of R0-3R0 from the bubble wall. This research model aims to enhance power ultrasonic vibration processing technology, and provide theoretical support for applications in related fields.

14.
Eur J Pharm Biopharm ; 198: 114246, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38479562

RESUMEN

Immunotherapy has revolutionized cancer treatment by boosting the immune system and preventing disease escape mechanisms. Despite its potential, challenges like limited response rates and adverse immune effects impede its widespread clinical adoption. Ultrasound (US), known for its safety and effectiveness in tumor diagnosis and therapy, has been shown to significantly enhance immunotherapy when used with nanosystems. High-intensity focused ultrasound (HIFU) can obliterate tumor cells and elicit immune reactions through the creation of immunogenic debris. Low-intensity focused ultrasound (LIFU) bolsters tumor immunosuppression and mitigates metastasis risk by concentrating dendritic cells. Ultrasonic cavitation (UC) produces microbubbles that can transport immune enhancers directly, thus strengthening the immune response and therapeutic impact. Sonodynamic therapy (SDT) merges nanotechnology with immunotherapy, using specialized sonosensitizers to kill cancer cells and stimulate immune responses, increasing treatment success. This review discusses the integration of ultrasound-responsive nanosystems in tumor immunotherapy, exploring future opportunities and current hurdles.


Asunto(s)
Neoplasias , Terapia por Ultrasonido , Humanos , Neoplasias/patología , Ultrasonografía , Inmunoterapia , Línea Celular Tumoral , Especies Reactivas de Oxígeno
15.
Ultrason Sonochem ; 109: 107011, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39121600

RESUMEN

Surface-attached micro- and nanobubbles are known for their resistance to external forces. This study experimentally and theoretically investigates their response to strong ultrasonic fields. Surface-attached micro- and nanobubbles with contact radii from 2 µm to 20 µm are generated in a microchannel and exposed to ultrasound through a vibrating glass substrate. At a driving frequency over 200 kHz up to 2 MHz tested, no significant response from the micro- and nanobubbles is observed. By contrast, at 100 kHz-200 kHz, ultrasonic cavitation bubbles appear in the microchannel and migrate toward the surface micro- and nanobubbles. Then the surface micro- and nanobubbles merge with the ultrasonic cavitation bubbles, detach from the substrate, and become free gaseous nuclei susceptible to further cavitation. Notably, the removal process leaves no observable residue. Theoretical analysis suggests that the directional migration of cavitation bubbles is driven by mutual acoustic radiation forces. This work demonstrates that ultrasonic fields can effectively remove surface micro- and nanobubbles, transforming them into free gaseous cavitation nuclei.

16.
Chemosphere ; 350: 141024, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38147929

RESUMEN

Environmental pollution and energy shortages are global issues that significantly impact human progress. Multiple methods have been proposed for treating industrial and dyes containing wastewater. Ultrasonic degradation has emerged as a promising and innovative technology for organic pollutant degradation. This study provides a comprehensive overview of the factors affecting ultrasonic degradation and thoroughly examines the technique of acoustic cavitation. Furthermore, this study summarizes the fundamental theories and mechanisms underlying cavitation, emphasizing its efficacy in the remediation of various water pollutants. Furthermore, potential synergies between ultrasonic cavitation and other commonly used technologies are also explored. Potential challenges are identified and future directions for the development of ultrasonic degradation and ultrasonic cavitation technologies are outlined.


Asunto(s)
Contaminantes Ambientales , Contaminantes Químicos del Agua , Humanos , Aguas Residuales , Ultrasonido , Acústica , Contaminación Ambiental , Contaminantes Químicos del Agua/análisis
17.
Nanomaterials (Basel) ; 14(3)2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38334547

RESUMEN

Defect engineering constitutes a widely-employed method of adjusting the electronic structure and properties of oxide materials. However, controlling defects at room temperature remains a significant challenge due to the considerable thermal stability of oxide materials. In this work, a facile room-temperature lithium reduction strategy is utilized to implant oxide defects into perovskite BaTiO3 (BTO) nanoparticles to enhance piezocatalytic properties. As a potential application, the piezocatalytic performance of defective BTO is examined. The reaction rate constant increases up to 0.1721 min-1, representing an approximate fourfold enhancement over pristine BTO. The effect of oxygen vacancies on piezocatalytic performance is discussed in detail. This work gives us a deeper understanding of vibration catalysis and provides a promising strategy for designing efficient multi-field catalytic systems in the future.

18.
J Colloid Interface Sci ; 669: 816-824, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38749220

RESUMEN

The precise and controllable preparation of carbon nanomaterials under mild conditions poses a great challenge, especially for metal-catalysed multiphase preparation. This work proposes an efficient method that utilizing high-density ultrasound to enhance the liquid-liquid interfacial reaction system. Iron-doped carbon dots (Fe-CDs) are successfully synthesized in such a normal temperature and atmospheric-pressure reaction condition. It is shown that transient cavitation provides a high-temperature and high-pressure microenvironment for the preparation of Fe-CDs. Moreover, the size of the reactant droplets is reduced from 200.0 ± 17.3 µm to 8.1 ± 2.9 µm owing to the acoustic flow and cavitation effects, which increases the specific surface area of the two reacting phases and improves the mass transfer coefficient by more than 252.0 %. As a result, the yield increases by more than an order of magnitude (from 0.7 ± 0.1 % to 11.9 ± 0.2 %) and the Fe doping rate reaches 20.9 %. The photocatalytic oxidation conversion of 1,4-Dihydropyridine (1,4-DHP) using the obtained Fe-CDs is as high as 98.2 %. This research gives a new approach for the efficient and safe production of Fe-CDs, which is promising for industrial applications.

19.
Ultrason Sonochem ; 108: 106957, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38901304

RESUMEN

In industrial production and scientific research, ultrasonic cavitation technology, with its outstanding physical and chemical processing capabilities, has been widely applied in fields such as material surface modification, chemical synthesis, and biotechnology, becoming a focal point of research and application. This article delves into the effects of different ultrasonic frequencies on cavitation outcomes through the combined use of numerical simulation, fluorescence analysis, and high-speed photography, specifically analyzing the quantitative improvement in the mechanical properties of TC17 titanium alloy under ultrasonic cavitation at frequencies of 20 kHz, 30 kHz, and 40 kHz. The study found that at an ultrasonic frequency of 20 kHz, the maximum expansion radius of cavitation bubbles can reach 51.4 µm, 8.6 times their initial radius. Correspondingly, fluorescence intensity and peak area also increased to 402.8 and 28104, significantly above the baseline level. Moreover, after modification by ultrasonic cavitation, the original machining marks on the surface of TC17 titanium alloy became fainter, with the emergence of new, uniformly distributed microfeatures. The microhardness of the material increased from 373.7 Hv to 383.84 Hv, 396.62 Hv, and 414.06 Hv, with a maximum improvement of 10.8 %. At the same time, surface height difference and roughness significantly decreased (to 3.168 µm and 0.61 µm respectively), with reductions reaching 45.1 % and 42.4 %, indicating a significant improvement in material surface quality. Notably, there is a negative correlation between the improvement of mechanical properties and ultrasonic frequency, suggesting that the improvement effects decrease as ultrasonic frequency increases. This research not only reveals the quantitative relationship between ultrasonic cavitation frequency and material surface modification effects but also provides a solid scientific basis and practical guidance for the application of ultrasonic cavitation technology in surface engineering, signifying the technology's potential for broad application in the future.

20.
Curr Med Chem ; 2024 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-38299292

RESUMEN

Functional nanomaterial graphene and its derivatives have attracted considerable attention in many fields because of their unique physical and chemical properties. Most notably, graphene has become a research hotspot in the biomedical field, especially in relation to malignant tumors. In this study, we briefly review relevant research from recent years on graphene and its derivatives in tumor diagnosis and antitumor therapy. The main contents of the study include the graphene-derivative diagnosis of tumors in the early stage, graphene quantum dots, photodynamics, MRI contrast agent, acoustic dynamics, and the effects of ultrasonic cavitation and graphene on tumor therapy. Moreover, the biocompatibility of graphene is briefly described. This review provides a broad overview of the applications of graphene and its derivatives in tumors. Conclusion, graphene and its derivatives play an important role in tumor diagnosis and treatment.

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