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1.
Hydrophilic degraded gelatin was modified with hydrophobic poly(ε-caprolactone) (PCL) via a chemical grafting route.Firstly,PCL with one hydroxyl end group was prepared by the ring-opening polymerization of εcaprolactone (ε-CL) with tin (Ⅱ) 2-ethylhexanoate as catalyst and n-butyl alcohol as initiator.Secondly,the PCL reacted with isophorone diisocyanate (IPDI) to prepare PCL with isocyanate functional group (PCL-NCO).Hydroxylamine was used to degrade gelatin by the cleavage between asparagine and glycine residues of gelatin.PCL-NCO reacted with the hydroxyl/amino groups of degraded gelatin in a homogeneous system and yielded the PCL modified gelatin copolymers.The gelatin grafted PCL copolymers were measured by means of XRD,FTIR,DSC and 1 H NMR.The results confirmed the conjugation of PCL onto gelatin chains.The PCL modified gelatin can be used as biomaterials owing to their biocompatibility and biodegradation. 相似文献
2.
由植物油提取的合成润滑剂的流变特性和摩擦特性 总被引：3，自引：0，他引：3
The double bonds in the vegetable oils can be conjungated and Diels-Alder react when they are heated in the existence of the catalyst. The percent of the double bond will decrease and the oxidative stability of the vegetable oils can be ameliorated. Dimmer acid can react with different carbon chain length of alcohols to form dimmer acid esters. A series of dimmer acid esters were synthesized and their rheological characteristics （viscosity, viscosity index, pour point） and tribological characteristics （the coefficient of friction at different load, the characteristic of extreine pressure （ PB ）, the wear scare diameter （ D30min^196N ） were evaluated and analyzed. The results showed that the characteristics of Di-iso-octanol dimmer acid ester were the best among the synthesized dimmer esters. It＇ s a lubricant with good properties（the viscosity is 94.5 mm^2/s, the viscosity index is high up to 141 and the pour point is - 49℃ ）. It is a kind of newly interesthing ester type lubricant. Its rheological and tribological characteristics are even better than those of the slap-up synthesized lubricant--pentaerythritol esters （C7-9 acidate）. The FT-IR spectrophotometer was used to analyze the structure of the synthetic esters. Their IR spectra are the same as the typical IR spectrum of ester. The test indicated that Di-iso-octanol dimmer acid ester could be used as a kind of base lubricant with excellent quantity. 相似文献
3.
Nutritional evaluation of caseins and whey proteins and their hydrolysates from Protamex 总被引：4，自引：0，他引：4
夏文水 《Journal of Zhejiang University. Science. B》2006,7(2):90-98
Whey protein concentrate （WPC 80） and sodium caseinate were hydrolyzed by Protamex to 5%, 10%, 15%, and 20% degree of hydrolysis （DH）. WPC 80, sodium caseinate and their hydrolysates were then analyzed, compared and evaluated for their nutritional qualities. Their chemical composition, protein solubility, amino acid composition, essential amino acid index （EAA index）, biological value （BV）, nutritional index （NI）, chemical score, enzymic protein efficiency ratio （E-PER） and in vitro protein digestibility （IVPD） were determined. The results indicated that the enzymatic hydrolysis of WPC 80 and sodium caseinate by Protamex improved the solubility and IVPD of their hydrolysates. WPC 80, sodium caseinate and their hydrolysates were high-quality proteins and had a surplus of essential amino acids compared with the FAO/WHO/UNU （1985） reference standard. The nutritive value of WPC 80 and its hydrolysates was superior to that of sodium caseinate and its hydrolysates as indicated by some nutritional parameters such as the amino acid composition, chemical score, EAA index and predicted BV. However, the E-PER was lower for the WPC hydrolysates as compared to unhydrolyzed WPC 80 but sodium caseinate and its hydrolysates did not differ significantly. The nutritional qualities of WPC 80, sodium caseinate and their hydrolysates were good and make them appropriate for food formulations or as nutritional supplements. 相似文献
4.
In the current studies a miniature silicon wafer fuel cell （FC） using L-ascorbic acid as fuel was developed. The cell employs L-ascorbic acid and air as reactants and a thin polymer electrolyte as a separator. Inductively coupled plasma （ICP） silicon etching was employed to fabricate high aspect-ratio columns on the silicon substrate to increase the surface area. A thin platinum layer deposited directly on the silicon surface by the sputtering was used as the catalyst layer for L-ascorbic acid electro-oxidation. Cyclic voltammetry shows that the oxidation of L-ascorbic acid on the sputtered platinum layer is irreversible and that the onset potentials for the oxidation of L-ascorbic acid are from 0.27 V to 0.35 V versus an Ag/AgCl reference electrode. It is found that at the room temperature, with 1 mol/L L-ascorbic acid/PBS （phosphate buffered solution） solution pumped to the anode at 1 ml/min flow rate and air spontaneously diffusing to the cathode as the oxidant, the maximum output power density of the cell was 1.95 mW/cm^2 at a current density of 10 mA/cm^2. 相似文献
5.
This paper reported an efficient and rapid method to produce highly monodispersed CdSe quantum dots （QDs）, in which the traditional trioctylphosphine oxide （TOPO） was replaced by paraffin liquid as solvent and oleic acid as the reacting media. The experimental conditions and the properties of QDs had been studied in detail. The resulting samples were confirmed of uniform size distribution with transmission electronic microscopy （TEM）, while UV-vis absorption and photoluminescence （PL） spectra clearly indicated that such synthesized QDs had good fluorescence properties. 相似文献
6.
Using carbon tetrachloride （CCl4） as extraction agent, the activated sludge from Tianjin Jizhuangzi Sewage Treatment Plant as inoculum, the test study on biodegradability of lubricants was carried out. The test flasks containing the mineral medium, the test oil and the inoculum were placed in incubation together with flasks containing poisoned blanks for periods of 0 and 21 days, respectively. Flasks containing the reference materials in place of the test oil were run in parallel. At the end of the incubation period, the contents of the flasks were subjected to sonic vibration, and were acidified and extracted by using CCI4. The extracts were then analysed by infra-red （IR） spectrometer to measure the maximum absorption of the C-H stretch of CH2-CH3 band at wavelength of 2 930 cm^-1. The absorption values were used to calculate the residual oil contents of the poisoned and test flasks. Consequently the biodegradability of the test oil was calculated. The test results indicate that the differences in the biodegradability of test materials in different tests are within 5.5%, and consistent with the data described in Coordinating European Council （CEC） L-33- A-93. The biodegradability of lubricants can be evaluated by this method effectively. 相似文献
7.
Abreu PR Almeida MC Bernardo RM Bernardo LC Brito LC Garcia EA Fonseca AS Bernardo-Filho M 《Journal of Zhejiang University. Science. B》2006,7(6):429-435
Psidium guajava （guava） leaf is a phytotherapic used in folk medicine to treat gastrointestinal and respiratory disturbances and is used as anti-inflammatory medicine. In nuclear medicine, blood constituents （BC） are labelled with technetium-99m （^99mTc） and used to image procedures. However, data have demonstrated that synthetic or natural drugs could modify the labelling of BC with ^99mTC. The aim of this work was to evaluate the effects of aqueous extract of guava leaves on the labelling of BC with ^99mTc. Blood samples of Wistar rats were incubated with different concentrations of guava extract and labelled with ^99mTc after the percentage of incorporated radioactivity （%ATI） in BC was determined. The results suggest that aqueous guava extract could present antioxidant action and/or alters the membrane structures involved in ion transport into cells, thus decreasing the radiolabelling of BC with ^99mTc. The data showed significant （P〈0.05） alteration of ATI in BC from blood incubated with guava extract. 相似文献
8.
Diisopropylidenated α-D-glucofuranose （1） was oxidated with CrO3-pyridine complex. Oxidated product and its hydrate were separated and were reduced together to synthesize diisopropylidenated α-D-allofuranose （ 3）. The yield of 3 increased by 8% than that with only oxidated product as reduction substrate. Benzoylated derivative of 3 was selectively nydrolyzed and dimesylated to synthesize 3-O-benzoyl-1 .2- O- isopropylidene-α-D-allofuranose （ 5 ） and its dimesylated derivative respectively. The overall yield of 5 from 1 was 36%. Each step and final products were analyzed by ^1H-NMR spectra and other methods. The experiments showed that the influence of acetic acid concentration on selective hydrolysis was obvious. The hydrolysis yield was 81.8%. Oxidation. reduction and other procedures were practical and had application potential. 相似文献
9.
Response surface methodology （RSM） was used to optimize the fermentation medium for enhancing pyruvic acid production by Torulopsis glabrata TP19. In the first step of optimization, with Plackett-Burman design, ammonium sulfate, glucose and nicotinic acid were found to be the important factors affecting pyruvic acid production significantly. In the second step, a 23 full factorial central composite design and RSM were applied to determine the optimal concentration of each significant variable. A second-order polynomial was determined by the multiple regression analysis of the experimental data. The optimum values for the critical components were obtained as follows： ammonium sulfate 0.7498 （10.75 g/L）, glucose 0.9383 （109.38 g/L） and nicotinic acid 0.3633 （7.86 mg/L） with a predicted value of maximum pyruvic acid production of 42.2 g/L. Under the optimal conditions, the practical pyruvic acid production was 42.4 g/L. The determination coefficient （R^2） was 0.9483, which ensures adequate credibility of the model. By scaling up fermentation from flask to jar fermentor, we obtained promising results. 相似文献
10.
Measurement and analysis of soil nitrogen and organic matter content using near-infrared spectroscopy techniques 总被引：2，自引：0，他引：2
Near infrared reflectance （N1R） spectroscopy is as a rapid, convenient and simple nondestructive technique useful for quantifying several soil properties. This method was used to estimate nitrogen （N） and organic matter （OM） content in a soil of Zhejiang Province, Hangzhou County. A total of 125 soil samples were taken from the field. Ninety-five samples spectra were used during the calibration and cross validation stage. Thirty samples spectra were used to predict N and OM concentration. NIR spectra of these samples were correlated using partial least square regression. The regression coefficients between measured and predicted values of N and OM was 0.92 and 0.93, and SEP （standard error of prediction） were 3.28 and 0.06, respectively, which showed that NIR method had potential to accurately predict these constituents in this soil. The results showed that NIR spectroscopy could be a good tool for precision farming application. 相似文献
11.
以三聚氯氰（CC）和4,4’-二氨基二苯乙烯-2,2’-二磺酸（DSD酸）为原料,利用缩合反应合成三嗪氨基二苯乙烯-丙烯酰氯生色团荧光单体,以过氧化二苯甲酰为引发剂,和苯乙烯共聚得到三嗪氨基二苯乙烯型均聚物.用紫外吸收光谱、荧光发射光谱、光致异构化现象等手段研究了它们在水溶液中光物理化学性质.研究表明,聚合型荧光增白剂中基本发色团的结构不变,具有传统荧光增白剂的光学性能;发色团与高分子链间的共价键使其光化学稳定性大大增强,荧光量子产率显著提高. 相似文献
12.
杨芝萍 《Journal of Zhangzhou Technical Institute》2005,7(2):1-4
2,6-二氯-4-三氟甲基苯胺经重氮化后与2,3-二氰基丙酸酯反应合成了1-(2,6-二氯-4-三氟甲基苯基)-3-氰基-5-氨基吡唑(1),1与乙酸酐、顺丁烯二酸酐、苯甲酰氯反应,得到1的乙酰胺2a、顺丁烯酰亚胺2b和苯甲酰胺2c.通过元素分析,红外光谱,核磁共振氢谱,核磁共振碳谱,质谱等手段对其结构进行了表征. 相似文献
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14.
Solubility of 2-amino-6-chloropurine in Mitsunobu solvents could be significantly improved after its exocyclic amino group is protected via N-tert-butoxycarbonylation. The bis-Boc protected 2-amino-6-chloropurine also shows excellent activity and N9 selectivity in the coupling with various alcohols by a Mitsunobu reaction. Then, a new practical and efficient method is established for the synthesis of penciclovir （PCV） from bis-Boc-2-amino-6-chloropurine 9 and the side chain of 5-（2-hydroxyethyl）-2,2-dimethyl-l,3-dioxane 5~the latter being a more easily prepared cyclic precursor of the diacetate side chain used in the conventional process. The coupling of 9 with 5 proceeded regioselectively at a N9 position of purine derivative for a good yield under Mitsunobu conditions. 相似文献
15.
氨基官能团存在于很多有生理活性的化合物中,氨基的保护策略选择对合成化学工作者非常重要。基于1,4,7,10-四氮杂环十二烷(Cyclen)的化合物应用广泛,为了合成基于Cyclen的具有不同结构和功能的产品,就需要系统的合成化学,尤其是对其仲胺的选择性保护。该设计实验以Cyclen为原料,分别采用(Boc)2O和Boc-OSu为胺基保护试剂,制备1,4,7-3 Boc-Cyclen和1,7-2 Boc-Cyclen;采用上一步合成的1,4,7-3 Boc-Cyclen为原料,Fmoc-Cl为保护试剂,制备1,4,7-3 Boc-10-Fmoc-Cyclen,再用CF3COOH脱掉Boc保护基制备Fmoc-Cyclen,以此得到单保护、对位二保护和三保护的Cyclen。结合1H NMR、13C NMR和HR-MS的鉴定结果,目标化合物结构正确。 相似文献
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17.
Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine. 相似文献
18.
Ethene/norbornene copolymerization by the catalyst system [Me2Si(3-tertBuCp)(NtertBu)]TiCl2/MAO was investigated in detail at 30℃, 60℃, and 90℃. A mass flow controller was used in this work to obtain kinetic data and investigate temperature's effects on activity, norbornene incorporation, copolymerization parameter, microstructure, glass transition temperature, and molar masses were described. High copolymerization values rE and high alternation are determined. The number of isotactic alternating sequences is much higher than that of the syndiotactic alternating sequences. 相似文献
19.
固体酸催化合成氯乙酸戊酯 总被引：1，自引：0，他引：1
固体酸是一种好的催化剂,它能够代替硫酸作为酯化催化剂．评述了对甲苯磺酸、磺酸盐、氨基磺酸、强酸性阳离子交换树脂、六水三氯化铁、五水四氯化锡、三氯化铝-硫酸铜复盐、结晶硫酸铝、一水硫酸氢钠、固体超强酸、杂多酸和分子筛等催化合成氯乙酸戊酯的合成方法．认为有机磺酸盐、氨基磺酸、强酸性阳离子交换树脂、结晶硫酸铝、一水硫酸氢钠、固体超强酸、杂多酸和分子筛等是合成氯乙酸正丁酯具有实用价值的催化剂． 相似文献
20.
以水热法合成了一个新的希夫碱大环配位聚合配合物M e6[14]N4Co[Cd（SCN）4]（M e6[14]N4=5,7,7,12,14,14,1—六甲基—1,4,8,11—四氮杂环十四—4,11—二烯）,并用红外光谱和元素分析的手段对其进行了表征. 相似文献