Identification of monoclonal antibodies against 2,4-D herbicide by ELISA and DNA sequencing

Seven hybridoma clones, E2/G2, E2/B5, E4/C2, G5/E10, F6/C10, B5/C3, and B7, produced within one fusion experiment in 1991 and the clone E4/C2 originated from 1995 were characterized by sequencing of genes coding for variable domains of the antibodies against 2,4-D herbicide. Amino acid sequences of selected antibodies, deduced from DNA analysis, were confirmed by mass spectrometry. Surprisingly, nucleotide sequence analysis of the clones E2/G2 and E2/B5, producing the most sensitive antibodies, proved to have sequence homology of their variable domains, although the IC(50) values determined for these antibodies 9 years prior to the DNA analysis were 2.0 and 8.2 ng/mL, respectively. The same findings arose from the comparison of the immunochemical to DNA data established for G5/E10, F6/C10, and B5/C3 clones producing antibodies with IC(50) values in the range of 26.3-43.1 ng /mL. The clone E4/C2, originating from the later fusion experiment, did not share nucleotide homology with any of the examined clones. Data obtained by ELISA, immunosensor, and DNA analysis within a 9 year period are discussed with respect to hybridoma stability, methodic artifacts, measurement reliability, and other possible factors influencing the result interpretation.     

Photoproduction of proton gradients with pi-stacked fluorophore scaffolds in lipid bilayers

Rigid p-octiphenyl rods were used to create helical tetrameric pi-stacks of blue, red-fluorescent naphthalene diimides that can span lipid bilayer membranes. In lipid vesicles containing quinone as electron acceptors and surrounded by ethylenediaminetetraacetic acid as hole acceptors, transmembrane proton gradients arose through quinone reduction upon excitation with visible light. Quantitative ultrafast and relatively long-lived charge separation was confirmed as the origin of photosynthetic activity by femtosecond fluorescence and transient absorption spectroscopy. Supramolecular self-organization was essential in that photoactivity was lost upon rod shortening (from p-octiphenyl to biphenyl) and chromophore expansion (from naphthalene diimide to perylene diimide). Ligand intercalation transformed the photoactive scaffolds into ion channels.     

大麦对赤霉病抗性遗传的研究

对二棱大麦６个品种之间进行完全双列杂交，分析大麦抗赤霉病的遗传方式．结果表明，大麦抗赤霉病是作用相加的很多基因起作用的数量性状遗传，这些基因之间不存在上位性，只存在显隐性关系，抗性强的基因是显性．所计算的广义遗传力为０．６０，狭义遗传力为０．４５．一部分品种中存在母性效应．     

松茸SCAR标记的建立

松茸群全球共报道15个种1变种,我国记载5个种1变种(臧穆,1990).长白山区有2种,即松茸(Tricholoma matsutake)和假松茸(T.bakamatsutake),同属于口蘑属.松茸是与松属(Pinus)树木共生的一种外生菌根菌,不仅菌肉肥厚、营养丰富、风味绝佳,而且具有抗癌作用(傅伟杰等,2005).     

Alcalase treatment for elimination of stickiness in pikeperch (Sander lucioperca L.) eggs under controlled conditions

Elimination of egg stickiness is an important factor in artificial reproduction of pikeperch (Sander lucioperca L.). This study was conducted to evaluate the effectiveness of Alcalase enzyme to remove the adhesive layer of pikeperch eggs. The eggs were treated with Alcalase at 0.5, 1.0, 1.5, 2.0 and 5.0 mL L^?1 or a milk/talc solution 2 min post insemination. Duration of exposure was 2 min in Alcalase and 60 min in milk/talc. The highest, albeit not significant, hatching rate (85.4%) was found with 1.5 mL L^?1 of Alcalase, but hatching rates were similar in 0.5, 1.0 and 2.0 mL L^?1. Hatching rates were significantly lower groups treated with 5.0 mL L^?1 Alcalase enzyme (56.4%) compared to groups treated with milk powder and talc (61.3%). Nominally complete removal of adhesiveness was observed in 1.5 and 2 mL L^?1. All Alcalase treatments led to significantly lower incubation duration compared with the traditional milk/talc treatment. The application of Alcalase successfully eliminated pikeperch egg stickiness in less time than with traditional milk/clay/talc methods.     

Sorption properties of iron impregnated activated carbon web for removal of methylene blue from aqueous media

In this study, impregnation of iron chloride was carried out on needle punched web of waste acrylic fibers, which was subsequently carbonized under layer of charcoal by physical activation in high temperature furnace to produce iron impregnated activated carbon (FeAC). For comparison purpose, one more sample of activated carbon (AC) was prepared without impregnation of iron chloride. Both the webs were carbonized at 1200 °C with no holding time, and characterization of BET surface area, SEM morphology, EDX elemental analysis, XRD crystalline structure was performed. The FeAC web was used as adsorbent for the removal of methylene blue from aqueous solution. The dye removal percentage was investigated at different experimental parameters like different dye concentrations, adsorbent dosage, stirring speed and different pH. The obtained results were analyzed using linear and non-linear forms of Langmuir and Freundlich isotherms and adsorption kinetics (i.e. pseudo first order and pseudo second order model).     

Mapping tree root systems with ground-penetrating radar

A ground-penetrating radar (GPR) technique was used to study the three-dimensional distribution of root systems of large (DBH = 14 to 35 cm) oak trees (Quercus petraea (Mattusch.) Liebl.) in relatively dry, luvisoil on loamy deluvium and weathered granodiorite. We used a pulse EKKO 1000 GPR system, a profile grid of 0.25 x 0.25 meters, at 0.05 m intervals, and a signal frequency of 450 MHz, to assure resolution of about 3 cm in both directions (further increases in resolution up to 1 cm are possible with the system). Coarse root density was 6.5 m m(-2) of stand area and 3.3 m m(-3) of soil volume. Maximum rooting depth of the experimental oaks was 2 m, and the root ground plan was significantly larger (about 1.5 times) than the crown ground plan. Based on earlier studies of Quercus robur L. from floodplain forests, where the extent of the root systems was much smaller (root ground plan:crown ground plan ratio of 0.6), we conclude that the high root ground plan:crown ground plan ratio indicates less favorable conditions of water supply at the experimental site than in the floodplain forest. The ground-penetrating radar system is noninvasive and allows relatively rapid and repeated measurements of the distribution of coarse root systems of trees.     

麦类赤霉病菌菌丝的伸长速度及其温度反应

供试赤霉病菌２４９个菌株，探讨菌丝的伸长速度和对温度的反应，结果表明：２５℃条件下，菌丝的伸长速度在菌株之间的差异很大，对高温或低温的耐性程度在菌株之间也有很大的差异，缩小菌株数，扩大温度梯度所做了试验结果表明：菌株之间对高温和低温耐性、温度反应、最适菌丝伸长温度等都有很大的差异。     

Fast Ecotoxicity Detection Using Biosensors

The article provides information about a new device, AlgaTox developed in the R&D project sponsored by the Technology Agency (n.TA02030179) and patented in Czech Republic (CZ 305687). Its functionality is based on the use of biosensor, and its main advantage is fast response rate. The toxicity detection is achieved through precise measurement of green algae oxygen production dynamics after their exposure to light of wavelength of 680 nm. Clark sensor with a resolution of 0.05% of the equilibrium oxygen concentrations and stability at a constant pressure and temperature of 0.1% of the equilibrium oxygen concentration at the 24-h measurement is used for the oxygen detection. Laboratory testing of the device has been made using silver nitrate, substance with known inhibitory effect on algae. Real samples of aqueous soil extracts and waste sample from old dried-up industrial tailing pond enriched with insecticide have been also tested. The values of oxygen production inhibition or stimulation determined with the new device in the evaluation of real samples were up to six times higher in comparison with the corresponding values of inhibition (stimulation) of growth rates determined by standard procedure.     

SPI-1-encoded type III secretion system of Salmonella enterica is required for the suppression of porcine alveolar macrophage cytokine expression

ABSTRACT: Genes localized at Salmonella pathogenicity island-1 (SPI-1) are involved in Salmonella enterica invasion of host non-professional phagocytes. Interestingly, in macrophages, SPI-1-encoded proteins, in addition to invasion, induce cell death via activation of caspase-1 which also cleaves proIL-1β and proIL-18, precursors of 2 proinflammatory cytokines. In this study we were therefore interested in whether SPI-1-encoded type III secretion system (T3SS) may influence proinflammatory response of macrophages. To test this hypothesis, we infected primary porcine alveolar macrophages with wild-type S. Typhimurium and S. Enteritidis and their isogenic SPI-1 deletion mutants. ΔSPI1 mutants of both serovars invaded approx. 5 times less efficiently than the wild-type strains and despite this, macrophages responded to the infection with ΔSPI1 mutants by increased expression of proinflammatory cytokines IL-1β, IL-8, TNFα, IL-23α and GM-CSF. Identical macrophage responses to that induced by the ΔSPI1 mutants were also observed to the infection with sipB but not the sipA mutant. The hilA mutant exhibited an intermediate phenotype between the ΔSPI1 mutant and the wild-type S. Enteritidis. Our results showed that the SPI-1-encoded T3SS is required not only for cell invasion but in macrophages also for the suppression of early proinflammatory cytokine expression.