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11.
Instructions are given for the construction of a charcoal-containing cartridge that allows the rapid recirculation through charcoal of any fluid in which the cartridge is submerged; recirculatory flow is achieved by magnetic stirring of the fluid by a stirring bar placed under the cartridge. The device is assembled from nylon mesh and conical sections cut from polypropylene beakers. The device can be used to accelerate the destaining of electrophoresis gels and to remove SDS (sodium lauryl sulfate) from SDS gels. The removal of SDS prior to staining is essential for the staining of SDS gels with Coomassie Brilliant Blue G-250.  相似文献   
12.
Nutritional risk in children is associated with food safety. This is the first study to identify the food type consumed by 6–17-year-old school-going children in Saudi Arabia. Eight permitted artificial food color additives, including Tartrazine (E102), Sunset Yellow (E110), Carmoisine (E122), Allura Red (E129), Indigo Carmine (E132), Brilliant Blue (E133), Fast Green (E143), and Black PN (E151), and two non-permitted ones, Erythrosine (E127) and Red 2G (E128), were determined using 24-h dietary recall questionnaires. Artificial color additives in 839 food products were divided into nine categories, including biscuits, cakes, chocolates, chips, ice cream, juices and drinks, candy, jelly, and chewing gum, are determined using high performance liquid chromatography and diode array detector. The results indicated a high intake of juices and drinks, ice cream, and cakes, but low consumption of chewing gum among school-going children. Among the permitted artificial food color additives, Brilliant Blue (E133) (54.1%) and Tartrazine (E102) (42.3%) were the most commonly used. Sunset Yellow (E110) in one chocolate sample, Tartrazine (E102) and Sunset Yellow (E110) in one and two juice and drink samples, respectively, and Brilliant Blue (E133) in two candy samples exceeded the permitted level. Therefore, further investigations are needed to provide insights into the possible adverse health effects of high intake of these additives in artificial food coloring on the test population are warranted.  相似文献   
13.
Glasshouse experiment was conducted to assess the impact of green chopped leaves of four test plants (Lantana camara, Ficus virens, Kigelia pinnata and Ficus bengalensis) and two nematicides (Phorate and Carbofuran) on the plant growth parameters of tomato cv. K25 and on the root-knot development. Results revealed that all the tested treatments significantly (p = 0.05) improved plant growth parameters and reduced root-knot development compared to control. Among the tested organic additives, chopped green leaves of Lantana camara added to soil gave the highest enhancement in plant growth parameters, including plant height, fresh and dry weight, number of fruits and fruit weight with the values of 94.2 cm, 106.8 g, 31.6 g, 7.2 and 153.3 g respectively, as well as a greater reduction of Meloidogyne javanica reproduction and development but exhibiting a lower response compared to nematicides. There was also significant reduction in root-knot development in tomato plants growing in other organic additive amended soil.  相似文献   
14.
The derivatives of 1,4‐dimethoxybenzene are thus far the best performing redox shuttle additives for overcharge protection of Li‐ion batteries. The most durable molecules of this kind typically possess two in‐plane methoxy groups that are equivalent by inversion symmetry. However, such geometry leads to a vanishing average dipole moment that causes poor solubility of these molecules in carbonate‐based electrolytes. In this study, a novel redox shuttle additive, 1,2,3,4‐tetrahydro‐6,7‐dimethoxy‐1,1,4,4‐tetramethyl‐naphthalene (TDTN), is introduced. It has been demonstrated that reversible oxidation at 4.05 V versus Li+/Li, high polarity, high solubility (around 0.4 m ), and excellent electrochemical stability (150 overcharge cycles at C/2 rate with 100% overcharge) can all be achieved simultaneously by the imposition of axial symmetry in the corresponding radical cation that is generated by electrochemical oxidation of TDTN in the battery. The intricate interplay between the symmetry and the chemical stability of the radical cation is scrutinized using magnetic resonance spectroscopy and electron structure modeling.  相似文献   
15.
A study was conducted to determine the efficacy of β-mannanase supplementation to a diet based on corn and soya bean meal (SBM) on growth performance, nutrient digestibility, blood urea nitrogen (BUN), faecal coliforms and lactic acid bacteria, and noxious gas emission in growing pigs. A total of 140 pigs [(Landrace × Yorkshire) × Duroc; average body weight 25 ± 3 kg] were randomly allotted to a 2 × 2 factorial arrangement with dietary treatments consisting of hulled or dehulled SBM without or with supplementation of 400 U β-mannanase/kg. During the 6 weeks of experimental feeding, β-mannanase supplementation had no effect on body weight gain, feed intake and gain:feed (G:F) ratio. Compared with dehulled SBM, feeding hulled SBM caused an increased feed intake of pigs in the entire trial (p = 0.05). The G:F ratio was improved in pigs receiving dehulled SBM (p < 0.05). Dietary treatments did not influence the total tract digestibility of dry matter, nitrogen and gross energy. Enzyme supplementation reduced (p < 0.05) the population of faecal coliforms and tended to reduce the NH3 concentration after 24 h of fermentation in a closed box containing faecal slurry. Feeding hulled SBM tended to reduce NH3 emission on days 3 and 5 of fermentation. In conclusion, mannanase supplementation had no influence on growth performance and nutrient digestibility but showed a positive effect on reducing coliform population and tended to reduce NH3 emission. Dehulled SBM increased G:F ratio and hulled SBM tended to reduce NH3 emission.  相似文献   
16.
在静置培养条件下,对粉被虫草cp菌株产N6-(2-羟乙基)腺苷(简称HEA)的培养基及其组分进行优化。采用单因素实验方法,以HPLC法对cp菌丝体中HEA进行检测,以HEA的产量为指标,结果表明查氏培养基有利于cp菌株产HEA,其产量是沙氏和PD培养基的3.7倍和4.48倍。以查氏培养基为基础培养基,进行碳、氮源的筛选中,最有利于cp菌株产HEA的是蔗糖和硝酸钠;在无机盐的筛选中,K2HPO4是促进cp菌株累积HEA最主要的无机盐,其HEA产量较CK增长了5 822.37%(提高了58.2倍);在查氏培养基上添加不同前体物和氨基酸,发现其结构类似物腺苷、次黄嘌呤和腺嘌呤都有促进cp菌株累积HEA的能力,其中腺苷和次黄嘌呤能提高其产量60%以上;而组氨酸是最有利于cp菌株累积HEA的氨基酸,产量达到(45.56±2.8)mg/L,较CK提高HEA产量251.68%,其次是L-谷氨酸增产184.19%。  相似文献   
17.
High‐capacity Li‐rich layered oxide cathodes along with Si‐incorporated graphite anodes have high reversible capacity, outperforming the electrode materials used in existing commercial products. Hence, they are potential candidates for the development of high‐energy‐density lithium‐ion batteries (LIBs). However, structural degradation induced by loss of interfacial stability is a roadblock to their practical use. Here, the use of malonic acid‐decorated fullerene (MA‐C60) with superoxide dismutase activity and water scavenging capability as an electrolyte additive to overcome the structural instability of high‐capacity electrodes that hampers the battery quality is reported. Deactivation of PF5 by water scavenging leads to the long‐term stability of the interfacial structures of electrodes. Moreover, an MA‐C60‐added electrolyte deactivates the reactive oxygen species and constructs an electrochemically robust cathode‐electrolyte interface for Li‐rich cathodes. This work paves the way for new possibilities in the design of electrolyte additives by eliminating undesirable reactive substances and tuning the interfacial structures of high‐capacity electrodes in LIBs.  相似文献   
18.
19.
为实现颗粒裂解肽抗菌结构域的高效表达并避免其对宿主菌的毒性,研究设计了共表达阴离子配体重组生产阳离子抗菌肽的方法。结果证明该方法可有效提高阳离子抗菌肽的表达产量。同时研究分析了颗粒裂解肽不同抗菌结构域在同一原核表达载体pACYCDuet-1中表达水平的实验数据。通过计算机程序对mRNA二级结构的模拟分析,计算并比较出其二级结构生成自由能之间的差异,提出了预测颗粒裂解肽抗菌结构域在E.coli中表达水平的几点依据,参考这些依据可以对不同抗菌肽基因进行改造以获得高效表达。  相似文献   
20.
Components of betel quid (BQ) have been investigated for genotoxicity, mutagenicity, and animal toxicity. However, little information exists regarding their carcinogenic characteristics. Considerable attention has already been focused on tumor promoters that occur environmentally for human uptake. In this study, the promoting effects of BQ and lime-piper additives (LPA) in BQ on epidermal hyperplasia in CD-1 mouse skin are investigated. In the present study, we found that BQ and LPA at concentrations of 25,50,75 mg/ml caused significant induction of hyperplasia, but only LPA caused an increase of epidermal ornithine decarboxylase (ODC). Treatment of mouse skin with LPA caused remarkable increases in the production of H(2)O(2) by 2.41-, 3.90-, and 3.76-fold (for the above-indicated concentrations respectively); as well as marked increases of myeloperoxidase (MPO) by 1.43-, 2.70-, and 2.29-fold. Application of LPA or BQ (50,100,150 mg/ml) also caused induction of protein kinase C-alpha (PKC-alpha) and NF-kappaB. LPA exhibited more significant effect than BQ. Thus, LPA might make a major contribution to the BQ-induced expression of PKC and NF-kappaB. These results indicated that BQ has the potential of being promoting agents, and that LPA should play a major role in increasing the effects of BQ-caused skin hyperplasia and inflammation. The promoting effects of BQ and LPA on mouse skin were associated with the induction of the expressions of PKC and NF-kappaB.  相似文献   
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