2016 Vol. 31, No. 4
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With the advantages of facile preparation,fast mass transfer,low backpressure and easy modification,monolithic materials have been widely used in chromatographic separation.In order to familiarize professionals of home and abroad with the present situation of monolithic materials,this review mainly summarizes the preparation methods of different kinds of monolithic materials (including organic polymer monoliths,silica-based monoliths,organic-inorganic hybrid silica monoliths) and their applications in the separation of proteins or peptides in proteomics.It was pointed out that compared with packed column, monolithic packed column efficiency was to be further improved from the performance of monolithic materials, such as specific surface area, pore size distribution, stablity and hydrophilicity.Taking advantage of the love backpressure of monolithic materials, the caoillary monolithic column with superlong and superfine inner diameter was prepared in order to make high efficient separation analysis of macro proteomics samples. With the further study of monolithic materials preparation technology, monolithic materials will play more important role in the fields of food safety, life science and environment.
73 kinds of mixed antibacterial drug standards were separated and ionized by ultra high performance liquid chromatography-Orbtrap high resolution mass spectrometry (UPLC-Orbitrap HRMS), the retention times and ionization mode of the the antimicrobial drugs were determined, and the antimicrobial drug accurate measurement of molecular weight and the retention time of the standard database were established.Feed samples were homogenized, first extracted with acetonitrile water solution 50% (v/v), second extracted with acetonitrile, purified by amino solid phase extraction cartridge, dried with nitrogen concentration and filtered for detection.The results showed that the recovery rate of this method was 34.51%~129.64%, the relative standard deviation was 0.1%~24.4%,and add amount of 5 μg·g-1 could be detected.
A high performance liquid chromatography (HPLC) method was developed for simultaneous determination of 20 restricted food additives in fruit and vegetable juice beverage.The method was based on extraction with methanol mixed with water.The separation was achieved on a ZORBAX SB-C18 column by using methanol and NH4Ac as mobile phase with the gradient eluent.Components were detected with a diode array detector (DAD).The quantification was performed by the external standard method.The results showed that the method exhibited an excellent linearity in the concentration range of 0.5~50.0 μg/mL with a correlation coefficient greater than 0.999 0 and a good repeatability with relative standard deviation of 1.5%~4.9%.The limits of detection were between 0.5 mg/kg and 12.5 mg/kg,the limit of quantitation were between 2.5 mg/kg and 40.0 mg/kg,and average recoveries ranged from 80.1% to 100.9%.The test result of the additives content of ten types of fruit and vegetable juice beverage on the market showed that the present method was simple,and had good separation effect.Its recovery and accuracy could meet the requirements for the simultaneous determination additives in fruit and vegetable juice beverage.
The current situation of plant resources, extraction, quality control and market situation of cosmetics were summarized.It was pointed out that in developing plant materials in cosmetics there were such problems as the violation of relevant forbidden terms,ignorance of the safety of natural components, and inscofficient emphasis of synergism means of plant materials. The future tendency was combining traditonal Chinese medicine theory such as Qi-blood theory, Yin and Yang theory, Five Elements theory, and "Principal, Assistant, Complement and Medating guide" prescription theory, with modern biological technology such as plant stem cell, bio-fermentation and nanotechnology to develop new types of cosmetics such as plant sunscreens, plant preservative, plant antifouling agent, plant pigment, plant function oil,botanical recombinant collagen and bionic composition.
The rhodiola crenulata extract was prepared by the method of ultrasonic extraction, and the quality concentration of the extract was 0.05 g/mL.The experiments of clearance rate of DPPH free radical and inhibition rate of tyrosinase were conducted to evaluate the whitening efficacy of biochemistry level of the rhodiola crenulata extract, and the test of mouse B16 melanoma cell was applied to evaluate the whitening efficacy of cell level.The results showed that under the concentration of 1.0 wt%, the clearance rate of DPPH was 92.2%, the inhibition rate of tyrosinase was 79.1%,melanoma cell comparative survival rate was up to 75%, and the inhibition rate of melanin synthesis to mouse B16 melanoma cell was 39.0%.It declared that the prepared rhodiola crenulata extract had good function of clearing DPPH free radical and inhibiting tyrosinase.Therefore, the rhodiola crenulata extract has excellent whitening efficacy on the biochemistry and cell level, which had a good potential to apply into the whitening cosmetics.
Nepeta cataria prescriptions were extracted with distilled water and the mass concentration of Nepeta cataria in the extract was 0.05 g/mL.The animal models of anti-pruritus,passive cutaneous anaphylaxis (PCA) and dehydrated skin of guinea pig after allergy were applied to study relieve itching,detumescence and allergic skin repair activity of the active extraction.Results showed that the extracts of Nepeta cataria prescriptions with mass concentration of 0.5 wt% could significantly mitigated the amount of the histamine phosphate and run up the threshold of itch at (154±31) μg.Further,vascular permeability by 15.5% with mass concentration of 2.0 wt% and the protection rate of water dispersion in allergic skin was 18% with mass concentration of 0.5 wt%.Meanwhile,the extract of Nepeta cataria prescriptions in cream matrix also could promote relieve itching,eliminate the redness of red and moisturize the allergic skin in clinical evaluation.
The research progress of botanical mosquito and insect aversion agents such as lemon eucalyptus, citronella, diego rosemary and sweet basil and botanical insect and mosquito bites driving agents such as elsholtzia,dogwood, tea polysaccharide, cardamon amomum and caltrop were summarized. It was pointed out that the priorities in the trend of developing botanical mosquito repellent and antiprutic product was the strengthening of mosquito aversion effect, the lengthening of protection time, the evaluation of botanical material safety and effect and the relevant factors of product transfer.
The inhibition of the different kinds of acidulants,such as citric acid,fumaric acid,tartaric acid and succinic acid,and the different concentrations of tartaric acid on the acrylamide of soaking cured beef were studied.The results showed that the fumaric acid,tartaric acid and succinic acid,all of them had significantly effects of reducing the acrylamide contents on cured beef,tartaric acid solution could inhibit 92.0% of the formed acrylamide.With the increase of tartaric acid solution,the inhibitation rate of acrylamide in fried cured beef decreased.When tartaric acid solution concentration was 0.25 wt%,the inhibitation rate of acrylamide was the highest and reached 92.5%.With the changes of the types and concentrations of acidulants,the moisture concent,reducing sugar content,free amino acids and protein content of cured beef had significant differences(P<0.05).In the actual production process could be soaked into 0.25 wt% concentration of tartaric acid solution to inhibit formation of acrylamide before frying.
Purple sweet potato flour was added to the traditional muffin to make purple sweet potat muffin.The amount of water,ratio of flours and amount of sugar on the texture and sensory characteristics of purple sweet potato muffin was analyzed by single factor and orthogonal experiments.Production technology of purple sweet potato was optimized,and traditional and purple sweet potato muffin were stored at 4℃ and their storage characteristics were compared.The results showed that the optimum processing conditions for purple sweet potato muffin were:water amount,50 wt%; ratio of glutinous rice flour,japonica rice flour and purple sweet potato flour,4:2:4; sugar amount,25 wt%.Under 4℃ storage,the moisture content and water-holding capacity traditional and purple sweet potato muffin were decreased with the increase of storage time.During the whole storage time,the moisture content and water-holding capacity of purple sweet potato muffin were higher than traditional muffin.With the increase of storage time,the hardness,adhesion,chewiness and springiness of the two kinds of muffin increased at first and then decreased.With the increase of storage time,the starch structure changed from A to V type in the two kinds of muffin.At the same storage time,the starch crystallinity degree of traditional muffin was higher than purple sweet potato muffin.
Through different sieves, the carrot powder was divided into different particle sizes of >250 μm,250~180 μm,180~150 μm,150~120 μm,120~109 μm,109~75 μm,<75 μm compared the color, rehydration capacity, oil-holding capacity, the carotene content, total sugar content,the vitamin C content and amino nitrogen content of different particle size of the carrot powder were compared.The results showed that the smaller the particle size of carrot powder,the whiter the powder.They had the trend of becoming darker at first and lighter at last in red, but they were almost the same in yellow.The oil-holding capacity decreased slowly and non-significantly, and the content of carotene, vitamin C decreased significantly, the rehydration capacity and the content of amino nitrogen were higher at first and became lower at last, but the content of total sugar was nearly the same.This showed that carrot powder with different particle size has different physical-chemical properties,so the particle size of carrot powder should be chosen according to the different use of carrot powder.
By designing different single-factor test,the influence of five process parameters of cylinder wall temperature, temperature of hot air, opening of hot air valve, moisture discharge valve, and revolving-speed of casing cylinder on the cigarette tar delivery were investigated.Through the establishment of a uniform design quadratic regression model of drying leaves set of samples and the corresponding parameters between tar delivery, according to the theoretical model,optimal bake thin wire process parameters of cut tobacco leave samples were obtained:the cylinder wall temperature was 135℃, air temperature was 130℃, opening of hot air valve was 100%,moisture discharge valve was 50%, revolving-speed of casing cylinder was 8 r/min.
According to the data of testing moisture content, as well as the processing data of sample quality change of two types of shredded tobacco's and six different varieties of filter rods',the effects of cigarette shredded tobacco moisture content by filter rod were analyzed.It turned out that the moisture absorption and initial moisture content of filter rods could affect the equilibrium relationship between the filter rod and shredded tobacco moisture content and further changes in moisture content during storage period.If the initial moisture content of filter rods was lower than the equilibrium moisture content,it showed the performance of moisture absorption and the moisture content of finished cigarette dropped; Conversely,it showed the performance of moisture desorption,and the moisture content of finished cigarette rose.The activated carbon-biological filter rod and ternary double-grooved cavity nanoparticles composite filter rods had strong moisture absorption, it would absorb moisture from the shredded tobacco, resulting in significant reduction in the moisture content of cigarette, a decrease respectively 0.234% and 0.634%.
In order to solve the problem of time consuming and error pronein selecting optimal "brick" to assemble functional protein expression vector,based on statistical language model (SLM), a dynamic programming algorithm of protein expression vector was carried out. By collecting the statistical parameters of BioBrick standard parts and transforming the assembling process into SLM, a dynamic programming algorithm could be performed to choose suitable parts to compose the final genetic construction. The result showed this method had high accuracy,redundant operations could be reduced and the time and cost required for conducting biological experiment could be minimized. The method could be not only used to optimize a design in a synthetic biological robotic platform, but also independently used to automate the DNA assembly process in synthetic biology. It could also be iterated and then give out different optimized results for consideration.
In order to deal with the problem that the prediction accuracy of subcellular localization of apoptosis proteins is not high, a method of predicting subcellular localization of apoptosis protein based on ensemble learning and Gene Ontology (GO) annotation database was proposed. This method utilized the GO features of apoptosis proteins and their homologous proteins combined with the two layer integration strategy to predict subcellular localization of apoptosis proteins. In the first layer, several sets of feature vectors were formulated by the different number of homologous proteins, then it selected the distance weighted K-nearest neighbor classifier as individual classifier, trained sub-prediction models, and integrated these models by majority voting. In the second layer, the prediction model of the first layer was used as the sub-prediction model, and it integrated the different nearest neighbors' sub-prediction models by the majority voting. The results of Jackknife test showed that prediction accuracy of the method reaches 96.2% on the CL317 apoptosis proteins dataset, which was superior to other methods. In addition,this method could reduce the impact of the data imbalance.
In view that the present natural products database data update was not in time, the data quantity was not big enough, the natural products database and knowledge discovery system was developed based on crowdsourcing.The system used the crowdsourcing technology to build a natural products database, used molecular fingerprint to encode molecular structure, and used the Tanimoto coefficient to calculate similarity to realize natural products and related literature retrieval,and could expand real-time for biologists to understand the current research hotspot and to offer reference to determine further research directions.
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Administered by:The Education Department Henan Province
Sponsored by:Zhengzhou University of Light Industry
Editor-in-chief:Wei Shizhong
Executive Editor-in-Chief:Zou Lin
Deputy Editor-in-Chief:Qu Shuanghong
Edited & published by:Editorial Department of Journal of Light Industry
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