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951.
药敏药片临床应用观察报告   总被引:1,自引:0,他引:1  
本文报导省市级三所医院同时用药敏药片和药敏纸片对国际标准质株做抑菌试验,其结果:药片片重差变异系数cv=2.5,纸片cv=14.4.抽样五种抗菌素抑菌环直径差变异系数分别为:药片平均cv=3.07,而纸片平均cv=6.85;均匀度L药片为2-3mm纸片为3-5mm.表明药片片间差小,均匀度、准确度合格,药物含量均匀,精密度好于纸片.  相似文献   
952.
Metal speciation in xylem and phloem exudates   总被引:5,自引:0,他引:5  
Summary Two computer programs based on simultaneous chemical equilibria were compared for calculation of chemical species in xylem exudates. The first program, CHELATE, was developed to calculate the chemical species in xylem exudates while GEOCHEM was developed to calculate the speciation of natural aquatic systems. The output of the two programs should be similar since they are based on similar calculations. Data input to the programs consisted of concentration data for Ca, Cu, Fe, Mg, Mn, Zn, NH4, PO4, pH and 28 organic ligands reported for xylem exudates from soybean (Glycine max (L.) Merr.) and tomato (Lycopersicon esculentum Mill.) plants grown in nutrient solution17. The organic ligands included amino acids and low molecular weight organic acids (e.g., citric and malic). With the exception of Fe, there were large differences between CHELATE and GEOCHEM in the calculated speciation of nearly all metals in the xylem exudates. In general, there was better agreement between the programs for the speciation of alkaline earth metals than for transition metals. Discrepancies between the two programs were attributed to differences in 1) species considered and 2) stability constants. GEOCHEM considered a greater number of possible complexes. In addition, stability constants for some complexes differed by as much as 10 fold between the two programs. When the data base for GEOCHEM and CHELATE were the same, the output from CHELATE and GEOCHEM was almost identical. Thus, computations performed by the two programs are equally valid, but it is essential that the data base used in chemical models be verified before interpreting the output. Average concentration data for Al, Au, Ca, Cu, Fe, K, La, Mg, Mn, Na, Rb, Zn, Cl, MoO4, PO4, SO4, HVO4, pH and 18 organic ligands in phloem exudates from Yucca (Yucca flaccida Haw.) were complied from available literature and analyzed by GEOCHEM. Amino acids were the predominant organic ligand analyzed. Calculations revealed that alkali metals existed almost totally as the free ionic species (≥99%) whereas alkaline earth metals were transported as complexes with organic acids (oxalic, malic, and asparagine). Aluminum and Fe were present as hydroxyl species while <1% of micronutrients were transported as the free ion. Major micronutrient species were Cu-glutamine, Mn-asparagine and Zn-alanine. Information on calculated species present in phloem exudates could be useful to guide studies for isolation of metal-ligand complexes in phloem exudates.  相似文献   
953.
Summary Massive infusion of conidia ofVerticillium albo-atrum into the xylem of tomato induces a cell wall coating response in resistant and susceptible near-isolines. In the early stages two types of coating material develop in the xylem vessels. The first, designated type A, is formed in association with xylem parenchyma cells that lack secondary walls; the localized accumulation of type A coating in the in the adjacent intercellular spaces, primary walls (i.e., pit membranes) and vessels occurs in conjunction with localized development of apposition wall layers within the parenchyma cells. Type B coating is initially formed in association with xylem parenchyma cells with secondary walls; the localized accumulation of typeB coating in the adjacent intercellular spaces, primary walls (i.e., pit membranes) and vessels occurs in conjunction with development of protective layers within the parenchyma cells. Most vessels are surrounded by a number of parenchyma cells including both cell types; therefore, in most vessels the coatings are mixed in later stages of development (i.e.,> 48 hours). The formation of both types of coating is stopped by the application of L--aminooxy--phenylpropionate, a specific inhibitor of phenylpropanoid synthesis. Histochemically, type A coating resembles lignin and type B, suberin. The data suggest that the coating response is due, wholly or in part to hypersecretion and/or chemical modification of normal cell wall components, induced by the pathogen.  相似文献   
954.
Summary An interspecific hybrid between Lycopersicon esculentum () and L. peruvianum has been raised by embryo rescue in vitro and used to confirm the presence of a new S-allelic specificity in its inbred L. peruvianum parent, a plant derived by enforced bud self-pollination of a self-incompatible clone with the genotype S 1 S 2. The inbred plant showed breeding behavior characteristic of both S 2 and a second specificity which was not S 1, S 2, S 3 or S f. Two-dimensional gel electrophoresis of stylar proteins, however, showed only a single typical S-associated component with the Mr and pI characteristic of S2. The alteration in specificity, therefore, was not associated with a detectable change in an S-associated protein. The F1 interspecific hybrid showed intermediacy of vegetative and reproductive characters, relatively high fertility and full self-incompatibility. Backcrossing to L. esculentum produced only abortive seeds requiring embryo culture. Backcrosses to L. peruvianum produced a very low proportion of filled germinable seeds. Pollen of the hybrid showed superior viability and tube growth rate compared with pollen of the two parent plants.  相似文献   
955.
我们于1984和1985年6月上、中旬,在广州市郊、县,湛江市郊以及广西南宁市郊、县,北海市郊和合蒲县等花生产区,调查花生病毒病时,除了发现花生轻斑驳病毒病外,还发现一种新的病毒病害。其症状特征是:病株顶端叶片上出现很多褪绿黄斑或环斑,有的环斑变  相似文献   
956.
Summary Growing tomatoes in low humified Sphagnum peat gave satisfactory results when using the peat bags in three successive seasons without any sterilization. Use of a complete nutrient solution showed an increase of phosphorus and boron from one season to the next. The pH varied with the electrical conductivity in the peat, dependent on the nutrient concentration used. The solution used for reused peat should have a lower content of phosphorus and boron compared to a solution used for one season peat.The air capacity is high and have to be considered as optimal also in reused peat. The effect of reusing the peat on physical properties as porosity and pore size distribution is therefore of no practical significance.  相似文献   
957.
Summary Alterations occur in the normal contents of the total and individual flavonoids with P, Mn and B deficiencies in tomato plants. Differences in flavonoid levels of several organs of the plant have been detected. P, Mn and B deficiencies display absence of flavonol in tomato roots. Flavanone concentration in tomato fruit increases 8-fold as compared with average concentration in the other organs.  相似文献   
958.
Abstract. 1. Leaves of tomato (cv. Moneymaker) were artificially damaged and offered to Spodoptera larvae at a range of intervals following damage. Grazing levels on these leaves were compared with those on undamaged leaves on the same or different plants.
2. In separate experiments, three leaves in a middle position on the main stem were clipped and after 48 h grazing levels on undamaged leaves above and below those damaged were compared with similar leaves from control plants.
3. Within 8 h, grazing levels on damaged leaves were significantly lower than those on control leaves, and within 24 h, leaves adjacent to damaged ones were similarly affected. These effects persisted for at least 7 days and leaves above and below those damaged were affected. There was up to nine-fold reduction in area consumed.
4. The possible ecological consequences of reduced palatability at these levels are discussed.  相似文献   
959.
The systemic fungicide methyl-1-(butylcarbamoyl)-2-benzimidazole carbamate (benomyl), is a broad spectrum fungicide. Benomyl at concentrations up to 50 mg/l does not inhibit the growth of suspension cultures ofNicotiana tabacum, Datura innoxia, Daucus carota, Glycine canescens, andSolanum tuberosum nor growth ofN. tabacum orN. plumbaginifolia protoplasts if benomyl is dissolved by autoclaving or boiling. Addition of benomyl dissolved in dimethyl sulfoxide results in a visible toxicity. Benomyl, at 6.25–50 mg/l preventsPenicillium spp. growth in both protoplast and cell cultures and can be used to remove fungal contaminates after one to three transfers without visibly retarding plant cell growth. Due to the broad spectrum of fungicidal activity, and nontoxicity at high concentrations when dissolved by boiling or autoclaving, benomyl can be used effectively to control or prevent fungal contamination in plant cell and protoplast cultures.  相似文献   
960.
Summary Sesquidiploid hybrids of L. esculentum (L) x S. lycopersicoides (S) were backcrossed to L via L. pennellii (P) as a bridging species in order to detect and measure recombination. Although use of P injected its traits into the populations, the investigated traits were proven to originate from S. The appearance of S traits in diploids in the immediate progeny of sesquidiploids but mainly of derived alien addition types proved the occurrence of recombination at rates varying from 1.6% to 16%. In subsequent BC's, these traits were inherited in dominant Mendelian fashion, except for deviations favoring recurrent parent alleles, sometimes with highly significant deviations from 11. Inheritance was investigated in BC and F2 ex BC for 13 traits with strong phenotypic modifications of morphological, physiological, and isozymic nature. Monogenic determination was confirmed in most instances by tight linkages. For most of the traits, small progenies allowed only rough estimates of linkage intensities, but for Wa (gene for White anthers, universal in S), a test cross with four markers on chromosome 8 established its locus 2 cM distal to dl, proximally on 8L. Also noteworthy is the linkage of Dls, a gene determining sensitivity of flowering to long days, close to sp, situated subterminally on 6L. For the majority of traits, these manifestations of linkage proved that the appearance of S traits resulted from recombination, not alien chromosome substitution — a conclusion also reinforced by observations of chromosome pairing in alien addition types and diploid derivatives. Recombined S alleles have loci in various chromosome positions. Although they were discovered on the shorter chromosomes (nos. 6–12), hybridization barriers precluded tests with the longer chromosomes. Thus, no evidence was found for restriction of recombination to certain chromosomes or chromosomal regions. The prospects therefore appear favorable for deriving valuable traits from the S parent.  相似文献   
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