134 resultados para 432


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Chang-Fu Wang, Xian-Qiu Ren, and Run-Lin Xu (2010) Composition, abundance, and diversity of the Peracarida on different vegetation types in the Qi'ao-Dan'gan Island Mangrove Nature Reserve on Qi'ao Island in the Pearl River estuary, China. Zoological Studies 49(5): 608-615. Almost nothing is known about the Peracarida in the Pearl River estuary. This is the 1st report to study the composition, abundance, and diversity of the Peracarida in the Qi'ao-Dan'gan I. Mangrove Nature Reserve on Qi'ao I., in the Pearl River estuary, southern China. Bimonthly samplings were carried out in 3 representative vegetation types (mangrove arbor, emergent plants, and seaweed) for 2 yr. Using a Peterson grab, 1940 individuals (id.) were collected in total, including 11 species of 6 genera, 5 families, and 3 orders (Amphipoda, Isopoda, and Tanaidacean). Discapseudes mackiei Bamber 1997 was the dominant species with the highest density of 1,432 incl./m(2). The effect of temperature on the abundance of Peracarida was significant (p < 0.01), and the optimum temperature was 22-23 degrees C in both the mangrove arbor and seaweed. The results showed that the abundance of the Peracarida was higher in the mangrove arbor, while the diversity, especially Amphipoda diversity, was higher in the seaweed. In contrast, emergent plants provided no suitable habitats for the Peracarida. http://zoolstud.sinica.edu.tw/Journals/49.5/608.pdf

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琼胶是一种从石花菜等红藻中提取的,目前生产工艺和结构等方面研究比较成熟的海藻多糖,广泛应用于医药、仪器等行业。但是,海藻多糖因为具有分子量大,粘度大,溶解度较小的等特点,而使其应用范围受到限制。利用降解的手段对其进行修饰,降低分子量和粘度,改善溶解性,可以拓展其应用范围。并且根据文献报道,琼 胶寡糖具有一些特殊的生物活性,如抗氧化性,抗炎症等。因此,对琼胶降解的研究具有生要意义。本研究中,为了选择一种合适的降解方法,进行了几种水解方法的尝试,其中包括在不同湿度和酸度下盐酸水解,过氧化氢和醋酸催化水解,Fenton体系羟基自由基降解。对于酸水解和Fenton体系氧化还原降解方法,通过粘度法对反应的速度进行了比较,表明氧化还原降解反应中琼胶的粘度降低比较快,并且具有代表性和新意,确定为本实验的降解琼胶的方法并对氧化还原降解所得的产物进行了活性实验。通过模仿自然界普遍存在的氧化还原降解反应,利用Vc诱导的Fenton体系产生的羟基自由基氧化还原降解琼胶得到低分子量的琼胶。降解产物经过高速离心、60%乙醇沉淀,除去分子量比较大的降解产物和磷酸盐,得到可溶于60%乙醇的分子量估计小于3000的降争产物,其产率为85%。利用经Sephadex-G25凝胶色谱分离所香的不同分子量的级分进行分子量和α-葡萄糖苷酶抑制活性关系的实验。降解产物对α-葡萄糖苷酶的抑制率和各级分的浓度呈线性正相关,并且各级分的IC_(50)则随着分子量的降低而降低。另外,对所得的降解产物混合物进行了红外吸收光谱、质子去偶核磁共震碳谱和负离子基质辅助激光诱导-飞行时间质谱结构分析。结果表明,氧化还原降解反应的专一性差,在得到寡糖的同时,在光谱图中出现一些比较复杂的副产物的结构信息。最后,根据MTT法的原理,以有体皮肤成纤维细胞为材料,通过紫外线辐射产生自由基造成氧化损伤,研究降解产物对成纤维细胞的保护作用。当无紫外线辐射时,降解产物对成纤维细胞具有显著的促进生长增殖作用:当经UVa、UBb辐射时则可以显著地表现出对损伤的保护作用,并且这种促进生长和保护作用呈显著的量效关系,表明降解产物具有清除基自由基的作用。但是,因为氧化还原降解以应的机理尚不十分明的以及琼羟胶的特殊结构,使得反应的副产物很难预测,也就使得分离工作难以进行,所以,根据目前所得的信息,尚不能确定是降解产物的什么级分产生的以上两种生物活性。

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贝类养殖作为我国传统的海水养殖产业,在我国沿海地区的经济发展中起重要作用。但由于近年来养殖扇贝病害的不断发生,不仅造成了巨大的经济损失,而且直接威胁到现有养殖产业的生存和发展。目前认为,机体抗病能力的下降是发生流行性死亡的主要原因之一。因此,深入研究扇贝免疫防御特性,能更好地了解和解决贝类养殖中的病害问题。本文比较了健康状态和重金属污染以及高温胁迫下海湾扇贝和栉孔扇贝部分免疫指标的变化,并对同龄不同大小的栉孔扇贝的部分免疫指标进行了比较,以期更好的了解贝类的防御机制,为扇贝病害防治提供资料。研究结果如下: 用流式细胞仪技术对血细胞死亡率、细胞吞噬率和呼吸爆发进行了测定,发现健康状态下两种扇贝的细胞死亡率相差不大,海湾扇贝为4.83%,栉孔扇贝为4.95%;细胞吞噬率差异显著(P<0.05),海湾扇贝为26.73%,栉孔扇贝为19.89%;呼吸爆发的基础值相差也不大,海湾扇贝为1.94,栉孔扇贝为1.56。另外用免疫化学方法对健康状态下栉孔扇贝和海湾扇贝血淋巴和肝胰腺中SOD、ACP活性和MDA含量也进行了测定与比较。发现在血淋巴和肝胰腺中,两种扇贝SOD活性均存在显著差异(P<0.05),其中海湾扇贝分别为995.43和113.99,栉孔扇贝分别为446.64和40.6;血淋巴和肝胰腺中ACP活性差异显著(P<0.05),海湾扇贝分别为90.19和432.36,栉孔扇贝分别为73.26和146.63;血淋巴中和肝胰腺中MDA含量差异不显著(P>0.05),海湾扇贝分别为3.37和92.46,栉孔扇贝分别为2.17和28.96。实验结果说明,海湾扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于栉孔扇贝,这为海湾扇贝比栉孔扇贝具有更高的抗逆性提供了证据。 用相同的方法对不同浓度(0, 0.2, 0.3, 0.5 mg L-1) Pb2+溶液浸泡后的栉孔扇贝和海湾扇贝的血细胞死亡率、细胞吞噬率和呼吸爆发进行了检测,同时测定了Pb2+处理后肝胰腺中SOD、ACP活性和MDA含量的变化。结果表明,栉孔扇贝的血细胞死亡率与对照组相比有上升趋势,且随着Pb2+浓度的增加而显著增加,而海湾扇贝在相同条件Pb2+的胁迫下,血细胞的死亡率明显低于栉孔扇贝。栉孔扇贝各实验组细胞吞噬率均低于对照组,而海湾扇贝在低浓度的Pb2+浸泡后,细胞的吞噬率与对照组相比有所降低,但随着浓度的继续增加,细胞的吞噬率反而上升,甚至略高于对照组。栉孔扇贝血细胞的呼吸爆发在Pb2+胁迫后较对照组有所升高,但随着浓度的增加,呼吸爆发有下降的趋势,而海湾扇贝的呼吸爆发随着Pb2+浓度的增加而显著增加。对两种扇贝体液免疫指标的测定发现,各实验组SOD的活性均比对照组高,且海湾扇贝的SOD活性高于栉孔扇贝;随着Pb2+浓度的增加,各实验组ACP的活性一直呈上升趋势,且海湾扇贝的ACP活性也高于栉孔扇贝;Pb2+处理后MDA的含量均显著增加,其中栉孔扇贝MDA含量的增幅明显高于海湾扇贝。该结果说明,Pb2+对两种扇贝的免疫系统都有一定的影响,但相同剂量的Pb2+对两种扇贝的毒害程度不同,海湾扇贝对Pb2+的耐受性似乎高于栉孔扇贝。 对海湾扇贝和栉孔扇贝的升温刺激实验发现,当养殖水体的温度从18℃缓慢升高到30℃后,栉孔扇贝在第三天开始出现大量死亡现象,而海湾扇贝未出现死亡。因而本文只对升温前后的海湾扇贝进行了细胞死亡率、吞噬率和呼吸爆发的测定和比较。结果发现,与升温前相比,血细胞的死亡率在温度升高后略有增加,但差异不显著(P>0.05);而细胞吞噬率在温度升高后显著下降;通过对呼吸爆发积聚的活性氧(Reactive Oxygen Species,ROS)的测定发现,升温后血细胞的ROS含量显著高于升温前(P<0.05)。该结果表明,高温会影响血细胞的功能,使机体的免疫防御能力下降,从而导致病害的发生。 另外,本文对同龄不同大小的栉孔扇贝的血细胞吞噬率以及血淋巴和肝胰腺中SOD、ACP活性和MDA含量进行了测定与比较。结果发现: 小扇贝的血细胞吞噬率略高于大扇贝,分别达到了22.82和20.96;在血淋巴及肝胰脏中,两组扇贝SOD酶的活性均差异显著(P<0.05),小扇贝分别为613.88和102.01,大扇贝分别为356.15和50.22;血淋巴中小扇贝ACP的活性极显著的高于大扇贝(P<0.01),分别为44.3和2.91,但肝胰腺中大扇贝和小扇贝ACP的活性相差不大,大扇贝为455.75,小扇贝为485.33;大扇贝和小扇贝血淋巴和肝胰脏中MDA含量相差不大,大扇贝分别为2.67和31.83,小扇贝分别为3.17和35.33。该结果说明,小扇贝对细菌等异物的吞噬和杀灭能力以及机体自身的抗氧化能力高于大扇贝,这为生长与抗逆性相颉抗提供了依据。

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在中国,孔石莼应用于医药方面已有几千年的历史,其煎剂常被当地居民用来治疗中暑和泌尿方面的疾病。实验室以前所做的工作表明,孔石莼的水溶多糖具有很好的抗高血脂活性,本论文在此研究的基础上主要就多糖的长期毒性、一般药理、多糖的衍生化、不同分子量孔石莼多糖的抗氧化活性、衍生物的抗氧化活性和动物调血脂活性进行了研究。 水提醇沉制备多糖,多糖主要由糖醛酸、鼠李糖、木糖、葡萄糖和硫酸根组成,还含有微量的半乳糖、甘露糖和阿拉伯糖。多糖中主要的二糖重复单位为[β-D-Glcp A-(1->4)- α-L-Rhap 3S] 和 [α-L-Idop A-(1->4)- α-L-Rhap 3S]。急性毒性实验表明,KM小鼠对孔石莼多糖的最大耐受量(MTD)大于4000 mg/kg,其腹腔注射雌性小鼠的半致死量(LD50)为408.7 mg/kg,雄性动物为432.7 mg/kg。长期毒性(6个月)实验表明孔石莼多糖无毒反应剂量为1.2 g/kg。一般药理研究表明孔石莼多糖对小鼠中枢神经系统无明显影响,对麻醉犬心血管系统和呼吸系统均无明显影响。 采用过氧化氢降解的方法制备了不同分子量的孔石莼多糖,并且测定了体外抗氧化活性;制备了高硫酸根含量的孔石莼多糖、乙酰化和苯甲酰化孔石莼多糖衍生物,测定了体外抗氧化活性和动物调血脂试验。结果表明,不同分子量的孔石莼多糖其抗氧化活性是不同的,分子量低的孔石莼多糖表现出了较强的抗氧化活性。孔石莼多糖的衍生物其抗氧化活性要优于孔石莼多糖。调血脂动物试验表明,孔石莼多糖以及其衍生物都具有很好的调血脂效果。高硫酸根含量孔石莼多糖的中、低剂量组的调血脂活性要优于高剂量组(低剂量组降低低密度脂蛋白的能力要稍弱于原料),而且,中剂量组与原料组相比,小鼠血清TG明显降低(P<0.05),LDL-C 明显降低(P<0.01)。低剂量组乙酰化衍生物降低甘油三酯(TG)和低密度脂蛋白(LDL-C)的能力要优于中高剂量组。对于孔石莼多糖以及衍生物调血脂的机制还需进一步的研究。

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A novel manganese superoxide dismutase (MnSOD) was cloned from bay scallop Argopecten irradians by 3' and 5' rapid amplification of cDNA ends (RACE) PCR. The full-length cDNA of MnSOD was of 1207 bp with a 678 bp open reading frame encoding 226 amino acids. The deduced amino acid sequence contained a putative signal peptide of 26 amino acids. Sequence comparison showed that the MnSOD of A. irradians shared high identity with MnSOD in invertebrates and vertebrates, such as MnSOD from abalone Haliotis discus discus (ABG88843) and frog Xenopus laevis (AAQ63483). Furthermore, the 3D structure of bay scallop MnSOD was predicted by SWISS-MODEL Protein Modelling Server and compared with those of other MnSODs. The overall structure of bay scallop MnSOD was similar to those of zebrafish Danio rerio, fruit fly Drosophila melanogaster, Chinese shrimp Fenneropenaeus chinensis, human Homo sapiens, and had the highest similarity to scallop Mizuhopecten yessoensis and abalone H. discus discus. A quantitative real-time PCR (qRT-PCR) assay was developed to detect the mRNA expression of MnSOD in different tissues and the temporal expression in haemocytes following challenge with the bacterium Vibrio anguillarum. A higher-level of mRNA expression of MnSOD was detected in gill and mantle. The expression of MnSOD reached the highest level at 3 h post-injection with V. anguillarum and then slightly recovered from 6 to 48 h. The results indicated that bay scallop MnSOD was a constitutive and inducible protein and thus could play an important role in the immune responses against V anguillarum infection. (c) 2008 Elsevier Ltd. All rights reserved.

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应用紫外分光光度法,对青海10个不同产地的五脉绿绒蒿样品总生物碱含量测定,结果显示,不同产地的总生物碱含量为0.0262%~0.0788%,平均0.0502%,与分布海拔呈正相关,与分布纬度无显著关联.

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对柴达木唐古特白刺种籽油的安全性和降血脂作用进行了研究。以超临界CO2萃取技术提取白刺种籽油,采用小白鼠进行急性毒性实验和安全性评价,以高脂例料诱导建立大鼠高脂动物模型,灌胃种籽油4w,测定动物血清血脂水平。结果表明,小鼠每日给予白刺籽油40ml/kg,连续观察14d,无毒性表现,服用安全;种籽油5g/kg和10g/kg剂量对高脂饲料诱导的大鼠血清TC、TG及LDL具有显著的抑制作用,可显著升高高血脂大鼠HDL/TC和HDL/LDL的比值,表明高剂量白刺种籽油具有显著的降血脂作用。

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报道了西藏鱼类染色体多样性的研究结果。黑斑原■的染色体数目2n = 48 ,核型公式为20 m + 12sm + 10 st + 6 t;同时还存在2n = 42 与2 n = 44 两种类型,并据此认为黑斑原■不应是■科鱼类中的最特化种。西藏高原鳅、尖裸鲤、拉萨裸裂尻鱼、异齿裂腹鱼和拉萨裂腹鱼的染色体数目与核型公式分别为2n = 50 = 14 m + 4sm + 22 st + 10 t,2n = 86 = 24 m + 12 sm + 22 st + 18 t,2n = 94 = 22 m + 8 sm + 46 st + 18 t ,2n = 106 = 24 m + 26 sm +30 st + 26 t ,2n = 112 = 26 m + 24 sm + 28 st + 34 t ,在数目和核型或图像上有别于前人的报道。首次报道小眼高原鳅、高原裸鲤的染色体数目、核型及巨须裂腹鱼的核型公式,依次为2n = 50 = 16 m + 12 sm + 12 st + 10 t,2n = 94 =24 m + 14 sm + 22 sm + 34 t,2n = 102 = 20 m + 28 sm + 22 st + 16 t 。佩枯湖裸鲤的染色体数目2n = 66,是裂腹鱼类中最少的。双须叶须鱼染色体的数目则极多,2n = 424~432,甚为罕见,两者都有待进一步研究。 西藏鱼类的染色体多样性十分丰富, 表现出裂腹鱼类、鳅科和■科鱼类各属、种之间的差别以及种内不同居群甚至同一个体的细胞之间的差异。该特点可能与鱼类物种形成所处的不稳定环境有关。在探讨鱼类分类地位和演化关系时, 染色体组型有一定的可信度, 但只有当一个类群或属或种的染色体组型完全稳定时才可作为依据予以采用。

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The Tarim Block is located between the Tianshan Mountains in the north and the Qinghai-Tibet Plateau in the south and is one of three major Precambrian cratonic blocks of China. Obviously, the Paleozoic paleogeographic position and tectonic evolution for the Tarim Block are very important not only for the study of the formation and evolution of the Altaids, but also for the investigation of the distributions of Paleozoic marine oil and gas in the Tarim Basin. According to the distributions of Paleozoic strata and suface outcrops in the Tarim Block, the Aksu-Keping-Bachu area in the northwestern part of the Tarim Block were selected for Ordovician paleomagnetic studies. A total of 432 drill-core samples form 44 sampling sites were collected and the samples comprise mainly limestones, argillaceous limestones and argillaceous sandstones Based on systematic study of rock magnetism and paleomagnetism, all the samples could be divided into two types: the predominant magnetic minerals of the first type are hematite and subordinate magnetite. For the specimens from this type, characteristic remanent magnetization (ChRM) could generally be isolated by demagnetization temperatures larger than 600℃; we assigned this ChRM as component A; whilst magnetite is the predominant magnetic mineral of the second type; progressive demagnetization yielded another ChRM (component B) with unblocking temperatures of 550-570℃. The component A obtained from the majority of Ordovician specimens has dual polarity and a negative fold test result; we interpreted it as a remagnetization component acquired during the Cenozoic period. The component B can only be isolated from some Middle-Late Ordovician specimens with unique normal polarity, and has a positive fold test result at 95% confidence. The corresponding paleomagnetic pole of this characteristic component is at 40.7°S, 183.3°E with dp/dm = 4.8°/6.9° and is in great difference with the available post-Late Paleozoic paleopoles for the Tarim Block, indicating that the characteristic component B could be primary magnetization acquired in the formation of the rocks. The new Ordovician paleomagnetic result shows that the Tarim Block was located in the low- to intermediate- latitude regions of the Southern Hemisphere during the Middle-Late Ordovician period, and is very likely to situate, together with the South China Block, in the western margin of the Australian-Antarctic continents of East Gondwana. However, it may have experienced a large northward drift and clockwise rotation after the Middle-Late Ordovician period, which resulted in the separation of the Tarim Block from the East Gondwanaland and subsequent crossing of the paleo-equator; by the Late Carboniferous period the Tarim Block may have accreted to the southern margin of the Altaids.

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采用超临界CO2流体萃取、素氏提取、水蒸汽蒸馏3种提取技术提取蓬莪术挥发油,并用GC-MS联用仪分析其化学成分,实验结果表明:超临界CO2流体萃取法在挥发油得率、有效抗肿瘤组分、工艺流程、有机溶剂残留、挥发油外观及香气等诸多方面均明显优于索氏提取法和水蒸汽蒸馏法,有较高的工业应用价值。

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姚安金矿床与富碱侵入岩体具有密切时空关系[1] 。本研究运用稀土元素地球化学示踪方法 ,探讨了富碱侵入岩与姚安金矿床之间可能的成因联系。1 地质背景我国滇西“三江”地区沿哀牢山—金沙江深大断裂及其附近 ,分布着一个总体呈这个北西走向的巨型富碱侵入岩带 ,带内分布着大量在第三纪时期的裂谷环境中由富集地幔部分熔融形成的富碱侵入体[1~ 4 ] 。姚安岩体属于这个富碱侵入岩带的一部分。姚安金矿床已探明金矿脉 19条 ,金品位为0 .4 5~ 2 9.95)g/t① 。矿区内的侵入体为姚安岩体 ,主要由正长斑岩和石英正长斑岩组成。矿体产于姚安岩体与侏罗系地层的内外接触带内。野外可见 ,姚安岩体形成后至金成矿前 ,区内再未有其它岩浆活动 ,这表明金成矿与姚安岩体具有密切的时空联系。矿区内出露的地层是侏罗系妥甸组 (J3t)灰黑色粉砂质泥岩 ,姚安岩体呈岩株状侵位于妥甸组地层中。区内的骨架构造为北西向的断裂 ,矿体呈脉状、豆荚状产于主断裂旁侧的次级断裂破碎带中。根据矿脉的穿插关系、矿石的结构构造和矿物组合 ,姚安金矿床可分为两个主要成矿阶段。早期硫化物阶段(阶段I) :矿石为细脉浸染型 ,主要矿石矿物有黄铁矿、黄铜矿、方..

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本文系统研究了哀牢山金矿带主要金矿床主成矿阶段石英流体包裹体的化学组成和物理化学性质。结果表明,金成矿流体中的阳离子主要为Na^+、K^+,阴离子主要为Cl^-,SO4^2-,F^-,气相组分中CO2含量普遍偏高,成矿流体属于中低温,中性-弱碱性,具相对还原性,中等含盐度的Na质溶液,其中的金主要以硫氢配合物形式迁移。