超声波对鱼卵孵化影响的研究

研究了一定频率与强度的超声波对金鱼(Carassius auratus)和大鳞副泥鳅(Parami-sgurnus dabryanus(Sauvagl))受精卵孵化的刺激作用,结果表明超声可以促进受精卵的发育,使胚体提前出膜,时间集中,并且仔鱼初期饲养成活率高。可以提高较低水温下的大鳞副泥鳅受精卵的孵化率,达50%。     

超声波对丰年虫卵孵化的影响

研究了固定频率和强度的超声波对饵料生物丰年虫卵（ｃｈｉｒｏｃｅｐｈａｌｕｓ）化的影响。实验结果表明,在适宜的超声波辐照下,丰年虫卵的孵化率比对照组提高８％,孵化时间提前２ｈ。     

基于近红外光谱的孵前种蛋检测

利用近红外漫反射光谱分析技术对种蛋中的无精蛋和受精蛋进行检测。通过不同波段范围、不同主成分因子数和不同光谱预处理方法对种蛋类型检测结果的比较分析,建立了种蛋的定性检测模型。结果表明:选取光谱范围为4 119.20～9 881.46cm-1,19个主成分因子数,原始光谱经过SNV+一阶导数+Norris微分过滤的预处理方法,利用马氏距离建立种蛋定性检测模型,校正集正确率达到92.50%,验证集正确率达到91.67%。该研究为上孵前无精蛋和受精蛋的无损检测提供了新的途径。     

Mass transfer enhancement of tuna brining with different NaCl concentrations assisted by ultrasound

The influence of different NaCl concentrations (2.5, 5, 7.5 and 10% (w/w)) on the mass transfer kinetics of tuna during brining process with and without ultrasound assistance was evaluated. Results showed that an increase in NaCl concentration and the application of ultrasound accelerated the salt diffusion in the tuna muscle, and the highest yield was obtained in 5% brine concentration. Moreover, the kinetics parameters were significantly affected by the NaCl concentration and ultrasound application during brining. The values of the mass transfer kinetics parameters (k₁, k₂) for total and water weight changes decreased as NaCl concentration increased with and without ultrasound assistance during brining. In contrast, the higher the NaCl concentration, the higher the value of the salting kinetics parameters for salt weight changes. The application of ultrasound enhanced the salt effective diffusion coefficient (De) from 402.8% to 653.21% during the brining process, and the highest De was also found at 5% brine concentration. The application of ultrasound can improve the uniformity of salt distribution, enhance water holding capacity, reduce hardness and chewiness, but have no significant effect on color of tuna muscle.     

Impact of ultrasound on extractability of native collagen from tuna by-product and its ultrastructure and physicochemical attributes

The effect of ultrasound treatment (300 W; 0, 5, 10, 15, 20 and 25 min) on the extractability of acid soluble collagen from yellowfin tuna skin and its structural, physicochemical and functional properties were investigated. Ultrasound treatments significantly increased collagen extraction yield from the tuna skin up to 2.7 times, compared to the conventional extraction with acetic acid. The level of proline, hydroxyproline and thermal stability of collagens increased by applying ultrasound while their native triple-stranded helical structure was well-preserved, as revealed by X-ray diffraction and FTIR spectroscopy. However, ultrasound treatment reduced the particle size of the collagens which increased their pH and salt induced solubility. The water holding capacity and the emulsifying properties of ultrasound treated collagens were also higher than those produced with the conventional method. Altogether, the results suggested that ultrasonication can be a promising assistant technology for improving native collagen extraction efficiency from tuna skin and its functionality but its duration should be carefully optimized.     

超声波在废橡胶再生中应用的最新进展

全世界每年产生大量废旧橡胶，它们需要很长时间才能降解，这既污染环境，又浪费资源，解决此问题的唯一方法是再生利用。在众多再生方法中，新近出现的超声波脱硫再生法，被认为是最有希望的方法，本文详细地介绍了这方面的最新进展情况。     

基于时间融合的波形方式高精度超声测厚

在超声测厚过程中使用波形方式利用闸门进行测量,可以方便自由地选取测量对象,有利于 避开盲区测量;同时还可以设置闸门和峰值或边沿的测量方式,有利于减小测量误差。在测量中,特 征计算采用基于采样序列较基于显示序列精度要高,采样率越高,精度越好;在此基础上,加入多时 间序列的融合算法可以将有效采样率成倍提高,精度也得到相应的改善。     

功率超声对酶促反应的影响

本文评述了功率超声在水溶液和有机中对酶促反应的影响,对固定化酶的影响,同时探讨了功率超声影响酶促反应的可能机理,并并评价功能超声作为一种工业生物化学反应促进手段的可能性。     

Effects of high-energy ultrasound on the functional properties of proteins

In recent years, high-energy ultrasound has been used as an alternative to improve the functional properties of various proteins, such as from milk, eggs, soy and poultry. The benefits of implementing this technology depend on the inherent characteristics of the protein source and the intensity and amplitude of the ultrasound, as well as on the pH, temperature, ionic strength, time, and all of the variables that have an effect on the physicochemical properties of proteins. Therefore, it is necessary to establish the optimal conditions for each type of food. The use of ultrasound is a promising technique in food technology with a low impact on the environment, and it has thus become known as a green technology. Therefore, this review focuses on the application of high-energy ultrasound to food; its effects on the functional properties of proteins; and how different conditions such as the frequency, time, amplitude, temperature, and protein concentration affect the functional properties.     

Effects of ultrasound-assisted heating on aroma profile,peptide structure,peptide molecular weight,antioxidant activities and sensory characteristics of natural fish flavouring

This study deals with the production of natural fish flavouring using ultrasound-assisted heating process. The effect of ultrasound pretreatment at different amplitudes (0, 15, 30, and 45%) on the Maillard reaction rate, antioxidant activities, flavour profile, and sensory characteristics of fish flavouring was investigated. Results showed that sonication markedly accelerated the Maillard reaction (MR) rate, as evidenced by the modification of peptide structure, a decrease in pH value, free amino acid content coupled with a rise in browning intensity. Also, ultrasound pretreatment significantly enhanced the antioxidant activities of fish flavouring (p ≤ 0.05). Moreover, sonication increased the type and content of aroma compounds significantly. Sensory analysis revealed that ultrasound pretreatment increased the fish-like and toasty aroma as well as umami and mouthfulness attributes coupled with the reduction of the bitter taste of the fish flavouring. This result was consistent with the GC–MS, electronic nose, cluster, and Partial Least Squares Regression (PLSR) analyses, which clearly showed that ultrasound pretreatment enhanced the fish-like aroma, which was associated with the increase in aldehydes, ketones, alcohols, thiophenes, pyrazine, and furans contents. Thus, it could be concluded that ultrasound pretreatment, coupled with the thermal process, could be a promising process for the production of natural fish flavouring with higher antioxidant activities.     

超声波对菠萝果蛋白酶活性和光谱的影响

以菠萝果为材料，用盐析法制备菠萝果蛋白酶粗酶，进一步经SephadexG-50和DEAE-纤维素柱层析纯化，其SDS—PAGE呈单一的电泳带，并获得了菠萝果蛋白酶结晶。一定参数的超声作用可以使酶活力提高，经光谱分析，超声处理后酶的吸收光谱不改变，而荧光发射峰由336nm红移到339nm，紫外差示光谱在一定的波长也呈现出明显的正峰和负峰。本文讨论了超声波影响菠萝果蛋白酶活性的机理。     

Effect of ultrasound on the immunogenic corn cob xylan

Changes in the structural, molecular and functional properties of the immunogenic corn cob xylan evoked by ultrasonication in water, 1% NaOH and 5% NaOH were investigated. The reduction of the high molar mass (MM) fraction was more intense than that of the medium MM fraction, depending on the sonic power, sonication time, and alkali concentration. The chain degradation was more effective in the alkaline media. The UV-absorbing component, accompanying the xylan polymers in the whole MM range, showed an accumulation in the high MM region as well as shiftening to higher sizes, particularly in 5% NaOH. The sugar composition and primary structure of the xylan was almost retained under all irradiation conditions studied. Although the biological activity of the xylan was affected by the ultrasound, no significant decrease of the biological response was found at short irradiation time and low sonic power.     

超声波对固定化酶活性的影响

本文介绍了超声波对固定化酶的影响，同时对作用过程中的影响因素进行了阐述，并探讨了超声波影响固定化酶的可能机理。     

Optimal dosage of ultrasound contrast agent for ultrasound surgery: Thermal effect of linear plane wave

The optimal dosage of ultrasound contrast agent model for ultrasound surgery was explored. A specific ultrasound contrast agent Albunex^® was chosen for simulation. The model was developed based on a dilute bubbly liquid model proposed by Ye and Ding [Z. Ye, L. Ding, Acoustic dispersion and attenuation relations in bubbly mixture, J. Acoust. Soc. Am. 98 (3) (1995) 1629–1636]. The numerical simulation suggests that 2 MHz is more efficient than 1 MHz to thermally treat cancer in deep tissue with the optimal dosage of 3 ml. On the other hand, the simulation also suggests 3 MHz center frequency with the optimal dosage of 1.6 ml is adequate for prostate cancer treatment with transrectal equipment. The simulation is expected to valid up to 2 MPa incident pressure due to the limitation of the linearized UCA model. Even though it is developed from a single ultrasound contrast agent, this model is expected to be useful for any ultrasound contrast agent as long as the necessary parameters are provided.     

Effect of ultrasound on the kinetics of anti-solvent crystallization of sucrose

The effect of ultrasound on the kinetics of anti-solvent crystallization of sucrose was studied. The influence of temperature, stirring rate, supersaturation and ultrasonic power on the anti-solvent crystallization of sucrose was investigated. The relationship between infrared spectral characteristic band of sucrose and supersaturation was determined with an online reaction analyzer. The crystal size distribution of sucrose was detected by a laser particle-size analyzer. Ultrasound accelerated the crystallization process, and had no impact on the crystal shape. Abegg, Stevens and Larson model was fitted to the experimental data, and the results were the following: At 298.15 K, the average size of crystals was 133.8 μm and nucleation rate was 4.87 × 10⁹ m⁻³·s⁻¹ without ultrasound. In an ultrasonic field, the average size was 80.5 μm, and nucleation rate was 1.18 × 10¹¹ m⁻³·s⁻¹. Ultrasound significantly reduced the average size of crystals and improved the nucleation rate. It was observed that the crystal size decreased with the increase of stirring rate in silent environment. When the stirring rate increased from 250 to 400 rpm, the average size decreased from 173.0 to 132.9 μm. However, the stirring rate had no significant impact on the crystal size in the ultrasonic field. In addition, the activation energy of anti-solvent crystallization of sucrose was decreased, and the kinetic constant of nucleation rate was increased due to the effect of ultrasound. In the ultrasonic field, the activation energy was reduced from 20422.5 to 790.5 J·mol⁻¹, and the kinetic constant was increased from 9.76 × 10² to 8.38 × 10⁸.     

Effect of ultrasound on protein functionality

The review focus on the effect of ultrasound on protein functionality. The presence of transient ultrasonic mechanical waves induce various sonochemical and sonomechanical effects on a protein. Sonochemical effects include the breakage of chains and/or the modification of side groups of aminoacids. Sonomechanical modifications by enhanced molecular agitation, might lead to the transient or permanent modification of the 3D structure of the folded protein. Since the biological function of proteins depends on the maintenance of its 3D folded structure, both sonochemical and sonomechanical effects might affect its properties. A protein might maintain its 3D structure and functionality after minor sonochemical effects, however, the enhanced mass transfer by sonomechanical effects might expose internal hydrophobic residues of the protein, making protein unfolding to an irreversible denatured state. Ultrasound enhanced mass transport effects are unique pathways to change the 3D folded structure of proteins which lead to a new functionality of proteins as support shield materials during the formation microspheres. Enzymes are proteins and their reactions should be conducted in a reactor set-up where enzymes are protected from sonic waves to maximize their catalytic efficiency. In this review, focused examples on protein dispersions/emulsions and enzyme catalysis are given.     

超声对近壁微气泡溃灭过程的影响

近壁微气泡溃灭特性的深入研究对靶向给药和基因治疗等技术具有较好的指导作用。该文基于数值模拟技术,采用有限体积法结合流体体积模型对超声作用下的近壁微气泡溃灭特性进行了研究,分析了超声对近壁微气泡溃灭动力学过程的影响。结果表明气泡溃灭最大射流速度与近壁距离无量纲参数γ在1.1～1.6范围内时成正比,与超声频率在10～60 Hz范围内时成正比,与气泡初始半径在50～100μm范围内时成反比;近壁气泡的二次溃灭最大射流速度大于一次溃灭,二次溃灭的作用更加明显。超声参数对近壁气泡溃灭过程存在较大影响,该研究为超声在医学上的应用提供了依据。     

Influence of ultrasound pretreatment on the subsequent glycation of dietary proteins

The influence of ultrasound treatment on the subsequent glycation process of proteins is controversial. Glycation behaviors of bovine serum albumin (BSA), β-lactoglobulin (β-Lg) and β-casein (β-CN) after ultrasound pretreatment (UP) were compared by both evaluating glycation kinetics and analyzing structural changes of proteins. UP resulted in both unfolding and aggregation behavior in protein samples, which altered the accessibility of the Lys and Arg. Five cycles of UP up-regulated the glycation degree of BSA and β-Lg, possibly due to the unfolding behavior induced by UP, which exposed additional glycation sites. In contrast, 30 cycles of UP induced a dramatic increase (by 97.9 nm) in particle size of BSA, thus burying portions of glycation sites and suppressing the glycation process. Notably, UP had minimal influence on glycation kinetics of β-CN, due to its intrinsic disordered structure. Based on proteomics analysis, the preference of Lys and Arg during glycation was found to be changed by UP in BSA and β-Lg. Four, 3 and 3 unique carboxyethylated lysine residues were identified in glycated BSA after 0, 5 and 30 cycles of UP, respectively. This study suggests that the protein glycation can be affected by UP, depending on the ultrasonication duration and native structure of the protein.     

超声在废水处理中的应用

超声波处理废水是一项新兴的废水处理技术,具有操作简单方便、降解速度快等优点,在处理毒性高、难降解的有机废水应用表现出广阔的前景。     

超声辐照对酶促反应影响的研究进展

综述了超声辐照对于酶活性和酶催化反应的影响,以及各种超声参数对反应的影响,并展望了超声辐照在酶促反应中的应用前景。