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排序方式: 共有267条查询结果,搜索用时 15 毫秒
1.
Comparison of 4 point‐of‐care blood gas analyzers for arterial blood gas analysis in healthy dogs and dogs with cardiopulmonary disease
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Giese C Miethe N Schlenker G 《Berliner und Münchener tier?rztliche Wochenschrift》2007,120(3-4):141-147
Estrogens of human and animal origin that reach the aquatic environment may enter human or animal organism and act as endocrine disruptors.To investigate the persistency of estrogens in laboratory experiments, estrone respectively 17beta-estradiol were added to stream water sampled from river Spree in Berlin. The concentration of estrone and 17beta-estradiol was quantified using enzyme-immuno-assay. The estrone concentration decreased to less than 5 % of the starting concentration at storage temperature of 5 degrees C within 56 days and at storage temperature of 20 degrees C within 14 days. If the estrone were added to autoclaved stream water, no biodegradation was observed. Biodegradation was enhanced when activated sludge was added. Escherichia coli, Pseudomonas fluorenscens and Aeromonas hydrophila in monoculture did not degrade estrone in autoclaved stream water.The concentrations of 17beta-estradiol and estrone decreased similarly.The logistic function proved to be suitable to describe the course of time for the decrease of concentration. 相似文献
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Expression of porcine endogenous retroviruses (PERVs) in melanomas of Munich miniature swine (MMS) Troll 总被引:1,自引:0,他引:1
Dieckhoff B Puhlmann J Büscher K Hafner-Marx A Herbach N Bannert N Büttner M Wanke R Kurth R Denner J 《Veterinary microbiology》2007,123(1-3):53-68
Porcine endogenous retroviruses (PERVs) are integrated in the genome of all pig breeds. Since some of them are able to infect human cells, they might represent a risk for xenotransplantation using pig cells or organs. However, the expression and biological role of PERVs in healthy pigs as well as in porcine tumours is largely unknown. Since we and others have recently shown overexpression of a human endogenous retrovirus, HERV-K, in human melanomas, we studied the expression of PERVs in melanomas of selectively bred Munich miniature swine (MMS) Troll. This breeding herd of MMS Troll is characterised by a high prevalence of melanomas, which histologically resemble various types of cutaneous melanomas in humans. Several genetic factors have been defined when studying inheritance of melanomas and melanocytic nevi in MMS Troll. Here we show that the polytropic PERV-A and PERV-B as well as the ecotropic PERV-C are present in the genome of all melanoma bearing MMS Troll investigated. Most interestingly, in the spleen, but not in other organs, recombinant PERV-A/C proviruses were found. PERV expression was found elevated in melanomas when compared to normal skin and viral proteins were expressed in melanomas and pulmonary metastasis-derived melanoma cell cultures. During passaging of these cells in vitro the expression of PERV mRNA and protein increased and virus particles were released as shown by RT activity in the supernatant and by electron microscopy. Genomic RNA of PERV-A, -B and -C were found in pelleted virus particles. Although PERV expression was elevated in melanomas and pulmonary metastasis-derived cell cultures, the function of the virus in tumour development is still unclear. 相似文献
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Journal of Plant Diseases and Protection - In the original publication, the article title was incorrectly published as ‘Impact of leave infestation by herbivorous insects on the elemental... 相似文献
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Intercropping or rotating of P‐efficient crop species which mobilize sparingly soluble P by their root exudates can have beneficial effects on growth and P uptake of P‐inefficient species. We aimed at studying the effect of intercropping or incorporating of crop residues of P‐efficient crops on the components of maize P‐uptake, i.e. the root‐system size and P influx (P‐uptake rate per unit root length). This was studied in 3 pot experiments in a low‐P sandy soil. In the first experiment, maize was intercropped with white lupine, sugar beet or oilseed rape, and with groundnut in the second experiment. In the third experiment, maize was grown after incorporating the crop residues of white lupine, sugar beet or oilseed rape. Maize growth and yield was strongly inhibited when intercropped with white lupine, sugar beet or oilseed rape, probably because of competition for nutrients. But with groundnut as the accompanying species, maize yield was increased by a factor of 3, mainly because of an enhanced P influx. Crop residues of oilseed rape and sugar beet increased the yield of maize by factors 2 and 1.6, respectively, because of a 3 and 2 times higher P uptake as compared to maize grown after maize without incorporation of crop residue. The reason for the higher maize P‐uptake after oilseed rape was an 11 times higher P influx as compared to maize without crop residues, and after sugar beet residues because of an enhanced root growth and a 4 times higher P influx. Lupine residues did not improve maize growth, mainly because of a low P influx, which was even less than that of maize grown without crop residues. The soil solution P concentration and calcium acetate lactate‐extractable P (CAL P) measured in this study did not reflect the P availability as indicated by the plants (P uptake, P influx). This indicates that other mechanisms such as P mobilization in the rhizosphere by root exudates or cell‐wall components were responsible for the increased P availability. These mechanisms need further investigation. 相似文献
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Norbert Domes 《Forstwissenschaftliches Centralblatt》1938,60(16):510-522
Ohne Zusammenfassung 相似文献
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Kocáková P Sláviková M Hajnická V Slovák M Gasperík J Vancová I Fuchsberger N Nuttall PA 《Folia parasitologica》2003,50(1):79-84
Interleukin-8 plays a critical role in inflammatory processes. Hence generation of molecules with anti-IL-8 activity is likely to be important for successful feeding and for survival of the ticks. Anti-IL-8 activity was studied in saliva of three ixodid tick species--Dermacentor reticulatus (Fabricius, 1794), Rhipicephalus appendiculatus Neumann, 1901, and Amblyomma variegatum (Fabricius, 1794). The greatest activity was shown in saliva prepared from D. reticulatus. The activity was attributed to tick salivary gland molecules that bind to IL-8, preventing binding of the chemokine to its specific receptor, rather than to occupation of the IL-8 cell receptor by the tick molecules. The distribution of anti-IL-8 activity in fast protein liquid chromatography (FPLC) fractions of salivary gland extracts (SGE) derived from adult female D. reticulatus, R. appendiculatus and A. variegatum was compared directly by both ELISA and receptor-binding inhibition assays. The correspondence in results with fractions of SGE from ELISA is consistent with detection of tick molecules that inhibit IL-8 binding to its receptor. As IL-8 is an important chemoattractant and activator of neutrophils, the presence of an anti-IL-8 activity in tick saliva indicates that neutrophils play an important role in the host response to parasitism by ticks. 相似文献