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71.
提要 鱿鱼(Ommastrephes bartrami)皮胶原蛋白提取液为红棕色,不利于在食品中广泛地应用。为了进一步利用鱿鱼皮胶原蛋白,本文采用活性炭吸附法脱除鱿鱼皮胶原蛋白提取液中色素,优化脱色条件。在确定该色素特征吸收波长为420 nm条件下,分别研究了活性炭添加量、脱色时间、溶液pH值和吸附温度对鱿鱼皮胶原蛋白液色素脱除效果影响。在单因素实验基础上,选择吸附时间30 min,进行活性炭添加量、溶液pH值、吸附温度三因素三水平Box-Behnken中心组合响应面分析试验。结果表明:活性炭吸附鱿鱼皮胶原蛋白液色素最佳条件为活性炭添加量4.2%,溶液pH值2.27,脱色温度35 ℃,该条件下鱿鱼皮胶原蛋白液的脱色率为45.6%,蛋白质和氨基酸损耗率分别为19.65%和22.93%。脱色后鱿鱼皮胶原蛋白的甘氨酸含量最高(136.02 mg/g,相对含量23.05%),谷氨酸、精氨酸和脯氨酸含量也较高,而半胱氨酸和蛋氨酸总量不到1%,符合水产蛋白氨基酸和I型胶原蛋白氨基酸特点。 相似文献
72.
High inorganic phosphate concentration in coral mucus and its utilization by heterotrophic bacteria in a Malaysian coral reef
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Ryota Nakajima Yasuaki Tanaka Teruaki Yoshida Tamami Fujisawa Asami Nakayama Yumi Fuchinoue Bin Haji Ross Othman Tatsuki Toda 《Marine Ecology》2015,36(3):835-841
Inorganic nutrient contents of mucus released by Acropora corals and its utilization by heterotrophic bacteria at several different hour intervals in the coral mucus were investigated at a coral reef in Malaysia. The dissolved inorganic phosphate (DIP) concentration was 135‐fold higher than in the ambient seawater, probably due to inorganic P release from the coral gut cavity. We experimentally confirmed that heterotrophic bacteria rapidly (within 8 h) consumed ca. 80% of the initial concentration of DIP derived from coral mucus. High DIP concentration in coral mucus may enhance heterotrophic bacterial production and associated carbon flow in the microbial loop of reef ecosystems. 相似文献
73.
西安某建筑工程结构复杂,平面不规整,荷载要求差异大,为自重Ⅲ级湿陷性黄土地基。根据岩土工程资料和上部荷载要求,分析本地常用的地基处理方案,并进行经济性、安全性和可行性比较,提出要根据不同的地基土参数和上部荷载要求,安全、经济、灵活地选择地基处理方案。考虑到统一工艺和施工的方便性,最终采用灰土挤密桩复合地基和桩基础方案。同时,对工程实施过程中具体的参数选择、注意事项也进行了阐述,为同类地基处理提供了参考。 相似文献
74.
This article derives the closed‐form solutions for estimating the vertical surface displacements of cross‐anisotropic media due to various loading types of batter piles. The loading types include an embedded point load for an end‐bearing pile, uniform skin friction, and linear variation of skin friction for a friction pile. The planes of cross‐anisotropy are assumed to be parallel to the horizontal ground surface. The proposed solutions are never mentioned in literature and can be developed from Wang and Liao's solutions for a horizontal and vertical point load embedded in the cross‐anisotropic half‐space. The present solutions are identical with Wang's solutions when batter angle equals to 0°. In addition, the solutions indicate that the surface displacements in cross‐anisotropic media are influenced by the type and degree of material anisotropy, angle of inclination, and loading types. An illustrative example is given at the end of this article to investigate the effect of the type and degree of soil anisotropy (E/E′, G′/E′, and ν/ν′), pile inclination (α), and different loading types (a point load, a uniform skin friction, and a linear variation of skin friction) on vertical surface displacements. Results show that the displacements accounted for pile batter are quite different from those estimated from plumb piles, both driven in cross‐anisotropic media. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
75.
76.
ZHU Jie ZHANG Xiumei and GAO Tianxiang Fisheries College Ocean University of China Qingdao P.R.China 《中国海洋大学学报(英文版)》2005,4(2)
Histological development of Japanese flounder Paralichthys olivaceus larval skin and ultrastructural difference of skin between reared normal and malpigmented Japanese flounder were studied with light microscopy (LM) and transmission electron microscopy (TEM). The results show that the skin develops slowly before the metamorphosis, while at the onset of metamorphosis, the skin develops quickly and becomes complete in structure till about 50d after being hatched. Ultrastructural observation on the normal and malpigmented skins shows that the iridophore and melanophore are adjacent to each other. Profile and structure of the two kinds of pigment cells are more complete in the skin of normal ocular side than in the skin of pigmented blind side. The ultrastructure of typical chloride cell was observed in the skin of Japanese flounder larvae for the first time. 相似文献
77.
几种鱼皮胶原蛋白的理化特性及其影响因素 总被引:13,自引:0,他引:13
利用水产加工废弃物研究了鳙鱼、鲈鱼、鲫鱼鱼皮胶原蛋白的氨基酸组成、粘度、凝胶强度、热变性温度(Td)等理化特性及其影响因素。结果表明,在0.1mol/L的乙酸溶液中鱼皮胶原蛋白溶液的粘度随着胶原蛋白浓度的增大而增大,随着温度的升高而下降。热水法提取鳙鱼、鲈鱼、鲫鱼鱼皮胶原蛋白的热变性温度分别为30℃,25℃,27℃。鱼皮胶原蛋白的凝胶强度则随着粘度、温度、pH值、外加介质等的变化而变化。 相似文献
78.
将抗高致病性副溶血弧菌(Vibrioparahaemolyticus)特异性卵黄抗体(AHPND-VpIgY)应用于育苗生产,通过测定氨氮、亚硝酸盐、细菌总数、弧菌总数、相对保护率和育苗成活率,评价了AHPND-VpIgY在育苗期对凡纳滨对虾(Litopenaeusvannamei)幼体的保护效果。结果表明,0.1g/m3和0.2g/m3AHPND-VpIgY组的相对保护率为35.7%和57.2%,两者均显著高于非特异性卵黄抗体组(P0.05);两组的育苗成活率为50.8%和57.2%,比对照组分别提高19.1%和25.6%。各实验组氨氮、亚硝酸盐、细菌总数及弧菌总数与对照组无显著差异,对水质无影响。综上,特异性的AHPND-VpIgY能在不改变水质的前提下,有效提高凡纳滨对虾幼体的存活率、相对保护率和育苗成活率,从而提高凡纳滨对虾苗种产量和质量。 相似文献
79.
Omri Gadol Gideon Tibor Uri ten Brink John K. Hall Gavrielle Groves-Gidney Gideon Bar-Am Christian Hübscher Yizhaq Makovsky 《Basin Research》2020,32(5):1156-1183
Understanding continental-slope morphological evolution is essential for predicting basin deposition. However, separating the imprints and chronology of different seafloor shaping processes is difficult. This study explores the utility of bathymetric spectral decomposition for separating and characterizing the variety of interleaved seafloor imprints of mass wasting, and clarifying their role in the morphological evolution of the southeastern Mediterranean Sea passive-margin slope. Bathymetric spectral decomposition, integrated with interpretation of seismic profiles, highlights the long-term shape of the slope and separates the observed mass transport elements into several genetic groups: (1) a series of ~25 km wide, now-buried slide scars and lobes; (2) slope-parallel bathymetric scarps representing shallow faults; (3) slope-perpendicular, open slope slide scars; (4) bathymetric roughness representing debris lobes; (5) slope-confined gullies. Our results provide a multi-scale view of the interplay between sediment transport, mass transport and shallow faulting in the evolution of the slope morphology. The base of the slope and focused disturbances are controlled by ~1 km deep salt retreat, and mimic the Messinian base of slope. The top of the open-slope is delimited by faults, accommodating internal collapse of the margin. The now-buried slides were slope-confined and presumably cohesive, and mostly nucleated along the upper-slope faults. Sediment accumulations, infilling the now-buried scars, generated more recent open-slope slides. These latter slides transported ~10 km3 of sediments, depositing a significant fraction (~3 m in average) of the sediments along the base of the studied slope during the past < 50 ka. South to north decrease in the volume of the open-slope slides highlight their role in counterbalancing the northwards diminishing sediment supply and helping to maintain a long-term steady-state bathymetric profile. The latest phase slope-confined gullies were presumably created by channelling of bottom currents into slide-scar depressions, possibly establishing incipient canyon headword erosion. 相似文献
80.
Cultured Apostichopus japonicus in China suffers from a kind of skin ulceration disease that has caused severe economic loss in recent years. The disease,
pathogens of which are supposed to be bacteria by most researchers, is highly infectious and can often cause all individuals
in the same culture pool to die in a very short time. The 16S rRNA gene phylogenesis of the culturable bacteria from the lesions
of diseased individuals was conducted to study the biodiversity of the bacterial communities in the lesions and to identify
probable pathogen(s) associated with this kind of disease. S. japonica samples were selected from a hatchery located in the eastern part of Qingdao, China. Bacterial universal primers GM5F and
DS907R were used to amplify the 16S rRNA gene of bacteria colonies, and touchdown PCR was performed to amplify the target
sequences. The results suggest that γ- proteobacteria (Alteromonadales and Vibrionales) of CFB group, many strains of which have been also determined as pathogens in other marine
species, are the predominant bacterial genera of the diseased Apostichopus japonicus individuals. 相似文献