氨基修饰二氧化硅对Cr^3+和直接桃红B12的吸附

该试验以硅烷偶联剂KH-550为改性剂,乙醇为溶剂合成氨基二氧化硅。利用红外光谱、扫描电镜、原子吸收光谱、可见分光光度法对改性前后SiO 2进行表征,研究其对铬离子及染料直接桃红B12的吸附情况。结果表明:25℃恒温振荡20 min,改性SiO 2吸附重金属离子Cr^3+效果明显,当其用量为0.04 g时,吸附率达99.01%,而相同条件下未改性SiO 2对Cr^3+吸附率只有25.13%;将其用于染料直接桃红B12的吸附,改性后SiO 2吸附率达91.97%,相同条件下未改性SiO 2的吸附率仅为34.23%。     

Histological, digestive, metabolic, hormonal and some immune factor responses in Atlantic salmon, Salmo salar L., fed genetically modified soybeans

The paper reports the second and final part of an experiment aiming to study physiological and health-related effects of genetically modified (GM) soybean meal (SBM) type Roundup Ready soybean (RRS) in diets for post-smolt Atlantic salmon. For 3 months salmon were fed diets containing 172 g kg(-1) full-fat SBM from RRS (GM-soy) or an unmodified, non-isogenic line (nGM-soy), or a reference diet with fishmeal as the sole protein source (FM). Slight differences in anti-nutrient levels were observed between the GM and nGM-soy. Histological changes were observed only in the distal intestine of the soy-fed fish. The incidence of moderate inflammation was higher in the GM-soy group (9 of 10 sampled fish) compared with the nGM-soy group (7 of 10). However, no differences in the concomitant decreases in activities of digestive enzymes located in the brush border (leucine aminopeptidase and maltase) and apical cytoplasm (acid phosphatase) of enterocytes or in the number of major histocompatibility complex class II+ cells, lysozyme activity, or total IgM of the distal intestine were observed. GM compared with nGM-soy fed fish had higher head kidney lysozyme (11,856 vs. 10,456 units g(-1) tissue) and a tendency towards higher acid phosphatase (0.45 vs. 0.39 micromol h(-1) kg(-1) body mass in whole tissue) activities, respectively. Plasma insulin and thyroxin levels, and hepatic fructose-1,6-bisphosphatase and ethoxyresorufin-O-deethylase activities were not significantly affected. It is not possible, however, to conclude whether the differences in responses to GM-soy were due to the genetic modification or to differences in soy cultivars in the soy-containing diets. Results from studies using non-modified, parental line soybeans as the control group are necessary to evaluate whether genetic modification of soybeans in diets poses any risk to farmed Atlantic salmon.     

In vivo growth and genomic characterization of rickettsia‐like organisms isolated from farmed Chinook salmon (Oncorhynchus tshawytscha) in New Zealand

A rickettsia‐like organism, designated NZ‐RLO2, was isolated from Chinook salmon (Oncorhynchus tshawytscha) farmed in the South Island, New Zealand. In vivo growth showed NZ‐RLO2 was able to grow in CHSE‐214, EPC, BHK‐21, C6/36 and Sf21 cell lines, while Piscirickettsia salmonis LF‐89^T grew in all but BHK‐21 and Sf21. NZ‐RLO2 grew optimally in EPC at 15°C, CHSE‐214 and EPC at 18°C. The growth of LF‐89 ^T was optimal at 15°C, 18°C and 22°C in CHSE‐24, but appeared less efficient in EPC cells at all temperatures. Pan‐genome comparison of predicted proteomes shows that available Chilean strains of P. salmonis grouped into two clusters (p‐value = 94%). NZ‐RLO2 was genetically different from previously described NZ‐RLO1, and both strains grouped separately from the Chilean strains in one of the two clusters (p‐value = 88%), but were closely related to each other. TaqMan and Sybr Green real‐time PCR targeting RNA polymerase (rpoB) and DNA primase (dnaG), respectively, were developed to detect NZ‐RLO2. This study indicates that the New Zealand strains showed a closer genetic relationship to one of the Chilean P. salmonis clusters; however, more Piscirickettsia genomes from wider geographical regions and diverse hosts are needed to better understand the classification within this genus.     

Evaluation of the feed value of a transgenic strain of the narrow‐leaf lupin (Lupinus angustifolius) in the diet of the marine fish,Pagrus auratus

This study assessed the nutritional and biological value of a noncommercial, transgenic line of the Australian sweet lupin, Lupinus angustifolius, (cv. Warrah), produced to increase the methionine content of the seed. An initial experiment demonstrated that differences in the methionine content of the transgenic and nontransgenic control lupins had no apparent influence on the growth of juvenile red seabream fed practical diets. Re‐evaluation of the nutritional characteristics of the lupin meals with subsequent digestibility studies allowed the determination of the digestible value of the protein and energy content of each of the varieties. The digestible protein content of either variety was similar, however significant differences in the digestible energy value of each variety existed (56.3% cf. 64.0%). This re‐evaluation of the nutritional value of the genetically manipulated (GM) and non‐GM lupin varieties enabled the reformulation of diets on a digestible protein and energy basis. A second growth trial was undertaken using sub‐satietal pair‐feeding regimes, with the experiment also involving protein‐restrictive diets to allow expression of the differences in the methionine content of the transgenic and nontransgenic lupin meals. A significant benefit of the enhanced methionine level in the transgenic lupin was observed. It is argued that in the high‐protein fish diets used, the importance of amino acid composition is relatively limited. Economic modelling of the potential value of the increased methionine in the transgenic lupin suggests that this will have limited benefit for aquaculture industries, and that greater value would be attributable to higher protein and energy levels in ingredients.     

1999～2005年浙江省海水养殖生物死亡原因分析

近年来,浙江省海水养殖业迅速增长,2003年、2004年海水养殖产量分别比上一年增加7.9%和1.2%,产量分别为9.184×106t和9.294×106t。但是在养殖规模不断扩大,养殖产量不断增加的同时,养殖生物死亡事故也不断发生,根据《中国渔业生态环境状况公报(2004年),》2004年浙江省发生海水     

SYBR Green I实时荧光PCR鉴定检测转基因油菜RT73品系

根据转基因油菜RT73品系转入的外源基因质粒图谱,设计品系鉴定的特异性引物,进行SYBR!Green I实时PCR检测,建立转基因油菜品系鉴定的SYBR Green I实时PCR方法。同时针对油菜FatA基因设计出内源基因。结果表明：应用实时PCR技术,利用SYBR Green I染料能选择性结合双链DNA的特点,可检测到RT73品系特异性靶序列扩增所产生的荧光信号,且通过溶解曲线确定其熔点值为80.2（±0.5）。SYBR Green I实时PCR能通过溶解曲线有效地区分特异性产物、非特异性产物以及引物二聚体,是鉴定转基因油菜RT73品系的新方法。     

瑶山雪梨MAP常温保鲜效果研究

试验采用厚度0.03mmPE、0.03mmPVC和0.05mmPVC保鲜膜处理,以不扎口作对照,研究瑶山雪梨MAP常温保鲜效果。结果表明:20℃MAP贮藏35d,显著(P<0.05)抑制果实呼吸强度,降低果肉硬度、可溶性固形物和可滴定酸含量,减少果实失重率和腐烂率。其中,0.05mmPVC保鲜效果最好,稳定阶段袋内O23.5%～5.5%、CO26.0%～7.0%;贮藏35d,果肉硬度5.3kg·cm-2,可溶性固形物、可滴定酸、失重率和腐烂率分别为10.9%,0.076%,7.2%,30%。     

2个有限渐近非扩张映射族的迭代序列的强收敛性

在希尔伯特空间中对2个有限渐近非扩张映射族引入了新的修正的Mann迭代序列,并证明了该迭代序列强收敛于这2个有限渐近非扩张映射族的公共不动点.     

成都消费者对转基因食品认知状况调查研究

在转基因食品高速发展的今天,其负面报道也屡见不鲜,因而其安全性也倍受争议。以成都市为例,调查了消费者对转基因食品的安全性认知情况及消费意愿和期望。结果表明,目前消费者对转基因食品安全性认知深度有待提高,多数受访者对转基因食品持谨慎态度,且当地消费者对转基因食品持消极态度,受访者认为提高转基因食品安全性主要靠加强当地的政府监管和行业自律。     

改性木屑处理含铬废水的研究

采用磷酸改性木屑后用于含铬废水吸附处理,探讨废水pH值、处理时间、木屑投加量、处理温度4个因素对铬去除率的影响;并拟合25℃改性木屑吸附处理含铬废水的动力学、等温线方程,估算热力学数据。结果表明:木屑对含铬废水有较强去除力,改性木屑去除力加强;改性木屑处理20ml浓度为50mg/L含铬废水的适宜条件为pH值=1～4,处理时间90min,木屑投加量1g,处理温度20～30℃;改性木屑吸附处理含铬废水的动力学特性符合颗粒内扩散方程和二级吸附速率方程;吸附等温线方程符合Langmuir吸附;25℃吸附过程ΔH=-20.489kJ/mol,ΔS=-78.426J/(mol.K),ΔG=2.89kJ/mol。