The effects of temperature upon the reproduction and respiration of a marine obligate psychrophile

1974 ◽  
Vol 20 (10) ◽  
pp. 1341-1345 ◽  
Author(s):  
R. R. Christian ◽  
W. J. Wiebe

The growth and respiration rates of a marine obligate psychrophile, Vibrio sp., were determined in a complex medium using optical density and viable counts and a polarized oxygen-electrode system. Growth rate was optimal at 7C and decreased at 10C, the maximum temperature for growth. Respiration increased continually from 1to 10C. Both growth and respiration rates were highly sensitive to small changes in temperature. For example, rates at 4C were 1.8 and 4.4 times higher than at 1C for growth and respiration, respectively. Growth efficiencies were calculated as generations per hour divided by respiration rate. Results indicated that the growth efficiency of this bacterium was much greater at the lower temperature range of growth.

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1919
Author(s):  
Huijeong Ahn ◽  
Gilyoung Lee ◽  
Geun-Shik Lee

Gout is a recurrent and chronic form of arthritis caused by the deposition of monosodium urate (MSU) crystals in the joints. Macrophages intake MSU crystals, the trigger for NLRP3 inflammasome activation, which leads to the release of interleukin (IL)-1β and results in the flaring of gout. The effects of temperature, an environmental factor for MSU crystallization, on IL-1β secretion have not been well studied. This study examined the effects of temperature on inflammasome activation. Specific triggers activated canonical inflammasomes (NLRP3, NLRC4, and AIM2) in murine macrophages at various temperatures (25, 33, 37, 39, and 42 °C). The maturation of IL-1β and caspase-1 was measured as an indicator for inflammasome activation. As expected, the optimal temperature of inflammasome activation was 37 °C. The MSU crystal-mediated activation of inflammasome increased at temperatures lower than 37 °C and decreased at higher temperatures. MSU crystals at lower temperatures enhanced IL-1β secretion via the NLRP3 inflammasome pathway. A lower temperature promoted the formation of MSU crystals without changing phagocytosis. Overall, lower temperatures form more MSU crystals and enhance NLRP3 inflammasome activation. In light of these findings, it is possible that hyperthermia therapy may reduce gout flaring.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wenfang Guo ◽  
Letai Yi ◽  
Peng Wang ◽  
Baojun Wang ◽  
Minhui Li

AbstractThe relationship between air temperature and the hospital admission of adult patients with community-acquired pneumonia (CAP) was analyzed. The hospitalization data pertaining to adult CAP patients (age ≥ 18 years) in two tertiary comprehensive hospitals in Baotou, Inner Mongolia Autonomous Region, China from 2014 to 2018 and meteorological data there in the corresponding period were collected. The exposure–response relationship between the daily average temperature and the hospital admission of adult CAP patients was quantified by using a distributed lag non-linear model. A total of 4466 cases of adult patients with CAP were admitted. After eliminating some confounding factors such as relative humidity, wind speed, air pressure, long-term trend, and seasonal trend, a lower temperature was found to be associated with a higher risk of adult CAP. Compared to 21 °C, lower temperature range of 4 to –12 °C was associated with a greater number of CAP hospitalizations among those aged ≥ 65 years, and the highest relative risk (RR) was 2.80 (95% CI 1.15–6.80) at a temperature of − 10 °C. For those < 65 years, lower temperature was not related to CAP hospitalizations. Cumulative lag RRs of low temperature with CAP hospitalizations indicate that the risk associated with colder temperatures appeared at a lag of 0–7 days. For those ≥ 65 years, the cumulative RR of CAP hospitalizations over lagging days 0–5 was 1.89 (95% CI 1.01–3. 56). In brief, the lower temperature had age-specific effects on CAP hospitalizations in Baotou, China, especially among those aged ≥ 65 years.


2005 ◽  
Vol 488-489 ◽  
pp. 453-456 ◽  
Author(s):  
Shi Hong Zhang ◽  
Yong Chao Xu ◽  
G. Palumbo ◽  
S. Pinto ◽  
Luigi Tricarico ◽  
...  

Comparing the formability with each other, extrusion and various rolling experiments were carried out to make fine-grained AZ31 Mg sheets, and uni-axial tensile tests were carried out at different strain rates and temperatures to investigate the effect of different variables. A warm deep drawing tool setup with heating elements, which were distributed under the die surface and inside the blank holder, was designed and manufactured, and deep drawing was performed. Extruded Mg alloy AZ31 sheets exhibit the best deep drawing ability when working in the temperature range 250-350°C. Extruded and rolled sheets of 0.8 mm thick were also deep drawn in the lower temperature range 105-170°C,showing good formability and reaching a Limit Drawing Ratio up to 2.6 at 170°C for rolled sheets. At last, a sheet cup 0.4 mm thick was deep drawn successfully at 170 °C.


2012 ◽  
Vol 610-613 ◽  
pp. 296-299
Author(s):  
Xin Jie Li ◽  
Dan Nan Jiang ◽  
Yue Jun Zhang

In order to learn the ClO2 decay behaviour in tap water, the kinetics of ClO2 decay in pure water was studied. Under the conditions of tap water treatment and keeping away from light, the effects of temperature and pH on ClO2 degradation were investigated. The results show that the ClO2 decay reaction in pure water is the first-order with respect to ClO2, the decay rate constants increase with increase in temperature or pH. At pH=6.87, the rate constants are 0.012h-1(15°C), 0.017h-1(25°C), 0.023h-1(35°C), and 0.029h-1(45°C), respectively. At 25°C, the rate constants are 0.0083h-1(pH=4.5), 0.0111h-1(pH=5.5), 0.0143h-1(pH=6.5), 0.0222h-1(pH=7.5), and 0.0351h-1(pH=8.5), respectively. The experimental data prove that ClO2 is more stable in acidic or lower temperature water than in neutral, alkalescent, or higher temperature water.


2004 ◽  
Vol 842 ◽  
Author(s):  
Seiji Miura ◽  
Kenji Ohkubo ◽  
Tetsuo Mohri

ABSTRACTThe authors have reported in the previous study that the sluggish decomposition of Nb3Si phase is effectively accelerated by Zr addition [1]. This is obvious at lower temperature range than the nose temperature of the TTT curve. In the present study a eutectic alloy containing 1.5 % of Zr was investigated. The crystallographic orientation relationships among phases, such as eutectic Nb and product phases formed by eutectoid decomposition of Nb3Si (eutectoid Nb and Nb5Si3phases) in the Zr-containing sample which was heat treated at 1300°C were investigated by FESEM/EBSD for further understanding of the decomposition process in alloy with a different microstructure.


1994 ◽  
Vol 267 (1) ◽  
pp. R62-R70 ◽  
Author(s):  
C. S. Churcott ◽  
C. D. Moyes ◽  
B. H. Bressler ◽  
K. M. Baldwin ◽  
G. F. Tibbits

Active salmonids maintain myocardial contractility at temperatures that are cardioplegic for mammals. We postulated that myofibrillar Ca2+ sensitivity in the trout heart might 1) exhibit lower temperature dependence and/or 2) be greater over the range of physiological temperatures. Temperature-induced changes in intracellular pH may also play a role as alkalosis typically increases calcium affinity of myofibrillar adenosinetriphosphatase (ATPase). Ca2+ sensitivities of ventricular myofibrillar ATPase were determined in rats and in rainbow trout (Oncorhynchus mykiss) over a physiological range of pH and temperatures. Maximal myofibrillar ATPase activities of each species were similar and equally affected by temperature. Trout myofibrillar ATPase lost Ca2+ dependence at 37 degrees C. At constant pH, reduced temperature decreased calcium affinity more in trout (0.35 pCa/10 degrees C) than in rat (0.08-0.16 pCa/10 degrees C). Under alpha-stat conditions, the effects of temperature were reduced in both trout (0.2 pCa/10 degrees C) and rat (no significant effect). Over trout physiological temperatures, Ca2+ sensitivity was greater than rat at 37 degrees C. Qualitatively similar results were observed in studies measuring tension in skinned trout ventricular fibers. One mechanism by which the trout heart is able to maintain contractility at low temperatures is through the inherent higher Ca2+ sensitivity of the contractile element compared with mammalian species.


2002 ◽  
Vol 48 (3) ◽  
pp. 269-272 ◽  
Author(s):  
Shinya Kohra ◽  
Nobuaki Tominaga ◽  
Yuji Takao ◽  
Masaki Nagae ◽  
Yasuhiro Ishibashi ◽  
...  

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 961 ◽  
Author(s):  
Wenqing Sun ◽  
Lidong Dai ◽  
Heping Li ◽  
Haiying Hu ◽  
Changcai Liu ◽  
...  

The experimental study on the electrical conductivities of schists with various contents of alkali ions (CA = K2O + Na2O = 3.94, 5.17, and 5.78 wt.%) were performed at high temperatures (623–1073 K) and high pressures (0.5–2.5 GPa). Experimental results indicated that the conductivities of schist markedly increased with the rise of temperature. Pressure influence on the conductivities of schist was extremely weak at the entire range of experimental temperatures. Alkali ion content has a significant influence on the conductivities of the schist samples in a lower temperature range (623–773 K), and the influence gradually decreases with increasing temperature in a higher temperature range (823–1073 K). In addition, the activation enthalpies for the conductivities of three schist samples were fitted as being 44.16–61.44 kJ/mol. Based on the activation enthalpies and previous studies, impurity alkaline ions (K+ and Na+) were proposed as the charge carriers of schist. Furthermore, electrical conductivities of schist (10−3.5–10−1.5 S/m) were lower than those of high-conductivity layers under the Tibetan Plateau (10−1–100 S/m). It was implied that the presence of schist cannot cause the high-conductivity anomalies in the middle to lower crust beneath the Tibetan Plateau.


2019 ◽  
Vol 11 ◽  
Author(s):  
Yuhua Duan

: Lithium aluminate has attracted researchers’ interests due to its wide applications. By combining electronic structural and lattice phonon thermodynamic calculations, the CO2 capture properties of γ-LiAlO2 and α-Li5AlO4 are investigated. Both γ-LiAlO2 and α-Li5AlO4 are insulators with wide band gaps of 4.70 and 4.76 eV respectively. Their 1st valence bands just below the Fermi level are mainly formed by p orbitals of Li, O and Al as well as s orbital of Li. By increasing the temperature from 0 K up to 1500 K, their phonon free energies are decreased while their entropies are increased. Targeting on developing post- and pre-combustion CO2 capture technologies, the obtained results indicated that γ-LiAlO2 is thermodynamically favorable to capture CO2 at lower temperature range (500-800 K) while α-Li5AlO4 could capture CO2 at higher temperature (800-1000 K) range in comparison with other solid sorbents, such as pure Li2O, Li4SiO4 and Li2ZrO3.


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