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1.
A new kinetic-spectrophotometric method is proposed for the determination of copper ( Ⅱ ). The method is based on the catalytic effect of copper ( Ⅱ ) on the oxidation of weak acid brilliant blue dye (RAWL) by hydrogen peroxide. The copper ( Ⅱ ) can be determined spectrophotometrically by measuring the decrease of absorbance of RAWL at λ = 626 nm using the fix-time method. The optimum reaction conditions are as follows: pH 7.20, buffer solution NaOH-KH2PO4, RAWL (200 mgL-1) 5.00 mL, H2O2 (30％) 0.50 mL, reaction temperature 80 ℃ and reaction time 20 min. The linear range of this method is between 0 μg L-1 and 12 μg L-1 and the limit of detection is 0.011 μg L-1, the relative standard deviation (RSD) in five replicate determinations for 2 and 8 μg L-1 copper ( Ⅱ ) are 3.2％ and 2.3％, respectively. Twenty ions do not interfere in the determination of copper ( Ⅱ ). The method has been applied satisfactorily to the determination of copper ( Ⅱ ) in freshwater samples (tap water and Yellow River water from Lijin, Shandong, China) and seawater samples (from the South China Sea), the recovery rates are 98.0％, 102.5％ and 96.0％, respectively. 相似文献
2.
Apostichopus japonicus(Holothuroidea,Echinodermata) is an ecological and economic species in East Asia.Conventional biometric monitoring method includes diving for samples and weighing above water,with highly variable in weight measurement due to variation in the quantity of water in the respiratory tree and intestinal content of this species.Recently,video survey method has been applied widely in biometric detection on underwater benthos.However,because of the high flexibility of A.japonicus body,video survey method of monitoring is less used in sea cucumber.In this study,we designed a model to evaluate the wet weight of A.japonicus,using machine vision technology combined with a support vector machine(SVM) that can be used infield surveys on the A.japonicus population.Continuous dorsal images of free-moving A.japonicus individuals in seawater were captured,which also allows for the development of images of the core body edge as well as thorn segmentation.Parameters that include body length,body breadth,perimeter and area,were extracted from the core body edge images and used in SVM regression,to predict the weight of A.japonicus and for comparison with a power model.Results indicate that the use of SVM for predicting the weight of 33 A.japonicus individuals is accurate(R~2=0.99) and compatible with the power model(R~2=0.96).The image-based analysis and size-weight regression models in this study may be useful in body weight evaluation of A.japonicus in lab and field study. 相似文献
3.
鱼汁、海泥抽出液和人尿对小环藻生长的影响 总被引：1，自引：0，他引：1
在室内条件下，通过单因子实验和正交实验的方法，研究了鱼汁、海泥抽出液和人尿对小环藻（Cyclotella sp．）种群生长的影响。结果表明，350mL的培养体积下，当鱼汁添加量为20mL时，小环藻生长效果最好，相对生长率（K）较对照组升高了33．3％，平均倍增时间（G）降低了34．9％，但随着浓度升高，藻细胞开始出现死亡。海泥抽出液添加量为20mL时，K值最大，较对照组增加35．6％，G值下降了25．15％。人尿添加量为10mL时，K值最大，较对照组增加17．9％，G值下降了15．77％。统计分析表明，鱼汁、海泥抽出液和人尿对小环藻实验种群的生长均有极显著影响。海泥抽出液对小环藻影响大，其次是鱼汁和人尿。正交实验表明，在鱼汁、海泥抽出液和人尿的添加量分别为2．5、15．0和1．0mL的组合实验组，小环藻的生长效果最好。 相似文献
4.
在室内条件下,通过单因子实验和正交实验的方法,研究了鱼汁、海泥抽出液和人尿对小环藻(Cyclotella sp.)种群生长的影响。结果表明,350 mL的培养体积下,当鱼汁添加量为2~3 mL时,小环藻生长效果最好,相对生长率(K)较对照组升高了33.3%,平均倍增时间(G)降低了34.9%,但随着浓度升高,藻细胞开始出现死亡。海泥抽出液添加量为20 mL时,K值最大,较对照组增加35.6%,G值下降了25.15%。人尿添加量为10 mL时,K值最大,较对照组增加17.9%,G值下降了15.77%。统计分析表明,鱼汁、海泥抽出液和人尿对小环藻实验种群的生长均有极显著影响。海泥抽出液对小环藻影响大,其次是鱼汁和人尿。正交实验表明,在鱼汁、海泥抽出液和人尿的添加量分别为2.5、15.0和1.0 mL的组合实验组,小环藻的生长效果最好。 相似文献
5.
The use of a microwave-assisted extraction(MAE) method for the extraction of phlorotannins from Saccharina japonica Aresch(S.japonica) has been evaluated with particular emphasis on the influential parameters,including the ethanol concentration,solid/liquid ratio,extraction time,extraction temperature,and microwave power.The MAE procedure was optimized using single-factor design and orthogonal array design(OAD).The content of total phlorotannins in S.japonica was determined using a Folin-Ciocalteu(FC) assay.A maximum total phlorotannin content of 0.644 mg of phloroglucinol equivalent per gram of dry weight plant(mg PGE/g DW) was obtained using the optimized model,which included an ethanol concentration of 55%,solid/liquid ratio of 1:8,extraction time of 25 min,irradiation power of 400 W,and temperature of 60°C.Under similar conditions,the application of a conventional extraction method led to a lower phlorotannin yield of 0.585 mg PGE/g WD.These results demonstrated that the MAE approach provided better results for the extraction of phlorotannins from S.japonica and was a promising technique for the extraction of phenolic compounds from S.japonica and other materials.In addition,screening tests for the inhibitory activity showed that the phlorotannin-containing extracts significantly inhibited the growth of human hepatocellular carcinoma cells(HepG2) by inducing their apoptosis.The morphological changes that occurred during cell apoptosis were characterized using Hoechst33258 staining. 相似文献
6.
Euphausia pacific is an important source of natural astaxanthin.Studies were carried out to assess the extractability of astaxanthin from E.pacific using subcritical 1,1,1,2-tetrafluoroethane(R134a).To examine the effects of multiple process variables on the extraction yield,astaxanthin was extracted under various conditions of pressure(30-150 bar),temperature(303-343 K),time(10-50 min),flow rate(2-10 g min-1),moisture content(5.5%-63.61%),and particle size(0.25-0.109 mm).The results showed that the extraction yield increased with temperature,pressure,time and flow rate,but decreased with moisture content and particle size.A maximum yield of 87.74% was obtained under conditions of 100 bar,333 K,and 30 min with a flow rate of 6 g min-1 and a moisture content of 5.5%.The substantial astaxanthin yield obtained under low-pressure conditions demonstrates that subcritical R134a is a good alternative to CO 2 for extraction of astaxanthin from E.pacific. 相似文献
7.
In nature, Apostichopus japonicus exhibits a behavioral characteristic of emerging at night and sheltering during the day. Hence, it was commonly believed that longer and darker light conditions are better for a population of A. japonicus. In aquaculture situations therefore, animals have commonly been cultured without lighting, especially during juvenile-hatching culture. However, how the length of darkness each day affects A. japonicus and what the mechanism is of behavioral response of A. japonicus to different photoperiods remain unclear, and are specifically addressed in this study. We applied nine photoperiod treatments (light:dark (LD) cycles at 0:24, 3:21, 6:18, 9:15, 12:12, 15:9, 18:6, 21:3, and 24:0 under 500 lx) to 60 individuals (29.73 ± 0.23 g) per treatment (with 3 replicates). The environmental conditions were set as: water temperature = 16.9 ± 0.3°C, dissolved oxygen>6.0 mg/L, ammonia<0.3 mg/L, pH = 7.8-8.2, and salinity = 30-32. Under experimental conditions of continuous darkness as well as continuous light, cyclic nocturnal activity patterns of A. japonicus (viz. the animals emerged and fed at night and sheltered during the day) were observed. However, they spent more and less time, respectively, moving and feeding under continuous darkness and continuous light, than those under a natural light cycle. Under photoperiods with 6-12 h of light, the animals showed one sheltering behavior transition and two emerging behavior transitions. These behavior transitions appeared to be governed by some internal physiological factors and induced by daily light variation. The behavior of the animals was significantly affected by different photoperiods, and the distribution rate (DR) of the animals emerging at "daytime" increased with lengthening "light time" (except for the LD 3:21 cycle). We also found that there was no significant difference in mean DR per day under LD cycles of 6:18, 9:15, 15:9, and 12:12. Mean DRs per day were significantly lower for these photoperiods, than for those under LD cycles of 0:24 and 3:21, and significantly higher than for those under LD cycles of 18:6, 21:3 and 24:0. These results imply that 6-15 h light per day were the similar photoperiods to natural sunlight. From the viewpoint of activity and feeding behaviors, these might be the optimal photoperiods for rearing A. japonicus. 相似文献
8.
The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-? converting enzyme (ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-I-inhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC50 of 5.75 μmol L?1. The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study. 相似文献
9.
10.
从金银花中提取绿原酸的工艺研究 总被引：7，自引：0，他引：7
用不同浓度的乙醇从金银花中提取绿原酸,以正交实验进行优化工艺研究,采用紫外分光光度法测定提取液中绿原酸的含量,探讨了乙醇浓度、乙醇倍量、回流时间、pH值、浸泡温度对绿原酸含量的影响。实验结果表明,最佳的工艺条件是:10倍量50%乙醇为浸提剂,浸泡温度为70℃,pH=7,回流时间为1h,提取次数为2次。 相似文献
11.
《中国海洋湖沼学报》2017,(1)
The kuruma prawn, Marsupenaeus japonicus, is one of the most cultivated and consumed species of shrimp. However, very few molecular genetic/genomic resources are publically available for it. Thus, the characterization and distribution of simple sequence repeats(SSRs) remains ambiguous and the use of SSR markers in genomic studies and marker-assisted selection is limited. The goal of this study is to characterize and develop genome-wide SSR markers in M. japonicus by genome survey sequencing for application in comparative genomics and breeding. A total of 326 945 perfect SSRs were identified, among which dinucleotide repeats were the most frequent class(44.08%), followed by mononucleotides(29.67%), trinucleotides(18.96%), tetranucleotides(5.66%), hexanucleotides(1.07%), and pentanucleotides(0.56%). In total, 151 541 SSR loci primers were successfully designed. A subset of 30 SSR primer pairs were synthesized and tested in 42 individuals from a wild population, of which 27 loci(90.0%) were successfully amplified with specific products and 24(80.0%) were polymorphic. For the amplified polymorphic loci, the alleles ranged from 5 to 17(with an average of 9.63), and the average PIC value was 0.796. A total of 58 256 SSR-containing sequences had significant Gene Ontology annotation; these are good functional molecular marker candidates for association studies and comparative genomic analysis. The newly identified SSRs significantly contribute to the M. japonicus genomic resources and will facilitate a number of genetic and genomic studies, including high density linkage mapping, genome-wide association analysis, marker-aided selection, comparative genomics analysis, population genetics, and evolution. 相似文献
12.
To study the changes of volatile compounds and antioxidant activity of fast fermented shrimp head paste during the fermentation processing,Penaeus vannamei boone head was used as the raw material,and compound starter was added for fermen-tation.During the 14 days of fermentation,the changes of free amino acids,volatile flavor compounds and main components were determined by SPME-GC-MS and electronic nose.The oxidation-resistance changes of water extract at different fermentation stages were evaluated.The results showed that the total free amino acids increased from original 2320 to 5640 mg(100 mL)?1.SPME-GC-MS analysis found that aldehydes,pyrazine compounds increased from 10.80%,1.94%to 24.35%,13.63%respectively during the fermentation process.The HO·scavenging ability of shrimp head paste increased from 52%to 86%.Our results showed that the shrimp paste produced from shrimp head fermentation could obtain good flavor and possess certain antioxidant activity of aquatic fermented condiment. 相似文献
13.
《中国海洋湖沼学报》2021,(4)
Skin ulceration syndrome(SUS) is the main diseases affected the development of sea cucumber(Apostichopus japonicus) culture industries.To better observe the changes in the sea cucumber A.japonicus with SUS and understand the pathogenesis of the disease,activities of superoxide dismutase(SOD),catalase(CAT),and level of malondialdehyde(MDA) in coelomic fluid were detected using the Assay Kit and metabolite s in the body wall were assessed using ultra-performance liquid chromatography and quadrupoletime of flight mass spectrometry.The re sults indicated that level of MDA was increased during SUS compared with healthy individuals(P0.01),but activities of SOD and CAT were reduced(P0.05).In metabolomics analysis,metabolites,such as adenosine,choline,betaine aldehyde,palmitic acid,and taurine,were found to be upregulated and 2-oxoadipic acid,anthranilic acid(vitamin L1),thioetheramide-PC,cholesterol-3-sulfate,and pentadecanoic acid were downregulated(VIP1 and P0.1).Pathway enrichment analysis indicated most enrichment of KEGG pathways were mainly related to energy metabolism,immunity,and osmoregulation such as ABC transporters,glycine,serine and threonine metabolism,tryptophan metabolism and neuroactive ligand-receptor interaction.Our study reflected the difference in enzyme activity and metabolites between A.japonicus with SUS and those without,which will provide reference data for investigating SUS. 相似文献
14.
针对现有的数字高程模型(DEMs)在自动提取虚拟河网过程中易受洼地、平原地区影响,产生不连续的或平行的错误河网的问题,本文基于Arc Hydro Tools,阐述了地表校正(Agree算法)和河道烧录(Stream burning)方法提取虚拟河网的关键步骤和基本思路,并以环渤海地区为例,分析了有(无)河网辅助信息下,河网提取结果的准确度。研究结果表明,增加辅助信息更有助于提高虚拟河网的精度和准确性,且河道烧录方法在虚拟河网的提取上比Agree算法更有优势。由于环渤海研究区平原面积广大,对提取结果有较大的影响,提取结果的精确度不高。针对这一问题,本文综合河道烧录和地表校正(Agree 算法)的特点,提出一种河网提取的改进思路,并选取滦河流域作为验证区。通过对比,改进后的河网提取结果与中国实际河网分布较为吻合,说明该改进思路是较为合理、可信的。 相似文献
15.
16.
《中国海洋大学学报(英文版)》2016,(4)
The present study was conducted to determine the change of digestive physiology in sea cucumber Apostichopus japonicus(Selenka) induced by corn kernels meal and soybean meal in diets. Four experimental diets were tested, in which Sargassum thunbergii was proportionally replaced by the mixture of corn kernels meal and soybean meal. The growth performance, body composition and intestinal digestive enzyme activities in A. japonicus fed these 4 diets were examined. Results showed that the sea cucumber exhibited the maximum growth rate when 20% of S. thunbergii in the diet was replaced by corn kernels meal and soybean meal, while 40% of S. thunbergii in the diet can be replaced by the mixture of corn kernels meal and soybean meal without adversely affecting growth performance of A. japonicus. The activities of intestinal trypsin and amylase in A. japonicus can be significantly altered by corn kernels meal and soybean meal in diets. Trypsin activity in the intestine of A. japonicus significantly increased in the treatment groups compared to the control, suggesting that the supplement of corn kernels meal and soybean meal in the diets might increase the intestinal trypsin activity of A. japonicus. However, amylase activity in the intestine of A. japonicus remarkably decreased with the increasing replacement level of S. thunbergii by the mixture of corn kernels meal and soybean meal, suggesting that supplement of corn kernels meal and soybean meal in the diets might decrease the intestinal amylase activity of A. japonicus. 相似文献
17.
Sea cucumber A postichopus japonicus stock enhancement by releasing hatchery-produced seeds is a management tool used to recover its population under natural environmental conditions. To assess the suitability of releasing sites, we examined the microbiota of the gut contents of A. japonicus from two populations(one in sandy-muddy seagrass beds and one in rocky intertidal reefs) and the microbiota in their surrounding sediments. The activities of digestive and immune-related enzymes in the A. japonicus were also examined. The results indicated that higher bacterial richness and Shannon diversity index were observed in all the seagrass-bed samples. There were significant differences in intestinal and sediment microorganisms between the two habitats, with a 2.87 times higher abundance of Firmicutes in the seagrass bed sediments than that in the reefs. Meanwhile, Bacteroidetes and Actinobacteria were significantly higher abundant in the gut content of A. japonicus from seagrass bed than those from the reefs. In addition, the seagrass-bed samples exhibited a relatively higher abundance of potential probiotics. Principal coordinates analysis and heatmap showed the bacterial communities were classifi ed into two groups corresponding to the two habitat types. Moreover, compared to A. japonicus obtained from rocky intertidal habitat, those obtained from the seagrass bed showed higher lysozyme, superoxide dismutase and protease activities. Our results suggest that bacterial communities present in seagrass beds might enhance the digestive function and immunity of A. japonicus. Therefore, compared with the rocky intertidal reef, seagrass bed seems to be more beneficial for the survival of A. japonicus. 相似文献
18.
以月腹刺鲀(Gastrophysus lunaris)卵巢为原料,利用超声波辅助提取河豚毒素(Tetrodotoxin,TTX)。通过单因素实验及二次回归旋转组合设计实验研究液料比、超声温度、超声时间等因素对提取率的影响,确定超声波辅助提取河豚毒素的最佳工艺条件。结果表明:在实验范围内影响河豚毒素得率的各因素大小依次为液料体积质量比、超声温度、超声时间;超声波辅助提取河豚毒素的最佳工艺条件为液料体积(mL)质量(g)比3.03∶1,超声温度39℃,超声时间22 min,该工艺条件下提取河豚毒素得率为63.57μg/g。 相似文献
19.
【目的】研究威氏海链藻在不同盐度条件下的生长和生化组分变化。【方法】设置盐度梯度为5、15、25、35、45,采用血细胞计数板计数法、热乙醇提取法、尼罗红染色法、苯酚硫酸法和考马斯亮蓝法,分别测定威氏海链藻在不同盐度下的生物量、叶绿素a、类胡萝卜素、中性脂质、总糖和蛋白质含量。【结果】盐度对威氏海链藻细胞密度影响显著(P<0.05),当盐度25和盐度35时,培养8 d细胞密度最高,均为2.0×106 mL-1;盐度对威氏海链藻叶绿素a和类胡萝卜素含量有显著影响(P<0.05),当盐度15时,细胞叶绿素a和类胡萝卜素含量均最高,分别为3.4814μg/mL(4 d)、2.3549μg/mL(8 d)。盐度对威氏海链藻可溶性总糖含量有显著影响(P<0.05),当盐度15时,8 d时可溶性总糖积累含量最高,为123μg/mL。当盐度35时,6 d时可溶性蛋白积累含量最高,为142.9μg/mL,且显著高于其他实验组(P<0.05)。盐度45时,8 d时中性脂含量最高,显著高于其他实验组(P<0.05)。【结论】盐度为15~35时,威氏海链藻生长速度较快,生化组成较为稳定,盐度15时最有利于藻细胞叶绿素a和类胡萝卜素、总糖的合成;盐度25和盐度35时,藻细胞平均增长速度较快,盐度35时最有利于藻细胞可溶性蛋白积累。 相似文献
20.
DNA barcoding is a new method for biological taxonomy, offering the ability to identify species from fragments in any life-history stage. Pleuronichthys cornutus and P. japonicus are two morphologically similar species. Pleuronichthys japonicus has never been found previously in China. However, in this study, we identified both species using DNA barcoding (cytochrome c oxidase subunit I (COI)), the mtDNA control region and cytochrome b. The results reveal that: 1) intraspecific variation in the DNA barcode ... 相似文献