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1.
Summary A sandy loam (pH 6.5) was incubated at 28°C at static moisture levels, ranging from 10 per cent saturation to 133 per cent saturation (waterlogging), for 6 and 12 weeks; other samples covering the same moisture range were first incubated for 6 weeks, and after changing all moisture levels to 50 per cent saturation were incubated for a further 6 weeks.With increasing static soil moisture level during incubation there was a slight reduction in Morgan-extractable phosphate up to 70 per cent saturation, but thereafter, due to anaerobic effects, there were considerable increases in extractable phosphate with increasing moisture level.With changing moisture level during incubation the effects of anaerobiosis became apparent where original moisture level was greater than 50 per cent saturation; extractable phosphate was reduced to levels lower than those occurring where the soil was maintained continuously at 50 per cent saturation. The extent of reduction in extractable phosphate increased with original soil saturation level. 相似文献
2.
A pot culture experiment was conducted on a loamy sand soil to study the effect of FYM and Fe on dry matter yield and uptake of nutrients by oats (Avena sativa) crop in green-house. Application of Fe @ 5 and 20 ppm increased dry matter yield by 5.11 and 11.55 per cent, respectively. The per cent increase in dry matter yield over control with the application of 0.5 and 1.0 percent FYM was 19.06 and 30.07, respectively. Application of FYM increased concentration and uptake of P significantly. Phosphorus uptake increased by 23.60, 54.38, 91.01 and 134.61 per cent over control with 0.5, 1.0, 2.0 and 4.0 per cent FYM, respectively. Phosphorus concentration decreased at 20 ppm Fe but uptake increased significantly at 5 ppm Fe. Concentration and uptake of Ca increased with increasing amounts of Fe and application of FYM decreased concentration of Ca but uptake increased upto 1.0 per cent FYM over control. The Mg concentration and uptake decreased significantly with increased amount of Fe. Application of FYM also decreased Mg concentration but its uptake increased upto 1.0 per cent FYM and then decreased.Iron concentration and uptake increased upto 2 per cent FYM and then decreased. Whereas concentration of Fe decreased with increased amount of applied Fe but its uptake increased nonsignificantly with increased amount of added Fe.Managenese concentration and uptake decreased significantly with increased amount of applied Fe. Managenese concentration increased upto 0.5 per cent FYM but its uptake continued increasing with increasing amounts of applied FYM. 相似文献
3.
EXPERIMENTALLY INDUCED CHANGES IN THE BASE COMPOSITION OF THE RIBONUCLEIC ACIDS OF ISOLATED NERVE CELLS AND THEIR OLIGODENDROGLIAL CELLS 总被引:3,自引:0,他引:3
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The effect of tricyano-amino-propene, a dimer of malononitrile, on the base composition of the RNA in isolated Deiters' nerve cells and their oligodendroglial cells has been studied using a microelectrophoretic method. Tri-a-p in a dose of 20 mg/kg has the effect of increasing the RNA and protein content per nerve cell by 25 per cent and decreasing the glia RNA by 45 per cent. The RNA base composition of the nerve cells from the control animals differs from that of their glial cells. The guanine of the nerve cell is significantly higher than that of the glia, but the content of cytosine is higher in the glia than in the RNA of nerve cell. The cytosine of nerve cells decreased significantly after tri-a-p administration. In the glial cells the cytosine showed a 20 per cent increase, and the guanine a 25 per cent decrease. Tri-a-p sharpened the difference in RNA composition already existing between the control nerve cells and their glial cells by almost 300 per cent for the guanine and by 400 per cent for the cytosine. The chemical and functional relationship between the nerve cell and its oligodendroglial cells is discussed. 相似文献
4.
C Lücke-Huhle L Hieber R D Wegner 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1983,43(2):123-132
Severe and partly irreversible G2 arrest caused by americium-241 alpha-particles in Chinese hamster V79 cells acted as a competing process to the yield of detectable aberrant mitoses at metaphase. With increasing dose of alpha-radiation an increasing fraction of cells was irreversibly arrested in G2 with the consequence of interphase death before the first post-irradiation mitosis. This irreversible G2 arrest (demonstrated by flow cytofluorometry and mitotic indices) could be overcome by adding caffeine 8 hours after irradiation, the time point of maximum G2 arrest (80-90 per cent of all cells). Within 3.5 hours the number of aberrant mitoses increased by this treatment from 54 to 96 per cent and from 65 to 99.9 per cent for doses of 1.75 and 4.38 Gy of alpha-particles, respectively. The aberration frequency per mitotic cell, scored as chromatid and isochromatid breaks, rings, interchanges and dicentrics increased by a factor of about 3 after releasing G2 arrested cells. The frequency distribution of aberrations per cell revealed that, after 4.38 Gy, 58 per cent of the formerly G2-arrested cells had more than five aberrations per cell compared to only 8 per cent without the interaction of caffeine. 相似文献
5.
P. Lähdesmäki 《Physiologia plantarum》1968,21(5):1097-1103
Free amino acids were determined quantitatively by thin-layer chromatography and identified by various chromatographic methods in the leaves of two floating water ferns. Special interest was paid to the amount of γ-amino butyric acid. Water soluble nitrogen compounds increase in the leaves of both plants during the growth of three to four weeks in darkness. Compounds especially accumulating are ammonia and the amides asparagine and glutamine. The amount of most proper amino acids is reduced in the dark, except γ-amino butyric acid, which, in addition to amides, is the main amino compound increasing in darkness. 0.1 M HCl extracts the greatest amount of nitrogen compounds of low molecular weight from the dried leaves of the experimental plants. If we denote the amount of the dissolved amino compounds as 100 per cent, we can say that water extracts 96 per cent of the amino compounds, and that an 80 per cent ethanol solution extracts 79 per cent of these compounds. 相似文献
6.
Purulent complications in the surgical treatment of patients with mouth cancer and their prevention]
M A Kropotov E G Matiakin A V Zheltova N V Dmitrieva 《Antibiotiki i khimioterapii͡a》1999,44(5):29-32
Local purulent complications after surgical operations for mouth cancer were recorded in 49 (61.3 per cent) out of 80 cases and were mainly due to associations of 2 or more pathogens. The analysis of the factors influencing the development of the complications showed that there was no reliable increase in the number of the complications in the patients subjected at the first stage to the treatment with various antitumor agents: 17 (53.1 per cent) events in the group of the patients subjected to radiotherapy in a total focal dose of 40 Gy, 8 (72.7 per cent) events in the group of the patients subjected to radiotherapy in a dose of more than 60 Gy, 13 (59.1 per cent) events in the group of the patients treated with antitumor drugs and 8 (66.7 per cent) events in the group of the patients operated at the first stage of the treatment. The incidence of osteomyelitis was significantly higher in the group of the patients subjected to radiotherapy before the operation: 13 (30.2 per cent) events vs. 2 (5.4 per cent) in the group of the patients not subjected to radiotherapy. With increasing of the radiation dose, the incidence of osteomyelitis as well increased: 8 (25.0 per cent) osteomyelitis events in the group of the patients subjected to radiotherapy in a dose of 40 Gy and 5 (45.5 per cent) events in the group of the patients subjected to radiotherapy in a dose of more than 60 Gy. The method of osteosynthesis of the lower maxilla with titanium miniplates was also of great importance. The use of various schemes for antibiotic prophylaxis of wound infection in such patients was equally efficient. 相似文献
7.
The mortality rate for cervical cancer in California declined during the period 1950-64. Indirect evidence shows that the incidence is also declining, but it is difficult to assess this decline because of the effect of the increasing use of cytologic examination on incidence rates for cervical cancer.Cervical cancer, in the 57 hospitals reporting to the California Tumor Registry, is being diagnosed at an earlier stage than in previous years. The proportion of cases diagnosed with the lesion still in the in situ stage rose from zero in 1942 to 56 per cent in 1963, and invasive cervical cancer, as a proportion of all invasive cancer in women, decreased from 15 per cent to 9 per cent. There is wide variation among hospitals in the proportion of cervical cancer cases that are in situ at time of diagnosis. 相似文献
8.
Summary A field experiment was designed to determine the salt tolerance of three varieties of sweet pepper for paprika, studying the
effects of four increasing levels of sodium chloride in the irrigation water (5, 10, 29 and 42 meq/l) on soil salinity, yields,
and quality of the fruits.
EC5:1 and the soluble sodium and chloride contents increased with increasing salinity. The yields were reduced by 5 per cent for
variety ‘Ramillete’, 19 per cent for ‘Tres cascos’, and 40 per cent for ‘Bola’ at the highest level. The fruit quality variables
studied (colour index and chloride contents) differed with the variety. re]19750925 相似文献
9.
The Influence of Temperature, Moisture, and Oxygen on Period of Seed Viability in Barley, Broad Beans, and Peas 总被引:3,自引:0,他引:3
The viability of seeds of barley, broad beans, and peas hasbeen examined in hermetic storage over a range of temperaturesfrom 25? to 45? C and over a range of moisture contents fromabout 12 to 18 per cent. It was found that the survival curvesunder nearly all conditions can be described as negative cumulativenormal distributions. Under very severe storage conditions,however, when the mean viability period is of the order of aweek or less, the survival curves may become slightly skew.The spread of the distribution is linearly proportional to themean viability period. There is a negative linear relationshipbetween log mean viability period and both temperature and moisturecontent. Because of these relationships it is possible to predictthe percentage germination of these species after any givenperiod under a wide range of storage conditions. This patternof loss of viability in barley, broad beans, and peas is consistentwith that previously shown for wheat and rice. Oxygen has been shown to have a deleterious effect on the viabilityof barley, beans, and peas. Most of the deleterious effect isproduced by increasing the oxygen level from 0 per cent (nominal)to 21 per cent at atmospheric pressure; a further increase to100 per cent has comparatively little effect. The deleteriouseffect of oxygen is more pronounced at high moisture contents.Experiments at a low moisture content (12 per cent) have demonstratedthat the effect of oxygen is independent of the activity ofmicro-organisms. There is also some indication that the effectof oxygen is independent of the rate of seed respiration. The gas-exchange of pea seeds has been investigated in hermeticstorage at 25? C and 18.4 per cent moisture content. The seedsshowed a constant rate of gas-exchange and a constant R.Q. (0.63)over a period of time during which the concentration of oxygendecreased from 21 to I.4 per cent and the carbon dioxide concentrationrose from 0.03 to 12 per cent. 相似文献
10.
Orchiopexy was performed upon 152 patients. Follow-up observation was inadequate, but of known results 14 per cent were poor. As an increasing number of investigators have observed spontaneous descent of undescended testes, this possibility should be considered in weighing indications for operation on boys before the age of puberty. Coexisting clinically demonstrable hernia (59 per cent in this series) is an indication for early operation. Otherwise, orchiopexy may be best delayed, perhaps until the twelfth year. This was done in 25 per cent of the cases in this series. Three methods of operation were used, the Torek, the Cabot-Nesbit, and the Bevan. There were fewer poor results with the Torek than with the Cabot-Nesbit procedure. The greatest number of poor results was in cases in which the Bevan technique was used. 相似文献
11.
W. H. Snyder Jr. William Van Valin Lawrence Chaffin 《The Western journal of medicine》1950,72(4):239-242
Orchiopexy was performed upon 152 patients. Follow-up observation was inadequate, but of known results 14 per cent were poor.As an increasing number of investigators have observed spontaneous descent of undescended testes, this possibility should be considered in weighing indications for operation on boys before the age of puberty. Coexisting clinically demonstrable hernia (59 per cent in this series) is an indication for early operation. Otherwise, orchiopexy may be best delayed, perhaps until the twelfth year. This was done in 25 per cent of the cases in this series.Three methods of operation were used, the Torek, the Cabot-Nesbit, and the Bevan. There were fewer poor results with the Torek than with the Cabot-Nesbit procedure. The greatest number of poor results was in cases in which the Bevan technique was used. 相似文献
12.
H. R. Casdorph 《The Western journal of medicine》1967,106(4):293-295
The results of administration of cholestyramine to 19 patients for periods of two to 21 months are reported.All patients consistently taking the drug obtained a significant reduction in the serum cholesterol. The average reduction was 26 per cent and the range was from 16 to 52 per cent.Cholestyramine acts as a bile acid sequestering resin, causing an increased loss of bile salts (cholates) in the stool. The drug acts by increasing the normal excretory pathway for cholesterol. 相似文献
13.
1. The foveal visual acuity of eleven subjects was studied in relation to illumination under normal atmospheric conditions and at simulated altitudes of 10,000 feet (14.3 per cent O2) and 18,000 feet (10.3 per cent O2). A mask was used to administer the desired mixtures of oxygen and nitrogen. At the end of each experiment, measurements were made while inhaling 100 per cent oxygen from a cylinder. A red filter (No. 70 Wratten) was used so as to study only the behavior of the cones of the retina. 2. The logarithm of illumination was plotted horizontally (abscissa) and the logarithm of visual acuity vertically (ordinate). The reduced oxygen tensions resulted in a shift of the curve to the right, along the intensity axis, the extent of the change being 0.24 of a log unit at 14.3 per cent O2 and 0.47 of a log unit at 10.3 per cent O2. These effects were completely counteracted within a few minutes by inhaling oxygen. 3. As a consequence of the shape of the curve, such a shift to the right resulted in a relatively large decrease of visual acuity at low illuminations. At increasing light intensities anoxia produced less and less change, until at very high illuminations the decrease was negligible. Thus with 10.34 per cent O2 the visual acuity at 0.144 photons decreased an average of 0.344 of a log unit, to 45 per cent of its normal value. At 1320 photons, however, it decreased only 0.026 of a log unit, to 94 per cent of its normal value for that intensity. 相似文献
14.
P Fritsch M Beauvallet B Jouniaux K Moutairou H Metivier R Masse 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1987,52(4):505-515
The transfer of various Np(IV) and Np(V) chemical forms across the small intestine of rats was measured in instilled and perfused jejunum. Instillation of Np(V) nitrate together with citrate or DTPA resulted in the same absorption of Np as after instillation of Np(V) nitrate alone (3 per cent per hour). Perfusion of Np(V) nitrate with bicarbonate or DTPA resulted in a similar transfer (2 per cent) but added citrate or ascorbate resulted in reduced transfer (0.8 per cent). Addition of phytate reduced Np transfer in both instilled and perfused jejunum (0.4 per cent). Np(IV) transfer was usually the same as, or less than that of, the corresponding Np(V) forms. Np(IV) transfer was similar in perfused and instilled jejunum, increasing from 0.2 per cent in the presence of citrate and phytate, to 1 per cent with EDTA and DTPA. Except for phytate, all the forms of Np(V) tested behaved like Np(V) nitrate after transfer from the intestine or after intravenous injection. By contrast, the behaviour of Np(IV) varied for all the forms tested and, for a given form, varied as a function of the experimental procedure used, i.e. jejunal instillation, perfusion, or intravenous injection. These findings suggest that the intestinal transfer of Np might occur via the intercellular pathway, and that it is controlled by both the molecular weight of the Np compound and its stability constant. 相似文献
15.
H S Targovnik S E Locher P V Hariharan 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1984,45(3):261-265
The production and removal of 254 nm ultraviolet-induced pyrimidine dimers was measured in the DNA of the free-living nematode Turbatrix aceti. Approximately 0.0035 per cent pyrimidine dimers are produced per J/m2. Following a fluence of 100 Jm2, approximately 50 per cent of the dimeric photoproducts were excised within 60 min. The number of pyrimidine dimers excised did not change with increasing U.V. fluence, indicating saturation of the U.V. repair system in T. aceti. The results indicate a highly efficient and selective repair system in Turbatrix aceti for dimeric photoproducts. 相似文献
16.
Myelination in rat brain: method of myelin isolation 总被引:62,自引:19,他引:43
Abstract— A procedure is described for the preparation from rat brain of myelin having the same degree of purity at all ages. Such a procedure is essential for the study of myelin composition during development. Microsomal contamination was successfully eliminated by adjusting the method to maintain a constant amount of brain per unit volume in the initial density gradient step, and by including two osmotic shocks and two low-speed centrifugation steps. Myelin prepared in this way from animals ranging from 15 days to 14months of age had a total ATPase activity of 0.3-2.0 μmol of Pi.h?1.mg?1 dry wt of myelin, representing 0.1-1.2 per cent recovery of the total homogenate activity; a Na+, K+- ATPase activity of 0.1-1.6 μfnol of Pi.h?1.mg?1 dry wt, representing 0.04-1.5 per cent recovery; a nucleic acid content of 0.2-0.7 per cent of myelin dry wt, representing 0.2-2.0 per cent recovery; and a ganglioside NANA content of 0.04-0.07 per cent of myelin dry wt. representing 0.2-4.6 per cent recovery. The myelin prepared from 20-day animals had the highest content of the first three constituents; otherwise the values of the four constituents were relatively constant per unit weight of myelin. The amounts of nucleic acid and ganglioside recovered in the myelin fractions increased with increasing age and myelin yield. 相似文献
17.
Heat shock (45 degrees C) results in an increase of nuclear matrix protein mass in HeLa cells 总被引:1,自引:0,他引:1
R L Warters L M Brizgys R Sharma J L Roti Roti 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1986,50(2):253-268
The nuclear matrix from HeLa cells heated at 45 degrees C was isolated to determine the effect of thermal shock on its composition and structure. The matrix from unheated cells contained about 10 per cent of total cell protein and was observed to be spherical particle with a diameter ranging from 3 to 5 microns with the major constituent polypeptides having molecular weights of 45, 47, 55, 57, 59 and 65 kilodaltons. The nuclear-matrix protein mass increased linearly with increasing exposure time at 45 degrees C with no observable change in its size or shape. The additional proteins were observed in general to have molecular weights greater than 45 kilodaltons, with marked increases in polypeptides of 28.5, 38.5, 60, 66, 75, 81, 88, 100 and 115 kilodaltons. An exponential relationship was observed between heat-induced cytotoxicity and the nuclear matrix protein mass increase. A 15 per cent increase in matrix protein mass was sustained prior to the onset of cytotoxicity, while a 35 per cent increase in matrix protein content was associated with a 63 per cent probability of cell killing. The results indicate that redistribution of cell protein or alterations in the mass or structure of the nuclear matrix may be involved in heat-induced cytotoxicity. 相似文献
18.
GILL J. J. B.; JONES B. M. G.; MARCHANT C. J.; MCLEISH J.; OCKENDON D. J. 《Annals of botany》1972,36(1):31-47
The chromosome numbers of 889 plants from 222 British populationsof Ranunculus ficaria were counted. 66.1 per cent of the populationscontained diploids (49.1 per cent of plants), 4.1 per cent containedtriploids (5.5 per cent of plants) and 43.2 per cent tetraploids(45.4 per cent of plants); 13.1 per cent of the populationscontained two or more polyplotypes. At the fruiting stage, tetraploidplants can be reliably distinguished from diploids by the presenceof axillary bulbils in the tetraploids and their absence inthe diploids. The production of well-developed heads of achenes,which is more characteristic of the diploids than of the tetraploids,is a less reliable character. Diploid plants are widespreadthroughout the British Isles but tetraploids are more commonin the east than in the west; 17.6 per cent of the diploid plantshad B-chromosomes and these plants were virtually confined tosouthern England and the Midlands. The occurrence of triploidsand of mixed populations of diploids and tetraploids are bothshown to be more common than previously supposed. 相似文献
19.
Abstract— —The lipid composition of human, bovine and sheep pineal glands was determined. No characteristic species difference was found in lipid content and composition. The total lipid was 2·9–4·0 per cent of wet weight of which phospholipid comprised 58–71 per cent and cholesterol 13·9–15·8 per cent in the three species. The phospholipid composition was 45 per cent phosphatidyl choline, 22 per cent phosphatidyl ethanolamine, 14 per cent sphingomyelin, 9 per cent phosphatidyl serine, 8 per cent monophosphoinositide, and 2 per cent diphosphatidyl glycerol. The major fatty acids found were C14:0, C16:0, C18:0, C16:1, and C18:1. In contrast to other tissues, pineal sphingomyelin has a low C24:1 content. No significant amounts of polyphosphoinositides or gangliosides were detected. When its lipid composition is compared with that of a number of other tissues, pineal is found to be most similar to testes and unlike pituitary and brain. 相似文献
20.
Axel Palmgren 《Acta zoologica》1948,29(2-3):377-392
Abstract The staining described in this paper fundamentally is performed by two manipulations, namely (1) the treatment of deparaffinized sections for about fifteen minutes in a solution containing 15 per cent silver nitrate, 10 per cent potassium nitrate and 0.05 per cent glycine, and (2) the reduction for one minute in a solution of 1 per cent pyrogallol, 55 per cent ethyl alcohol and a trace (0.002 per cent) of nitric acid. After toning, dehydrating and mounting in the usual manner the sections generally are ready for examinations within less than an hour. The method is available for specimens fixed in the ordinary fixatives but those containing oxidizing metal compounds. The procedure is discussed from a theoretical point of view and some results are shown in photomicrographs. 相似文献