scholarly journals Effects of temperature on actin polymerized by Ca2+. Direct evidence of fragmentation

1985 ◽  
Vol 232 (1) ◽  
pp. 297-300 ◽  
Author(s):  
E Grazi ◽  
G Trombetta
Keyword(s):  
Electron Microscopy ◽  
Direct Evidence ◽  
Monomer Conversion ◽  
Effect Of Temperature ◽  
Specific Viscosity ◽  
Effects Of Temperature

When the temperature is lowered from 20 to 4 degrees C, the specific viscosity of actin polymerized in the presence of either 4 mM-CaCl2 or 2 mM-MgCl2, but not of actin polymerized in the presence of 90 mM-KCl, is decreased by 50% in the absence of free ATP. Addition of ATP restores the viscosity of the actin polymerized by Mg2+, but not that of actin polymerized by Ca2+, to the original value. The effect of temperature on actin polymerized in the presence of Ca2+ is due to (a) polymer-into-monomer conversion, (b) latero-lateral aggregation of filaments, and (c) fragmentation of the filaments. Fragmentation, as demonstrated by fractional centrifugation and electron microscopy, was the most important of these.

Nucleation of Disorder in Fe3Al Alloys

1967 ◽  
Vol 25 ◽  
pp. 312-313
Author(s):  
P. R. Swann ◽  
W. R. Duff ◽  
R. M. Fisher
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Annealing Temperature ◽  
Antiphase Domain ◽  
Effect Of Temperature ◽  
Domain Structures ◽  
Transmission Electron ◽  
Domain Boundaries ◽  
Higher Temperature ◽  
The One

Recently we have investigated the phase equilibria and antiphase domain structures of Fe-Al alloys containing from 18 to 50 at.% Al by transmission electron microscopy and Mössbauer techniques. This study has revealed that none of the published phase diagrams are correct, although the one proposed by Rimlinger agrees most closely with our results to be published separately. In this paper observations by transmission electron microscopy relating to the nucleation of disorder in Fe-24% Al will be described. Figure 1 shows the structure after heating this alloy to 776.6°C and quenching. The white areas are B2 micro-domains corresponding to regions of disorder which form at the annealing temperature and re-order during the quench. By examining specimens heated in a temperature gradient of 2°C/cm it is possible to determine the effect of temperature on the disordering reaction very precisely. It was found that disorder begins at existing antiphase domain boundaries but that at a slightly higher temperature (1°C) it also occurs by homogeneous nucleation within the domains. A small (∼ .01°C) further increase in temperature caused these micro-domains to completely fill the specimen.

Effect of temperature during the synthesis process of CdSe nanoparticles using the colloidal technique

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3389-3395
Author(s):  
R. González-Díaz ◽  
D. Fernández-Sánchez ◽  
P. Rosendo-Francisco ◽  
G. Sánchez-Legorreta
Keyword(s):  
Scanning Tunneling Microscope ◽  
Electron Cloud ◽  
Cdse Nanoparticles ◽  
Effect Of Temperature ◽  
Synthesis Process ◽  
Scanning Tunneling ◽  
Tunneling Microscope ◽  
First Results ◽  
Effects Of Temperature ◽  
Scanning Electron

AbstractIn this work, the first results of the effects of temperature during the production of Se2- ions and the effect during the interaction of Cd2+ and Se2- ions in the synthesis process of CdSe nanoparticles are presented. The synthesis of CdSe was carried out by the colloidal technique, in the first one we used a temperature of 63 °C to produce Se2- ions and in the second one an interaction temperature of 49 °C. The samples were characterized using a Scanning Electron Microscope (SEM) and a Scanning Tunneling Microscope (STM). From the SEM micrographs it was possible to identify the thorns formation and irregular islands. STM micrographs reveal elliptical shapes with a regular electron cloud profile.

Carbon Nanotubes Grown on Metallic Wires by Cold Plasma Technique

2002 ◽  
Vol 737 ◽  
Author(s):  
D. Sarangi ◽  
A. Karimi
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotubes ◽  
Growth Conditions ◽  
Effect Of Temperature ◽  
Rutherford Back Scattering ◽  
Novel Approach ◽  
Transmission Electron ◽  
Back Scattering ◽  
Metallic Wires ◽  
Metal Wires

ABSTRACTCarbon nanotubes on metallic wires may be act as electrode for the field emission (FE) luminescent devices. Growing nanotubes on metallic wires with controlled density, length and alignment are challenging issues for this kind of devices. We, in the present investigation grow carbon nanotubes directly on the metal wires by a powerful but simple technique. A novel approach has been proposed to align nanotubes during growth. Methane, acetylene and dimethylamine have been used as source gases. With the same growth conditions (viz. pressure, growth temperature and plasma) methane does not produce any nanotube but nanotubes grown with dimethylamine show shorter length and radius than acetylene. The effect of temperature to control the radius, time to control the density, plasma conditions to align the nanotubes has been focused. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM) and Rutherford Back Scattering (RBS) are used to characterize the nanotubes.

scholarly journals The Effect of Temperature and Humidity May Reduce the Growth Rate of the Coronavirus Disease 2019 Epidemic

2020 ◽  
Author(s):  
Lei Qin ◽  
Qiang Sun ◽  
Jiani Shao ◽  
Yang Chen ◽  
Xiaomei Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Relative Humidity ◽  
Effect Of Temperature ◽  
Average Temperature ◽  
Temperature And Humidity ◽  
Scatter Plots ◽  
Low Humidity ◽  
Average Relative Humidity ◽  
Effects Of Temperature ◽  
The Relationship

Abstract Background: The effects of temperature and humidity on the epidemic growth of coronavirus disease 2019 (COVID-19)remains unclear.Methods: Daily scatter plots between the epidemic growth rate (GR) and average temperature (AT) or average relative humidity (ARH) were presented with curve fitting through the “loess” method. The heterogeneity across days and provinces were calculated to assess the necessity of using a longitudinal model. Fixed effect models with polynomial terms were developed to quantify the relationship between variations in the GR and AT or ARH.Results: An increased AT dramatically reduced the GR when the AT was lower than −5°C, the GR was moderately reduced when the AT ranged from −5°C to 15°C, and the GR increased when the AT exceeded 15°C. An increasedARH increased theGR when the ARH was lower than 72% and reduced theGR when the ARH exceeded 72%.Conclusions: High temperatures and low humidity may reduce the GR of the COVID-19 epidemic. The temperature and humidity curves were not linearly associated with the COVID-19 GR.

Enhanced thermoelectric performance of layered SnS crystals: the synergetic effect of temperature and carrier concentration

RSC Advances ◽  
2015 ◽  
Vol 5 (69) ◽  
pp. 56382-56390 ◽  
Author(s):  
Bao-Zhen Sun ◽  
Zuju Ma ◽  
Chao He ◽  
Kechen Wu
Keyword(s):  
Carrier Concentration ◽  
Synergetic Effect ◽  
Thermoelectric Performance ◽  
Effect Of Temperature ◽  
Effects Of Temperature

The synergistic deployment of the effects of temperature and carrier concentration raises the ZT of SnS to a high value (1.61 ± 0.02).

scholarly journals Studies in the geotropism of the pteridophyta V—Some effects of temperature on growth and geotropism in Asplenium bulbiferium

1935 ◽  
Vol 116 (800) ◽  
pp. 479-493 ◽  
Keyword(s):  
Growth Rate ◽  
Effect Of Temperature ◽  
Horizontal Position ◽  
Present Position ◽  
Minimum Period ◽  
Plant Life ◽  
Latent Time ◽  
Presentation Time ◽  
Effects Of Temperature ◽  
The Given

Although temperature and gravity both influence plant life, and although both factors have been studied for many decades, there is surprisingly little literature decades, there is surprisingly little literature dealing with the relation between the two; and none, so far as I can discover, on the effect in any Pteridophyte. Navez (1929) who criticized the work of some investigators on the effect of temperature on the geotropism of a few seedlings, sums up the present position in his remark that the conclusions of workers are very different and often in opposition. The present paper gives the results of 1100 experiments carried out mainly between the years 1922 and 1927, and though it is realized that much remains to be done on the question, it is believed that the results which have been obtained are of some value. For general methods, reference may be made to previous “Studies” in this series. Geotropic sensitivity, as measured by presentation time at different stages in development of the frond, was fully worked out by Waight (1923) for 20°C, and is adopted here as a standard of reference. The growth rate recorded in the tables is that for the particular frond under investigation, or is the average of the fronds examined during the day of the experiment. Nearly all the experiments included in the tables were conducted during the months of April-October, as I have since been able to show that there is an annual rhythm in geotropic irritability. A decrease in sensitivity occurs in winter, and hence experiments performed in November-March are not strictly comparable with those carried out in the summer. The following abbreviations are used:- P.S. = period of stimulation. P.T. = presentation time, i. e ., the minimum period of stimulation in a horizontal position, which, under the given conditions, will cause a movement of approximately 5° in about 80% of the fronds. L.T. = latent time (Prankerd, 1925) in hours. N = “normal time,” i. e ., the P.T. For different stages of the frond at 20°C (see Waight, 1923).

scholarly journals Direct Evidence of Lack of Colocalisation of Fluorescently Labelled Gold Labels Used in Correlative Light Electron Microscopy

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Benjamin T. Miles ◽  
Alexander B. Greenwood ◽  
David Benito-Alifonso ◽  
Hugh Tanner ◽  
M. Carmen Galan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Direct Evidence

SIZE-INDUCED EFFECTS IN NANOSTRUCTURED NiFe2O4

2010 ◽  
Vol 24 (30) ◽  
pp. 5973-5985
Author(s):  
M. GUNES ◽  
H. GENCER ◽  
T. IZGI ◽  
V. S. KOLAT ◽  
S. ATALAY
Keyword(s):  
Electron Microscopy ◽  
Annealing Temperature ◽  
Structural Parameters ◽  
Hydrothermal Process ◽  
Lattice Parameter ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

NiFe 2 O 4 nanoparticles were successfully prepared by a hydrothermal process, and the effect of temperature on them was studied. The particles were annealed at various temperatures ranging from 413 to 1473 K. Studies were carried out using powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analysis, thermogravimetric analysis and a vibrating sample magnetometer. The annealing temperature had a significant effect on the magnetic and structural parameters, such as the crystallite size, lattice parameter, magnetization and coercivity.

scholarly journals Effect of Temperature and Moisture Period on Infection of Rhododendron ‘Cunningham's White’ by Phytophthora ramorum

2009 ◽  
Vol 99 (9) ◽  
pp. 1045-1052 ◽  
Author(s):  
Paul W. Tooley ◽  
Marsha Browning ◽  
Kerrie L. Kyde ◽  
Dana Berner
Keyword(s):  
The United States ◽  
Phytophthora Ramorum ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Detached Leaf ◽  
Wide Range ◽  
Effects Of Temperature ◽  
Gradient Plate ◽  
Whole Plants ◽  
Moisture Conditions

We investigated the temperature and moisture conditions that allow Phytophthora ramorum to infect Rhododendron ‘Cunningham's White’. Most experiments were performed with a single P. ramorum isolate from the NA1 clonal lineage. For whole plants incubated in dew chambers at 10 to 31°C, the greatest proportion of diseased leaves, 77.5%, occurred at the optimum temperature of 20.5°C. Disease occurred over the entire range of temperatures tested, although amounts of disease were minor at the temperature extremes. For whole plants exposed to varying dew periods at 20°C and then incubated at 20°C for 7 days, a dew period as short as 1 h resulted in a small amount of disease; however, at least 4 h of dew were required for >10% of the leaves to become diseased. Moisture periods of 24 and 48 h resulted in the greatest number of diseased leaves. In detached-leaf, temperature-gradient-plate experiments, incubation at 22°C resulted in the greatest disease severity, followed by 18°C and then 14°C. In detached-leaf, moisture-tent experiments, a 1-h moisture period was sufficient to cause disease on 67 to 73% of leaves incubated for 7 days at 20°C. A statistical model for disease development that combined the effects of temperature and moisture period was generated using nonlinear regression. Our results define temperature and moisture conditions which allow infection by P. ramorum on Cunningham's White rhododendron, and show that P. ramorum is able to infect this host over a wide range of temperatures and moisture levels. The results indicate that P. ramorum has the potential to become established in parts of the United States that are outside its current range.

The Influence of Temperature and Humidity on Instar Length in Calandra Granaria Linn

1947 ◽  
Vol 24 (1-2) ◽  
pp. 79-94
Author(s):  
L. E. S. EASTHAM ◽  
F. SEGROVE
Keyword(s):  
Growth And Development ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Food Utilization ◽  
Optimum Temperature ◽  
Atmospheric Humidity ◽  
Larval Instars ◽  
Balance Sheets ◽  
Temperature And Humidity ◽  
Effects Of Temperature

1. The effects of temperature and humidity on the duration of each instar of the life cycle of Calandra granaria Linn. have been examined. The insects were reared at temperatures ranging from 15 to 30° C. and at atmospheric humidities ranging from 40 to 80% R.H. 2. A method is described for assessing the effect of temperature as an independent factor. 3. The temperatures employed fall within the ‘vital zone’. Extrapolation indicates the threshold temperature to be approximately 11° C. for the egg and larval instars though somewhat lower for the pupa. 30° C. is below the optimum temperature. 4. The durations of the egg and pupal stages are not affected by atmospheric humidity. 5. The duration of all larval instars is affected by moisture. It is suggested that this is largely due to atmospheric humidity and that food water is of little significance. 6. Shortage of moisture acts as an obstacle to development. Evidence is presented which indicates that drier atmospheres tend to desiccate the insect and that desiccation is responsible for retarded growth and development. 7. Since much earlier work on temperature and moisture has been done on fasting insects and, therefore, on insects deficient in one of the most important environmental factors, we suggest that our results, incomplete as they are, indicate the need for new approaches to be made. More complete data on feeding insects under controlled conditions of food, temperature and moisture are required, from which can be drawn up more complete balance sheets of development involving measurements of food utilization and respiratory rates.

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