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931.
932.
Background
Mass poisonings with methanol are rare but occur regularly both in developed and in developing countries. Data from the poisoning episodes are often published, but follow-up-data is scarce. We therefore conducted a six year follow-up study after the large methanol outbreak in Estonia in September 2001. 相似文献933.
934.
Johanson Lennart Underdal Bjarne Grøsland Knut Whelehan Oliver P. Roberts Terence A. 《Acta veterinaria Scandinavica》1983,24(1):1-13
The bacteriological quality of beef and pig carcasses was assessed at 9 Norwegian abattoirs by sampling 10 carcasses at multiple sites on each of several visits. On beef carcasses the following sites consistently carried higher numbers of bacteria: the Brisket, the Fore-ribs, the Flank groin, and the Round medial. There was no evidence that beef slaughter and dressing in the hanging position was superior to methods where the carcass was lying until the hide puller. On pork carcasses the Cheek, and the Abdomen lateral surface (belly) were most heavily contaminated. The hygienic quality of pork carcasses in abattoirs where singeing was a separate step tended to be better than where a combined singeing and dehairing machine was used. This survey suggests that bacteriological monitoring of slaughter at this level of sampling and visiting is able to detect consistently poor hygienic practices. Where direct comparisons with data from other countries could be made, the present investigation indicates that the bacterial counts on Norwegian beef and pork carcasses are of the same order or better. 相似文献
935.
A case of generalized avian tuberculosis in sheep is described. The case was somewhat unusual. No calcification and slight encapsulation together with scanty participation of epithelioid cells in the inflammations were typical features. The source of the infection, in an area where this disease is rare, is not known. 相似文献
936.
Aldoses are degraded by vanadium pentaoxide in m sulphuric acid into formic acid and the next lower aldose, and aldonic acids are degraded into carbon dioxide and the next lower aldose. Each reaction consumes two equivalents of oxidant. Glycoaldehyde is oxidized to formic acid via glyoxal, and glycolic acid is oxidized to carbon dioxide and formic acid via glyoxylic acid. 相似文献
937.
Mette Johansen Finn Tnnesen Knut E. Rasmussen 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1992,573(2)
A sensitive and selective method for the detection of pholcodine and its metabolite morphine in urine using high-performance liquid chromatography is described. It involves on-line clean-up of urine on a trace enrichment column packed with a polymeric strong cation-exchange material. Pholcodine and its metabolites were separated on two analytical columns with different selectivities. Pholcodine was detected by a fluorescence detector and morphine was detected electrochemically. One system, based on reversed-phase chromatography, applied a polystyrene—divinylbenzene column and gradient elution. The other system was based on normal-phase chromatography with a silica column and isocratic elution. Morphine was confirmed to be a metabolite of pholcodine by reversed-phase chromatography and electrochemical detection. Two unidentified metabolites of pholcodine were separated from pholcodine by normal-phase chromatography and detected by fluorescence detection. 相似文献
938.
Knut Norstog 《American journal of botany》1967,54(7):831-840
The locomotor apparatus of the spermatozoid of Zamia integrifolia consists of numerous flagella having the typical 9 + 2 substructure connected through basal bodies to a spiral band of complex structure. Basal bodies have a fine structure somewhat resembling that found in algae, mosses, and ferns, but they are much longer. They are composed of a circle of 9 double fibers just beneath the plasma membrane, changing to 9 doublets interconnected by fibrils in a star-pattern, giving over to a centriolar type of 9 triplet fibers embedded in an electron-dense layer of the spiral band, and ending in a “cartwheel” configuration. A system of microtubules arranged in a spiral, secondary to the flagellated spiral, is thought to underlie the plasma membrane in flagellated regions. It is suggested that this system accounts for “euglenoid” movements of the sperm. Other details of cellular fine structure are described. 相似文献
939.
Conventional studies of nitrogen (N) cycling in forest ecosystems have focused on inorganic N uptake as the primary source of N for plant metabolism. More recently, however, alternative sources of N for plant nutrition, such as free amino acids, have gained attention, particularly in nutrient-limited systems. Using a multiple stable isotope (13C and 15N) design, that allowed us to simultaneously assess root uptake of ammonium (NH4 +) and glycine, we compared the cycling dynamics of NH4 + and amino acid N within the soils of several interior Alaskan floodplain balsam poplar stands. Our design included multiple sampling periods extending from 45 min to 14 days, which permitted us to study interpool transfers of our carbon (C) and N isotopes over time. Microbial biomass N was the largest sink of both 15N-ammonium and glycine. Percent recovery of 15N for this pool was an order of magnitude larger than fine-root 15N uptake for most sampling periods. Although recovery of 15N in fine-root biomass was small, amino acid N and NH4 + were assimilated at approximately the same rate irrespective of sampling period, and total recovery was still increasing 2 weeks after application. Recovery of 15N in bulk soil samples did not vary significantly over time for either treatment. However, bulk soil 13C declined steadily during the experiment, measuring less than 30% recovery of added label after 14 days. We suspect that the majority of 13C lost from our soils was respired. Soil microorganisms strongly outcompeted plants in the short term for both NH4 + and amino acid N. However, amino acid N appears to cycle through soil N pools at approximately the same rate as inorganic N forms. The similarity in uptake patterns for inorganic and organic N suggests that these stands are meeting part of their N requirements directly from amino acids. 相似文献