Ultrasound Power Research Articles

The ultrasound leaching kinetics of copper in the H2SO4 dissolution process

ABSTRACT The atmospheric immersion copper dissolution method, commonly employed in the current copper foil production process, is confronted with challenges such as low oxidation ability and the formation of passivation layers on the copper surface. These issues result in slow copper dissolution rates, significantly restricting copper foil production. To overcome this limitation, ultrasound is used to improve the copper dissolution process. The impact of ultrasound on the rate and kinetics of copper dissolution in a sulfuric acid solution was studied. Various factors, including ultrasound power, temperature, Cu2+ concentration, sulfuric acid concentration, and air flow rate, were analysed to assess their influence on the rate of copper dissolution. The optimised dissolution conditions were determined to be 30 g/L Cu2+, 120 g/L sulfuric acid, 300 mL/min air flow, 60°C, and 300 W ultrasonic power. The copper dissolution rate is 1.96 times higher when ultrasound is applied compared to conventional conditions. According to the kinetic study, ultrasound reduced the apparent activation energy from 61.12 kJ/mol to 46.44 kJ/mol, significantly lowering the potential barrier for copper dissolution. This study provides valuable insights for accelerating the dissolution process of copper using ultrasound-assisted technology.

Ultrasonographic Synovitis Is Associated with the Development of Joint Destruction in Patients with Psoriatic Arthritis.

Psoriatic arthritis (PsA) is characterized by enthesitis. As persistent inflammation around joints results in bone and cartilage destruction and physical impairment, a detailed assessment of inflammation is essential. We previously reported the difference between clinical assessment (tenderness) and ultrasound (US) assessment (inflammation) of entheses. Herein, we investigated whether clinical or US assessment of joints and entheses can predict the progression of joint destruction in Japanese patients with PsA. Thirty joints and 14 entheses in 47 patients were assessed using US and clinical examination. The US greyscale (GS) and power Doppler (PD) scores at the ultrasonographic synovitis, the US active enthesitis count, and the clinical tender joint/entheses count were assessed. Additionally, the yearly radiographic progression of the Sharp-van der Heijde scoring method for PsA was assessed. Their correlations were investigated. About half of the patients with PsA experienced joint destruction during a follow-up period of 20.4 months. Progression of joint destruction in patients with PsA only correlated with joint GS and PD scores, reflecting the severity of ultrasonographic synovitis, not with the tender joint/entheses count. US examinations are essential for preventing joint destruction and physical impairment in patients with PsA.

Study on high-efficiency sulfide removement using sulfate radical-based AOPs and its oxidation mechanism of refractory gold ore

Pyrite enclosure poses a significant challenge in refractory gold ore processing, inhibiting gold leaching. This study explores Sulfate Radical-based Advanced Oxidation Processes (SR-AOPs) as an effective alternative for pretreating such ores. The oxidation pretreatments were performed under heat and ultrasound activation methods, including heat and ultrasound, and the influences of pretreatment time, pH, ultrasound power, pretreatment temperature, and precursor (PDS) concentration were investigated. Both ultrasonic and heat activation effectively mitigate the negative impact of pyrite enclosure on gold leaching. Specifically, the gold leaching rate improved from 21.9 % to 46.1 % and 74.9 % with heat and ultrasound activation, respectively The and generated by PDS dominate the pyrite oxidation according to EPR and quenching tests. Meanwhile, the SR-AOPs treatment also promotes the interactions between pyrite enclosure and leaching agent, reducing the negative influences of pyrite. Kinetic studies indicated that the oxidation processes are different under heat and ultrasound activation. Heat activation is governed by an interfacial chemical reaction, with an activation energy of 25.57 kJ/mol. In contrast, ultrasound-induced cavitation and microjets remove the oxidation layer, disrupt the pyrite crystal structure, and expose encapsulated gold. These effects accelerate pyrite oxidation, shifting the kinetic control step from interfacial chemical reaction to internal diffusion, with a reduced activation energy of 35.06 kJ/mol.

Combination with ultrasound and Fe0 in sulfite activation to degrade Tribromophenol: Synergistic performance and mechanism

A novel advanced oxidation process combining low-frequency ultrasound (US) with zero-valent iron (Fe0) and sulfite (S(IV)) has been systematically developed. The combination showed significant synergy and considerable selectivity in the degradation of 2,4,6-tribromophenol (TBP). An 89.6 % removal of TBP was achieved within 30 min using a S(IV) concentration of 0.5 mmol/L and a Fe0 dosage of 0.05 g/L at pH 7.0, accompanied by ultrasonication at 40 kHz in the US/Fe0/S(IV) system. Mechanistic studies have indicated that SO4•− and •OH are the main reactive species in the system, and that •H plays an important role in the conversion of reactive species. The S(IV) activation mode by Fe0 has been found to be divided into homogeneous activation and heterogeneous activation during US. Moreover, US can improve the reactions by promoting mass transfer in the aqueous phase and between the solid and liquid. In the US/Fe0/S(IV) system, TBP degradation is promoted by increases in either US power, Fe0 dosage, or temperature. Too low or too high S(IV) concentration, pH, or dissolved oxygen can have an adverse effect on the reaction. Cations have little influence on the system, except for Cu2+, while anions inhibit the degradation of TBP, except for SO42−. The presence of humic substances (humic acid and fulvic acid) significantly inhibits TBP degradation. Overall, this work provides a new technique for water treatment with high efficiency and application potential.

Ultrasonic-assisted pulse electrodeposition process for producing nanocrystalline nickel films and their corrosion behavior: Competition between mass transport and nucleation

Ultrasonic-assisted pulse electrodeposition of nanocrystalline nickel (NC-Ni) coatings from Watts bath on copper substrate was investigated. Direct (DC), pulsed (PC), and pulse reversed (PRC) current electrodeposition techniques were employed to electrodeposit NC-Ni coatings in the absence and presence of ultrasound wave with a nominal power ranging from 95 W to 200 W and their surface morphology, hardness, and crystalline microstructure were compared. We observed that as the ultrasound power increases, the cathodic efficiency and the microhardness increase, whereas the crystallite size and surface roughness decrease for NC-Ni electrodeposited by the three techniques in the same way. However, the effect of pulse waveform is dominant. The finest crystallite size (24 nm) and highest hardness (585 HV) were achieved for NC Ni coatings PC electrodeposited using an ultrasound with 200 W nominal power. It is believed that the coating produced by PC and PRC techniques develops a preferential orientation in (111) and (100) planes, respectively. The application of ultrasound wave and increasing its nominal power changes the preferential orientation of all obtained coatings to (111) planes. The corrosion behavior of NC Ni coatings, as investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in NaOH solution, demonstrates the effect of nanocrystalline on the passivation and corrosion resistance of NC-Ni coatings.

Ultrasonic-Assisted Extraction and Gastrointestinal Digestion Characteristics of Polysaccharides Extracted from Mallotus oblongfolius

The polysaccharides were extracted from the leaves of Mallotus oblongifolius (MO) using an ultrasonic-assisted extraction method in this study. The main variables affecting the yield of polysaccharides extracted from Mallotus appallatus (MOPS) were identified and optimized while concurrently investigating its antioxidant capacity, hypoglycemic activity, and digestive properties. The results indicated that the optimal ultrasound-assisted extraction of MOPS involved an ultrasound power of 200 W, a liquid-to-solid ratio of 25:1 (mL:g), an extraction temperature of 75 °C, and an ultrasound time of 45 min, leading to an extraction yield of (7.36 ± 0.45)% (m/m). The MOPS extract exhibited significant scavenging activity against DPPH and ABTS radicals with IC50 values of (25.65 ± 0.53) μg/mL and (100.38 ± 0.38) μg/mL, respectively. Furthermore, it effectively inhibited the enzymatic activities of α-glucosidase and α-amylase with IC50 values of (2.27 ± 0.07) mg/mL and (0.57 ± 0.04) mg/mL, respectively. The content of MOPS remained relatively stable in the stomach and small intestine; however, their ability to scavenge DPPH radicals and ABTS radicals and exhibit reducing power was attenuated, and the inhibition of α-amylase and α-glucosidase activity was diminished. In conclusion, the ultrasonic extraction of MOPS showed feasibility and revealed antioxidant and hypoglycemic effects. However, the activities were significantly reduced after gastric and small intestinal digestion despite no significant change in the MOPS content.

Impact of ultrasound on nutrition recovery and physicochemical properties of oat beverage

Oat beverage has become increasingly popular, yet its processing removes valuable nutritional components and results in waste stream. This study evaluated the use of ultrasound as a pre-treatment technology to improve nutrient recovery in oat beverage preparation. Various ultrasound power levels (60, 240, and 960 W) and treatment times (1, 5, and 9 min) were investigated for their effects on physical and chemical changes during oat beverage preparation. Ultrasound effectively reduced the size of larger oat grain fibrous particles while largely leaving smaller size compounds unaffected. Partial disintegration of cell wall structures was also observed under confocal laser scanning microscopy. This resulted in a significant increase (up to 39%) in β-glucan recovery with minor alteration to its molecular weight in oat beverage, preserving its inherent health benefits. Protein recovery was not improved, but ultrasound led to partial unfolding of tertiary structure, improving protein solubility and foaming properties of oat beverage, which could be beneficial in developing coffee-based beverages and desserts. The shear-thinning behavior of oat beverage was maintained after ultrasound treatment, benefiting processing efficiency and mouthfeel. Overall, these findings highlight the potential of ultrasound as a sustainable pre-treatment technology to enhance the nutritional quality and physicochemical properties of oat beverage.

Effects of operating parameters on single-stage ultrasonic separation of ethanol from its aqueous solutions

The effects of operating parameters on separation of ethanol from its aqueous solutions using ultrasonic atomization were investigated in a single-stage process. With an experimental setup similar to those used in previous work, we measured the degree of enrichment and the combined molar collection rate of ethanol and water for a single combination of the ultrasound power and frequency at 126 combinations of bulk liquid depth, composition, and temperature; carrier-gas inlet/outlet elevation and flow rate; and collection temperature. Enrichment depends strongly on bulk liquid composition, reaching a maximum at an ethanol mole fraction below 0.1, with the maximum enrichment depending on bulk liquid depth and inlet/outlet elevation. The collection rate depends strongly on inlet/outlet elevation and bulk liquid pool depth, and for high ethanol mole fractions is nearly independent of bulk liquid composition. Enrichment and collection rate increase with increasing bulk liquid temperature and decreasing collection temperature. The fact that increasing the carrier-gas flow rate increases the collection rate and decreases enrichment is interpreted in terms of size-selective transport of drops from the ultrasonically-generated fountain where they are atomized, to the cold trap where they are collected. The results are discussed in terms of operating parameters, transport phenomena (including evaporation and gravitational settling of atomized drops), the ultrasonically-induced fountain, and previously reported drop-size distributions. The duration of the experiments, conducted in batch, was such that the results should be relevant to both batch and continuous-flow operation. The work provides guidance and critical data for process scale-up.

Ultrasound-assisted intensification of Pickering interfacial biocatalysis preparation of vitamin A aliphatic esters

A novel approach to ultrasound-assisted Pickering interfacial biocatalysis (PIB) has been proposed and implemented for the efficient enzymatic transesterification production of vitamin A fatty acid esters. This is the first instance of exploiting the synergistic effect of ultrasound and the bifunctional modification of enzyme supports to accelerate biocatalytic performance in PIB systems. The optimal conditions were determined to be ultrasound power of 70 W, on/off time of 5 s/5 s, substrate molar ratio of 1:1, enzyme addition of 2 %, and a volume ratio of n-hexane to PBS of 3:1, a temperature of 40 °C, and a time of 30 min. The application of ultrasound technology not only improved lipase activity but also allowed for a reduction in emulsion droplet size to enhance interfacial mass transfer.Bifunctional modification of silica-based supports enhanced stability of immobilized enzymes by increasing hydrogen bonding while maintaining the active interface microenvironment. Compared with a non-ultrasound-assisted PIB system stabilized by mono-modified immobilized enzyme particles, the catalytic efficacy (CE) of the novel system reached 8.18 mmol g−1 min−1, which was enhanced by 3.33-fold, while the interfacial area was found to have increased by 17.5-fold. The results facilitated the conversion of vitamin A palmitate (VAP), vitamin A oleate (VAO), vitamin A linoleate (VAL), and vitamin A linolenate (VALn), with conversion rates of approximately 98.2 %, 97.4 %, 96.1 %, and 94.7 %, respectively. This represents the most efficient example that has been reported to our knowledge. Furthermore, the system demonstrated improved reusability, with a conversion rate of 62.1 % maintained even after 10 cycles. The findings presented in this paper provide valuable insights into an efficient and conveniently promising protocol for the development of PIB systems.

Ultrasound-induced yield increase of yuba (protein-lipid film from soybean milk) and changes in structural, physicochemical, and digestive properties during film-peeling process

Yuba, as a traditional soybean food, is protein-lipid film from soybean milk. This study proposed a novel ultrasound-assisted yuba preparation strategy and investigated the structural, physicochemical, and digestive properties of yuba during the film-peeling process. The process parameters of yuba preparation were optimized using response surface method and Box-Behnken design. The results showed that total yield of 5 yuba films was 39.8 ± 0.3% under the optimum conditions (315 W ultrasound power, 8 min ultrasound time, and 1:9 solid-to-liquid ratio) with an increase rate of 12.6%, compared with that of the control group. With the increasing yuba film-peeling times, protein and lipid contents in yuba decreased, whereas carbohydrate content displayed an increasing trend. The analyses of mechanical properties, protein secondary structure, X-ray diffraction, disulfide bond, and microstructure showed that the protein network structure of yuba films became looser with film-peeling progression. Furthermore, in vitro simulated digestion experiments indicated that yuba obtained in the early film-peeling stage (the first four films) exhibited better protein degradation performance and higher degree of lipid hydrolysis. This study provides technical references for the process innovations of yuba and theoretical basis for systematically evaluating yuba quality and better utilizing its nutritional value.

Microbiological interpretation of weak ultrasound enhanced biological wastewater treatment – using Escherichia coli degrading glucose as model system

The Escherichia coli (E.coli) degrading glucose irradiated by ultrasound irradiation (20 W, 14 min) was investigated as the model system, the glucose degradation increased by 13 % while the E.coli proliferation decreased by 10 % after culture for 18 h. It indicated a tradeoff effect between substrate degradation and cell proliferation, which drove the enhanced contaminants removal and excess sludge reduction in a weak ultrasound enhanced biological wastewater treatment. The enzymatic activities (catalase, superoxide dismutase, adenosine triphosphatases, lactic dehydrogenase, membrane permeability, intracellular reactive oxygen species and calcium ion of E. coli increased immediately by 12 %, 63 %, 124 %, 19 %, 15 %, 4-fold and 38-fold, respectively by ultrasound irradiation power of 20 W for 14 min. Furthermore, the membrane permeability of irradiated E. coli increased by 26 % even though the ultrasound stopped for 10 h. Additionally, pathways associated with glucose degradation and cell proliferation were continuously up-regulated and down-regulated, respectively.

An ultrasonic fabrication process for carbides reinforced Inconel 718 alloy composites

A novel approach was proposed to prepare carbides reinforced Inconel 718 alloy composites by ultrasonicating graphite mold to introduce carbon element into liquid phase. The graphite mold was designed to resonate with three-dimensional (3D) power ultrasounds, which stimulated cavitation effect and acoustic streaming to promote uniform carbon dispersion and the subsequent incorporation of various carbides with alloy solidification process. It was found that the carbon content infiltrated into liquid alloy increased with ultrasound amplitude and dimension, which attained the maximum of 2.64 wt% C. Ultrasound accelerated the peritectic L+TiC→NbC reaction, forming a blocky (Ti, Nb)C phase instead of shell-core structured (TiC+NbC) phases. A new (Cr, Fe)7C3 phase was produced due to the extended carbon solubility into liquid alloy under 3D ultrasounds. Meanwhile, the synergistic orientation relationships between γ(Ni) and carbide phases were enhanced by high-frequency vibration. The ultrasonically solidified composites exhibited excellent wear resistance and hardness as compared with other IN718 alloy-based composites.

The Effects of Assisted Freezing with Different Ultrasound Power Rates on the Quality and Flavor of Braised Beef.

This study investigated the effects of ultrasound-assisted immersion freezing (UIF) at different power rates (0, 200, 400, and 600 W) on the changes in beef quality and flavor after braising. The results demonstrated that UIF treatment at 400 W significantly reduced the juice loss (cooking loss decreased from 49.04% to 39.74%) and fat oxidation (TBARS value decreased from 0.32 mg/kg to 0.20 mg/kg) of braised beef. In addition, the tenderness (hardness value decreased from 5601.50 g to 2849.46 g) and color stability of braised beef were improved after UIF treatment. The flavor characteristics of braised beef were characterized using an electronic nose and an electronic tongue. The PCA analysis data showed that the cumulative contribution rates of the first and second principal components were 85% and 93.2%, respectively, with the first principal component accounting for a higher proportion. The UIF-400 W group had the highest concentration for the first principal component, and the differentiation was not significant compared to the control group. The total amino acid values of different power UIF treatment groups were improved compared to the AF treatment group, indicating that UIF can effectively reduce the losses caused by freezing. The results demonstrate that ultrasound-assisted freezing treatment is beneficial in enhancing the tenderness and flavor attributes of beef after braising, providing new insights into the processing of meat products with desirable quality characteristics.

Ultrasound treatment improved the physicochemical properties of pea protein with pectin ink used for 3D printing

Pectin, as a gelling agent enhancer, is capable of augmenting the strength of plant protein gels; however, their direct blending often results in insignificant crosslinking efficiency. The application of ultrasonication has been found to effectively promote crosslinking interactions between pectin and plant proteins. This study primarily probes into the physicochemical impacts on the pea protein system instigated by ultrasonicated apple pectin (AP), citrus pectin (CP), and high methoxyl pectin (HM) variances. It has been revealed that the incorporation of pectin, subsequent to ultrasonication, ameliorates the textural and rheological traits of the pea protein matrix. Nevertheless, the introduction of high methoxyl pectin excessively enhances these identical properties, rendering it unsuitable for use in food development and three-dimensional (3D) printing technologies. Under an ultrasound power setting of 390 W, the citrus pectin variant outperforms other variants with its superior hardness, elasticity, and viscoelasticity, thereby significantly bolstering the self-supporting capability and malleability of the pea protein system for potential utilization in 3D printing applications. In conclusion, the ultrasonically treated pectin-pea protein amalgam optimizes the physicochemical attributes of the pea protein system, contributing to the stability enhancement of 3D printed products.

Sono-assisted photocatalytic degradation of ciprofloxacin in aquatic media using g-C3N4/MOF-based nanocomposite under visible light irradiation.

This research study is centered on the sono-assisted photocatalytic degradation of a well-known antibiotic (ciprofloxacin; CIP) in aquatic media using a g-C3N4/NH2-UiO-66 (Zr) catalyst under visible light irradiation. Initially, the catalyst was prepared by a simple method, and its physiochemical features were thoroughly analyzed by XRD, FT-IR, FE-SEM, EDX, EDS-Dot-Mapping, and UV-Vis analytical techniques. After that, the impact of several influential factors affecting the performance of the applied sono-assisted photocatalytic process such as the initial concentration of CIP, solution pH, catalyst dosage, light intensity, and ultrasound power was fully assessed, and the optimal conditions were established. After 75min of the sono-assisted photocatalytic treatment, the complete degradation of CIP (10mg/L) was accomplished under the condition as follows: g-C3N4/NH2-UiO-66 (Zr), 0.6g/L; pH, 5.0, and ultrasound power, light intensity 75 mw/cm2, 200 W/m2. Meanwhile, the photocatalytic degradation of CIP followed the pseudo-first-order kinetic model. In addition, the scavenger experiments demonstrated that OH˚ and O2°- radicals played a key role in the sono-assisted photocatalytic degradation process. It is also acknowledged that the applied catalyst was reused for five consecutive runs with a minor loss observed in its degradation efficiency. In a further experiment, a significant synergistic effect with regard to the degradation of CIP was observed once all three major parameters (visible light, ultrasound waves, and catalyst) were used in combination compared to each used alone. To sum up, it is thought that the integration of g-C3N4/MOF-based catalyst, ultrasound waves, and visible light irradiation could be potentially applied as a promising strategy for the degradation of various pharmaceuticals on account of high degradation performance, simple operation, excellent reusability, and eco-friendly approach.

Low‐intensity continuous ultrasound effect on proliferation and morphology of fibroblast cells

AbstractRecently, the use of ultrasound (US) for triggering drug release to specific tissues was explored, but its direct effects on cells have not been thoroughly understood. For this reason, this study aimed to investigate the impact of US powers and US irradiation times on fibroblast cells (NIH‐3T3). The results showed that the diverse US settings had varying effects on cell proliferation and distribution in the polystyrene culture dish. Interestingly, at 10 W, 43 kHz with changing exposed time up to 30 min either stimulated or inhibited fibroblast cell growth after 24 and 72 h of cultivation compared to the control sample in the absence of US, while longer US exposure time led to a moderate reduction in cell quantity. Moreover, higher US levels of 20 and 30 W could cause an aggregation of cells and sublethal damage to the cells. Importantly, the morphology of fibroblast was changed from stellate‐shape to round‐shape under greater US powers. Elevated US power also influenced interactions between proteins and lipids, affecting the atomic and molecular charges, leading to changes in both zeta potential and pH of the dispensed cell solution.

Regulation of fat crystals in water-in-oil emulsions by high-intensity ultrasound: Crystal size and tracing of droplet distribution

In this paper, two emulsion systems with high and low solid fat contents were prepared from 20 % water phase and 80 % oil phase by adjusting the palm oil/palm stearin/soybean oil ratio. Different ultrasonic power and time were used for the pretreatment of emulsion with different solid fat content, and the application characteristics of ultrasonic in W/O emulsions were explored and evaluated. Directly using high-intensity ultrasound to prepare fatty emulsions would weaken the hardness and storage modulus G' of the samples. Although ultrasound reduced the size of fat crystals in emulsions, the interaction between water droplets and fat crystals needs to be considered. After ultrasonic treatment, water droplets were difficult to immobilize on the crystal surface and thus acted as an active filler to stabilize the emulsion together with the fat crystal network. In high solid fat emulsion systems, an increase in ultrasound power (from 100 W to 200 W) could more affect the crystallization behavior of fats than an increase in ultrasound duration (from 30 s to 60 s), and the distribution of crystals and droplets was more uniform. In the low solid fat emulsion system, the texture of the sample after ultrasonic treatment was softer, and the surface was more delicate and smoother. However, the higher ultrasonic intensity (200 W) was not conducive to the preparation of the spread. Although the ultrasound with excessive intensity promoted the formation of small crystals, it would also lead to the aggregation of small crystals. These small crystals cannot form a uniform crystal network, which increases the fluidity of emulsions.

Investigating the impact of ultrasound on the structural, physicochemical, and emulsifying characteristics of Dioscorin: Insights from experimental data and molecular dynamics simulation

This study investigated the impact of ultrasound treatment on dioscorin, the primary storage protein found in yam tubers. Three key factors, namely ultrasound power, duration, and frequency, were focused on. The research revealed that ultrasound-induced cavitation effects disrupted non-covalent bonds, resulting in a reduction in α-helix and β-sheet contents, decreased thermal stability, and a decrease in the apparent hydrodynamic diameter (Dh) of dioscorin. Additionally, previously hidden amino acid groups within the molecule became exposed on its surface, resulting in increased surface hydrophobicity (Ho) and zeta-potential. Under specific ultrasound conditions (200 W, 25 kHz, 30 min), Dh decreased while Ho increased, facilitating the adsorption of dioscorin molecules onto the oil-water interface. Molecular dynamics (MD) simulations showed that at lower frequencies and pressures, the structural flexibility of dioscorin's main chain atoms increased, leading to more significant fluctuations between amino acid residues. This transformation improved dioscorin's emulsifying properties and its oil-water interface affinity.

Evaporating crystallization effect of ammonium sulfate at atmospheric pressure under the action of ultrasound

Ultrasound enhanced evaporating crystallization has been proposed to solve the problems of low crystallization yield and uneven particle size in the evaporating crystallization process of ammonium sulfate solution at atmospheric pressure. The effects of key operating parameters, including the ultrasound power, stirring speed, pH value, and ultrasound time, on the yield of ammonium sulfate product and the duration of solid–liquid transformation time are studied. The results show that the ultrasound crystallization can increase the ammonium sulfate yield by 52.9 %, reduce the solid–liquid transformation time of ammonium sulfate by 10 %, and obtain ammonium sulfate products with higher crystallinity and more uniform particle size. Ultrasound promotes the crystallization of ammonium sulfate by enhancing the transfer of heat in the solution and reducing the supersolubility of the ammonium sulfate solution from 937.5 g/L to 833.33 g/L. This study provides experimental justification for the use of ultrasound in atmospheric evaporative crystallization.

Subclinical joint inflammation in rheumatoid arthritis: comparing thermal and ultrasound imaging at the metacarpophalangeal joint

BackgroundWhile ultrasound and MRI are both superior to clinical examination in the detection of joint inflammation, there is presently a lack of data whether thermography may be similarly useful in the assessment of joint inflammation in patients with RA. Our study aims to evaluate the use of thermography in detecting subclinical joint inflammation at clinically quiescent (non-tender and non-swollen) metacarpophalangeal joints (MCPJs) in patients with rheumatoid arthritis (RA). The outcomes from thermography in our study will be compared with ultrasonography (which is a more established imaging tool used for joint inflammation assessment in RA).MethodsThe minimum (Tmin), average (Tavg) and maximum (Tmax) temperatures at the 10 MCPJs of each patient were summed to obtain the Total Tmin, Total Tavg and Total Tmax, respectively. Ultrasound grey-scale (GS) and power Doppler (PD) joint inflammation (scored semi-quantitatively, 0–3) at the 10 MCPJs were summed up to derive the respective TGS and TPD scores per patient. Pearson’s correlation and simple linear regression were respectively used to assess correlation and characterize relationships between thermographic parameters (Total Tmin, Total Tavg and Total Tmax) and ultrasound imaging parameters (TGS, TPD and the number of joint(s) with PD ≥ 1 or GS ≥ 2).ResultsIn this cross-sectional study, 420 clinically non-swollen and non-tender MCPJs from 42 RA patients were examined. All thermographic parameters (Total Tmin, Total Tavg and Total Tmax) correlated significantly (P-values ranging from 0.001 to 0.0012) with TGS score (correlation coefficient ranging from 0.421 to 0.430), TPD score (correlation coefficient ranging from 0.383 to 0.424), and the number of joint(s) with PD ≥ 1 or GS ≥ 2 (correlation coefficient ranging from 0.447 to 0.465). Similarly, simple linear regression demonstrated a statistically significant relationship (P-values ranging from 0.001 to 0.005) between all thermographic parameters (Total Tmin, Total Tavg and Total Tmax) and ultrasound imaging parameters (TPD and TGS).ConclusionFor the first time, thermographic temperatures were shown to correlate with ultrasound-detected joint inflammation at clinically quiescent MCPJs. The use of thermography in the detection of subclinical joint inflammation in RA appears promising and warrants further investigation.