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1.
Summary Cellular fatty acids inLactobacillus büchneri were transmethylated with H2SO4 catalyst in methanol at elevated temperature. By optimising the reaction time and the amounts of catalyst and methanol used at a fixed temperature it was possible to maximise the lactobacillic acid yield. The yield of lactobacillic acid with this method was better than with the traditional method using base-catalysed saponification followed by HCL-catalysed methylation.  相似文献   
2.
In producing power, humans move the nutrients nitrogen (N) and phosphorus (P) from their long‐term geological and biological stocks and release or emit them in soil, water, and the atmosphere. In Finland, peat combustion is an important driver of N and P fluxes from the environment to human economy. The flows of N and P in the Finnish energy system were quantified with partial substance flow analysis, and the driving forces of emissions of nitrogen oxides (NOx) were analyzed using the ImPACT model. In the year 2000 in Finland, 140,000 tonnes of nitrogen entered the energy system, mainly in peat and hard coal. Combustion released an estimated 66,000 tonnes of N as nitrogen oxides (NOx) and nitrous oxides (N2O) and another 74,000 tonnes as elemental N2. Most of the emissions were borne in traffic. At the same time, 6,000 tonnes of P was estimated to enter the Finnish energy system, mostly in peat and wood. Ash was mainly used in earth construction and disposed in landfills; thus negligible levels of P were recycled back to nature. During the twentieth century, fuel‐borne input of N increased 20‐fold, and of P 8‐fold. In 1900–1950, the increasing use of hard coal slowly boosted N input, whereas wood fuels were the main carrier of P. Since 1970, the fluxes have been on the rise. NOx emissions leveled off in the 1980s, though, and then declined in conjunction with improvements in combustion technologies such as NOx removal (de‐NOx) technologies in energy production and catalytic converters in cars.  相似文献   
3.
To elucidate the position of the peptide bond in glutamyl-taurine this dipeptide was extracted from calf brain synaptic vesicles and subjected to paper electrophoresis. It was analyzed further in an automatic amino acid analyzer prior and subsequent to acid hydrolysis. Both alpha- and gamma-forms were found to be present in approximately equal amounts.  相似文献   
4.
Abstract In a previous study, we have described unusual cross-reactions among monoclonal antibodies (Mabs) to bacteria and in particular to the Inaba and Ogawa serotypes of Vibrio cholerae . In this study, the extent to which the binding sites of both antibodies and antigens overlap has been investigated by competitive binding and idiotypic analysis. The competitive binding data indicate that the cross-reactive binding of the Inaba Mabs to the Ogawa vibrios can be abolished by incubation with higher affinity Ogawa Mabs. However, rabbit antiserum raised against the Inaba series does not react with the Ogawa series, indicating that anti-Inaba Mabs do not share idiotypic determinants with anti-Ogawa Mabs. The results therefore suggest that the two sets of antibodies recognise different determinants which are closely related in spatial terms, and which consequently do not permit simultaneous binding of the two types of monoclonal antibody.  相似文献   
5.
Summary A knowledge based system has been shown to be a powerful tool for diagnosing microbial activities during a fermentation process. Knowledge about lactic acid fermentation was collected by an experimental study ofLactobacillus casei. The effects of the inoculum properties and sterilization time on the cultivation were expressed in a form of a fuzzy rule-based knowledge network. The system was able to detect abnormal inoculum or sterilization conditions which caused malfunctions in the cultivations.  相似文献   
6.
Two experiments were carried out to compare the cardiorespiratory and metabolic effects of cross-country skiing and running training during two successive winters. Forty-year-old men were randomly assigned into skiing (n = 15 in study 1, n = 16 in study 2), running (n = 16 in study 1 and n = 16 in study 2) and control (n = 17 in study 1 and n = 16 in study 2) groups. Three subjects dropped out of the programme. The training lasted 9-10 weeks with 40-min exercise sessions three times each week. The training intensity was controlled at 75%-85% of the maximal oxygen consumption (VO2max) using portable heart rate metres and the mean heart rate was 156-157 beats.min-1 in the training groups. In the pooled data of the two studies the mean increase in the VO2max (in ml.min-1.kg-1) on a cycle ergometer was 17% for the skiing group, 13% for the running group and 2% for the control group. The increase in VO2max was highly significant in the combined exercise group compared to the control group but did not differ significantly between the skiing and running groups. The fasting serum concentrations of lipoproteins and insulin did not change significantly in any of the groups. These results suggested that training by cross-country skiing and running of the same duration and intensity at each session for 9-10 weeks improved equally the cardiorespiratory fitness of untrained middle-aged men.  相似文献   
7.
Pekka Hello 《Ecography》1985,8(2):120-132
Breeding bird communities in five stages of secondary forest succession were studied in northeastern Finland in 1980–82. Three groups of communities were distinguished: open land, brush phase and forest communities, dominated by Motacilla alba and Oenanthe oenanthe, Phylloscopus trochilus and Anthus trivialis, Phylloscopus trochilus and Fringilla montifringilla , respectively.
Pair density, number of species, biomass of adult birds and species diversity increased in the course of succession, none of these, however, monotonously. Average bird weight showed a decreasing trend although the variation was considerable. The degree of specialization in communities (measured by ratios derived from numbers of species, genera and families) increased in the course of succession with the exception that the initial stage had relatively high values. Species nesting and feeding in trees and shrubs increased in numbers during forest regeneration whereas species nesting and feeding on the ground showed the opposite trend. The proportions of hole-nesting and sedentary species increased with increasing forest age.
The initial stages of forest succession in the north are occupied by specialized open habitat species breeding originally on open bogs and shores. These communities thus clearly differ from those predicted from the general theory of succession, which postulates that the pioneer stages of succession are dominated by habitat generalists and that these communities should have relatively low values of community diversity.  相似文献   
8.
9.
Mass Spectrometric Analyses of Brain Synaptic Peptides Containing Taurine   总被引:2,自引:2,他引:0  
The structure of a number of low-molecular-weight acidic peptides containing taurine prepared from calf brain synaptosomes and their subcellular vesicles was studied using electron impact mass spectrometry. At least seven sequences could be identified: N-acetylaspartyl-glutamyl-taurine, N-acetylaspartyl-taurine, N-acetylglutamyl-taurine, glutamyl-taurine, aspartyl-taurine, seryl-glutamyl-seryl-taurine, and seryl-taurine.  相似文献   
10.
Strain while skiing and hauling a sledge or carrying a backpack   总被引:1,自引:0,他引:1  
Eight soldiers on skis transported three loads of different weights on the level, uphill and downhill. The load was placed either on a cargo sledge or in a backpack or divided between the sledge and the backpack. The sledge had a new type of haulage-shaft, which was fixed to both sides of the pelvis. A service belt spread the pull over the whole upper body. The physical stain of different transport methods and the serviceability of the sledge was studied by measuring heart rate (HR), oxygen consumption, ventilation, and perceived exertion. The results indicate that both absolute and relative strain were systematically lower when pulling the load on the sledge than when carrying it in the backpack and on the sledge. HR when pulling a load equal to the human body weight on the sledge was on average 133 beats X min-1; HR was significantly higher 144 beats X min-1 when the load was divided between backpack and sledge. At the lower load level the differences between the transport methods were not significant for HR, oxygen consumption or ventilation. Uphill travel increased oxygen consumption by about 50% over that on the level. Perceived exertion at all load levels was significantly lower with the sledge than with the backpack alone or in combination. The estimated maximal allowable working time emphasized the advantage of the sledge and the importance of high physical working capacity. The maneuverability of the sledge with the new haulage shaft was good and the braking mechanisms worked well.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
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