A collaborative contour detector by gradient and active contours for ultrasound kidney images

In the process of urinary system disease diagnosis, a complete kidney contour is crucial to estimate its size, area, volume and other properties. These properties can effectively help doctors diagnosis and prepare treatment plans. However, ultrasound images suffer from low signal-to-noise ratio, speckle, missing boundaries and other artefacts. Traditional contour detection algorithms can hardly extract a continuous and accurate kidney contour. To solve the problem, we propose a collaborative contour detector by gradient and active contour. It not only can make sure that the extracted contour is continuous and accurate but also is simple and suitable to use in practice. Both the simulated experiments and clinical experiments show that the proposed algorithm achieves a good performance in ultrasound kidney images and can effectively assist doctors in diagnosis.     

Fermentation of Chortan (heated strained yoghurt) by Lactobacillus helveticus: sonication treatment and biological activities

In the present study, the effects of continuous and pulsed ultrasound (100 W, 30 kHz, 25–75% amplitudes for 30 min) and fermentation process (37°C for 24 h) by Lactobacillus helveticus PTCC 1332 on biological activities of Chortan were investigated. The obtained results showed that fermentation enhanced protease content (36.27% (neutral), 37.57% (acid), 39.28% (alkaline) protease), peptide concentration (45.27%) and antioxidant activity (33.69% (DPPH), 132.85% (ABTS)) of samples compared to unfermented ones. Additionally, an increase in ultrasound amplitude (except for continuous at 75%) promoted the protease enzymes, peptides and radical scavenging activity of the fermented and unfermented samples. Our results indicated that the ultrasound and fermentation treatments complemented each other. Depending on the experimental conditions, the effect of continuous ultrasound on samples was sometimes lower, sometimes similar and sometimes higher than that of pulsed treatment. Therefore, selection of an appropriate ultrasound mode and amplitude can improve the biological activity of Chortan.     

Effect of ultrasonication treatment and fermentation by probiotic Lactobacillus plantarum strains on goat milk bioactivities

In the present research, the effects of continuous ultrasound treatment (100 W, 30 kHz; 0%, 30%, 60% and 90% amplitudes, 15 min) and fermentation process (37°C, 24 h) on the growth of Lactobacillus plantarum LP3 and LU5 strains and bioactive properties (peptide content, α-amylase and α-glucosidase inhibition, anticancer and antioxidant activities and exopolysaccharide content) of goat milk were investigated. According to our results, the ultrasonication of milk up to 60% amplitude promoted the growth of Lactobacillus strains and enhanced the bioactive properties compared with control during fermentation, while, the ultrasonication at 90% amplitude had negative effects on the mentioned parameters. Exopolysaccharide content, α-amylase inhibition, α-glucosidase inhibition, antioxidant activity and anticancer activity of treated samples at 60% amplitude at the end of fermentation in comparison to its beginning were increased 18.09, 12.79, 12.44, 9.4 and 1.92 folds, respectively. Also, the increase of assayed characteristics was found strain-dependent, so that L. plantarum LP3 was more effective than LU5 strain.     

基于粒子群优化的超声共振谱法测量材料弹性常数

超声共振谱法是一种基于材料样品的自由共振频率,再反推其弹性常数的高精度材料力学属性求取方法,该方法在高Q值(品质因素)固体材料的弹性常数计算方面应用广泛。然而对于具有较高黏弹性阻尼的材料来说,受共振谱线平缓、共振频率提取困难等影响,该方法的应用存在一定困难。建立了关于弹性常数的贝叶斯模型,结合粒子群优化(PSO)的全局搜索能力,寻找弹性常数的最大后验概率密度点,最终实现材料的弹性估计。测量了皮质骨模拟材料的弹性常数,与传统方法相比较,基于PSO的超声共振谱方法对弹性常数初始值不敏感,可用于高阻尼材料弹性常数的测量。     

直肠腔内超声在直肠癌术前环周切缘评估中的作用

目的　评估直肠腔内超声（endorectal ultrasound，ERUS）诊断直肠癌环周切缘（circumferential resection margin，CRM）的可行性和准确性。方法　回顾性分析2010年5月至2013年12月在北京协和医院行术前ERUS评估的直肠癌患者120例。纳入患者仅采用直肠全系膜切除术切除肿瘤，未采用术前新辅助放化疗治疗。患者行术前ERUS检查时测量CRM，即肿瘤的最外缘与直肠系膜筋膜的最短距离。以病理结果为金标准，比较不同CRM诊断标准下ERUS的诊断价值。分析ERUS对不同位置、距肛缘距离、分期的CRM诊断准确性差异。结果　ERUS可以显示直肠系膜筋膜114例，显示率为95%。采用不同探头频率，直肠系膜筋膜显示的差异存在统计学意义（P=0.034）。以CRM≤2 mm为标准时，ERUS诊断CRM的敏感性、准确性、阴性预测值最高，分别为100%、98.2%、100%。ERUS对不同位置、距肛缘距离、病理分期病灶的诊断准确性差异不具有统计学意义（P＞0.05)。结论　ERUS可以准确诊断直肠癌环周切缘，同时具有较高的阴性预测值，可为判断预后及制定临床治疗方案提供可靠依据。     

Structural changes and stress relaxation behavior of κ‐carrageenan cold‐processed gels: Effects of ultrasonication time and power

Ultrasound has been used for cold gelation of κ‐carrageenan hydrocolloid. In this work, the effect of ultrasound conditions such as power (50–150 W) and time (20–240 s) of sonication has been investigated. The application of ultrasound to hydrocolloid dispersion caused an increase in water solubility. The texture profile analysis test was used in order to evaluate the mechanical properties of gels. Textural parameters of κ‐carrageenan gels, enhanced with increasing sonication time and power up to a certain level (usually 2.5 min) and longer sonication times had negative effects. In addition, intrinsic viscosities of sonicated specimens were measured to investigate the molecular characteristics of all samples. An increase in the process time and power reduced the intrinsic viscosity. The microstructural observation by scanning electron microscope determined that applying power ultrasound on κ‐carrageenan dispersions influenced the formation of gel networks significantly.     

Extract of Salicornia europaea in fresh pasta to enhance phenolic compounds and antioxidant activity

Extract from Salicornia europaea was added to durum wheat fresh pasta. Sensory properties, cooking quality, microbiological stability, content in bioactive compounds and antioxidant activity, before and after pasta digestion were studied. The extract was obtained by ultrasound-assisted extraction. From the technological point of view the extract did not affect pasta dough and the cooking parameters and sensory properties of the enriched samples were found similar to the control pasta. No antimicrobial effect was exerted by the extract. From the chemical point of view interesting findings were recorded for pasta before and after digestion. Specifically, data of bioaccessible fraction of digested sample showed a significantly higher amount of total phenols and flavonoid content (11.52 mg gallic acid g⁻¹ and 0.55 mg quercetin g⁻¹ respectively) than digested control pasta (9.54 mg gallic acid g⁻¹ and 0.23 mg quercetin g⁻¹ respectively). The antioxidant activity of enriched sample also increased compared to the control pasta (6.20 vs. 2.50 μmoles FeSO₄ g⁻¹).