Elevated Temperature Treatment Induced Alteration in Thylakoid Membrane Organization and Energy Distribution between the Two Photosystems in Pisum sativum

2002 ◽  
Vol 57 (9-10) ◽  
pp. 836-842 ◽  
Author(s):  
Prasanna Mohanty ◽  
Bagawatula Vani ◽  
Jogadhenu S. S. Prakash
Keyword(s):  
Heat Treatment ◽  
Elevated Temperature ◽  
Pisum Sativum ◽  
Fold Increase ◽  
Blue Shift ◽  
Temperature Treatment ◽  
Cd Spectra ◽  
Pea Seedlings ◽  
Heat Treated

Two-week-old pea (Pisum sativum var. Arkal) plants were subjected to elevated temperature (38 °C/42 °C) in dark for 14−15 h. The effect of heat treatment on light- induced phosphorylation of LHCII and LHCII migration in the thylakoid membranes were investigated. The heat treatment did cause a substantial (more than two fold) increase in the extent of LHCII phosphorylation as compared to the control. Upon separation of appressed and nonappressed thylakoid fractions by digitonin treatment, the heat-treated samples showed a decrease in LHCII-related polypeptides from the grana stack (appressed region) over the control. Further, a small increase in the intensity of these (LHCII-related) bands was detected in stromal thylakoid fraction (non-appressed membranes). This suggests an enhanced extent of migration of phosphorylated LHCII from appressed to non-appressed regions due to in vivo heat treatment of pea plants. We also isolated the LHCII from control and heat treated (42 °C) pea seedlings. Analysis of CD spectra revealed a 5D6 nm blue shift in the 638 nm negative peak in heat treated samples suggesting alteration in the organization of Chl b in the LHCII macro-aggregates. These results suggest that in vivo heat stress not only alters the extent of migration of LHCII to stromal region, but also affects the light harvesting mechanism by LHCII associated with the grana region.

Therapy of Virus-Infected Plants by Heat Treatment I. Some Properties of Tomato Aspermy Virus and Its Inactivation at 36°C

1974 ◽  
Vol 22 (3) ◽  
pp. 437 ◽  
Author(s):  
GR Johnstone ◽  
GC Wade
Keyword(s):  
Heat Treatment ◽  
Order Reaction ◽  
Optimum Temperature ◽  
Tobacco Plants ◽  
Tomato Aspermy Virus ◽  
Induced Stress ◽  
Heat Treated ◽  
Enzyme Class

An isolate of tomato aspermy virus (TAV) was inactivated both in vivo and in vitro at 36°C. Inactivation took the form of a second or higher order reaction, which indicated that loss of infectivity was not due solely to a direct effect of high temperature on the virus. The concentration of polyphenoloxidases increased greatly in tobacco plants grown at 36°C, and evidence was obtained to indicate that this enzyme class, either directly or indirectly, enhanced the inactivation of TAV during heat treatment. The concentration of ribonucleases also increased in heat-treated tissues and these may have aided the inactivation, as the infectivity of TAV was shown to be destroyed by RNase in tests in vitro. The pH and ionic strength of the sap decreased in heated plants and these changes may have been significant as TAV had critical requirements of buffer pH and molarity for optimum infectivity. The alterations in cellular metabolism responsible for these changes result from heat-induced stress. Therefore, the optimum temperature for therapy of many viruses by heat treatment is likely to vary with the host in which it is treated, depending upon the host's heat tolerance.

A Study on the Interface between Oxide Film on the Titanium Surface and Bone Tissue

2007 ◽  
Vol 342-343 ◽  
pp. 545-548
Author(s):  
Li Ping Wang ◽  
Bang Cheng Yang ◽  
Ji Yong Chen ◽  
Xing Dong Zhang
Keyword(s):  
Heat Treatment ◽  
Oxide Film ◽  
Titanium Oxide ◽  
Titanium Surface ◽  
The Other ◽  
Apatite Formation ◽  
Titanium Oxide Film ◽  
Heat Treated

The bioactivities of titanium oxide film on titanium surface received from different chemical treatment methods were studied in SBF in vitro and mechanically and histologically investigated in vivo. Three groups of titanium specimens were prepared: untreated titanium(S), acid-alkali treated titanium (H), and acid-alkali and heat-treated titanium(X). The oxide film of X surface resulted in more apatite formation and significantly higher strength of the interface between the samples and bone than those of the other titanium groups. The surface of the acid-alkali treated titanium and that further treated by heat treatment had higher bioactivity and stronger bone-bonding ability.

scholarly journals Viability Status-Dependent Effect of Bifidobacterium longum ssp. longum CCM 7952 on Prevention of Allergic Inflammation in Mouse Model

2021 ◽  
Vol 12 ◽  
Author(s):  
Marcelina Joanna Pyclik ◽  
Dagmar Srutkova ◽  
Agnieszka Razim ◽  
Petra Hermanova ◽  
Tereza Svabova ◽  
...  
Keyword(s):  
Bifidobacterium Longum ◽  
Allergic Inflammation ◽  
Specific Ige ◽  
Temperature Treatment ◽  
Human Organism ◽  
Effector Molecules ◽  
Beneficial Effects ◽  
Heat Treated

The classical definition of probiotics states that bacteria must be alive to be beneficial for human organism. However, recent reports show that inactivated bacteria or their effector molecules can also possess such properties. In this study, we investigated the physical and immunomodulatory properties of four Bifidobacterium strains in the heat-treated (HT) and untreated (UN) forms. We showed that temperature treatment of bacteria changes their size and charge, which affects their interaction with epithelial and immune cells. Based on the in vitro assays, we observed that all tested strains reduced the level of OVA-induced IL-4, IL-5, and IL-13 in the spleen culture of OVA-sensitized mice. We selected Bifidobacterium longum ssp. longum CCM 7952 (Bl 7952) for further analysis. In vivo experiments confirmed that untreated Bl 7952 exhibited allergy-reducing properties when administered intranasally to OVA-sensitized mice, which manifested in significant suppression of airway inflammation. Untreated Bl 7952 decreased local and systemic levels of Th2 related cytokines, OVA-specific IgE antibodies and simultaneously inhibited airway eosinophilia. In contrast, heat-treated Bl 7952 was only able to reduce IL-4 levels in the lungs and eosinophils in bronchoalveolar lavage, but increased neutrophil and macrophage numbers. We demonstrated that the viability status of Bl 7952 is a prerequisite for the beneficial effects of bacteria, and that heat treatment reduces but does not completely abolish these properties. Further research on bacterial effector molecules to elucidate the beneficial effects of probiotics in the prevention of allergic diseases is warranted.

The most prevalent protein in a heat-treated extract of pea (Pisum sativum) embryos is an LEA group I protein; its conformation is not affected by exposure to high temperature

1997 ◽  
Vol 7 (2) ◽  
pp. 117-124 ◽  
Author(s):  
Pauline S. Russouw ◽  
Jill Farrant ◽  
Wolf Brandt ◽  
George G. Lindsey
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Pisum Sativum ◽  
Fluorescence Spectroscopy ◽  
Trypsin Digestion ◽  
Antibody Affinity ◽  
Embryonic Axes ◽  
Group I ◽  
Heat Treated ◽  
Before And After

AbstractThe LEA-like protein previously isolated from a homogenate of pea (Pisum sativum L.) embryonic axes heated at 80°C for 10 min (Russouw et al., 1995) was purified without exposure to heat. Peptides produced by trypsin digestion were separated by HPLC and sequenced. The protein was identified as a member of the LEA group I family. The conformation of the protein was compared before and after heat treatment by antibody affinity, circular dichroism spectroscopy, fluorescence spectroscopy and 8-anilino-1-naphthalenesulfonic acid binding. No differences could be detected, demonstrating that the protein was not irreversibly denatured by exposure to high temperature.

Short-Term Responses of Photosystem II to Heat Stress in Cold-Acclimated Atrazine-Resistant and Susceptible Biotypes of Erigeron canadensis (L.)

1999 ◽  
Vol 54 (9-10) ◽  
pp. 665-670 ◽  
Author(s):  
Sándor Dulai ◽  
István Molnár ◽  
Evelin Péli ◽  
Endre Lehoczki
Keyword(s):  
Heat Treatment ◽  
Heat Stress ◽  
Elevated Temperature ◽  
Photosystem Ii ◽  
Significant Shift ◽  
Short Term ◽  
Erigeron Canadensis ◽  
Heat Treated ◽  
Temperature Dependences

When leaves of atrazine-resistant (AR) and atrazine-sensitive (S) Erigeron canadensis (L.) plants grown at 5 °C were exposed to an elevated temperature (35 °C) for 30 min, the critical (Tc) and peak temperatures (Tp) of the F0 vs. T curves were considerably higher for the leaves of the S biotype, but not for those of the AR biotype. The temperature dependences of Fv/Fm and ΔF/Fm′ were not greatly different for the heat-treated cold-acclimated AR biotype, in contrast with the situation for the S plants. This short-term heat treatment resulted in a more significant shift in the optimal thermal interval of CO2 fixation for the S than for the AR biotypes

The C14-to-C15 Transformation in Cr2Hf

1994 ◽  
Vol 364 ◽  
Author(s):  
K. S. Kumar ◽  
P. M. Hazzledine
Keyword(s):  
Heat Treatment ◽  
Phase Diagram ◽  
Solid Solution ◽  
Elevated Temperature ◽  
Room Temperature ◽  
Single Phase ◽  
Higher Order ◽  
Two Phase ◽  
Heat Treated ◽  
Order Structures

AbstractThree alloys, single-phase Cr2Hf, a two-phase alloy consisting of Cr solid solution and Cr2Hf, and a two-phase alloy consisting of Hf solid solution and Cr2Hf were cast and heat treated. The C14-to- C15 transformation of the Laves phase, Cr2Hf was studied as a function of heat treatment. According to the existing phase diagram, the Cr2Hf phase exhibits a C14 structure at elevated temperature but transforms to the C15 structure at lower temperatures. Such transformations are known to be extremely sluggish. In the present study, the Cr2Hf phase was found to retain the C14 structure at room temperature in all three compositions in the cast or cast and forged conditions; upon subsequent heat-treatment at various temperatures and time-at-temperatures, however, the C14 structure decomposes to a variety of higher order structures including the 16H, 10H, and 4H structures. These superstructures can be viewed as containing various percentages of the cubic and hexagonal stacking. The C15 structure was not observed for any of the conditions considered.

scholarly journals Influence of Film Thickness and Heat Treatment on the Physical Properties of Mn Doped Sb2Se3 Nanocrystalline Thin Films

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
I. K. El Zawawi ◽  
Manal A. Mahdy ◽  
E. A. El-Sayad
Keyword(s):  
Thin Films ◽  
Heat Treatment ◽  
Film Thickness ◽  
Energy Gap ◽  
Blue Shift ◽  
Amorphous Structure ◽  
Treatment Temperature ◽  
Optical Energy Gap ◽  
Heat Treated ◽  
Nanocrystalline Thin Films

Nanocrystalline thin films of Sb37.07Mn1.95Se60.98 with different thickness (7, 20, 40, and 80 nm) were successfully prepared via inert gas condensation technique. As-deposited films showed amorphous structure by grazing incident in-plane X-ray diffraction (GIIXD) technique. All films of different thicknesses were heat treated at 433 K for 90 min. The GIIXD pattern of annealed films showed nanocrystalline orthorhombic structure. The effect of thickness of annealed films on the structure and optical properties was studied. Calculated particle sizes are 20.67 and 24.15 for 40 and 80 nm thickness of heat treated film. High resolution transmission electron microscope HRTEM images and their diffraction patterns proved that 40 nm film thickness annealed at different temperature has nanocrystalline nature with observed (high) crystallinity that increases with annealing temperature. Blue shift of optical energy gap was observed from 1.68 to 2 eV with decreasing film thickness from 80 to 7 nm. Film thickness of 40 nm was exposed to different heat treated temperatures from 353 to 473 K to detect its effect on structure and optical and electrical properties. Blue shift from 1.73 to 1.9 eV was observed in its optical band gap due to direct transition as heat treatment temperature decreasing from 473 to 353 K. Electrical conductivity was studied for different heat treated films of thickness 40 nm, and intrinsic conduction mechanism is dominant. The activation energy Ea was affected by heat treatment process.

scholarly journals Bacterial luciferase alpha beta fusion protein is fully active as a monomer and highly sensitive in vivo to elevated temperature

1989 ◽  
Vol 86 (17) ◽  
pp. 6528-6532 ◽  
Author(s):  
A Escher ◽  
D J O'Kane ◽  
J Lee ◽  
A A Szalay
Keyword(s):  
Elevated Temperature ◽  
Fusion Protein ◽  
Transcriptional Control ◽  
Light Emission ◽  
Fold Increase ◽  
Wild Type ◽  
Bacterial Luciferase ◽  
T7 Promoter ◽  
Alpha Beta

A 2.2-kilobase-pair (kbp) DNA fragment from Vibrio harveyi contains the luxA and luxB genes separated by a 26-base-pair (bp) intergenic region. The two genes were converted to a single open reading frame by site-specific mutagenesis. A full-length fusion protein is obtained when the new gene is placed under transcriptional control of a T7 promoter in Escherichia coli. Bioluminescence of colonies containing the gene fusion is 0.002% of the wild-type luciferase [alkanal monooxygenase (FMN-linked); alkanal, reduced-FMN:oxygen oxidoreductase (1-hydroxylating, luminescing), EC 1.14.14.3] at 37 degrees C. Growth at 23 degrees C results in a greater than 50,000-fold increase in light emission in cells containing fusion protein, whereas only a 3-fold increase in observed with cells containing the luxAB dicistron. Purified fusion protein isolated from E. coli grown at 19 degrees C exists in both monomeric and dimeric forms with specific bioluminescence activities comparable to the heterodimeric wild-type enzyme at 23 degrees C and 37 degrees C. These findings show that the alpha beta fusion polypeptide is functional as a monomer and suggest that its folding is drastically affected at elevated temperature. We hypothesize that the two-subunit bacterial luciferase may have evolved from a monomer as a result of a temperature increase in the environment.

Effect of a Complex Heat Treatment on the Structure of 300M Steel

1981 ◽  
Vol 39 ◽  
pp. 312-313
Author(s):  
R. Padmanabhan ◽  
W. E. Wood
Keyword(s):  
Heat Treatment ◽  
Metal Carbides ◽  
Austenite Grain Size ◽  
300M Steel ◽  
Heat Treated ◽  
Strain Fracture ◽  
Prior Austenite Grain Size ◽  
Short Time ◽  
Final Tempering ◽  
Similar Yield

Intermediate high temperature tempering prior to subsequent reaustenitization has been shown to double the plane strain fracture toughness as compared to conventionally heat treated UHSLA steels, at similar yield strength levels. The precipitation (during tempering) of metal carbides and their subsequent partial redissolution and refinement (during reaustenitization), in addition to the reduction in the prior austenite grain size during the cycling operation have all been suggested to contribute to the observed improvement in the mechanical properties. In this investigation, 300M steel was initially austenitized at 1143°K and then subjected to intermediate tempering at 923°K for 1 hr. before reaustenitizing at 1123°K for a short time and final tempering at 583°K. The changes in the microstructure responsible for the improvement in the properties have been studied and compared with conventionally heat treated steel. Fig. 1 shows interlath films of retained austenite produced during conventionally heat treatment.

“In vitro” and in Animal Model Studies on a Double Virus- Inactivated Factor VIII Concentrate

1995 ◽  
Vol 74 (03) ◽  
pp. 868-873 ◽  
Author(s):  
Silvana Arrighi ◽  
Roberta Rossi ◽  
Maria Giuseppina Borri ◽  
Vladimir Lesnikov ◽  
Marina Lesnikov ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Animal Model ◽  
Factor Viii ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Virus Inactivation ◽  
Enveloped Viruses ◽  
Model Studies ◽  
Heat Treated

SummaryTo improve the safety of plasma derived factor VIII (FVIII) concentrate, we introduced a final super heat treatment (100° C for 30 min) as additional virus inactivation step applied to a lyophilized, highly purified FVIII concentrate (100 IU/mg of proteins) already virus inactivated using the solvent/detergent (SID) method during the manufacturing process.The efficiency of the super heat treatment was demonstrated in inactivating two non-lipid enveloped viruses (Hepatitis A virus and Poliovirus 1). The loss of FVIII procoagulant activity during the super heat treatment was of about 15%, estimated both by clotting and chromogenic assays. No substantial changes were observed in physical, biochemical and immunological characteristics of the heat treated FVIII concentrate in comparison with those of the FVIII before heat treatment.

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