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111.
112.
Jason Pierson Ulrike Ziese Musa Sani Peter J. Peters 《Journal of structural biology》2011,173(2):345-349
Vitreous cryo-section-induced compression influences the interpretation and the reliability of electron microscopy images and tomographic reconstructions. Previous studies of this deformation have been focused at the cellular level where considerable compression occurs, yet the degree of possible intracellular macromolecular deformation has remained unclear. Here, electron cryo-tomographic reconstructions of vitreous cryo-sections show that 80S ribosomes, both intracellular and in an isolated state, appear able to resist section-induced compression. Our observations indicate that vitreous section-induced compression is non-uniform between whole cells that have been sectioned and their intracellular macromolecular complexes. We conclude that electron cryo-tomography of vitreous cryo-sections, in spite of section-induced compression, is a suitable technique for charting the structural organization of cellular nanomachines, such as ribosomes, in a cellular environment. 相似文献
113.
Natural cell membranes are composed of a remarkable variety of lipids, which provide specific biophysical properties to support membrane protein function. An improved understanding of this complexity of membrane composition may also allow the design of membrane active drugs. Crafting a relevant model of a cell membrane with controlled composition is becoming an art, with the ability to reveal the molecular mechanisms of biological processes and lead to better treatment of pathologies. By matching physiological observations from in vivo experiments to high-resolution information, more easily obtained from in vitro studies, complex interactions at the lipid interface are determined. The role of the lipid network in biological membranes is, therefore, the subject of increasing attention. 相似文献
114.
115.
Welders or metal workers not being an exception are exposed to metals ions or oxides (fumes) at trace concentrations either through direct contact supplementation at occupational sites or indirectly through uptake from contaminated food, water or contaminated soil, dust, or air. The study aims to determine the effects of welding fumes exposure on haematological parameters in blood of experimental animals. The fumes were collected from welding sites during the activity by a skilled welder. 130 male experimental animals were utilized and made into 13 groups. 12 groups were given dosages calculated to correspond to real life workers exposure regimes and 1 group served as control. The dosages were administered intratracheally after been anaesthetized weekly for 12 weeks. The animals were sacrificed and whole blood samples were taken which was then subjected to haematological analysis. The parameters have revealed changes in values whereby RBC, WBC, % lymphocytes, HGB, HCT, MCV, MCH, PLT, PCT and P-LCC have exceeds the control groups values. There was an increase across the treatment groups. However, lymphocytes, MID, granulocytes, % granulocytes, MCHC and MPV have values which were less than the control and no different from one another statistically. This indicates that exposure to welding fumes could cause alterations to most RBC, WBC and PLT indices majorly by effecting an increase. Further studies should be carried out on the response of other markers of toxicity so as to have a broad perception of the effects. 相似文献
116.
Abstract Fast-green absorption of cells localized in different regions of Allium cepa root cap.—The nuclear and cytoplasmic protein content of two cell population (C2 = columella cells; P2 = peripheral cells) has been determined by Barr and Stroud cytophotometer after Fast-green staining (after DNA extraction and without DNA extraction). The collected data seem indicate that: 1) histone content is higher in nuclei of C2 cells than in nuclei of P2 ones; 2) acid proteins content is higher in nuclei of P2 cells than in those of C2 ones; 3) the cytoplasmic proteins of the two cell populations are quite different in their Fast-green reactivity. 相似文献
117.
118.
Plasma Copper, Zinc, and Selenium Levels and Correlates with Metabolic Syndrome Components of Lebanese Adults 总被引:1,自引:0,他引:1
Obeid O Elfakhani M Hlais S Iskandar M Batal M Mouneimne Y Adra N Hwalla N 《Biological trace element research》2008,123(1-3):58-65
Zinc, copper, and selenium statuses were reported to be linked to the development of chronic diseases, especially coronary heart disease (CHD). Metabolic syndrome, a known CHD risk factor, was found to be highly prevalent in Lebanon. Nevertheless, no data are available on the statuses of plasma zinc, copper, and selenium, especially in terms of their relation to the components of the metabolic syndrome. A sample of 398 men and women aged 18-65 years was drawn from 23 health centers across Lebanon; anthropometric measurements and biochemical analyses of fasting plasma samples were performed. Subjects were found to have normal plasma statuses of copper and selenium but were at elevated risk of zinc deficiency. Plasma selenium levels correlated positively with all the components of the metabolic syndromes, while that of copper correlated only with total, high-density lipoprotein and low-density lipoprotein cholesterol. Plasma zinc did not correlate with any of the metabolic syndrome components. 相似文献
119.
Slim Abdelkafi Marc Labat Zouhaier Ben Ali Gam Jean Lorquin Laurence Casalot Sami Sayadi 《World journal of microbiology & biotechnology》2008,24(5):675-680
During growth on ferulic acid, Halomonas elongata DSM 2581T was capable of promoting the formation of a significant amount of vanillic acid. The products were confirmed by high-performance
liquid chromatography and gas chromatography mass-spectrometry analyses. To enhance the formation of vanillic acid and prevent
its degradation, a resting-cell method using Halomonas elongata was developed. The growth state of the culture utilized for biomass production, the concentration of the biomass, the amount
of ferulic acid that was treated and the reutilization of the biomass were optimized. The optimal yield of vanillic acid (82%)
was obtained after a 10-h reaction using 10 mM ferulic acid and 5 g/l of cell pregrown on ferulic acid and harvested at the
end of the exponential phase. 相似文献
120.
The lignin peroxidase (isoenzyme H8) of Phanerochaete chrysosporium was expressed in Aspergillus niger under the control of plant nopaline synthase (NOS) promoter and terminator. H8 mRNA was produced in this heterologous system. Western blot analysis showed that the recombinant protein was of size similar to the native H8. The extracellular lignin peroxidase activity in these primary constructs was positive, though weak (1.12 nKat mg–1). 相似文献