Changes in the number and volume of fibrillar centres with the inactivation of nucleoli at erythropoiesis

1988 ◽  
Vol 91 (3) ◽  
pp. 439-448
Author(s):  
O.V. Zatsepina ◽  
P.V. Chelidze ◽  
Y.S. Chentsov
Keyword(s):  
Optical Density ◽  
Mouse Embryo ◽  
Structural Components ◽  
Interphase Cell ◽  
Complete Series ◽  
Ultrathin Sections ◽  
Embryo Liver ◽  
The Mean ◽  
Basophilic Erythroblast

The number and volume of fibrillar centres, the structural components of interphase cell nucleoli on the surface of which rRNA is synthesized, have been studied in differentiating erythroblasts of mouse embryo liver. Complete series of ultrathin sections of erythroblast nuclei have been used at the main stages of differentiation: proerythroblast, basophilic erythroblast, polychromatophilic erythroblast and normoblast. It has been shown that in the active nucleoli of proerythroblasts the number of fibrillar centres is correlated with cell ploidy and exceeds by several-fold the number of nucleolus-organizing regions of chromosomes. The total volumes of fibrillar centres in 2C (0.369 micron 3) and 4C (0.749 micron 3) proerythroblasts are proportional to number of nucleolus-organizing regions. With the maturation of erythroblasts the total number of fibrillar centres declines and in normoblasts it is 3- to 10-fold less than that of the nucleolus-organizing regions. The total volume of fibrillar centres in normoblasts (0.102 micron 3) is threefold smaller than that in proerythroblasts (0.369 micron 3), even though the mean volumes of individual fibrillar centres are significantly higher (0.0042 micron 3 in proerythroblasts and 0.039 in normoblasts). The optical density of fibrillar centres in normoblasts can be higher compared with that of proerythroblasts. It has been suggested that the inactivation of nucleoli at erythropoiesis is accompanied by the fusion of individual fibrillar centres and, possibly, by the compaction of their material.

scholarly journals Inelastic displacement ratios for non-structural components in steel framed structures under forward-directivity near-fault strong-ground motion

2021 ◽  
Author(s):  
M. A. Bravo-Haro ◽  
J. R. Virreira ◽  
A. Y. Elghazouli
Keyword(s):  
Strong Ground Motion ◽  
Ground Motions ◽  
Structural Elements ◽  
Structural Components ◽  
Framed Structures ◽  
Inelastic Displacement ◽  
Near Fault ◽  
Forward Directivity ◽  
The Mean ◽  
Strong Ground

AbstractThis paper describes a detailed numerical investigation into the inelastic displacement ratios of non-structural components mounted within multi-storey steel framed buildings and subjected to ground motions with forward-directivity features which are typical of near-fault events. The study is carried out using detailed multi-degree-of-freedom models of 54 primary steel buildings with different structural characteristics. In conjunction with this, 80 secondary non-structural elements are modelled as single-degree-of-freedom systems and placed at every floor within the primary framed structures, then subsequently analysed through extensive dynamic analysis. The influence of ground motions with forward-directivity effects on the mean response of the inelastic displacement ratios of non-structural components are compared to the results obtained from a reference set of strong-ground motion records representing far-field events. It is shown that the mean demand under near-fault records can be over twice as large as that due to far-fault counterparts, particularly for non-structural components with periods of vibration lower than the fundamental period of the primary building. Based on the results, a prediction model for estimating the inelastic displacement ratios of non-structural components is calibrated for far-field records and near-fault records with directivity features. The model is valid for a wide range of secondary non-structural periods and primary building fundamental periods, as well as for various levels of inelasticity induced within the secondary non-structural elements.

Propolis and Commonly Used Intracanal Irrigants. Comparative Evaluation of Inflammatory Potential

2013 ◽  
Vol 37 (4) ◽  
pp. 373-376 ◽  
Author(s):  
M Jolly ◽  
N Singh ◽  
M Rathore ◽  
S Tandon ◽  
S Sharma
Keyword(s):  
Calcium Hydroxide ◽  
Optical Density ◽  
Saline Solution ◽  
Short Term ◽  
Model Method ◽  
Short Term Evaluation ◽  
Term Evaluation ◽  
Physiologic Saline ◽  
The Mean ◽  
Mean Optical Density

The present study evaluated the inflammatory/irritant potential of propolis in comparison with commonly used intracanal irrigants such as chlorhexidine and calcium hydroxide, with normal saline solution as control using an animal (Wistar rats) model. Method: 2% Evans blue was intravenously injected into the lateral caudal vein. 0.1 ml each of the test solutions was intradermally injected into the experimental sites designed on their shaved backs. The animals were then sacrificed after 1½ and 3 hours respectively. Each piece of skin containing the injected solution was excised, immersed in 4ml formamide and incubated at 45°C for 72 hours. After filtration with glass wool, optical density(OD) was measured using a spectro-photometer and analyzed statistically. Results: At 620 nm irrespective of time, the mean optical density with Calcium Hydroxide was found to be maximum (0.197±0.095) while that with DMSO Propolis was found to be minimum (0.070±0.016). Both at 90 min and 180 min, the mean optical density with Calcium Hydroxide was found to be maximum. Conclusions: On short term evaluation, maximum inflammation was seen with calcium hydroxide followed by chlorhexidine and DMSO extract of propolis. Minimum inflammation was seen with sterile physiologic saline. With progress of time, maximum inflammation was seen with calcium hydroxide followed by chlorhexidine and DMSO extract of propolis which was non-significant.

scholarly journals Correlation between Macular Pigment Optical Density and Neural Thickness and Volume of the Retina

Nutrients ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 888
Author(s):  
Norihiro Nagai ◽  
Teru Asato ◽  
Sakiko Minami ◽  
Misa Suzuki ◽  
Hajime Shinoda ◽  
...  
Keyword(s):  
Optical Density ◽  
Retinal Thickness ◽  
Outer Nuclear Layer ◽  
Plexiform Layer ◽  
Macular Pigment ◽  
Inner Plexiform Layer ◽  
The Mean ◽  
Short Wavelength Light ◽  
The Impact ◽  
Adult Volunteers

Macular pigment (MP), which is composed of lutein/zeaxanthin/mezo-zeaxanthin, is concentrated in the central part of the retina, the macula. It protects the macula by absorbing short-wavelength light and suppressing oxidative stress. To evaluate whether MP levels are related to retinal neural protection and resulting health, we analyzed the association between the MP optical density (MPOD), and the macular thickness and volumes. Forty-three eyes of 43 healthy adult volunteers (21 men and 22 women; age: 22–48 (average 31.4 ± 1.1) years) were analyzed. Highly myopic eyes (<-6 diopters) were excluded. MPOD was measured using MPS2®, and the neural retinal thickness and volume were measured using optical coherence tomography. The mean MPOD was 0.589 ± 0.024, and it positively correlated with the central retinal thickness (P = 0.017, R = 0.360) and retinal volume of the fovea (1-mm diameter around the fovea; P = 0.029, R = 0.332), parafovea (1–3-mm diameter; P = 0.002, R = 0.458), and macula (6-mm diameter; P = 0.003, R = 0.447). In the macular area (diameter: 6 mm), MPOD was correlated with the retinal neural volume of the ganglion cell layer (P = 0.037, R = 0.320), inner plexiform layer (P = 0.029, R = 0.333), and outer nuclear layer (P = 0.020, R = 0.353). Thus, MPOD may help in estimating neural health. Further studies should determine the impact of MP levels on neuroprotection.

scholarly journals DIAGNOSTIC CAPABILITIES OF DIGITAL FLUOROGRAPHY IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE

2015 ◽  
Vol 14 (1) ◽  
pp. 24-31
Author(s):  
N. A. Gorbunov ◽  
A. P. Dergilev ◽  
L. D. Sidorova ◽  
V. I. Kochura
Keyword(s):  
Chronic Obstructive Pulmonary Disease ◽  
Pulmonary Disease ◽  
Optical Density ◽  
Stage I ◽  
Chronic Obstructive ◽  
Forced Expiration ◽  
Obstructive Pulmonary Disease ◽  
Mean Values ◽  
Digital Chest ◽  
The Mean

The purpose of the study – to examine the capabilities of the method of digital chest fluorography in diagnosis of chronic obstructive pulmonary disease (COPD) of different stages. By chest digital fluorography 247 patients with clinically diagnosed COPD stage I–III were examined. The average age of the patients was (55.3  1.7) years (16 to 88 years), forced expiration volume for the first second (FEV1) was (59.17  16.28) %. It was shown that for patients with COPD stage I most characteristic radiographic symptom was emphysema of the lung in the upper regions (26 (48%) of 54 patients); the mean values of the inspiratory lung optical density (ILOD) ranged from (703.48  2.15) to (807.47  5.61) optical density units (ODU), the expiratory lung optical density (ELOD) – from (786.05  6.15) to (830.23  4.71) ODU. For patients with COPD stage II the most common radiographic sign was the presence of amplification and deformation pulmonary pattern (95 (89%) of 107 patients); the mean values of ILOD ranged from (646.20  4.94) to (791.38  2.81) ODU, ELOD – from (677.34  9.91) to (813.91  3.29) ODU. Patients with COPD stage III were characterized by a combination of amplification and deformation pulmonary pattern (77 (90%) of 86 patients) with lung emphysema (51 (59%) of 86 patients); the mean values of the inspiratory lung optical density ranged from (765.93  16.4) to (863.37  15.83) ODU, expiratory lung optical density – from (826.80  11.64) to (881.37  4.29) ODU. Thus, we concluded that the method of digital chest fluorography, possessing low dose burden to the patient, can detect the characteristic radiological symptoms and determine the stage of the disease up to the values of the lung optical density in patients with COPD.

scholarly journals Morphological Study of Heat-Sensitive and Heat-Resistant Spores of Clostridium sporogenes, Using Transmission Electron Microscopy

2008 ◽  
Vol 71 (5) ◽  
pp. 953-958 ◽  
Author(s):  
JAE-HYUNG MAH ◽  
DONG-HYUN KANG ◽  
JUMING TANG
Keyword(s):  
Heat Resistance ◽  
Structural Components ◽  
Structural Determinants ◽  
Clostridium Sporogenes ◽  
The Core ◽  
Heat Resistant ◽  
Transmission Electron ◽  
Thickness Standard ◽  
The Mean ◽  
Coat Layer

To investigate the primary structural determinants affecting heat resistance of Clostridium sporogenes spores, electron micrographs of heat-sensitive (D121°C = 0.56 min) and heat-resistant (D121°C = 0.93 min) spores of C. sporogenes were taken with a transmission electron microscope. The mean thickness (± standard deviation [SD]) of coat layers and cortex regions of heat-sensitive spores were 82.9 ± 14.5 and 86.0 ± 22.7 nm, while those of heat-resistant spores were 106.9 ± 45.7 and 111.7 ± 32.1 nm, respectively. The thickness of coat (P = 0.031) and cortex (P = 0.006) showed statistically significant differences, suggesting that heat-resistant spores have a thicker coat and cortex than do heat-sensitive spores. The mean sizes (± SD) of cores were 467.0 ± 88.7 nm for heat-sensitive spores and 460.2 ± 98.5 nm for heat-resistant spores, respectively, which showed no statistically significant differences. The ratios (± SD) of the core size to the sporoplast size were 0.84 ± 0.05 for heat-sensitive spores and 0.80 ± 0.07 for heat-resistant spores, respectively, showing statistically significant differences (P = 0.030), which indicated that the ratio is negatively related to heat resistance. Accordingly, the structural components of heat-sensitive spores were severely damaged by heat treatment, whereas those of heat-resistant spores were unlysed under the same conditions. Based on the structural analyses of spores, it was elucidated that the thickness of coat layer and cortex region are significantly correlated with heat resistance of C. sporogenes spores, and that cortex region plays a major role in protecting the spore from heat damage.

Isolation and characterization of bacterial diversity from soils supplemented with electrical transformer fluids

2011 ◽  
Vol 1 (2) ◽  
pp. 107-113
Author(s):  
Nwinyi Obinna C ◽  
Alade Adetutu ◽  
Leo‐ Akpan Imaobong R ◽  
Oladele Bolaji.O
Keyword(s):  
Optical Density ◽  
Culture Medium ◽  
Agricultural Land ◽  
Agricultural Soils ◽  
Bacterial Species ◽  
Minimal Salt Medium ◽  
Isolation And Characterization ◽  
The Mean ◽  
Biomass Increase

Repetitive enrichment of soils samples from an agricultural land and newly marked dumpsite on electrical transformer fluid yielded six bacterial species that have the capacity to utilize electrical transformer fluids (askarel) as carbon and energy source. Bacterial species namely: Micrococcus, Arthrobacter, Pseudomonas putida, Pseudomonas spp, Norcadia and Corynebacterium were identified using morphological and biochemical characteristics. The abilities of these bacterial species to utilize the electrical transformer fluids as carbon source in minimal salt medium (MSM); sub cultured in concentrations of 5, 10, 15 and 20μL of electrical transformer fluids were investigated for twenty‐one days period. Physiological changes in terms of biomass increase were monitored by measuring the pH and optical density of the culture medium. From the results obtained, there was observed a general decrease in the pH and  increase in Optical density (O.D). The mean pH and O.D. readings ranged between (4.34‐6.13 and 0.073‐0.386) respectively. The decreased pH could justify for the acidic metabolites produced in the course of utilization of askarel as growth substrates. This study suggested that, the tropical ecosystems can provide exotic bacterial species that are capable of degrading or mineralizing polychlorinated biphenyls and their derivatives from dumpsites and agricultural soils.

scholarly journals A stereological study of the glomerular filter in the rat. Morphometry of the slit diaphragm and basement membrane.

1975 ◽  
Vol 67 (2) ◽  
pp. 436-443 ◽  
Author(s):  
S M Shea ◽  
A B Morrison
Keyword(s):  
Basement Membrane ◽  
Slit Diaphragm ◽  
Hydrodynamic Theory ◽  
Solute Flux ◽  
Albino Rats ◽  
Normal Male ◽  
Arterial Perfusion ◽  
Slit Length ◽  
Ultrathin Sections ◽  
The Mean

Kidney from normal male albino rats, of body weight 170-200 g, was fixed by arterial perfusion with buffered tannic acid-glutaraldehyde, and postfixed with osmium tetroxide. Random and isotropic ultrathin sections from 23 different glomeruli from five rats were mounted on slot grids for staining and electron microscopy. Prints of whole glomeruli at a magnification of 3,909 were analyzed by stereological methods. The mean glomerular volume was (8.048 +/- 0.474) X 10(5) mum3 if the glomeruli are treated as spheres. The area of the basement membrane was 0.281 +/- 0.017 mm2 per glomerulus, of which 0.184 +/- 0.011 mm2 represents peripheral basement membrane. The aggregate epithelial slit length per glomerulus was 65.19 +/- 3.84 cm, of which 48.69 +/- 2.87 cm represents epithelial slits abutting on the peripheral basement membrane. Assuming that a slit diaphragm is 390 A wide, and that the pores of the slit diaphragm represent 26% of its area, the mean pore area is 3.96 cm2, of which 2.96 cm2 represents the area of peripheral pores. These findings are discussed in the context of the hydrodynamic theory of glomerular ultrafiltration. We conclude that the porous substructure of the glomerular slit diaphragm is significant in determining the hydraulic conductivity of the glomerulus and hence also solute flux during ultrafiltration.

DEVELOPMENT OF SAMPLING TECHNIQUES AND LIFE TABLES FOR THE FIR ENGRAVER SCOLYTUS VENTRALIS (COLEOPTERA: SCOLYTIDAE)

1968 ◽  
Vol 100 (11) ◽  
pp. 1138-1147 ◽  
Author(s):  
Alan A. Berryman
Keyword(s):  
Population Density ◽  
Life Table ◽  
Sampling Design ◽  
Life Tables ◽  
Sampling Techniques ◽  
Sample Unit ◽  
Complete Series ◽  
The Mean ◽  
Individual Trees

AbstractMethods are presented for sampling and constructing life tables for Scolytus ventralis LeConte with the objective of comparing the histories of populations inhabiting individual trees. A bark area of 72 sq. in. was an effective sample unit. Within-tree variation was minimized by taking two sample units from two vertical strata at each sampling date. Trees were serially sampled several times during development of the insect.Population tables were constructed for each sampling date and life tables were developed from the complete series of population tables. The precision of the life table estimates varied between 10% and 40% of the mean and generally decreased as population density diminished during development. A sampling design is presented for increasing the precision of life tables, and methods are given for determining the number of trees required for estimating the mean density when studying populations occupying large areas.

scholarly journals Hydrocarbon Degradation Potential of Heterotrophic Bacteria Isolated from Oil Polluted Sites in Sakpenwa Community in Rivers State

2019 ◽  
pp. 1-12 ◽  
Author(s):  
R. N. Akwukwaegbu ◽  
P. O. Okerentugba ◽  
G. C. Okpokwasili ◽  
H. O. Stanley ◽  
C. J. Ugboma
Keyword(s):  
Optical Density ◽  
Heterotrophic Bacteria ◽  
Bacterial Species ◽  
Colour Change ◽  
Hydrocarbon Degradation ◽  
Gravimetric Analysis ◽  
Bacterial Counts ◽  
Biodegradation Study ◽  
The Mean ◽  
Rivers State

In this study, hydrocarbon degradation potentials of heterotrophic bacteria isolated from oil-polluted soil were examined. Samples were collected from Sakpenwa, an oil producing community in Tai LGA of Rivers State, Nigeria and analyzed for physicochemical and microbiological properties using standard techniques. Hydrocarbon utilizing bacteria (HUB) were isolated by vapour phase transfer method using mineral salt medium. The biodegradation study was carried out on a standard laboratory shaker for 30 days in Bushnell -Haas agar supplemented with 5% of crude oil. Fifteen (15) bacterial isolates were screened for hydrocarbon degradation potentials of which five isolates exhibited high hydrocarbon degradability.  The following parameters were monitored using each of the five isolates and a consortium during the biodegradation study: Colour change, Optical density (OD), pH, Total Petroleum Hydrocarbon (TPH), Total Hydrocarbon Contents (THC) and Total Cuturable Heterotrophic Bacterial Counts (TCHBC). The mean TCHBC ranged from 1.65×107 to 2.27×108cfu/ml while the mean Total Culturable Hydrocarbon Utilizing Bacterial Counts ranged from 1.09×104 to 3.9×105. The optical density varied from 0.09±0.02 - 2.57±0.00 and pH ranged from 2.98±0.09 - 6.98±0.09. The optical density varied to .09±0.02 - 2.57±0.00 and pH ranged from 2.98±0.09 -0.98±0.09. The gravimetric analysis showed that Bacillus sp., Pseudomonas sp. Alcaligenes sp. and Acinetobacter sp. were able to degrade 96.90%, 99.60%, 99.20% and 99.70% of the hydrocarbons respectively. This study demonstrated that indigenous bacterial species were highly efficient in the biodegradation of petroleum hydrocarbons.

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