scholarly journals Dynamics of pigment complex from three species of wild rose upon hyperthermia

2016 ◽  
Vol 21 (2) ◽  
pp. 36-39
Author(s):  
N. Nuzhyna ◽  
O. Tkachuk ◽  
A. Fukalyak
Keyword(s):  
High Temperature ◽  
Photosynthetic Pigments ◽  
Short Term ◽  
Short Term Exposure ◽  
Pigment Complex

The data about changing of the content of photosynthetic pigments in leaves of plants Rosa donetzica, Rosa spinosissima, Rosa reversa after short-term exposure to high temperature (+40°C) are presented. It was established that the plants of species Rosa donetzica are is the least resistant of the studied species.

scholarly journals Various antioxidant responses to hyperthermia in anatomically different species of the genus Rosa

2019 ◽  
Vol 27 (3) ◽  
pp. 193-199 ◽  
Author(s):  
N. V. Nuzhyna ◽  
O. O. Tkachuk
Keyword(s):  
Superoxide Dismutase ◽  
High Temperature ◽  
Temperature Stress ◽  
Photosynthetic Pigments ◽  
Drought Resistance ◽  
Lipid Peroxide ◽  
Antioxidant Response ◽  
High Temperature Stress ◽  
Short Term ◽  
Pigment Complex

The heat and drought resistance of plants depend on their anatomical and biochemical features. In the present study, the adaptive features of three species of wild rose (Rosaceae, Rosales) under the short-term impact of high-temperature stress have been characterized. Plants of the species Rosa donetzica Dubovik, R. reversa Waldst. et Kit. and R. spinosissima L. were exposed to a temperature of 40 degrees C for 3 hours, following which peroxidase and superoxide dismutase activity, photosynthetic pigments and flavonoids’ content, and lipid peroxide oxidation level in the leaf were determined. In our investigation, the anatomical structure of leaves and drought resistance of three species of Rosa were studied. Xeromorphic features are the most expressed for R. reversa and R. spinosissima and almost absent for R. donetzica. It has been established that R. spinosissima is photophilous whereas R. donetzica is shade-tolerant. The relatively lower development of epidermic tissue in R. donetzica could probably contribute to more active destruction of the pigment complex under high temperature stress. The obtained data about changes in activity of peroxidase, superoxide dismutase, content of photosynthetic pigments and flavonoids, and level of lipid peroxidation indicate the low heat resistance of R. donetzica in comparison with the other two species. R. reversa, R. spinosissima were more tolerant to short-term hyperthermia. They showed faster antioxidant response, mainly due to the induction of peroxidase activity under stress. The species with the most expressed xerophytic features of anatomical structures have rapid antioxidant response and are more resistant to short-term hyperthermia. The induction of some activity of antioxidant enzymes "in reserve" is a less effective form of adaptation in wild roses. Such activation of enzymes is observed in plants with a more mesophytic structure. Flavonoids and superoxide dismutase were thermolabile to short-term influence of high temperature; therefore they play an insignificant role as antioxidants in the protecton against oxidative stress caused by high temperature stress in wild roses.

Shape stability of chosen thin wood based panels after heating

2019 ◽  
Vol 106 ◽  
pp. 85-89
Author(s):  
MACIEJ SYDOR ◽  
Bartosz Pałubicki
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Thin Plate ◽  
Dimensional Stability ◽  
Power Supplies ◽  
Short Term ◽  
Shape Stability ◽  
Short Term Exposure ◽  
The Impact

Shape stability of chosen thin wood based panels after heating. Lignocellulose board materials are commonly used for furniture construction. Typically, these are particle boards, fibreboard or plywood with thicknesses from 10 to 20 mm, however, some furniture elements are made of thin boards with a thickness of 3-4 mm (back walls, bottoms of drawers and others). Modern furniture uses built-in components that are a source of heat, such as lamps, power supplies, ovens. Local high temperature may negatively affect the shape stability of thin lignocellulose plates. The aim of the research described in this article was to determine the impact of shortterm exposure to high temperature on the dimensional stability of selected thin plate furniture materials. Four different HDF boards with nominal thicknesses of 3 mm and four different plywood boards with nominal thicknesses of 2 to 4 mm were tested. The test samples were subjected to a short-term exposure to temperatures of up to 250°C. As a result of the tests, it was found that HDF boards are characterized by a much higher shape stability at elevated temperature than boards made of plywood.

scholarly journals Out-of-hospital cardiac arrests in a large metropolitan area: synergistic effect of exposure to air particulates and high temperature

2019 ◽  
Vol 27 (5) ◽  
pp. 513-519 ◽  
Author(s):  
Eleonora Tobaldini ◽  
Simona Iodice ◽  
Rodolfo Bonora ◽  
Matteo Bonzini ◽  
Annamaria Brambilla ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
High Temperature ◽  
Metropolitan Area ◽  
Cardiac Event ◽  
Cumulative Exposure ◽  
Maximum Effect ◽  
Short Term ◽  
Short Term Exposure

Aims Air pollution and climate change are intrinsically linked to emerging hazards for global health. High air particulate matter (PM) levels may trigger out-of-hospital cardiac arrest (OHCA). High temperature could act synergistically with PM in determining OHCA. The aim of the present study was to investigate the effect of PM exposure alone, and in combination with temperature, on the risk of OHCA, in a large European metropolitan area with population >4 million. Methods We evaluated the association between short-term PM exposure, temperature, and the risk of OHCA over a two-year study period, allowing us to investigate 5761 events using a time-stratified case-crossover design combined with a distributed lag non-linear model. Results Higher risk of OHCA was associated with short-term exposure to PM10. The strongest association was experienced three days before the cardiac event where the estimated change in risk was 1.70% (0.48–2.93%) per 10 µg/m3 of PM. The cumulative exposure risk over the lags 0–6 was 8.5% (0.0–17.9%). We observed a joint effect of PM and temperature in triggering cardiac arrests, with a maximum effect of 14.9% (10.0–20.0%) increase, for high levels of PM before the cardiac event, in the presence of high temperature. Conclusion The present study helps to clarify the controversial role of PM as OHCA determinant. It also highlights the role of increased temperature as a key factor in triggering cardiac events. This evidence suggests that tackling both air pollution and climate change might have a relevant impact in terms of public health.

The Effect of Dimethyl Sulfoxide on In Vitro Platelet Function

1976 ◽  
Vol 36 (01) ◽  
pp. 221-229 ◽  
Author(s):  
Charles A. Schiffer ◽  
Caroline L. Whitaker ◽  
Morton Schmukler ◽  
Joseph Aisner ◽  
Steven L. Hilbert
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Dimethyl Sulfoxide ◽  
Platelet Function ◽  
Platelet Volume ◽  
Short Term ◽  
Platelet Factor ◽  
Short Term Exposure ◽  
Structural Abnormalities

SummaryAlthough dimethyl sulfoxide (DMSO) has been used extensively as a cryopreservative for platelets there are few studies dealing with the effect of DMSO on platelet function. Using techniques similar to those employed in platelet cryopreservation platelets were incubated with final concentrations of 2-10% DMSO at 25° C. After exposure to 5 and 10% DMSO platelets remained discoid and electron micrographs revealed no structural abnormalities. There was no significant change in platelet count. In terms of injury to platelet membranes, there was no increased availability of platelet factor-3 or leakage of nucleotides, 5 hydroxytryptamine (5HT) or glycosidases with final DMSO concentrations of 2.5, 5 and 10% DMSO. Thrombin stimulated nucleotide and 5HT release was reduced by 10% DMSO. Impairment of thrombin induced glycosidase release was noted at lower DMSO concentrations and was dose related. Similarly, aggregation to ADP was progressively impaired at DMSO concentrations from 1-5% and was dose related. After the platelets exposed to DMSO were washed, however, aggregation and release returned to control values. Platelet aggregation by epinephrine was also inhibited by DMSO and this could not be corrected by washing the platelets. DMSO-plasma solutions are hypertonic but only minimal increases in platelet volume (at 10% DMSO) could be detected. Shrinkage of platelets was seen with hypertonic solutions of sodium chloride or sucrose suggesting that the rapid transmembrane passage of DMSO prevented significant shifts of water. These studies demonstrate that there are minimal irreversible alterations in in vitro platelet function after short-term exposure to DMSO.

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