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1.
[Objective]The aim was to describe the extraction of polysaccharides from pitaya stems.[Method]The hot water,enzyme-assisted and microwave-assisted methods were used,with the microwave-assisted extraction being deemed optimal by general evaluation.[Result]The main factors affecting the yield of polysaccharides in the microwave-assisted extraction,by order of magnitude,were as follows:time >microwave power >temperature;additionally,optimal conditions included a 10 min extraction time,an 80℃ extraction temperature and a microwave setting of 200 W.Using these optimal conditions,the yield of PSPS(Polysaccharides from Pitaya Stems) was 1.42%.After purification,the yield of PSPS was 0.74%.[Conclusion]The PSPS was analyzed by IR,MALDI-TOF-MS and an element analysis technique.It was shown to be a polysaccharide mixture,and the molecular weight was between 3 900 and 4 300 Da.  相似文献   

2.
[目的]优化复合酶法提取南瓜多糖的工艺条件,研究南瓜多糖的抗氧化性。[方法]采用单因素试验设计研究了不同提取时间、温度、料液比、pH值对南瓜多糖提取率的影响,并通过正交试验确定了提取南瓜多糖的最佳复合酶配比和最佳提取条件。采用水杨酸法检测南瓜多糖对羟基自由基(.OH)和改进的邻苯酚自氧化法检测其对超氧阴离子自由基(O-2)的清除效果。[结果]当纤维素酶的浓度为1.0%、果胶酶为1.5%、木瓜蛋白酶为1.0%时,以及温度为40℃、pH=4.6、料液比为1∶30、提取时间为30 m in的条件下南瓜多糖的提取率最高;南瓜多糖对.OH具有较好的清除效果,对O-2有部分清除作用。[结论]该研究为南瓜多糖的研究及应用提供了基础资料。  相似文献   

3.
油莎豆淀粉提取工艺的研究   总被引:3,自引:0,他引:3  
采用石灰水浸泡工艺提取油莎豆淀粉,并对提取工艺进行优化.得到最佳提取条件为:料液比1:4,浸泡时间4 h,石灰水浓度0.5%,淀粉最大提取率为57.9%.此法工艺简单,成本低,油莎豆淀粉提取率较高,淀粉精制容易,淀粉产品质量好.
Abstract:
A technique of Cyperus esculentus starch extraction was developed using limewater as the soa-king agent.Through an orthogonal test, the extracting technology was optimized: material: liquid ratio 1 :4, extracting time 4h and limewater concentration 0.5%.Under these conditions, the extraction ratio of starch was 57.9%.This simple extracting technique proved to be cost-effective, and the starch extracted was of good quality.  相似文献   

4.
Objective To determine the optimum extraction method and condition of poly-saccharides fromTrollius chinensis (TCP).Methods With the yield of TCP as index and water as solvent,reflux extraction,ultrasonic extraction and supercritical CO_2 extraction were employed to determine the efficient extraction method of TCP.Moreover,the conditions of reflux extraction were optimized by single factor test and orthogonal test.The content of polysaccharide was measured with phenol-sulfuric acid method.Results The data displayed that the crude polysaccharide(CPS)yield of regular reflux extraction was(11.7±0.12)%,superior to ultrasonic extraction and supercritical CO_2 extraction.The optimum conditions of reflux extraction were as follows:extraction temperature of 95℃,extraction time of 3hand the liquid-solid ratio of 20∶1.Under these conditions,the polysaccharide yield was (1.45±0.03)%,which was well in close agreement with the predicted value.Conclusion Regular reflux extraction was regarded as the optimal extraction method of TCP.The optimum conditions of reflux extraction were as follows:extraction temperature of 95℃,extraction time of 3hand the liquid-solid ratio of 20∶1.  相似文献   

5.
Ultrasonic-assisted extraction (UAE) of American ginseng polysaccharides (AGP) was investigated using response surface methodology. Three-factor-three-level Box-Behnken design was employed to optimize the ultrasonic power, extraction time and ratio of water to raw material to obtain a high AGP yield. The analysis of variance and response surface plots indicated that ultrasonic power was the most important factor affecting the extraction yield. The optimal conditions were ultrasonic power 400 W, extraction time 71 min, and ratio of water to raw material 33 mL g-1. Under these conditions, the yield of AGP was 8.09%, which was agreed closely to the predicted value. Gas chromatography (GC) analysis showed that AGP was composed of arabinose, rhamnose, galactose, glucose, and galacturonic acid. Fourier transform infrared spectra revealed the general characteristic absorption peaks of AGP. In addition, AGP exhibited good immunostimulating activities by up-regulating the production of nitric oxide and cytokines. Compared with hot water extraction, UAE required shorter extraction time and gave a higher extraction yield, without changing the structure and immunostimulating activity of AGP. The results indicated that UAE could be an effective and advisable technique for the large scale production of plant polysaccharides.  相似文献   

6.
复合酶提取灵芝多糖工艺及其抗氧化能力研究   总被引:1,自引:1,他引:0  
[目的]获得复合酶提取灵芝多糖的最佳工艺,探讨灵芝多糖的体外抗氧化能力。[方法]以多糖提取率为指标,在单因素试验的基础上,采用正交试验对复合酶用量配比、酶解条件进行优化;采用清除1,1-二苯基苦基苯肼(DPPH)自由基模型评价灵芝多糖的体外抗氧化能力。[结果]复合酶提取优于单酶提取,酶用量最佳配比为纤维素酶1.5%、木瓜蛋白酶0.8%、菠萝蛋白酶3.5%(质量分数,相对于底物浓度);最佳酶解条件为pH5.5,温度50℃、酶解时间为100 min。复合酶提取的灵芝多糖具有良好的清除DPPH自由基作用,其清除能力优于水提灵芝多糖(P〈0.01),且在浓度0.8~4.8 mg/ml范围内,其对DPPH自由基的清除率随浓度增大而增大。[结论]该研究为灵芝多糖的开发提供了科学依据。  相似文献   

7.
Using 2-3 weeks kid abomasums as materials, the ultrasound intensity, extracting time, NaC1 concentration and pH value in extracting solution and ratio of abomasums to extracting solution were studied by ultrasonic method. The results showed that the main factor affecting kid rennet activity during extraction was ultrasound intensity, and then NaCl concentration, extracting time and ratio of abomasums to extracting solution in order. Kid rennet activity reached peak with ultrasound intensity 30 W cm^-2, extraction time 40 min, NaCl concentration 8%, pH value 3.0, ratio of abomasums to extracting solution 1:15.  相似文献   

8.
The extraction of leaf protein from modern-slam was studied with the thermal method, acid-base method, acidified thermal method and fermented acid one. The experiment results showed that the acidified thermal one (pH=4.0,72℃) is available to get the protein content of the product 63.23%, the ratio of extraction 36.09% and the ratio of obtaining 1.82%.  相似文献   

9.
《农业科学与技术》2013,(10):1486-1490,1494
[Objective] This study aimed to investigate the optimal technology for en- zymolysis of jeUyfish brain protein by bromefain. [Method] Effects of enzymolysis temperature, the amount of added enzyme, solid/liquid ratio, enzymolysis time and pH on the enzymolysis of total protein were investigated through single factor ex- periments, and some technical parameters were optimized by orthogonal experi- ments. [Result] The results revealed that enzymolysis temperature of 55℃, the amount of added enzyme of 4 000 U/g, solid/liquid ratio of 1:4, the amount of added enzyme time for 5 h and pH 7 were the optimal combination of parameters for the enzymolysis; the average degree of hydrolysis obtained from the verification tests was 36.9%, indicating that the optimized results of the orthogonal experiment were credible. [Conclusion] This study provides the optimized conditions reliable theo- retical foundation and technical support for the exploitation and utilization of jellyfish resources as medicines or functional food in China.  相似文献   

10.
[Objective] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [Method] The extraction and storage conditions for free radicals scavenging substances from sweet potato leaves were optimized by orthogonal test and the bioactive components in extracts were investigated by correlation analysis. [Result] Sweet potato leaves contain the bioactive substances scavenging DPPH free radical and hydroxyl free radical. Extracting solvent species is the most important factor that influencing extraction yield. The optimal extraction and storage conditions are as following: water as solvent,pH 8.0 of extracting liquid,storage at 25 ℃. There is a good positive linear relationship between the content of total phenols in sweet potato leaves and corresponding scavenging rates against both the DPPH free radical and hydroxyl free radical. For the content of total flavones in sweet potato leaves,just a correlation with scavenging rate against hydroxyl free radical shown in test. [Conclusion] The phenols in extracts could effectively scavenge both the DPPH free radical and hydroxyl free radical,whereas the flavones in extracts can only function on the hydroxyl free radical.  相似文献   

11.
依据最新NDB数据库中蛋白质-DNA复合物晶体结构数据,基于修正的DNA结构统计力学模型,利用蒙特卡洛多重积分计算DNA动力学结构的有关参数,并对计算得到的结果进行时间复杂度和精确度分析. Abstract: Based on protein-DNA complex crystal structural data in up-to-date Nucleic Acid Database,the related parameters of DNA Kinetic Structure were investigated by Monte-Carlo Multiple Integrals on the base of modified DNA structure statistical mechanical model,and time complexity and precision were analyzed on the calculated results.  相似文献   

12.
牛体外发育胚胎特定阶段差异表达基因的研究   总被引:1,自引:0,他引:1  
[目的]研究不同发育时期牛体外受精胚胎在基因表达模式上的差异.[方法]利用单个胚胎mRNA差异显示技术,对单个8细胞期胚胎与囊胚进行mRNA差异显示,获得1条特异表达条带,对其进行克隆、测序,并与GenBank进行对比.[结果]该序列与牛核糖体蛋白131基因(ribosomal protein 131,RPL3])具有99%的同源性.采用实时定量PCR技术检测8细胞期和囊胚期胚胎RPL31的mRNA表达量,结果表明,RPL31在8细胞期胚胎的相对表达量为囊胚期胚胎的3.2倍.[结论]为揭示和阐明控制牛早期胚胎发育的相关机理提供依据. Abstract: The cattle different stage embryos obtained from in vitro was studied using the technology of single preimplantation embryo mRNA different display:single 8-cell and blastocyst stage embryos were studied using technology of mRNA different display and one different fragment was found.The result suggested that this fragment displayed high homology (99%) to cattle mRNA for ribosomal protein L31.Then to detect the expression of RPL31 mRNA in 8 cell and blastocyst stage embryos by real-time quantitative PCR,the result showed the relative amount of 8 cells was 3.2 times of blastocyst's.  相似文献   

13.
[目的]构建抗黄瓜花叶病毒RNAi载体,并将载体转入烟草.[方法]采用RT-PCR方法,扩增黄瓜花叶病毒NS04加工番茄分离物的RNA2基因组的序列选取CMV RAN2基因组中的复制酶片段作为靶序列,构建pBi35SCR2真核表达载体,并对表达载体时行鉴定;通过农杆菌介导的方法将表达载体转入烟草,用PCR的方法检测载体是否转入.[结果]系统进化树分析结果表明,RNA2中编码CMV-2a的序列与中国浙江的DQ412731 分离物有较高核苷本乡酸及氨基酸同源性,分别达到98.0%和96.5%;RCR结果表明,试验成功构建了pBi35SCR2真核表达载体,并成功将表达载体转入烟草[结论]试验获得的转基因烟草可作为后期攻毒试验的材料,并为研究加工番茄抗黄瓜花叶病毒奠定了基础. Abstract: [Objective] Aimed to construct RNAi vector resistant to cucumber mosaic virus and transferred this vector into tobacco.[Method]RT-PCR method was used to amplify cucumber mosaic virus NSO4 and process RNA2 gene sequen of tomato isolates.The analysis results of phylogenetic tree demonstrated that the sequence in RNA2 encoded CMV-2a had 98.0% and 96.5% homology with nucleotide and amino acid of DQ412731 isolate of Zhejiang,China.The replicase fragment in CMV RAN2 gene was taken as target sequence to construct pBi35SCR2 eukaryotic expression vector,then the expression vector was identified.Through agrobacterium-mediated method,the expression vector was transferred into tabacco and PCR method was used to check the transfer.The PCR results demonstrated that the experiment had successfully construct eukaryotic expression vector of pBi35SCR2 and the expression vector was successfully transferred into tabacco. [Conclusion] The obtained transgenic tobacco could be used as challenge test material in following experiment and provided foundation for studying processing tomato resist cucumber mosaic virus.  相似文献   

14.
底栖鱼类对水田上覆水中磷素动态的扰动效应   总被引:2,自引:0,他引:2  
[目的]研究底栖鱼类泥鳅对水田上覆水中磷素动态的扰动效应,探讨生物扰动机制.[方法]基于模拟试验,使用离子色谱法和分光光度法,对比分析上覆水中磷素含量在有/无泥鳅活动时的差异.[结果]扰动组的TP、DTP和PP浓度在试验开始阶段与对照组无显著差异,在试验中、后期显著高于对照(P<0.05).扰动组要的PP/TP高于对照组,扰动组中TP浓度的增加主要是由于PP的增加,扰动组的DIP/DT在试验中、后期显著高于对照(P<0.05).[结论]底栖鱼类对水田上覆水中的磷素产生了扰动作用,增加了水稻生长可利用的的磷素养分. Abstract: [Objective] The research aimed to investigate the bioturbation effects of benthic fish Misgurnus anguillicaudatus on phosphorus dynamic in overlying water of paddy field,as well as to explore the bioturbation mechanism.[Method]Based on simulation experiment,the phosphorus contents in overlying water were analyzed comparatively with and without Misgurnus anguillicaudatus by the using of ion chromatography and spectrophotometry. [Result] The concentrations of total phosphorus (TP),dissolved total phosphorus(DTP)and particular phosphorus(PP) in bioturbation group had no significant differences with those in control group in initial stage of experiment,and became significantly higher than control group in middle and late stages of experiment(P<0.05).The PP/TP ratios in bioturbation group were bigger than those in control group,the increase of TP concentration in bioturbation group was mainly due to the increase of PP.The ratios of dissolved inorganic phosphorus(DIP) to DTP (DIP/DTP) were significantly bigger than those in control group in middle and late stages of experiment (P<0.05). [Conclusion] The benthic fish had bioturbation effects on phosphorus in overlying water of paddy field,which increased the available phosphorus for rice growth.  相似文献   

15.
提出基因之间传递共表达可作为一个重要因素来连接同一代谢通路中的基因,而同一代谢通路中的功能相似的基因都是高表达相关的.因此可通过求代谢通路下的最短路径,南同在一条最短路径上的与未知基因高表达相关的已知基因来预测末知基因的功能.通过用最短路径算法分析拟南芥代谢通路下的共表达数据对未知基因的功能进行预测,证明了此方法可以预测出拟南芥代谢通路下未知基因的功能,并验证了通过在代谢通路下求最短路径来预测基因功能的方法具有一定的可行性和有效性. Abstract: The present paper predicted the function of unknow genes by analyzing the co-expression data of Arabidopsis thaliana from biological pathway based on the shortest-path algorithm.This paper proposed that transitive co-expression among genes can be used as an important attribute to link genes of the same biological pathway.The genes from the same biological pathway with similar functions are strongly correlated in expression.Moreover,the function of unknown genes can be predicted by the known genes where they are strongly correlated in expression lying on the same shortest-path from the biological pathway.Analyzing the Arabidopsis thaliana from the biological pathway,this study showed that this method can reliably reveal function of the unknown Arabidopsis thaliana genes and the approach of predicting gene function by transitiving coexpression in shortest-path is feasible and effective.  相似文献   

16.
一株产紫杉醇的曼地亚红豆杉内生真菌的分离及鉴定   总被引:1,自引:0,他引:1  
[目的]分离并鉴定1株产紫杉醇的曼地亚红豆杉内的内生真菌.[方法]从曼地亚红豆杉树皮内表皮中分离得到32株内生真菌,并通过高效液相色谱法检测其发酵产物.[结果]筛选获得1株可以产紫杉醇的内生真菌M57,其紫杉醇产量为45~50μg/L,并通过对M57菌落的形态学观察以及18S rDNA序列分析初步将其鉴定为根霉属(Rhizopus)真菌.[结论]该菌株的发现为微生物发酵法生产紫杉醇提供了具有潜在应用价值新的菌种. Abstract: [Objective] The aim was to isolate and identify a taxol-producing endophytic fungus from Taxus media.[Method]32 strains of endophytic fungi were identified form the inner bark of T.media,and their fermentation products were detected by high performance liquid chromatography (HPLC). [Result] Through the screening,a strain of taxol-producing endophytic fungi M57 was obtained,which could produce 45-50 μg/L of taxol,and M57 was defined as Rhizopus sp.through morphological observation and 18S rDNA sequence analysis. [Conclusion] The finding of Rhizopus sp.M57 provided a promising strain for producing taxol with taxol-producing fungi fermentation process.  相似文献   

17.
[目的]研究催产素(OT)在广西本当水牛下丘脑、垂体及卵巢的分布上的联系,进而了解OT在下丘脑、垂体及卵巢3者之间分泌释放途径.[方法]采用免疫组织化学SuperPicTureTM二步法检测5头广西本地水牛的下丘脑、垂体和卵巢中催产素(OT)的分布情况.[结果]下丘脑中分泌OT的神经元主要分布在弓状核、视上核及室旁核,在腹内侧核、腹外侧核、交叉上核、背内侧核、乳头体、下丘脑前核等核团也有一定数量的阳性神经元;在腺垂体发现OT免疫反应阳性产物,自垂体柄和正中隆起的一侧可见到平行排列的OT阳性神经纤维断续地延伸至神经部;卵巢中只在生殖上皮、卵泡颗粒细胞和黄体细胞发现有大量OT免疫阳性产物.[结论]首次发现OT存在于广西本地水牛下丘脑-垂体-卵巢轴的各个环节,并且下丘脑中各主要核团均有OT免疫阳性神经元的分布,尤其以弓状核、视上核、室旁核分布最多,为进一步研究OT的合成和作用机制提供形态学依据,并对广西本地水牛的繁殖育种及泌乳起到一定的参考指导作用. Abstract: To study the association of oxytocin (OT)'s distribution in hypothalamatic,pituitary and ovary,and understand how the OT secrete releasing in hypothalamus,pituitary and ovaries,the paraffin section immunohistochemistry SuparPicTureTM two step method was used to detect the distribution of OT in hypothalamatic-pituitary-ovary axis of five femal Guangxi local buffalo.The test results could provide morphology according to study the OT's synthesis and mechanism of action ,and could play reference and directions part in breeding Guangxi local buffalo.The test results display:oxytocin immuno reactive (OT-IR) neuronsw eremainly distributed arcuate nucleus,supraoptic nucleus and paraventricular nucleus,and OT-IR neurons was also found in ventrornedial nucleus,ventrolateralis nucleus,suprachiasrnaticus nucleus,dorsomediai nucleus,mamillary body,anterior hypothalamic nucleus and so on.The OT immunoactive production was found in pituitary and few OT-IR nerve fibers extended to post pituitary from hypophyseal stalk and medium eminence.In ovaries,OT immunoactive productions were only distributed in germinal epithelium cells,granulosa cells and lutein ceils.The OT was first discovered in singulorum link of hypothalamatic-pituitary-ovary axis of Guangxi local buffalo.The OT immunoactive neurons were first discovered in every main nucleus of Guangxi local buffalo hypothalamus,especially distributed in arcuate nucleus,supraoptic nucleus and paraventricular nucleus.  相似文献   

18.
干旱胁迫对苗期甘蔗叶片水分和叶绿素荧光参数的影响   总被引:6,自引:0,他引:6  
[目的]研究干旱胁迫对甘蔗叶片水分和叶绿素荧光参数的影响,为甘蔗生产及评价研究提供依据.[方法]选取7个抗旱性不同的甘蔗品种,在苗期进行干旱胁迫,并测定胁迫条件下甘蔗叶片水分含量和叶绿素荧光参数的变化.[结果]甘蔗叶片水势和相对含水量与土壤相对含水量存在一定的内在联系,耐旱强的品种对土壤水分的利用率较高;相关分析和因子分析表明茁期干旱存活率、Fc/Fm、叶片水势和相对含水量可被用作抗旱性评价指标.[结论]水势表现为一个相对独立的影响因子,对甘蔗抗早性有支配作用,并验证了Fv/Fm作为甘蔗抗旱评价指标的可靠性. Abstract: [Objective] The aim was to explore the effects of water stress on leaf water and chlorophyll fluorescence parameters of sugarcane seedling,as well as to provide basis for the study on sugarcane production and evaluation.[Method]Seven different sugarcane varieties were studied at the seedling stage under drought stress,and the changes of leaf water and chlorophyll fluorescence parameters under stress conditions were detected. [Result] leaf water potential,leaf relative water content and soil relative water content showed a certain amount of internal relationship,the sugarcane varieties that had more tolerant to drought had higher utilization rate of soil water;the correlation analysis and factor analysis suggested that the survival rate at seedling stage under drought stress,Fv/Fm,leaf water potential and relative water content could be used as drought resistance evaluation indicators. [Conclusion] As a relatively independent influencing factor,water potential had dominating effect on drought resistance,and the reliability of Fv/Fm as drought resistance evaluation indicator had been verified.  相似文献   

19.
中草药提取液对黄瓜苗期杀根结线虫的活性研究   总被引:1,自引:0,他引:1  
[目的]研究中草药提取液对黄瓜苗期杀根结线虫的活性.[方法]利用植物水培技术,结合生长条件易控制、根系生长过程易连续观察的特点,应用5种具有较强室内触杀根结线虫活性的植物提取液及其与阿维菌素的复配液,对黄瓜苗期水培根系杀线活性进行系统研究.[结果]胡黄连和石榴皮提取液可以在不影响水培黄瓜苗期植株生长的前提下表现出对根结线虫良好的活体植株根系寄生防治和杀灭活性,且达到了与阿维菌素相近的作用水平;而狗脊、木香和蛇床子提取液对黄瓜的生长表现出不同程度的抑制作用,其对根结线虫的防治效用和杀灭活性也较弱.[结论]触杀效果和杀线活性成分能否被植物吸收利用共同制约着具有杀线活性中草药提取液的开发应用. Abstract: Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the rootknot nematode parasitized on the cucumber seeding stage.It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin;while the extracts from Cibotium barornetz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.  相似文献   

20.
[目的]揭示土地利用方式对球囊霉素相关土壤蛋白(GRSP)的影响.[方法]测定了海南岛5种主要土地利用方式下GRSP、土壤有机碳(Soil oaganic carbon)与土壤质地(Soil texture)在0~10、10~20、20~50cm3个土壤层次中的分布情况.[结果]相对于保持较好的次生林,4种不同耕作土壤的GRSP与有机碳含量均有所下降.GRSP在海南岛5种主要土地利用方式土壤中的含量为0.53~4.80 mg/g,占有机碳的百分比为7.9%~23.4%,是碳库的重要组成部分.GRSP占有机碳的比例在不同土地利用方式下差异显著,在土层之间差异不显著,GRSP和有机碳含量在土壤剖面上垂直分布较明显.GRSP与有机碳、砂粒含量呈显著正相关,与粉粒和粘粒呈显著负相关.[结论]砂粒含量在很大程度上决定了CRSP的含量,壤土相对粘土更有利于GRSP的累积. Abstract: [Objective] The aim was to reveal the effects of different land use types on soil composition.[Method]GPRS,Soil organic carbon content and soil texture in 3 depths(0-10,10-20,20-50 cm)of 5 main kind of selected land use type were examined in Hainan. [Result] The results showed that GRSP and SOC content of four artificial land use types decreased compared with the natural sacondary foreSt land,the GRSP content of all samples ranged from 0.53-4.80 mg/g,accounting for 7.9%-23.4% of the SOC,which means that GRSP was one important component of SOC pool in soil.The ratio of GRSP to SOC was signiflcantly different among land use types but the depths.GRSP and SOC exhibited obvious vertical distribution pattern.GRSP was significantly positively related to SOC and sand content but negatively related to silt and clay content. [Conclusion] The sand content determined the GRSP content significantly and Joarn was better matrix for GRSP accumulation than clay.  相似文献   

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