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排序方式: 共有421条查询结果,搜索用时 62 毫秒
1.
Bhaskaran S. Smith R. H. Paliwal S. Schertz K. F. 《Plant Cell, Tissue and Organ Culture》1987,9(3):189-196
Plant Cell, Tissue and Organ Culture (PCTOC) - Sorghum bicolor (L.) Moench, plants were regenerated from 4 to 5 month old callus cultures originally derived from seedling explants. Somaclonal... 相似文献
2.
R K Gaur S Paliwal P Sharma K C Gupta 《Journal of biochemical and biophysical methods》1989,18(4):323-329
A simple and sensitive method for the quantitative determination of free amino groups on solid support is described. This approach is a modification of Ngo's [(1986) J. Biochem. Biophys. Methods 12, 349-354] method reported earlier. The method is based on the reaction of the solid support with an excess of 5'-O-(4,4'-dimethoxytrityl)-thymidine-3'-O-(2,4-dinitrophenyl) succinate (DTDS) in the presence of a catalytic amount of 4-dimethylaminopyridine. After removing the excess reagent, solid support is treated with perchloric acid to release 4,4'-dimethoxytrityl cation into the solution. The released 4,4'-dimethoxytrityl cation, which has a strong absorption at 498 nm (epsilon 498 = 70,000), is then determined spectrophotometrically. A comparative study of DTDS, N-succinimidyl-3-(2-pyridyldithio)propionate and 4,4-dimethoxytrityl chloride is also included. The method was found to be very useful to determine those amino groups which are available for functionalization of solid supports, especially, monitoring the functionalization of solid supports for affinity chromatography and synthesis of biopolymers. 相似文献
3.
Recently attempts have been made to establish the presence and to determine the metabolic versatility of microorganisms in
the terrestrial deep subsurface at the Savannah River Plant, Aiken, SC, USA. Sediment samples obtained at 20 different depths
of up to 526 m were examined to determine carbon mineralization under aerobic, sulfate-reducing, and methanogenic conditions.
The evolution of14CO2 from radiolabelled glucose was observed under aerobic conditions in all sediments, whereas pyridine was transformed in 50%
of the 20 sediments and indole was metabolized in 85% of the sediments. Glucose mineralization in certain sediments was comparable
to that in the surface environment. Sulfate was reduced in only five sediments, and two were carbon limited. Methane production
was detected in ten sediments amended with formate only after long-term incubations. The transformation of indole and pyridine
was only rarely observed under sulfate-reducing conditions and was never detected in methanogenic incubations. This study
provides information concerning the metabolic capability of both aerobic and anaerobic microorganisms in the deep subsurface
and may prove useful in determining the feasibility of microbial decontamination of such environments. 相似文献
4.
Vipin K. Paliwal Krishan K. Kohli Mridula Sharma Ravindra Nath 《Molecular and cellular biochemistry》1986,71(2):139-147
Metallothionein (MT) a low molecular weight, Cd-binding, cysteine rich, cytosolic protein has been isolated, purified and characterized from cadmium exposed Rhesus monkeys maintained on protein calorie malnourished (PCM) diet. Metallothionein was resolved into three isoforms i.e. MTa, MTb and MTVc. The ratio of Cd, Zn and Cu varied in these isometallothioneins. MTc was the major isometallothionein. UV Spectra of MTc revealed the presence of mercaptide bonds and absence of aromatic amino acids. These observations were further confirmed by amino acid analysis of MTc which demonstrated high cysteine content (22.6) followed by serine, glycine and lysine. The molecular weight of MTc as determined by gel filtration and amino acid analysis was 13000 and 6398 daltons respectively. This demonstrates that MTc is a non-globular ellipsoid polypeptide. MTc showed a unique property of binding selenium. Monkey liver metallothionein was immunologically identical with human metallothionein. All the characteristics of MTc obtained in the present study reveal a similarity between monkey and human metallothionein probably due to closer phylogenetic relationship between the two species. 相似文献
5.
The larvae of the dipteran insect, Chironomus ramosus, found in Shillong, India, contain eleven (11) hemoglobin (Hb) components of which three are monomers (CI, CIV and CVI) and seven are dimers (CIII, CV, CVII, CVIII, CIX, CX and CXI), while one (CII) exists in both monomeric and dimeric states.Four monomeric components were isolated, purified and partially characterized. The N-terminal amino acids were determined and showed glycine for CI and leucine for the other components (CII, CIV and CVI).Three hemoglobin components were found to be present in all stages of larval development, except the first instar larvae. Some Hb components were synthesized in a particular instar, as revealed by electrophoretic appearance.Electrophoretic mobilities of seven components and N-terminal amino acid residues of two components of Hb were similar in both Chironomus ramosus and Chironomus thummi thummi. 相似文献
6.
Bahman Tabaraie Bal Krishan Sharma Praveen Rishi nee Sharma Rakesh Sehgal Nirmal Kumar Ganguly 《Microbiology and immunology》1994,38(7):553-559
Porins were prepared from smooth strain of Salmonella typhi 0–901 and chemotype of rough mutant of S. typhimurium Ra-30. Mice were immunized with both the porin preparations in different groups and challenged with S. typhimurium LT2–71 and S. enteritidis SH-1269. Porin immunized mice showed significant protection (P <0.01) against challenge with homologous as well as heterologous strains. Hence, the use of porins may be attempted in future to protect against salmonellosis. 相似文献
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9.
A rapid pigmentation test for identification ofCryptococcus neoformans is described. The method is based on the formation of a characteristic, mousegrey to violaceous-black pigment when shake cultures ofC. neoformans in a phosphate-buffered,l-DOPA — ferric citrate medium are incubated at 37 C for one hour.This work was carried out in part with financial support from the Council of Scientific and Industrial Research, New Delhi. 相似文献
10.
Aging biology is intimately associated with dysregulated metabolism, which is one of the hallmarks of aging. Aging‐related pathways such as mTOR and AMPK, which are major targets of anti‐aging interventions including rapamcyin, metformin, and exercise, either directly regulate or intersect with metabolic pathways. In this review, numerous candidate bio‐markers of aging that have emerged using metabolomics are outlined. Metabolomics studies also reveal that not all metabolites are created equally. A set of core “hub” metabolites are emerging as central mediators of aging. The hub metabolites reviewed here are nicotinamide adenine dinucleotide, reduced nicotinamide dinucleotide phosphate, α‐ketoglutarate, and β‐hydroxybutyrate. These “hub” metabolites have signaling and epigenetic roles along with their canonical roles as co‐factors or intermediates of carbon metabolism. Together these hub metabolites suggest a central role of the TCA cycle in signaling and metabolic dysregulation associated with aging. 相似文献