Phenolic acetogenins secreted by rhododendron lace bug,Stephanitis rhododendri Horvath (Hemiptera: Tingidae)

Nymphs of the rhododendron lace bug produce from specialized setae a liquid secretion from which a number of related acetogenins have been identified. Two (2,6-dihydroxyphenyl)-1,3-diketones are the principal components and are accompanied by the corresponding chromones as well as by chromones bearing an additional phenolic oxygen.Mention of a company name or proprietary product does not constitute an endorsement by the U.S. Department of Agriculture.     

The rheological properties of exudates from cured porcine muscle: effects of added non‐meat proteins

Meat exudates were collected from massaged cured porcine M semimembranosus using a model massaging unit. Exudates were used to observe changes in gelation properties due to the incorporation of commercially available non‐meat proteins. These included: soya isolate (90%), sodium (Na) caseinate (85%) and high gelling whey protein concentrates (WPCs, A‐35%, B‐75% and C‐β‐lactoglobulin (55%), as well as a regular 76% protein, WPC D. Compositional analysis ( n=6) showed that incorporation of non‐meat proteins significantly (P<0.05) increased the protein concentration of test exudates in all cases compared to controls. The viscoelastic properties of control and test meat exudate samples (n=6) were analysed using control stress rheology in oscillatory mode. All exudates were heated from 20 to 80°C at 1°C min⁻¹, and subsequently cooled after 30 min back down to 20°C at 1°C min ⁻¹. Addition of WPCs at a 1, 2 and 3% residual powder level and soya isolate at a 1% residual level, resulted in increased storage modulus G′ (Pa) values compared with controls. A 1% residual level of Na caseinate was detrimental to meat exudate gelation, resulting in lower final G′ (Pa) values than those observed for the control. © 1999 Society of Chemical Industry     

The rheological properties of exudates from cured porcine muscle: effects of added carrageenans and whey protein concentrate/carrageenan blends

Meat exudates were collected from massaged cured porcine M semimembranosis using a model massaging unit. Exudates were used to observe changes in gelation properties of test exudates containing carrageenans and whey protein concentrate (WPC) and carrageenan blends. Three carrageenan powders iota (ι ), kappa (κ), as well as a kappa/locust bean gum mix, were assessed at a 1% residual level, both individually and as blends. WPCs assessed included high gelling A‐35, B‐75 and C 55% protein β‐lactoglobulin powders, as well as a regular 76% protein, WPC D. All WPCs were incorporated at a 2% residual powder level in the final meat. Treatment and control meat samples and resulting exudates were prepared in duplicate with analysis performed in triplicate. The viscoelastic properties of control and test meat exudate samples (n=6) were analysed using control stress rheology in oscillatory mode. All exudates were heated from 20 to 80°C at 1°C min⁻¹ , and subsequently cooled after 30 min back down to 20°C at 1°C min⁻¹. Combinations of high gelling WPCs, especially β‐lactoglobulin together with iota and kappa‐carrageenans A and B, were found to increase storage modules G′ (Pa) values when compared with control values. Significant (p<0.05) synergies were observed on blending high gelling WPCs with carrageenans A and B. © 1999 Society of Chemical Industry     

Measurement of Muscle Exudate Protein Composition as an Indicator of Beef Tenderness

The objective of this study was to determine the relationship between the protein composition of muscle exudates and meat tenderness in beef. Frozen, intact beef strip loins (n = 24) were each divided into 3 equal portions (anterior, middle, and posterior). Steaks were removed from each portion, individually vacuum packaged, thawed at 4 °C, and aged for 0, 7, or 14 d. After the designated aging period, exudate was collected from the packaging and 1 steak from each strip loin portion was utilized for shear force measurements. Muscle exudates were analyzed for protein content (biuret assay) and composition (sodium dodecyl sulfate–polyacrylamide gel electrophoresis). Shear force decreased (P < 0.0001) with aging from 0 to 14 d. The protein concentrations of the muscle exudates were not influenced by the aging period and were not related to the amount of exudate expressed. Electrophoretic analyses of the muscle exudates indicated that with aging the relative abundance of 4 proteins decreased (P < 0.01) and 10 proteins increased (P < 0.05) within the protein profiles of the exudates. The relative abundance of the 167, 97, and 47 kDa proteins in exudates at day 0 were significantly correlated (|r| = 0.57 to 0.77) to shear force at day 14. These data demonstrate that exudate protein composition changes with postmortem aging and beef tenderness.     

结合局部熵和鲁棒主成分分析的眼底图像硬性渗出物检测方法

针对眼科医生诊断眼底图像工作耗时且易出错的问题，提出一种无监督的眼底图像硬性渗出物检测方法。首先，通过形态学的背景估计方法去除血管、暗病变区域和视盘；然后，以图像亮度通道为初始图像，利用硬性渗出物在眼底图像中的局部性和稀疏性，结合局部熵和鲁棒主成分分析方法分解得到低秩矩阵和稀疏矩阵；最后，归一化稀疏矩阵得到硬性渗出物区域。实验结果显示，在e-ophtha EX和DIARETDB1公开数据库上，所提方法在病灶水平上灵敏性为91.13%和特异性为90%，在图像水平上准确率为99.03%，平均运行时间0.5 s；与支持向量机（SVM）和K-means方法相比灵敏性高且耗时少。     

基于IHBMO-RF的眼底硬性渗出物检测

随着社会经济的发展, 糖尿病视网膜病变患者越来越多, 为了减少患者的致盲率, 早期诊断至关重要. 其中眼底硬性渗出物的检测是诊断的重要环节, 传统的检测方法受到主观因素的影响, 准确度不高且效率较低, 为了辅助医生进行检测, 本文提出了一种基于IHBMO-RF算法的眼底硬性渗出物的检测算法, 通过引入佳点集原理对蜂群进行初始化, 不但能保持蜂群的多样性, 而且还能加快蜂群的收敛速度, 解决了机器学习中面临的局部最优的困境. 在公开的眼底数据库DiaretDB1下进行实验显示, 本文使用的算法准确率达到了95.4%, 与现有研究对比, 取得了较好的效果, 对辅助检测眼底硬性渗出物具有一定的意义.     

碱性土壤藤稔葡萄嫁接在不同砧木上的表现

在碱性土壤上,把藤稔嫁接在少毛变叶葡萄LDP-191、Ln33和巨峰砧木上,以藤稔自根苗为对照,研究了伤流产生和持续的时间、伤流总量和伤流成分,并在黄化发生期间调查黄化程度和测定叶绿素含量。成熟后对藤稔嫁接在3个砧木上的生产表现进行了对比。结果表明,藤稔嫁接在少毛变叶葡萄LDP-191、Ln33上经济性状和生理活性均优于自根藤稔和巨峰砧木;自根藤稔又优于巨峰砧木,表明在碱性土壤上,以少毛变叶葡萄LDP-191、Ln33做藤稔砧木要比以巨峰做藤稔砧木更为适宜。     

Rheological and structural characteristics of peach tree gum exudate

The peach tree (Prunus persica), after mechanical injury or infection by microorganisms, produces a copious gum exudate on its trunk and branches. After aqueous extraction, peach gum (cv. ‘chimarrita’) yielded a soluble aqueous extract (AE) and a particle-rich hydrogel fraction (RG). After freeze-drying, AE was solubilized in water and added to excess ethanol to give a polysaccharide (POLY) precipitate. RG, AE, and POLY were composed of Ara, Xyl, Man, Gal, and uronic acids in 46:14:2:32:6, 54:12:1:27:6, and 47:13:1:33:6 molar ratios respectively, with traces of Rha. The ¹³C NMR spectra of all fractions were similar, with C-1 signals of α-l-Araf (δ 109.6–107.4) and main ones from β-d-Galp units (δ 103.7, 103.2), suggesting the presence of arabinogalactan-type polysaccharides. Rheological analyses were carried out with AE and POLY. Solutions of both fractions at 4% (w/v) had a non-Newtonian shear-thinning behavior, however that of AE showed higher apparent viscosity than that of POLY. The presence of salts decreased the apparent viscosity of AE dispersion. Dynamic oscillatory analyses showed that 4% (w/v) AE and POLY had a gel-like structure, being AE hydrogel a stronger gel when compared with POLY. This suggests that other compounds, in addition to polysaccharide, are involved in the gel network in aqueous dispersions of AE. Weaker gels were formed with 2% (w/v) AE in water and 4% (w/v) AE in various salt solutions. These results showed that the peach gum had an interesting rheological behavior and that it could have a future application.     

有机氯农药污染土壤的植物修复机理研究进展

受有机氯农药污染土壤的植物修复是一项具有广泛应用前景的技术,对其修复机理的探讨有助于深入研究修复技术与应用推广。综合分析植物修复受有机氯农药污染土壤的机理,主要体现在:植物直接吸收和转运有机氯农药;植物释放分泌物去除有机氯农药;植物微生物联合体系对有机氯农药的转化。     

Acyclohexanediones from setal exudate of Hawthorn lace bug nymphCorythucha cydoniae (Hemiptera: Tingidae)

The three major components of setal exudate from nymphs of the Hawthorn lace bug,Corythucha cydoniae, were identified as 3,6-dihydroxy-2-[1-oxo-6(E),8(E)-tetradecadienyl]cyclohex-2-en-1-one; 3,6-dihydroxy-2-[1-oxo-dodecanyl]-cyclohex-2-en-1-one; 3,6-dihydroxy-2-[1-oxo-8-dodecenyl] cyclohex-2-en-1-one. An additional 10 minor components were partially characterized.