呋喃妥因代谢物海特因单克隆抗体的制备

通过制备单克隆抗体能够高效准确的检测呋喃妥因代谢物海因特。把间羧基苯甲醛跟海特因的衍生物接到牛血清白蛋白上作为免疫原,接到卵清蛋白上作为检测抗原,制备了特异的单克隆抗体。利用7号细胞株产生的抗体,Elisa检测海特因的邻硝基苯甲醛衍生物,灵敏度达到0.1 ng/m L,对呋喃唑酮的代谢物AOZ、呋喃它酮的代谢物AMOZ、呋喃西林的代谢物SEM的邻硝基苯甲醛衍生物交叉反应性<0.1%。

利用单克隆抗体检测呋喃妥因代谢物海特因方法的研究

[目的]建立敏感、快速、特异的呋喃妥因代谢物海特因的检测方法。[方法]通过将间羧基苯甲醛和海特因的衍生物接种到牛血清白蛋白上免疫Balb/C小鼠,应用杂交瘤技术制备单克隆抗体,采用ELISA检测海特因的邻硝基苯甲醛衍生物。[结果]采用ELISA检测海特因的邻硝基苯甲醛衍生物,灵敏度达到0.1 ng/ml。制备的单克隆抗体具有特异性高、灵敏的优点。[结论]该研究可为酶联免疫试剂盒的研制奠定基础。

Distribution of heavy metals in suspension in Bohai Bay

Selecting suspension sample 51 stations in Bohai Bay contents of heavy metals(Fe, Mn, Si, Ba) analysis, studied the distribution of the suspension of heavy metals. It Showed that in the study area, the content of iron was the highest, silicon content was lowest; in descending order: Fe>Mn>Ba>Si; the coefficient of variation is between 7.60 and 110.35; except barium greater the degree of dispersion(coefficient of variation is greater than 100).With the samples of stations, the 4 kinds of heavy metals are from low to high, from the south to the north. Silicon content was the highest in 51 stations. The other 3 elements appeared in 50 stations.

The Sediment and Hydrographic Characteristics of Three Horseshoe Crab Nursery Beaches in Hong Kong

Horseshoe crab juveniles have been recorded from sand and sandy-mud nursery beaches at Pak Nai (western New Territories), San Tau and Shui Hau (Lantau Island), Hong Kong. In order to provide a better understanding of these beaches and to identify those plausible factors which have made them preferred by spawning horseshoe crabs, environmental parameters, including temperature, salinity, pH and dissolved oxygen content of the water, and particle size distribution and organic matter content of the sediments at the three sites, were determined and compared. The hydrographic and sediment data obtained for the three study sites have revealed some common environmental features. The three nursery beaches are relatively remote, and far (in Hong Kong terms) from urbanized and densely populated areas. The beaches are generally well sheltered from strong wave action and inundated regularly by estuarine waters. Horseshoe crab adults tend to select these beaches for spawning as their protected features ensures the laid eggs are less likely to be washed out of the sand, and hatched juveniles can feed on the meiofauna and grow. Sediments of the three beaches largely comprise medium-sized sand particles and are moderately sorted, suggesting medium porosity and good water permeability. Such a sand type, with the generally high oxygen levels in incursing waters, may help create a well-oxygenated micro-environment for the normal development of horseshoe crab eggs, larvae and juveniles. Lantau Island beaches at San Tau and Shui Hau are relatively free from organic pollution, as reflected in generally high dissolved oxygen level, and low BOD 5 and ammonia nitrogen values. Pak Nai is, however, more polluted.

Characterization of SNAP-25 gene from marine teleostean, Lateolabrax japonicus

The t-SNARE protein SNAP-25 (synaptosome-associated protein of 25 kDa) plays an essential role in regulating fusion between the vesicle and plasma membranes during exocytosis. To clone and characterize SNAP-25 gene, the first step in the functional study of SNARE proteins in marine teleostean, was to obtain the cDNA of sea perch SNAP-25 (SPsn25) by RT-PCR and RACE-PCR amplification of a Japanese sea perch. The full-length cDNA of 831bp contains a CDS of 615 bp, coding 204 amino acid residues, and a 5′UTR of 219bp. Bioinformatic analysis revealed that SPsn25 corresponds with SNAP-25a isoform and shares 91.1% identity with SNAP-25a of a goldfish and a zebrafish. The SPsn25 expression in both mRNA and protein levels in the Japanese sea perch had been identified through semi-quantitative RT-PCR and Western Blot assay. Together, these data again confirmed the nerve tissue specificity of the fish SNAP-25 gene expression.

Theoretical Analysis of Coral Reef Stability in South Sea

In this paper,we utilize the variational limiting equilibrium(LE) procedure to theoretically determine the slope stability of homogeneous coral sand in the South China Sea.By establishing a reasonable functional and calculating its extremum,we can deduce the stability factor of a coral reef identical to that obtained by upper bound analysis.To determine the accuracy of the results obtained using the variational LE procedure,we present some classical examples of homogeneous sand slopes without a hard shell and compare our results with those obtained by the upper bound theorem of plasticity.A series of extensive calculations and comparisons reveal that the results obtained by our proposed analysis method and those obtained using classical methods are slightly different,but the variational results are believable.On the other hand,our method solves some stability factors for reef slopes covered with a hard shell,which indicates that the existence of a hard reef shell may significantly enhance the stability of a reef slope,and that there is strong nonlinear relationship between reef stability and the mechanical characteristics of the reef shell,such as its thickness and strength.Finally,based on the variational results presented in this paper,we present a useful chart that offers a convenient and straightforward way to determine the maximum stability factor of reef slopes.Taking into account the influence of the hard reef shell,we found that,in some limit equilibrium cases,the limit stability factor and critical height of a coral slope could be improved significantly.Therefore,this issue deserves careful attention in engineering practice.

Impact Factors on Distribution and Characteristics of Natural Plant Community in Reclamation Zones of Changjiang River Estuary

To identify impact factors on the distribution and characters of natural plants community in reclamation area, with survey data from 67 plant quadrats in July 2009, soil properties data from 216 sampling points in April 2009, and TM (30 m) data in 2006, the composition and characteristics of natural plants community in different time of the Fengxian area in the Changjiang (Yangtze) River estuary were analyzed with two-way indicator species analysis (TWINSPAN), multivariate analysis of variance (MANOVA), detrended canonical correspondence analysis (DCCA) and canonical correspondence analysis (CCA). The results show that: 1) The plant communities in the reclaimed area are mainly mesophytes and helophytic-mesophytic transitional communities, showing a gradient distribution trend with the change in reclamation years. Species richness (MA), species diversity (H) and above-ground biomass also increase with the increase of reclamation years. Nevertheless, they appear to decline slightly in the middle and late reclamation period (> 30 years). 2) With the rise in land use levels, the changes in species richness and species diversity tend to increase at first and then decrease; species dominance (D), however, tends to decline; and above-ground biomass increases slightly. 3) The distribution of the plant community is mainly influenced by the following factors: land use levels (R = 0.55, p < 0.05), soil moisture (R = 0.53, p < 0.05), soil salinity (R = 0.43, p < 0.05) and reclamation time (R = 0.40, p < 0.05).

Dynamic Characteristics of a Damaged Nine-story Building during the 2011 off the Pacific Coast Tohoku Earthquake

This paper describes the dynamic characteristics of a damaged nine story building in Sendal during the 2011 Tohoku Earthquake. Dynamic hysteresis characteristic is investigated. The system identification using the extended Kalman filter determined the amplitude dependency of natural frequency and damping factor, which are consistent with damage feature. Occurrence of partial uplifting in the transverse direction is suggested by the induced higher harmonics based on the wavelet analysis. Historical change of the amplitude dependent dynamic characteristics is also discussed based on the long-term monitoring data from microtremor level to strong motion level.

Reproductive Strategies of a Terrestrial Snail along an Altitudinal Gradient on an Oceanic Island

This study reports how the reproductive cycle of a land snail endemic from an oceanic island is shaped by abiotic factors over an altitudinal gradient of 800 m. In addition, the validity of two morphometric shell parameters （maximum diameter and total height） was assessed, as maturation diagnostic characteristics. The authors＇ findings suggest that, at Piedade （200 m）, individuals are active and mature from October/November to March, and they exhibit dormancy in the remaining months, as a consequence of soil dryness. Thus, at low altitude, gonadal maturation was considered to be primarily influenced by photoperiod, rainfall and temperature At Cabeqo da Bola （1000 m）, in turn, individuals are mature from March to July/August and they seem to have minimal gametogenic conditions throughout the remaining months of the year to reproduce. As soil moisture is never a limiting factor, gonadal maturation is mainly shaped by photoperiod and temperature at high altitude. The morphometric shell parameters under analysis were unable to diagnose gonadal maturation, as recently described for related Azorean species.

Distribution, features, and influence factors of the submarine topographic boundaries of the Okinawa Trough

Based on multiple types of data, the topographical features of the Okinawa Trough(OT) have been characterized and a computation method has been proposed to determine the break point of continental shelf(BOS), foot point of the continental slope(FOS), the central axial point, and the maximum depth point. A total of 48 topographical profiles that crosscut the continental slope have been used to determine the trends of the BOS and FOS(the BOS and FOS lines) in the East China Sea(ECS). The trend of central axial points in the OT has been similarly determined by analyzing 39 topographical profiles across the axis of the trough. The BOS line forms the boundary between the continental shelf and slope. In the ECS, the BOS line roughly follows the 200 m isobath, continuously in the northern and middle parts of the OT, but jumping about somewhat in the south. The FOS line is the boundary between the continental slope and the bottom of the trough. The depth of the FOS increases gradually from north to south in the OT. Intense incisions by canyons into the slope in the southern part of the trough have led to the complex distribution of FOS. Topographical profiles crosscutting the northern, middle, and southern parts of the OT exhibit features that include: a single W-shape, a composite W-shape, and a U-shape, respectively, which suggests that in the middle and northern parts of the trough the central axial points are always located on seamount peaks or ridges associated with linear seamounts, whereas in the south they are found in the center of en echelon depressions. The line formed by the central axial points is the east-west dividing line of the OT, which indicates that the trough is a natural gap that prevents the extension of ECS continental shelf to the east. The distributions of the BOS and FOS lines are influenced by fluctuation of sea levels and submarine canyons, whereas the distribution of axis lines is controlled by tectonics and deposition.

Biomolecular characterization, identification, enzyme activities of molds and physiological changes in sweet potatoes(Ipomea batatas) stored under controlled atmospheric conditions

Microbial attacks during storage are one of the primary causes of product deterioration, and can limit the process of prolonging the shelf-life of harvested food. In this study, sweet potatoes were stored at temperatures of 13, 21, and 29 ℃ for 4 weeks. Samples were collected during storage and plated on potato dextrose agar, from which axenic mold cultures were obtained and identified using 26S rRNA gene sequences. Physiological changes of potato tubers were assessed with respect to pathogenicity, enzyme activity, and atmospheric storage conditions. Six fungal species were identified, namely Penicillium chrysogenum （P. rubens）, P. brevicompactum, Mucor circinelloides, C/adosporium cladosporiodes, P. expansum, and P. crustosum. The following fungal isolates, namely P. expansum, P. brevicompactum, and Rhizopus oryzae, were recovered from the re-infected samples and selected according to their levels of enzyme activity. This study revealed high levels of activity for cellulase and pectinase, which were most notable during the initial three days of testing, and were followed by a steady decrease （P〈0.05）. Polygalacturonase activity was prominent with values ranging from 12.64 to 56.79 U/mg （P. expansum） and 18.36 to 79.01 U/mg （P. brevicompactum）. Spoilage was obvious in the control group, which had a 100% decay at the end of the experimental period compared with samples treated with iprodione and sodium hypochlorite, in which the decay rates were 5% and 55%, respectively. The data for the iprodione- and sodium hypochlorite-treated samples at the end of the 3-month storage period showed that they were significantly different （P=0.041）, with the sodium hypochlorite-treated samples producing twice the rate of infection compared to the iprodione-treated samples. The comparative rate of the pro- gression of decay in the treated samples can be expressed as iprodione〈sodium hypochlorite〈control. This study demonstrates that sweet potato tissue damage is due to the activities of microbial enzymes and, in particular, the pectinases of the organisms isolated from the infected potato tissues, and suggests the advantages of utilizing iprodione as a curing agent for potato tubers before storage.