Biosorption of copper by marine algae Gelidium and algal composite material in a packed bed column

Marine algae Gelidium and algal composite material were investigated for the continuous removal of Cu(II) from aqueous solution in a packed bed column. The biosorption behaviour was studied during one sorption–desorption cycle of Cu(II) in the flow through column fed with 50 and 25 mg l⁻¹ of Cu(II) in aqueous solution, at pH 5.3, leading to a maximum uptake capacity of ≈13 and 3 mg g⁻¹, respectively, for algae Gelidium and composite material. The breakthrough time decreases as the inlet copper concentration increases, for the same flow rate. The pH of the effluent decreases over the breakthrough time of copper ions, which indicates that ion exchange is one of the mechanisms involved in the biosorption process. Temperature has little influence on the metal uptake capacity and the increase of the ionic strength reduces the sorption capacity, decreasing the breakthrough time. Desorption using 0.1 M HNO₃ solution was 100% effective. After two consecutive sorption–desorption cycles no changes in the uptake capacity of the composite material were observed. A mass transfer model including film and intraparticle resistances, and the equilibrium relationship, for adsorption and desorption, was successfully applied for the simulation of the biosorption column performance.     

偶联剂在生物涂层中的应用

综述了生物材料的研究及问题,论述了偶联剂的种类及其作用机理,在此基础上介绍了偶联剂的研究现状与应用概况。重点论述了偶联剂在生物涂层中的应用及其前景。     

Comparative Risk Assessment Methods and Their Applicability to Dredged Material Management Decision-Making

This article reviews the status of comparative risk assessment within the context of environmental decision-making; evaluates its potential application as a decision-making framework for selecting alternative technologies for dredged material management; and makes recommendations for implementing such a framework. One of the most important points from this review for decision-making is that comparative risk assessment, however conducted, is an inherently subjective, value-laden process. There is some objection to this lack of total scientific objectivity (“hard version” of comparative risk assessment). However, the “hard versions” provide little help in suggesting a method that surmounts the psychology of choice in decision-making schemes. The application of comparative risk assessment in the decision-making process at dredged material management facilities will have an element of value and professional judgment in the process. The literature suggests that the best way to incorporate this subjectivity and still maintain a defensible comparative framework is to develop a method that is logically consistent and allows for uncertainty by comparing risks on the basis of more than one set of criteria, more than one set of categories, and more than one set of experts. It should incorporate a probabilistic approach where necessary and possible, based on management goals.     

Seasonal and spatial variation in the diet of brown trout (Salmo trutta L.) in the subarctic River Laxá, north-east Iceland

This study examines seasonal and spatial patterns in the diet composition, stomach fullness and condition of a landlocked population of brown trout (2.5–61.3 cm) in the lake-fed River Laxá in NE-Iceland. The stomach contents consisted predominantly of benthic invertebrates, such as blackfly larvae Simulium vittatum (58%), chironomids (24%) and the freshwater snail Radix peregra (7%). The seasonal and spatial patterns of S. vittatum in the stomach contents were consistent with published studies on the life cycle and production of S. vittatum in the River Laxá. Close to the Lake Myvatn outlet (0–16 km), S. vittatum constituted 63% of the stomach content volume, and exhibited two peaks (i.e., generations) in its seasonal contribution to the stomach contents, whereas further downstream (16–35 km) S. vittatum constituted 45% of the volume and showed only clear evidence of one generation. Seasonal fluctuations in S. vittatum availability appear to affect the stomach fullness and the condition factor of the trout, especially close to the lake outlet where the fluctuations are pronounced.     

大型真菌分子生物学实验材料的保存方法介绍

介绍了几种保存大型真菌分子生物学实验材料的方法 ,用这几种方法所保存的材料提取的基因组核糖体脱氧核糖核酸 (DNA)质量适于系统生物学及其他分子生物学研究之用。     

不同烤瓷牙内冠材料对产生龈缘黑线影响的分析

目的：分析镍铬合金,金合金材料制作烤瓷内冠以及镍铬合金内冠涂制金粉对冠修复后产生龈缘黑线的影响。方法：对3052例烤瓷冠病例,分别用镍铬合金,金合金制作内冠以及运用金粉涂制镍铬合金内冠进行修复,经一年以上随访。对上述三种材料对产生龈缘黑线状况进行评价。结果：采用金合金制作内冠及对镍铬合金内冠粉制金涂制作烤瓷冠未产生龈缘黑线,而单纯用镍铬合金制作内冠,可能产生龈缘黑线。结论：镍铬合金烤瓷内冠不可避免会产生龈缘黑线,金合金烤瓷内冠避免了上述缺点,而镍铬合金内冠涂制金粉则是一条经济,实效的制作工艺。     

Kinorhyncha from the stomach of the shrimp Pleoticus muelleri (Bate, 1888) from Comodoro Rivadavia, Argentina

Six kinorhynchs were found in the stomachs of the Argentine red shrimp, Pleoticus mulleri (Bate, 1888) from the Argentine coast of Patagonia. Three new species are described: Condyloderes storchi n. sp., Pycnophyes argentinensis n. sp. and P. neuhausi n. sp. A fourth species, Kinorhynchus anomalus Lang, 1953 was previously known only from the coast of Chile. This is the third known record of kinorhynchs documented as a food source. Condyloderes storchi, n. sp. is the fourth new species in this genus. It is distinguished by its paradorsal cuspidate spines on segments 7 and 9, lateral accessory and ventrolateral spines on segments 3, 6, 7, 10 and 11. P. argentinensis, n. sp. has nearly equal sternal width for segments 3–11 (about 7% of the trunk length), episternal plates with three distinct areas along the anterior margin, mid-sternal plate with even margin, mid-dorsal spinose protrusions along the terminal borders of segments 11 and 12, and lateral terminal spines 176 μm long, about 21% of trunk length. P. neuhausi, n. sp.has a prominent posterior elongation of the tergal plate of segment 3, uneven lateral margins of the mid-sternal plate, a maximum sternal width at segment 3, no mid-dorsal spinose processes and mid-ventral thickenings on segments 10–12.     

Sensitivity of Petri disease pathogens to hot-water treatments in vitro

Petri disease pathogens ( Phaeoacremonium spp. and Phaeomoniella chlamydospora ) are able to colonize the vessels in the xylem of grapevine propagating material. Hot-water treatment (HWT) protocols at 50°C for 30 min have been applied in grapevine nurseries to control these pathogens with variable results. The effect of HWT in vitro at higher temperatures on Pa.   chlamydospora , Phaeoacremonium aleophilum and Phaeoacremonium parasiticum isolates was determined by placing conidial suspensions and plugs of agar with mycelia in Eppendorf vials and incubated in hot water at 49, 50, 51, 52, 53 or 54°C for 30, 45 or 60 min. Conidial germination and the colony growth rate decreased with increased temperature and time combinations. Pa.   chlamydospora was more sensitive than Phaeoacremonium spp. to the experimental temperatures for all periods of time. Pa.   chlamydospora tolerated temperatures of 53°C, while Pm.   aleophilum and Pm.   parasiticum tolerated temperatures of 54°C, although the treatments above 51–52°C drastically reduced conidial germination and mycelial growth. These results highlight the need to develop HWT using temperatures above 51°C to reduce the incidence of fungal infections and ensure high-quality propagating material for grapevine growers.     

uPA binding increases UPAR localization to lipid rafts and modifies the receptor microdomain composition

UPAR is a GPI anchored protein, which is found in both lipid rafts and in more fluid regions of the plasma membrane. We have studied the role of the ligand uPA on uPAR localization and on the composition of the lipid membrane microdomains. We have analyzed the glycosphingolipid environment of uPAR in detergent resistant membrane (DRM) fractions prepared by cell lysis with 1% Triton X-100 and fractionated by sucrose gradient centrifugation obtained from HEK293-uPAR cells. The uPAR specific lipid membrane microdomain has been separated from the total DRM fraction by immunoprecipitation with an anti-uPAR specific antibody under conditions that preserve membrane integrity. We have also tested uPA-induced ERK phosphorylation in the presence of methyl-β-cyclodextrin, which is known to disrupt lipid rafts by sequestering cholesterol from such domains. Our results show that uPAR is partially associated with DRM and this association is increased by ligands, is independent of the catalytic activity of uPA, and is required for intracellular signalling. In the absence of ligands, uPAR experiences a lipid environment very similar to that of total DRM, enriched in sphingomyelin and glycosphingolipids. However, after treatment of cells with uPA or ATF the lipid environment is strongly impoverished of neutral glycosphingolipids.     

Expressing the yeast HAL1 gene in tomato increases fruit yield and enhances K+/Na+ selectivity under salt stress

The yeast HAL1 gene facilitates K⁺/Na⁺ selectivity and salt tolerance of cells. Ectopic expression of HAL1 in transgenic tomato (Lycopersicon esculentum Mill.) plants minimized the reduction in fruit production caused by salt stress. Maintenance of fruit production by transgenic plants was correlated with enhanced growth under salt stress of calli derived from the plants. The HAL1 transgene enhanced water and K⁺ contents in both leaf calli and leaves in the presence of salt, which indicates that HAL1 functions in plants using a similar mechanism to that in yeast, namely by facilitating K⁺/Na⁺ selectivity under salt stress.