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31.
Multivalent nanoparticles have several key advantages in terms of solubility, binding avidity, and uptake, making them particularly well suited to molecular imaging applications. Herein is reported the stepwise synthesis and characterization of NIR viral nanoparticles targeted to gastrin-releasing peptide receptors that are over-expressed in human prostate cancers. The pan-bombesin analogue, [β-Ala11, Phe13, Nle14]bombesin-(7-14), is conjugated to cowpea mosaic virus particles functionalized with an NIR dye (Alexa Fluor 647) and polyethylene glycol (PEG) using the copper(I)-catalyzed azide-alkyne cycloaddition reaction. Targeting and uptake in human PC-3 prostate cells is demonstrated in vitro. Tumor homing is observed using human prostate tumor xenografts on the chicken chorioallantoic membrane model using intravital imaging. Further development of this viral nanoparticle platform may open the door to potential clinical noninvasive molecular imaging strategies.  相似文献   
32.
The assembly of plasmonic nanoparticles with precise spatial and orientational order may lead to structures with new electromagnetic properties at optical frequencies. The directed self‐assembly method presented controls the interparticle‐spacing and symmetry of the resulting nanometer‐sized elements in solution. The self‐assembly of three‐dimensional (3D), icosahedral plasmonic nanosclusters (NCs) with resonances at visible wavelengths is demonstrated experimentally. The ideal NCs consist of twelve gold (Au) nanospheres (NSs) attached to thiol groups at predefined locations on the surface of a genetically engineered cowpea mosaic virus with icosahedral symmetry. In situ dynamic light scattering (DLS) measurements confirm the NSs assembly on the virus. Transmission electron micrographs (TEM) demonstrate the ability of the self‐assembly method to control the nanoscopic symmetry of the bound NSs, which reflects the icosahedral symmetry of the virus. Both, TEM and DLS show that the NCs comprise of a distribution of capsids mostly covered (i.e., 6–12 NS/capsid) with NSs. 3D finite‐element simulations of aqueous suspensions of NCs reproduce the experimental bulk absorbance measurements and major features of the spectra. Simulations results show that the fully assembled NCs give rise to a 10‐fold surface‐averaged enhancement of the local electromagnetic field.  相似文献   
33.
The effects of a hydrothermal treatment consisting of tempering (to 41% moisture) and heating to 153 °C (micronisation) on the structural and physicochemical characteristics of two cowpea varieties were studied. The untreated varieties had similar cooking times, although cooked Bechuana white cowpeas were significantly (P ≤ 0.05) softer and had a higher incidence of splitting than Var. 462 cowpeas. This may be due in part to differences in cotyledon structure affecting water uptake during cooking. The hydrothermal treatment changed the physical structure and chemical properties of the cowpea seeds. This led to significant (P ≤ 0.05) reductions in the cooking time of micronised Bechuana white and Var. 462 cowpeas, by 47 and 36% respectively, as compared with control samples. Micronisation caused physical fissuring of the seed coat and cotyledon and significantly (P ≤ 0.05) reduced the bulk density of treated seeds. These changes in the physical structure significantly (P ≤ 0.05) improved the initial water uptake during soaking and cooking, increased the enzyme‐susceptible starch and reduced the protein solubility and hydration capacity of the cowpea seeds. Cooked (60 min) micronised cowpeas also had significantly (P ≤ 0.05) more splits and a significantly (P ≤ 0.05) softer texture than control samples. Copyright © 2005 Society of Chemical Industry  相似文献   
34.
采用固相微萃取(SPME)-气相色谱-质谱联用(GC-MS)和电子舌技术分析接种不同发酵剂浅渍发酵豇豆的挥发性风味成分及滋味特征,并对结果进行主成分分析(PCA)。结果表明,植物乳杆菌(Lactobacillus plantarum)SD-7和植物乳杆菌 FM-LP-9单独发酵豇豆中都检测出47种风味物质,菌株SD-7与FM-LP-9混菌(1∶1)发酵和自然发酵豇豆中分别检测出59种和44种风味物质,表明混菌发酵有利于增加发酵产品风味种类;通过主成分分析,可将酸类、酯类等8类风味成分对豇豆风味品质的影响分为4种,且在该主成分评价模型下可区分接种发酵和自然发酵。电子舌分析结果显示,自然发酵豇豆的酸味、苦味和涩味影响值高于接种发酵。综上,混合接种发酵可提高豇豆发酵产品的风味组分和改善产品的滋味。  相似文献   
35.
The behavioral responses of cowpea weevil,Callosobruchus chinensis to the leaf extracts of the aquatic weed, water hyacinth,Eichhornia crassipes (Mart) Solms. was evaluated by three different methods. The petroleum ether-soluble fraction ofE. crassipes induced high weevil attraction in all methods employed. The olfactometer assay provided a reading on weevil chemosensory responses, whereas the free-choice tests measured response and preference of weevils to the untreated or extract-treated food grain of their choice over a longer period. The extracts were also presented under no choice test conditions to assay them for the presence of oviposition stimulants. In all these methods the extracts of water hyacinth evoked a quick directional response. Another interesting feature is that the extract, besides producing attraction, also caused mortality of the insects.  相似文献   
36.
The southern cowpea weevil, Callosobruchus chinensis (Coleoptera: Bruchidae), is a major pest of stored legumes in warm temperate and tropical climates. The female sex attractant pheromone was extracted from filter-paper shelters taken from containers that housed virgin females. The extracts were purified by various chromatographic techniques, and the biologically active components in the fractions were screened by gas chromatographic–electroantennographic detection analysis with male antennae. Two compounds that elicited electrophysiological responses were isolated, and gas chromatography–mass spectrometry, nuclear magnetic resonance, and micro-chemical analyses suggested that the active compounds were homofarnesals, (2Z,6E)- and (2E,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals. Males of C. chinensis were significantly attracted to filter paper discs loaded with the synthetic compounds at 0.01–0.1 ng compared to solvent control in a Y-tube olfactometer assay. These pheromone components represent unique chemical structures within the genus Callosobruchus.  相似文献   
37.
通过研究豇豆加工过程中百菌清、哒螨灵、苯醚甲环唑及氯氰菊酯残留变化规律,为有效进行膳食评估提供依据。采用气相色谱法检测不同清洗及烹饪处理前后豇豆中农药残留量,结果显示:豇豆中百菌清、哒螨灵、苯醚甲环唑及氯氰菊酯的清洗加工因子分别为0.152~0.722、0.620~0.903、0.464~0.922、0.581~0.882;烹饪加工因子分别为0.077~0.311、0.194~0.554、0.198~0.479、0.443~0.732。不同清洗方式对豇豆充分清洗后农药去除效果相差不大,不同烹饪方式对加工因子的影响主要与样品质量变化有关。综上所述,通过清洗和烹饪处理,可明显减少豇豆中农药残留量,将加工因子引入膳食暴露量评估,能够更真实的反映食品安全现状,对保障食品安全具有重要意义。  相似文献   
38.
Immunotherapy holds tremendous potential in cancer therapy, in particular, when treatment regimens are combined to achieve synergy between pathways along the cancer immunity cycle. In previous works, we demonstrated that in situ vaccination with the plant virus cowpea mosaic virus (CPMV) activates and recruits innate immune cells, therefore reprogramming the immunosuppressive tumor microenvironment toward an immune-activated state, leading to potent anti-tumor immunity in tumor mouse models and canine patients. CPMV therapy also increases the expression of checkpoint regulators on effector T cells in the tumor microenvironment, such as PD-1/PD-L1, and we demonstrated that combination with immune checkpoint therapy improves therapeutic outcomes further. In the present work, we tested the hypothesis that CPMV could be combined with anti-PD-1 peptides to replace expensive antibody therapies. Specifically, we set out to test whether a multivalent display of anti-PD-1 peptides (SNTSESF) would enhance efficacy over a combination of CPMV and soluble peptide. Efficacy of the approaches were tested using a syngeneic mouse model of intraperitoneal ovarian cancer. CPMV combination with anti-PD-1 peptides (SNTSESF) resulted in increased efficacy; however, increased potency against metastatic ovarian cancer was only observed when SNTSESF was conjugated to CPMV, and not added as a free peptide. This can be explained by the differences in the in vivo fates of the nanoparticle formulation vs. the free peptide; the larger nanoparticles are expected to exhibit prolonged tumor residence and favorable intratumoral distribution. Our study provides new design principles for plant virus-based in situ vaccination strategies.  相似文献   
39.
山药、豇豆复合发酵保健酸奶的研究   总被引:4,自引:1,他引:3  
由山药、豇豆和牛奶为主原料,研制出了集山药、豇豆和酸奶的保健功能于一体的新型保健饮料-山药、豇豆复合功能性酸奶。采用正交试验筛选出最优组合,结果表明,豇豆汁:山药汁比例为2:3,接种量为5%,加糖量为7%为最佳的工艺条件,得到的酸奶的品质最好。  相似文献   
40.
为了提高鲜切豇豆的品质,本文研究了海藻酸钠(0.6%,m/m)和羧甲基纤维素钠(0.8%,m/m)两种涂膜剂对其贮藏期间的呼吸强度、维生素C、叶绿素等品质指标变化规律的影响。研究发现,与对照相比,在贮藏期间,海藻酸钠和羧甲基纤维素钠涂膜均有效降低鲜切豇豆的呼吸强度,维持较高的可溶性固形物含量,减少鲜切豇豆维生素C和叶绿素的损失,保持较高的过氧化物酶活性,减少丙二醛的积累。贮藏至12 d,海藻酸钠涂膜的鲜切豇豆呼吸强度为237.67 mg/(kg·h),处于较低水平;其维生素C、叶绿素及可溶性固形物含量分别比羧甲基纤维素钠涂膜的高13.06 mg/100 g、0.62 mg/g、0.49%,但丙二醛含量低11.36%。研究结果表明,海藻酸钠涂膜更有利于保持鲜切豇豆的品质及延长贮藏期,其用于豇豆的保鲜贮藏具有潜在的应用前景。  相似文献   
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