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1.
Food Chem ; 398: 133913, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35964560

RESUMO

This experiment investigated the underlying mechanism of ultrasonic-assisted stewing to enhance the aroma intensity of chicken broth by measuring fat content, oil droplet sizes, zeta potential, viscosity, surface protein loading, lipid oxidation, and aroma compound concentrations. As the thermo-ultrasound time increased, the fat content increased from 0.3 % to 1.2 %, resulting in a milky white appearance. After 1 h of thermo-ultrasound, the broth had the smallest particle size and the highest surface protein load, viscosity, and emulsion stability, as well as the highest total amount of aroma-active compounds of 314.70 ng/mg. With the further extension of thermo-ultrasound time, lipid oxidation increased, but the stability of chicken broth decreased, lowering the content of aroma-active compounds. These outcomes suggested that thermo-ultrasound could enhance the aroma intensity of chicken broth by increasing the fat content and the emulsion stability of the broth.


Assuntos
Galinhas , Odorantes , Animais , Emulsões/química , Lipídeos , Proteínas de Membrana , Odorantes/análise , Ultrassom
2.
Ultrasonics ; 127: 106834, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36103756

RESUMO

A point contact/Coulomb coupling technique is generally used for visualizing the ultrasonic waves in Lead Zirconate Titanate (PZT) ceramics. The point contact and delta pulse excitation produce a broadband frequency spectrum and wide directional wave vector. In ultrasonic, the signal is corrupted with several types of noises such as speckle, Gaussian, Poisson, and salt and pepper noise. Consequently, the resolution and quality of the images are degraded. The reliability of the health assessment of any civil or mechanical structures highly depends on the ultrasonic signals acquired from the sensors. Recently, deep learning (DL) has been implemented for the reduction of noises from the signals and in images. Here, we have implemented deep learning-based convolutional autoencoders for suitable noise modeling and subsequently denoising the ultrasonic images. Two different metrics, PSNR and SSIM are calculated for quantitative analysis of ultrasonic images. PSNR provides higher visual interpretation, whereas the SSIM can be used to measure much finer similarities. Based upon these parameters speckle-noise demonstrated better than other noise models.


Assuntos
Aprendizado de Máquina , Ultrassom , Reprodutibilidade dos Testes , Razão Sinal-Ruído
3.
Ultrasonics ; 127: 106847, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36174314

RESUMO

l-Alanine has Physiological significance, and their molecular interaction is subjected to the Gibbs energy barrier. The present study has reported the Gibb's energy barrier of l-Alanine (l-Ala) from 20.095 to 20.055 KJ/mol by performing the ultrasonic experiment at 4 MHz for 0.0075 M to 0.01 M l-Ala in water solvation. This barrier is also analyzed by DFT for the six distinct types of basis sets. The smallest barrier of a normal to zwitterion conversion has been identified for the SVP and def2-SVPas -22.08 KJ/molby DFT. Their absolute values reported near to the experimental estimated values by regression (as 20.2 KJ/mol). Few thermodynamic potentials are also analyzed. The study is further rendering to predict the bandgap, quantum descriptors, and their changes in account of chemical reactivity, stability for the different basis sets. Ultrasonic stimulation is seen responsible for reverting the form. Detail about necessary fundamental aspects have been discussed successfully.


Assuntos
Ultrassom , Água , Alanina , Simulação por Computador , Termodinâmica , Água/química
4.
Artigo em Inglês | MEDLINE | ID: mdl-36007820

RESUMO

Many symptoms used routinely for human psychiatric diagnosis cannot be directly observed in animals which cannot describe their internal states. However, the ultrasonic vocalizations (USV) rodents use to communicate their emotional states can be measured. USV have therefore become a particularly useful tool in brain disease models. Spontaneously hypertensive rats (SHR) are considered an animal model of attention deficit hyperactivity disorder (ADHD) and schizophrenia. However, the specifics of SHR's behavior have not been fully described and there is very little data on their USV. Recently, we developed a communication model, in which Wistar rats are exposed to pre-recorded playbacks of aversive (22-kHz) or appetitive (50-kHz) USV, and their vocal responses depend on the extent of prior fear conditioning (0, 1, 6 or 10 shocks). Here, we investigated SHR's behavior and heart rate (HR) in our communication model, in comparison to Wistar rats employed as controls. In general, SHR emitted typical USV categories, however, they contained more short 22-kHz and less 50-kHz USV overall. Moreover, fewer SHR, in comparison with Wistar rats, emitted long 22-kHz USV after fear conditioning. SHR did not show a 50-kHz playback-induced HR increase, while they showed a profound 22-kHz playback-induced HR decrease. Finally, the number of previously delivered conditioning shocks appeared to have no effect on the investigated vocal, locomotor and HR responses of SHR. The phenomena observed in SHR are potentially attributable to deficits in emotional perception and processing. A lower number of 50-kHz USV emitted by SHR may reflect observations of speech impairments in human patients and further supports the usefulness of SHR to model ADHD and schizophrenia.


Assuntos
Ultrassom , Vocalização Animal , Humanos , Ratos , Animais , Ratos Wistar , Ratos Endogâmicos SHR , Emoções , Roedores
5.
Food Chem ; 403: 134273, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36174345

RESUMO

Herein, an ultrasound-assisted dispersive solid phase microextraction (UA-DSPME) approach has been described for trace level analysis of triazole fungicides in real samples. For this purpose, a new nanosorbent was prepared through modification of carboxymethylcellulose biopolymer with zinc-based metal-organic framework and graphene oxide, and fully characterized. Then, the effect of extraction parameters on extraction efficiency was optimized for the microextraction process. Finally, desorbed triazole fungicides with ethanol were determined using gas chromatography equipped with flame ionization detector. This technique provided good linearity (R2 > 0.99), low detection limits (0.3-1.5 ng mL-1), high preconcentration factors (419-426), good relative recoveries (91.6-102 %), and high repeatability (RSD < 4.1 %) at optimized conditions (amount of sorbent: 15 mg; pH of solution: 7.0; and extraction time; 4 min). Ultimately, this approach was applied to determine triazole fungicides in different water and food samples.


Assuntos
Fungicidas Industriais , Microextração em Fase Líquida , Nanocompostos , Microextração em Fase Sólida/métodos , Fungicidas Industriais/análise , Verduras/química , Triazóis/análise , Frutas/química , Água/análise , Celulose/análise , Ultrassom , Nanocompostos/análise , Microextração em Fase Líquida/métodos , Extração em Fase Sólida , Limite de Detecção
6.
Sci Total Environ ; 856(Pt 1): 158787, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36116655

RESUMO

The commonly used consumer product of an ultrasonic humidifier (e.g., cool mist humidifier) emits fine particles containing metals from tap water used to fill the humidifier. The objectives are: 1) predict emitted indoor air inhalable metal concentrations produced by an ultrasonic humidifier filled with tap-water containing As, Cd, Cr, Cu, Mn, and Pb in 33 m3 or 72 m3 rooms with varying air exchange rates; 2) calculate daily ingestion and 8-h inhalation average daily dose (ADD) and hazard quotient (HQ) for adults and children (aged 0.25-6 yr); and 3) quantify deposition in respiratory tract via multi-path particle dosimetry (MPPD) model. Mass concentrations of indoor air metals increase proportionally with aqueous metal concentrations in fill water, and are inversely related to ventilation. Inhalation-ADDs are 2 magnitudes lower than ingestion-ADDs, using identical water quality for ingestion and fill-water. However, in the 33 m3, low 0.2/h ventilated room, inhalation-HQs are >1 for children and adults, except for Pb. HQ inhalation risks exceed ingestion risks at drinking water regulated levels for As, Cd, Cr, and Mn. MPPD shows greater dose deposits in lungs of children than adults, and 3 times greater deposited doses in a 33 m3 vs 72 m3 room. Rethinking health effects of drinking water and consumer products to broaden consideration of multiple exposure routes is needed.


Assuntos
Poluição do Ar em Ambientes Fechados , Água Potável , Metais Pesados , Criança , Adulto , Humanos , Poluição do Ar em Ambientes Fechados/análise , Umidificadores , Qualidade da Água , Cádmio , Ultrassom , Chumbo , Medição de Risco , Monitoramento Ambiental , Metais Pesados/análise
7.
Facial Plast Surg Clin North Am ; 31(1): 143-154, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36396285

RESUMO

Ultrasonic rhinoplasty and ultrasonic septoplasty reshape the nasal bones using piezoelectric instruments specifically developed for these operations. They allow the realization of precise osteotomies under direct visual control after having performed first an open or closed extended approach, but also ostectomies and rhinosculpture. Piezoelectric instruments preserve bone stability by not damaging bone support structures and avoiding unwanted fractures. They allow precise control of nasal bone movements, their orientation, and their final position. The different inserts of ultrasonic rhinoplasty and ultrasonic septoplasty are detailed, with their scope of action. The applications to dorsum preservation and structural remodeling of dorsum are presented.


Assuntos
Rinoplastia , Humanos , Ultrassom , Nariz/cirurgia , Osso Nasal , Osteotomia
8.
Behav Brain Res ; 437: 114157, 2023 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-36241070

RESUMO

Vocal communication, cognition, and affective state are key features of sustained health and wellness, and because vocalizations are often socially-motivated, social experience likely plays a role in these behaviors. The monoaminergic systems of the ventral tegmental area (VTA) and the locus coeruleus (LC) are associated with social and reward processing, vocalization production, and neurotransmitter changes in response to environmental stressors. The effect of social isolation on these complex behaviors and the underlying neural mechanisms is relatively unknown. To add to this body of literature, we randomized adult male Long-Evans rats to control (housed with a cagemate) or isolated (housed individually) conditions and assayed ultrasonic vocalizations, cognition (novel object recognition test), anxiety (elevated plus maze) and anhedonia (sucrose preference test) at 2, 4, 6, 8, and 10 months of age. At 10 months, VTA and LC samples were assayed for dopamine, norepinephrine, and serotonin using high performance liquid chromatography. We tested the hypotheses that isolation 1) diminishes vocalizations and cognition, 2) increases anxiety and depression, and 3) increases levels of dopamine, norepinephrine, and serotonin in the VTA and LC. Results showed isolation significantly reduced vocalization tonality (signal-to-noise ratio) and increased maximum frequency. There were no significant findings for cognition, anxiety, or anhedonia. Dopamine and serotonin and their respective metabolites were significantly increased in the VTA in isolated rats. These findings suggest chronic changes to social condition such as isolation affects vocalization production and levels of VTA neurotransmitters.


Assuntos
Locus Cerúleo , Ultrassom , Animais , Masculino , Ratos , Anedonia , Cognição , Dopamina/metabolismo , Neurotransmissores/metabolismo , Norepinefrina/metabolismo , Ratos Long-Evans , Serotonina/metabolismo , Isolamento Social , Área Tegmentar Ventral , Vocalização Animal/fisiologia
9.
Ultrasound Med Biol ; 49(1): 347-355, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36266143

RESUMO

The study described here was aimed at investigating the feasibility of using the ultrasonic through-transmission technique to estimate human musculoskeletal and fat properties. Five hundred eighty-two volunteers were assessed by dual-energy X-ray absorptiometry (DXA) and ultrasonic transmission techniques. Bone mineral density (BMD), muscle and fat mass were measured for both legs and the whole body. Hip BMD and spine BMD were also measured. Ultrasonic transmission measurements were performed on the heel, and the measured parameters were broadband ultrasound attenuation (BUA), speed of sound (SOS), ultrasonic stiffness index (SI), T-score and Z-score, which were significantly correlated with all measured BMDs. The optimal correlation was observed between SI and left-leg BMD (p < 0.001) before and after adjustment for age, sex and body mass index (BMI). The linear and partial correlation analyses revealed that BUA and SOS were closely associated with muscle and fat mass, respectively. Multiple regressions revealed that muscle and fat mass significantly contributed to the prediction of transmission parameters, explaining up to 17.83% (p < 0.001) variance independently of BMD. The results suggest that the ultrasonic through-transmission technique could help in the clinical diagnosis of skeletal and muscular system diseases.


Assuntos
Calcâneo , Sistema Musculoesquelético , Humanos , Ultrassom , Ultrassonografia , Absorciometria de Fóton/métodos , Densidade Óssea/fisiologia , Calcâneo/diagnóstico por imagem
10.
Food Chem ; 401: 134129, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36099821

RESUMO

In this study, quantitative monitoring of low-frequency (20 kHz) and high-frequency (355 kHz) ultrasound-induced inactivation of Kunitz (KTI) and Bowman-Birk inhibitor (BBI) using RP-HPLC was achieved, and its consistency with a traditional TI activity assay was verified. The effect of TI concentration, ultrasonic frequency, power density and pH on inactivation kinetics of KTI and BBI was explored. Results showed that the pseudo-first-order kinetic rate constants of KTI and BBI were decreased by over 60% when the initial TI concentration was increased from 100 mg/L to 1000 mg/L. Also, the amounts of inactivated KTI and BBI were increased by around 4-fold at the higher TI concentration of 1000 mg/L (20 kHz, 1.71 W/mL and pH 4). The colloidal environment and ultrasonic conditions influenced the secondary and tertiary structure and particle size of TIs in LF-induced inactivation. In comparison, the abovementioned conditions affected the oxidation of methionine and the conformational change of TIs in HF-induced inactivation.


Assuntos
Inibidor da Tripsina de Soja de Bowman-Birk , Inibidor da Tripsina de Soja de Bowman-Birk/química , Inibidor da Tripsina de Soja de Kunitz/química , Inibidores da Tripsina/química , Cinética , Ultrassom , Metionina
11.
Ultrasonics ; 128: 106886, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36371881

RESUMO

At present, with the development of high technology and materials science, the traditional laser processing (NLP) method is no longer sufficient for the preparation of special surface profiles in the field of cutting-edge manufacturing. Ultrasonic vibration assisted laser processing (UVLP) is gradually being developed by researchers, but is largely experimental study in nature. In this paper, a mathematical model of the transverse ultrasonic composite laser ablation trajectory of metals is developed, and the feasibility of the model is verified by numerical simulations and experiments by using aluminum as the base material. Error rates for ablation widths and trajectory cycle times range from 2.18% to 6.50%. The error of the crater lap rate is 3.88%-19.62%. The influence of ultrasonic and laser frequencies on the ablation trajectories is analyzed. The frequency selection rules for the preparation of special morphologies are given. This study presents a theoretical model of a new processing method, which has a guiding significance for the parameters selection of laser processing and the special surface morphology preparation.


Assuntos
Lasers , Metais , Ondas Ultrassônicas , Ultrassom , Modelos Teóricos
12.
Ultrasonics ; 128: 106888, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36402114

RESUMO

BACKGROUND: Ultrasound neurostimulation (USNS) is a non-invasive neuromodulation technique that might hold promise for treating neuropsychiatric disorders with regards to its noninvasiveness, penetration depth, and high resolution. OBJECTIVE: We sought in this experimental study to provide detailed and optimized protocol and methodology for a successful ultrasonic neurostimulation of the Primary Motor Cortex (M1) in mice addressed to young researchers/students beginning their research in the field of ultrasonic neurostimulation and encountering practical challenges. METHODS: A 500 kHz single-element transducer was used for stimulating the primary motor cortex at different acoustic pressures in C57BL/6 mice at various anesthesia levels. To further illustrate the effect of anesthesia, real time visual observations of motor responses validated with video recordings as well as electromyography were employed for evaluating the success and reliability of the stimulations. RESULTS: Detailed experimental procedure for a successful stimulations including targeting and anesthesia is presented. Our study demonstrates that we can achieve high stimulation success rates (91 % to 100 %) at acoustic pressures ranging from 330 kPa to 550 kPa at anesthesia washout period. CONCLUSIONS: This study shows a reliable and detailed methodology for successful USNS in mice addressed to beginners in ultrasonic brain stimulation topic. We showed an effective USNS protocol. We offered a simple and consistent non-invasive technique for locating and targeting brain zones. Moreover, we illustrated the acoustic pressure and stimulation success relationship and focused on the effect of anesthesia level for successful stimulation.


Assuntos
Córtex Motor , Animais , Camundongos , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes , Ultrassom , Acústica
13.
Ultrasonics ; 128: 106865, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36260963

RESUMO

Microfluidics is an emerging technology that is playing increasingly important roles in biomedical and pharmaceutical research and development. Surface acoustic waves (SAWs) have been combined with microfluidics technology to establish a SAW-based microfluidics technology that uses the unique interaction between the two techniques to manipulate substances effectively in fluids on the surface of a substrate. This paper reports a method to generate SAWs using conventional planar ultrasonic transducers and acoustic lenses. Additionally, this method is introduced to manipulate particles effectively on a substrate surface. It is demonstrated that the particle positions can be manipulated precisely in any direction on the substrate surface, thus enabling high-precision particle manipulation. We also proposed the generation of nonplanar SAWs via appropriate design of the acoustic lens and realized directional particle transport. In addition, structures to enhance forward-propagating acoustic beams are proposed. The proposed method has potential for use in microfluidics and biomedical applications, allowing tasks such as flexible cell manipulation on a chip to be performed without complex design or micromachining.


Assuntos
Acústica , Som , Microfluídica , Transdutores , Ultrassom
14.
Ultrasonics ; 128: 106858, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36272297

RESUMO

The ultrasonic Non-Destructive Testing and Evaluation (NDT&E) has been widely used for Structural Health Monitoring (SHM). The conventional linear ultrasonic technique which is suitable for detecting macro-scale defects is routinely used in industry; however, it often fails to detect the micro-scale defects. Generally, micro-defects in a material appear first due to dislocations at grain boundaries. These micro-defects then grow and coalesce to form macro-defects. The crack growth rate is much faster for macro-defects than micro-defects. Therefore, monitoring micro-defects is important to avoid catastrophic failures of structures. Nonlinear ultrasonic techniques help to detect micro-defects. A recently developed nonlinear ultrasonic technique called Sideband Peak Count - Index (SPC-I) technique has some inherent advantages over other nonlinear techniques for monitoring progression of micro-defects. In this research, the SPC-I technique is further modified. This modified technique, Sideband Peak Intensity (SPI) technique, is shown to be more robust and easier to implement. Both SPC-I and SPI techniques are used to monitor the damage progression in impact induced damages in metals. Similarities and dissimilarities between these two techniques are investigated. Then it is concluded that the SPI technique is good as a general-purpose robust damage monitoring tool that can be used by less skilled users while the SPC-I technique although requires more skills has more sensitivity and has the flexibility for an in-depth damage analysis in materials.


Assuntos
Ultrassom
15.
Ultrasonics ; 128: 106877, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36351345

RESUMO

This work investigates the longitudinal modes of surface-bonded piezoelectric wafer active transducers (PWaTs) and how they influence the PWaT resonances. Unlike conventional one-dimensional bar structures that essentially have only one non-dispersive longitudinal mode, the bonded PWaT has two dispersive longitudinal modes, with one evanescent (non-propagating) wave mode below a cut-off frequency. Their propagation characteristics, such as wave numbers, attenuations, and mode conversion at the PWaT edges, clarify two research questions raised from the time-frequency analysis of the PWaT electromechanical impedance (EMI) signature and the associated broadband pitch-catch signal. The study also revealed that the PWaT resonances stem from the Fabry-Perot interference of the waves reflected at the two edges of the PWaT, providing a sound theoretical foundation that further explains the influence of the adhesive on the PWaT resonances. These theoretical discoveries will lead to physics-based interpretation of EMI and ultrasonic pitch-catch signals generated by surface bonded PWaTs, which could lead to new sensing mechanisms in future.


Assuntos
Transdutores , Vibração , Som , Ultrassom
16.
Colloids Surf B Biointerfaces ; 221: 113021, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36403415

RESUMO

The phenomenon of foam-induced inactivation is a common challenge during foam fractionation of proteins. In this work, we attempted to use ultrasound to treat foam out of the foam fractionation column with the aim of minimizing the foam-induced protein inactivation using pepsin as a model protein. Firstly, the mechanisms by which ultrasound prevented the foam-induced pepsin inactivation during defoaming were explored. The results showed that ultrasound promoted the refolding of unfolded pepsin molecules at the gas-liquid interface to restore their activities during the desorption process from the interface and before dissolving into the foamate. Subsequently, the effects of ultrasonic power on the pepsin renaturation were analyzed, which revealed that the unfolding degree of pepsin in the foamate gradually decreased and then increased as the ultrasonic power increased. Correspondingly, the specific activity of pepsin in the foamate increased and then decreased. Finally, we explored the effects of defoaming efficiency, type of gas and pH. The results indicated that the decrease in defoaming efficiency and gas solubility in water facilitated the ultrasound-assisted pepsin renaturation in the pH range from 1.0 to 2.5. When air was applied in the foaming process, the specific activity of pepsin in the foamate with ultrasonic treatment was not significantly different from that in the feed solution at ultrasonic power of 400 W and pH 2.0. Collectively, these results indicate the ultrasonic treatment of foam effectively prevented the foam-induced pepsin inactivation.


Assuntos
Fracionamento Químico , Pepsina A , Fracionamento Químico/métodos , Ultrassom , Aerossóis , Água
17.
Food Chem ; 402: 134250, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36126583

RESUMO

Magnetic nanoparticles (MNPs) have a dual role in acting as magnetic and sonosensitizer agents, which can combine the synergistic effects of microwave and ultrasonic waves. To study the effects of MNPs combined ultrasonic-microwave thawing (NUMT) on the water holding capacity (WHC), oxidation of protein and lipid, and protein conformation, jumbo squid mantles were subjected to cold storage thawing (CST), MNPs combined ultrasonic thawing (NUT), MNPs combined microwave thawing (NMT) and NUMT. Results showed that NUMT treatment had a higher WHC, lower oxidation, effectively reduced myofibrillar protein aggregation and degradation, and stabilized the structure of the protein of the jumbo squid. The muscle fiber structure of NUMT treated jumbo squid mantles was dense, orderly with a smooth surface, and the fiber network gaps were small and uniformly distributed. This study shows that NUMT can ameliorate the thawing qualities of jumbo squid, and is an effectively thawing method.


Assuntos
Nanopartículas , Ultrassom , Animais , Ultrassom/métodos , Água/química , Micro-Ondas , Agregados Proteicos , Decapodiformes/química , Proteínas , Conformação Proteica , Fibras Musculares Esqueléticas , Lipídeos
18.
Food Chem ; 402: 134301, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36137381

RESUMO

In this study, CO2-triggered switchable hydrophilicity solvents (SHSs) based on different amines and water were employed in the ultrasonic-assisted extraction of Polygonatum sibiricum polysaccharides (PSPs). When CO2 was pumped into the amine, the solution became hydrophilic and could be used as an extractant for PSPs extraction. When CO2 was removed, the solution switched hydrophobicity, with the extractants being separated from the extract and further recycled and reused. The factors affecting the solid-liquid extraction of PSPs were studied. The maximum extraction yield of 399.2 mg/g was obtained at a solid-liquid ratio of 1:20, extraction time of 60 min, extraction temperature of 50 °C, and ultrasonic power of 500 W. SHSs could be recovered and reused with 88.4% recovery after the fifth cycle. The molecular weights and monosaccharide compositions of PSPs were also determined. This study provides a new strategy for sustainable extraction of plant polysaccharides and other bioactive ingredients.


Assuntos
Polygonatum , Solventes , Dióxido de Carbono , Ultrassom , Polissacarídeos , Interações Hidrofóbicas e Hidrofílicas , Água , Aminas , Monossacarídeos , Extratos Vegetais
19.
Food Chem ; 402: 134237, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36174350

RESUMO

This study developed two novel food packaging films, oat protein/pullulan (Op/Pul) and Nisin-loaded oat protein/pullulan (Nis@Op/Pul) films. Ultrasound was introduced to improve its mechanical, structural and physicochemical properties. The Op/Pul film has lower light transmittance, water vapour and oxygen permeability (OP) and improved film uniformity than pure oat protein and pullulan film. The addition of Nisin led to a significant decrease in the composite films' transparency, moisture content, and total soluble matter (TSM). The ultrasound treatment significantly increased the elongation at break and transparency of Nis@Op/Pul film by 18.37% and 8.03% and decreased its TSM and OP by 8.33% and 2.78%, respectively, compared to the conventional method. The structure analysis shows ultrasound enhances intermolecular hydrogen bonding, reduces the crystallinity and formed a more regular, uniform surface. Moreover, the Nis@Op/Pul film prepared by ultrasound treatment could effectively delay the decay and deterioration of fresh strawberries and prolong their shelf life.


Assuntos
Nisina , Nisina/química , Avena , Vapor/análise , Ultrassom , Embalagem de Alimentos , Permeabilidade , Oxigênio/análise
20.
J Acoust Soc Am ; 152(4): 2082, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36319263

RESUMO

Numerous studies have performed in vitro ultrasonic measurements of cancellous bone in water to develop techniques for ultrasonic bone assessment. Because cancellous bone is a highly porous medium, ultrasonic reflections at the water-bone interface may be frequency dependent. The goal of this study was to investigate the effect of porosity on the frequency dependence of the reflected power. Ultrasonic measurements were performed in a water tank at room temperature on 15 specimens of cancellous bone prepared from the proximal end of 9 human femurs using single element, broadband transducers with center frequencies of 3.5, 5, 7.5, and 10 MHz. Power spectra of pulses reflected from the water-specimen interface were corrected for the frequency response of the measurement system to obtain the reflected power in decibels RdB(f). To suppress random phase cancellation effects, RdB(f) was averaged over multiple sites on multiple specimens. A frequency dependence of RdB(f) was observed in the 2.6-10 MHz range. The frequency dependence was moderate, with a maximum change of less than 6 dB over the entire frequency range. RdB(f) was greatest for low porosity specimens. The frequency averaged intensity reflection coefficient ranged from 7.4 × 10-4 to 7.8 × 10-3 for high and low porosity specimen groups, respectively.


Assuntos
Osso Esponjoso , Ultrassom , Humanos , Ultrassom/métodos , Osso Esponjoso/diagnóstico por imagem , Água , Ultrassonografia/métodos , Espalhamento de Radiação
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