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901.
Summary Between 3 Nov. 1983 and 9 Apr. 1984, six applications of fertiliser N (ammonium, nitrate or urea) were given to four autumn
sown (26 Oct. 1983)Vicia faba L cultivars, Banner Winter (BW) and Maris Beagle (MBg), cold tolerant cultivars normally sown in the autumn, and Herz Freya
(HF) and Maris Bead (MBd), cold sensitive cultivars more commonly sown in the spring. The effects of additional N were determined
by comparison with plants given zero-N (controls).
Application of N, regardless of form, had no effect on % emergence at the first sampling (15 Dec. 1983); >90% for BW, MBg
and HF, but only 40–60% for MBd. At this time the dry weight, carbon content and nitrogen content of all cultivars was approximately
20% less than that of the seed on planting. No more plants emerged after 15 Dec. 1983. Between 15 Dec. 1983 and 20 Feb. 1984,
all cultivars, regardless of N treatment, showed little change in dry weight, carbon content and nitrogen content but the
proportion of total plant dry weight, carbon content and nitrogen content in the cotyledons decreased while the proportions
in root, stem and leaf tissue increased. On 20 Feb. 1984 there were no N effects. All cultivars but especially BW and MBg,
showed progressive increases in dry weight, carbon content and nitrogen content during the period 20 Feb. 1984 to 8 May 1984.
Pooled results for all four cultivars indicated that on 8 May 1984, plants given ammonium and urea had a greater dry weight,
carbon content and nitrogen content than controls.
At harvest (1–3 Sep. 1984), BW and MBg outyielded (g dw seed m−2) HF and MBd. Pooled results for all cultivars indicated that application of N regardless of form gave increased yield and
an increased N concentration (mg N g−1 dw) in the seed. 相似文献
902.
Quantitative histology of the hypertrophied human heart 总被引:1,自引:0,他引:1
Myocardial hypertrophy accompanies systemic hypertension and aortic stenosis, i.e., pressure overload. In man cardiac failure only appears after years of pressure overload, during which time cardiac function had been maintained. The structural correlates of cardiac failure have been a subject of much interest for many years. Several hypotheses relating alterations in muscle fiber alignment, capillary density, or collagen content have been offered. The application of morphometric techniques has provided essential quantitative information on the structural components of the normal and diseased heart. These data indicate that muscle fiber alignment remains normal in the pressure overloaded heart despite the presence of hypertrophy or the appearance of clinical failure. On the other hand, capillary density is decreased and collagen content is increased in hypertrophied hearts. Chemical studies on collagen concentration however have yielded inconsistent results. The relative contribution of the microcirculation and collagenous structure of the myocardium on its respective O2 availability, mechanical behavior, and deterioration in pump function will require further investigation. 相似文献
903.
904.
L I Moteiunas I S Meshcheriakova T N Demidova 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1984,(2):67-71
There are practically no records of cases of tularemia among humans in the Lithuanian SSR. Nevertheless, the mass sero-allergic survey of the population for tularemia, carried out 10-12 years ago, showed that 2.3% of the adult population in the Republic had had contacts with the causative agent of this infection. The work was aimed at the determination of the present activity of the foci of tularemia. During 6 years in 22 rural districts 2582 samples of avian excrements, containing bones and wool of small animals, were collected and studied by means of the antibody neutralization test (ANT). In 132 (5.1 +/- 0.4%) excrement samples collected on the territory of 12 districts Francisella tularensis antigen was detected. The average ANT titer was 45.2, the maximum titer (10 excrement samples) reached 1: 160. The study revealed the existence of the natural foci of tularemia in Lithuania at present, but their activity proved to be low. The most unfavorable situation was found to exist in western districts of the Republic. 相似文献
905.
906.
J M Eaton 《BMJ (Clinical research ed.)》1980,281(6242):758-759
907.
908.
Detailed methods are presented for measurement and study of in vivo mutations and in vitro mutagenesis in human lymphocytes. The methods described include preparation of conditioned medium containing interleukin-2, enumeration of mutant clones, in vitro mutagenesis, and expansion of mutant clones for further study. 相似文献
909.
910.
Cytosolic protein phosphotyrosine phosphatases from rabbit kidney. Purification of two distinct enzymes that bind to Zn2+-iminodiacetate agarose 总被引:14,自引:0,他引:14
Cytosolic protein phosphotyrosine (PPT) phosphatase was measured using a new substrate, Tyr(32P)-labeled bovine serum albumin. Kidney was found as a particularly rich tissue source of PPT-phosphatase activity, containing twice as much as liver and over 10-fold more than brain, heart, lung, or skeletal muscle. An affinity column of Zn2+-iminodiacetate agarose adsorbed up to 60% of the PPT-phosphatase present in kidney extracts. Subsequent chromatography on DEAE-Sepharose separated the phosphatase into two peaks, labeled I and II, that had Mr = 34,000 and 37,000, respectively, upon gel filtration with Sephadex G-75 Superfine. Overall purification of 850- and 1100-fold was achieved with a net 4% yield. Both phosphatases hydrolyzed p-nitrophenylphosphate as well as the protein substrate in the presence of EDTA. Peak I phosphatase activity displayed a neutral pH optimum, had an absolute requirement for sulfhydryl compounds, and was sensitive to trypsin, whereas Peak II activity had an acidic pH optimum and was active without mercaptans. The two proteins also gave different fragmentation patterns by gel electrophoresis after digestion with S. aureus V8 protease. The results show that multiple forms of PPT phosphatase specifically interact with Zn2+ and provide a basis for further structural and functional comparisons among different members of the phosphoprotein phosphatase family. 相似文献