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991.
The interest in black raspberry products has been increasing due to its flavor and potential health benefits. While black raspberries grown in North America are Rubus occidentalis, there has been some confusion regarding the identity of black raspberry grown in Korea (known as bokbunja; Rubus coreanus). As such, there is a need to define the anthocyanin profile of R. coreanus fruit collected from a verified source. We analyzed three genotypes of bokbunja fruit for anthocyanin profiles. While each varied in its anthocyanin proportions and total concentration, bokbunja fruit contained three anthocyanins: cyanidin-3-glucoside, cyanidin-3-rutinoside, and pelargonidin-3-glucoside, and lacked the xylose containing glycosides characteristic of R. occidentalis: cyanidin-3-sambubioside, and cyanidin-3-xylosylrutinoside. Due to mix-ups of bokbunja identity, research claiming to be conducted on bokbunja fruit requires confirmation that the fruit was sourced from a correctly identified plant. The distinct anthocyanin profiles between the two species can be used to confirm plant identity. 相似文献
992.
Paul J. Molino Zhilian Yue Binbin Zhang Anthony Tibbens Xiao Liu Robert. M. I. Kapsa Michael J. Higgins Gordon G. Wallace 《Advanced Materials Interfaces》2014,1(3)
Organic conducting polymers (OCPs) are currently the subject of intense research in the area of biomaterials and bioelectronics. Of the OCPs, poly(3,4‐ethylenedioxythiophene) (PEDOT) has attracted significant interest, however there has been little work on investigating the incorporation of biological compounds as the dopant species in the polymer which are aimed at enhancing the biocompatibility and biofunctionality of the material. Here, we incorporate the biological dopants dextran sulphate, chondroitin sulphate, and alginate, into PEDOT polymers and investigate their influence on a suite of physicochemical and electrochemical properties. We employ QCM‐D to study the mass of adsorption and the viscoelastic properties of the important extracellular matrix proteins fibronectin and collagen. Furthermore, we use QCM‐D to study the adhesion of PC12 neural cells to the PEDOT‐biodopant polymers with and without an adsorbed protein conditioning layer. QCM‐D was found to be an excellent tool with which to study conducting polymer–biological interactions, with this report the first time that QCM‐D has been used to study cell interactions with conducting polymer biomaterials. 相似文献
993.
An optimised structure is one which uses the smallest quantity of the best material to perform its function, with adequate
safety factor or margin for error. Structural optimisation occurs not only in mechanical engineering, but also in nature:
plants with hollow stems or stalks gain a height advantage, and are thus more efficient, by approaching the optimum shape.
Here we consider the optimisation of orthotropic tubes, typifying, in a mechanical sense, stalk and stem. The stiffness and
strength of orthotropic tubes of initially circular section are reviewed, and diagrams are proposed which allow the optimum
section shape to be selected. 相似文献
994.
Desorption electrospray ionization mass spectrometry (DESI MS) is rapidly becoming accepted as a powerful surface characterization tool for a wide variety of samples in the open air. Besides its well-established high-throughput capabilities, a unique feature of DESI is that chemical reactions between the charged spray microdroplets and surface molecules can be exploited to enhance ionization. Here, we present a rapid screening assay for artesunate antimalarials based on reactive DESI. Artesunate is a vital therapy for Plasmodium falciparum malaria, but artesunate tablets have been counterfeited on a very large scale in SE Asia, and more recently in Africa. For this reason, faster and more sensitive screening tests are urgently needed. The proposed DESI assay is based on the formation of stable noncovalent complexes between linear alkylamines dissolved in the DESI spray solution and artesunate molecules exposed on the tablet surface. We found that, depending on amine type and concentration, a sensitivity gain of up to 170x can be obtained, in comparison to reagent-less DESI. Hexylamine (Hex), dodecylamine (DDA), and octadecylamine (ODA) produced proton-bound noncovalent complexes with gas-phase stabilities, increasing in the order [M + Hex + H]+ < [M + DDA + H]+ < [M + ODA + H]+. Tandem MS experiments revealed that complex formation occurred by hydrogen bonding between the amine nitrogen and the ether-like moieties within the artesunate lactone ring. After the reactive DESI assay was fully characterized, it was applied to a set of recently collected suspicious artesunate tablets purchased in shops and pharmacies in SE Asia. Not only did we find that these samples were counterfeits, but we also detected the presence of several wrong active ingredients. Of particular concern was the positive detection of artesunate traces in the surface of one of the samples, which we quantified with standard chromatographic techniques. 相似文献
995.
996.
An object-oriented analysis-synthesis coder is presented which encodes arbitrarily shaped objects instead of rectangular blocks. The objects are described by three parameter sets defining their motion, shape and colour. Throughout this contribution, the colour parameters denote the luminance and chrominance values of the object surface. The parameter sets of each object are obtained by image analysis based on source models of moving 2D-objects and coded by an object-dependent parameter coding. Using the coded parameter sets an image can be reconstructed by model-based image synthesis. In order to cut down the generated bit-rate of the parameter coding, the colour updating of an object is suppressed if the modelling of the object by the source model is sufficiently exact, i.e., if only a relatively small colour update information would be needed for an errorless image synthesis. Omitting colour update information, small position errors of objects denoted as geometrical distortions are allowed for image synthesis instead of quantization error distortions. Tolerating geometrical distortions, the image area to be updated by colour coding can be decreased to 4% of the image size without introducing annoying distortions. As motion and shape parameters can efficiently be coded, about 1 bit per pel remains for colour updating in a 64 kbit/s coder compared to about 0.1 bit per pel in the standard reference coder (RM8) of the CCITT. Experimental results concerning the efficient coding of motion and shape parameters are given and discussed. The coding of the colour information will be dealt with in further research. 相似文献
997.
本文介绍了针对轻轨列车的新型储能装置——新一代牵引变流器MITRAC TC520。该装置安装在MITRAC Energy Saver ES500型号的轻轨列车上。这种新型列车于2009年6月交付运行,目前越来越多这一类型列车由曼海姆公共交通运行商RNV投入商业运行。本文所阐述的使用超级电容的车载储能装置在原型轻轨车上运行超过四年时间,证明了其合理性。本装置可节省30%能量。目前RNV公司在19列轻轨车上装上这种MITRAC节能器,这个成功的项目得到RNV公司客户的一致好评。在地铁列车上安装MITRAC装置最直接的技术效果就是节能,并且减少了第三轨的能量需求,同时可以作为停电时的辅助救援手段保证列车继续运行到下一个车站,保证乘客安全。 相似文献
998.
Hyeongnam Kim Michael L. Schuette Jaesun Lee Wu Lu James C. Mabon 《Journal of Electronic Materials》2007,36(9):1149-1155
The Ni/AlGaN interfaces in AlGaN/GaN Schottky diodes were investigated to explore the physical origin of post-annealing effects
using electron beam induced current (EBIC), current–voltage (I–V) characteristics, and X-ray photoelectron spectroscopy (XPS). The EBIC images of the annealed diodes showed that the post-annealing
process reduces electrically active states at the Schottky metal/AlGaN interfaces, leading to improvement of diode performance,
for example a decrease in reverse leakage current and an increase in Schottky barrier heights. Pulsed I–V characteristics indicate the Fermi level is up-shifted after annealing, resulting in a larger sheet carrier density at the
AlGaN/GaN interface. Unintentional oxidation of the free AlGaN surface during the post-annealing process, revealed by XPS
analysis, may prevent electron trapping near the drain-side of the gate edges. We suggest that the post-annealing process
under an optimized conditions can be an effective way of passivating AlGaN/GaN heterojunction field-effect transistors. 相似文献
999.
Estrogen content of dairy and swine wastes 总被引:3,自引:0,他引:3
Raman DR Williams EL Layton AC Burns RT Easter JP Daugherty AS Mullen MD Sayler GS 《Environmental science & technology》2004,38(13):3567-3573
Naturally occurring estrogens in animal wastes may cause negative environmental impacts, yet their abundance in animal waste treatment and storage structures is poorly documented. To better quantify estrogen concentrations in animal wastes, multiple waste samples were collected from treatment and storage structures at dairy and swine facilities and analyzed for concentrations of 17beta-estradiol (E2), estrone (E1), and 17alpha-estradiol by gas chromatography-mass spectroscopy and by enzyme linked immunosorbent assay (E2 only). Mass ratios of each estrogen to the macronutrients nitrogen, phosphorus, and potassium were also determined. Because manure application rates are typically macronutrient-based, estrogen to macronutrient ratios are proportional to areal mass application rates of estrogen to fields. Swine farrowing waste (from farrowing sows and piglets) had the highest ratios of E2 to macronutrients. Mean ratios in swine farrowing waste were roughly twice those in swine finishing waste (from growing male and nonpregnant female animals) and more than four times higher than those in dairy waste (from lactating cows in various stages of their reproductive cycles); these differences were statistically significant (alpha = 0.05). Estrone followed a similar trend. In contrast, ratios of 17alpha-estradiol to macronutrients were highest in dairy operations. These results can be used to better predict estrogen loading rates on fields receiving swine and dairy wastes. 相似文献
1000.
Increasing the moisture content of imitation cheese: effects on texture, rheology and microstructure 总被引:1,自引:0,他引:1
Paul J. Hennelly Peter G. Dunne Michael O’Sullivan Dolores O’Riordan 《European Food Research and Technology》2005,220(3-4):415-420
Increasing moisture content may be a practical and cost-effective means to control the functional properties of imitation cheese. Imitation cheeses with moisture contents of 46, 50, 52 and 54 g/100 g were manufactured. An increase in the moisture content of the imitation cheese resulted in significantly increased meltability, tan values and decreased hardness (all P<0.05). The relationship between moisture content (x) and meltability (y) was described by the model
(r2=0.99). A linear relationship emerged between moisture content (x) and hardness (y), where
(r2=0.95) but cohesiveness was unaffected by moisture content. Increasing the moisture content to 52 or 54 g/100 g led to pockets of free water within the cheese and larger but fewer fat globules. The maximum level of moisture that the cheese matrix can retain appears to be 54 g/100 g. 相似文献