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1.
2.
Ramesh Chand Manoj Kumar Chanda Kushwaha Kavita Shah Arun K. Joshi 《Current microbiology》2014,69(2):202-211
Eighteen barley isolates of Bipolaris sorokiniana belonging to wild and clonal type of black, mixed and white subpopulations were quantitatively assayed for their melanin content and aggressiveness with respect to production of some of the extracellular enzymes such as cellulase, pectinase, amylase and protease. Cellulase and pectinase constituted major portion of the enzymes recovered from the black, mixed and white isolates. Enzyme production and aggressiveness were relatively higher in melanin devoid or low melanin isolates. The melanin deficient isolates were also differentiated from black and mixed isolates on the basis of variation in internal transcribed spacer region of the ribosomal DNA. Higher enzyme productions positively correlated with area under disease progress curve (AUDPC) and lesion development. Melanin content was negatively correlated with extracellular enzymes and aggressiveness of the isolates. Based on melanin content, lesion size, AUDPC and extracellular enzymes, the isolates were grouped in two major clusters (I and II) with further division of cluster II into two sub-clusters (II-A and II-B). The results appears to indicate a possible role of melanin in release of extracellular enzymes and hence in evolution and selection of aggressive isolates of B. sorokiniana in barley. 相似文献
3.
S. P. Goyal P. K. Ghosh T. O. Sasidharan Phool Chand 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1988,158(1):127-134
Summary The relative body water conservation efficiency of two Indian desert gerbil species,Meriones hurrianae (diurnal/crepuscular) andTatera indica (nocturnal), has been examined under near-natural conditons in different seasons.A mean urine osmolarity of 3180 mosmol/l (maximum 4645 mosmol/l) inM. hurrianae and a mean value of 5128 mosmol/l (maximum 7547 mosmol/l) inT. indica have been recorded during summer.Urine osmolarity and urea levels indicated that whileM. hurrianae remain sufficiently hydrated mainly by virtue of their feeding habit,Tatera indica may depend on the relatively higher concentrating capacity of their kidneys. 相似文献
4.
M Cikrt A Mravcová I Malátová V Bencko 《Journal of hygiene, epidemiology, microbiology, and immunology》1988,32(1):17-29
The exposure of man to isolated toxic agent in the environment is rather a rare phenomenon. Therefore the study of a combined action of toxic substances is of increasing importance. The excretion and distribution of 74As (500 micrograms As.kg-1 b.wt.; Na74AsO2) and 75Se (525 micrograms Se.kg-1 b.wt.; Na275SeO3) was studied in rats after their separate and simultaneous i.v. injections. After simultaneous administration urinary as well as biliary excretion of 75Se and urinary excretion of 74As was increased in comparison with that in animals injected the radionuclides separately. Simultaneous administration of 74As and 75Se decreased concentration of 75Se in liver and increased concentration of 74As in kidney. In rats drinking water containing As (III) (0.66 mmol.l-1), Se(IV) (0.13 mmol.l-1) or combination As(III) + Se(IV) (at the same concentrations) for 7 or 28 days was studied the excretion and distribution of 74As and 75Se after their simultaneous i.v. injection (at the same concentrations and labelled compounds as mentioned above). The pretreatment with one element or with the combination of both elements significantly modified the distribution and excretion of subsequently administered 74As and 75Se. 相似文献
5.
Arvind Kumar Bhatt Tek Chand Bhalla Hari Om Agrawal N. Sharma 《Letters in applied microbiology》1992,15(1):1-4
An extracellular chitosanase produced by Rhodotorula gracilis CFR-1 that catalyses a limited degradation of chitosan with no detectable generation of glucosamine or reducing groups was identified. Ultracentrifugation, polyacrylamide gel electrophoresis and gel permeation studies suggest that chitosan of average molecular mass 36000 Da was reduced by the enzymic catalysis to nearly one-fourth this size without further hydrolysis of the products. The enzyme, produced constitutively by this yeast, was partially purified and some of its properties were studied. 相似文献
6.
Oxyhaemoglobins from erythrocytes of different animals including fish, amphibians, reptiles, birds, mammals and human beings
have been isolated by ion-exchange chromatography over phosphocellulose and the comparative rates of autoxidation of oxyhaemoglobin
studied. The mechanism of autoxidationin vitro has been elucidated using toad as well as human oxyhaemoglobin. Autoxidation is markedly inhibited by carbon monoxide as
well as by anion ligands, namely, potassium cyanide, sodium azide and potassium thiocyanate. The inhibition by anions is in
the same order as their strength as nucleophiles, indicating that it is the oxyhaemoglobin and not the ligand-bound deoxy
species which undergoes autoxidation. The structure of oxyhaemoglobin is considered to be mainly
and determination of the rate of autoxidation with or without using superoxide dismutase and catalase indicates that the
initial process of autoxidation takes place by dissociation of
to methaemoglobin and superoxide to the extent of 24%. The superoxide thus produced reattacks oxyhaemoglobin to produce further
methaemoglobin and hydrogen peroxide. H2O2 is a major oxidant of oxyhaemoglobin producing methaemoglobin to the extent of 53%. A tentative mechanism of autoxidation
showing the sequence of reactions involving superoxide, H2O2 and OH has been presented. 相似文献
7.
Primary structure of -chain of pigeon is presented. It was determined by amino acid sequence analysis of intact -chain and its peptides obtained by the enzymatic and chemical cleavage. Comparison of amino acid sequence of the chain with other available data shows 14 Ile, 61 Lys, and 113 Ile as residues specific to pigeon. One important replacement at 11 contact is 55 MetSer. 相似文献
8.
J. Haplová V. Farkaš M. Hejtmánek R. Koďousek J. Malínský 《Archives of microbiology》1994,161(4):340-344
Rylux BSU, a new fluorescent brightener from the family of 4,4-diaminostilbene-2,2disulfonic acid derivatives, inhibited growth and cytokinesis of the yeast Saccharomyces cerevisiae. In the presence of 0.1–1 mg/ml Rylux BSU the cells grew in clumps, had irregular shape and were larger than controls. They formed apparently normal primary septa but their secondary septa and lateral cell walls, especially those in older cells, were abnormally thick with large deposits of amorphous wall material in the periplasmic spaces all over the cell surface. Chitin content in the cell walls of cells grown in the presence of Rylux BSU was increased 2 to 5 times in comparison to that of the controls and glucan content was reduced by up to 30%. In the in vitro assays with particulate membrane fractions, Rylux BSU acted as a non-competitive inhibitor of -1,3-glucan synthase with inhibitory constant K
i=1.75 mg/ml whereas the chitin synthase was inhibited to a much lesser extent. From the difference of the effects of Rylux BSU on the synthesis of chitin in vivo and in vitro it is concluded that the brightener interacts with chitin synthase only indirectly, possibly by influencing the properties of integral plasma membrane.Abbreviations RBSU
Rylux BSU, 1,4-benzenedisulfonic acid-2,2-[ethyleneidy]bis[(3-sulpho-4,1-phenylene)imino[6-bis(2-hydroxyethyl)amino]-1,3,5-triazine-4,2-diylamino]]bis-, hexasodium salt
- FB
fluorescent brightener 相似文献
9.
Baljinder Singh Devinder Dhawan Bakhshi Chand Pralhad Chand Mangal 《Biological trace element research》1994,40(3):287-293
The impact of lead as an environmental pollutant on the I-131 uptake and retention in rat thyroid was assayed alone and in combination with lithium treatment. Lead treatment significantly stimulated the 2- and 24-h uptake of I-131 in the thyroid, and the 24-h uptake showed the maximum stimulation after 3 mo of lead treatment. On the contrary, lithium supplementation reduced the uptake significantly and the maximum decrease was noticed after 2 mo of lithium administration. Further, simultaneous lead and lithium treatment resulted in more pronounced increase in the uptake of I-131 by the thyroid, which was maximum after 3 mo of combined treatment. The thyroidal biological half-life of I-131 (T biol) was found to be increased significantly following lead and lithium treatments when given separately. Interestingly, combined lead and lithium treatment given up to 2 mo further prolonged theT biol of I-131, thus reflecting its increased retention. 相似文献
10.
Suresh Chand Purnima Basu Neeti Maheshwari 《Journal of plant biochemistry and biotechnology.》1994,3(1):53-54
Somatic embryogenesis and regeneration of plantlets was achieved In callus cultures derived from cotyledonary leaf pieces of Hyoscyamus muticus L on MS medium enriched with 2 mg/l 2,4–0 and 0.5 mg/l BAP. For embryogenesis and organogenesis varying concentrations of NAA with or without BAP were added In the medium. Organogenesis was also achieved when callus was transferred to the hormone free medium. 相似文献