272 EFFECT OF DIETARY RESTRICTION ON SPERM CHARACTERISTICS AND OXIDATIVE STATUS ON TESTICULAR TISSUE IN YOUNG RATS EXPOSED TO LONG-TERM HEAT STRESS

2015 ◽  
Vol 27 (1) ◽  
pp. 225
Author(s):  
N. Aydilek ◽  
O. Varisli ◽  
M. S. Kaya ◽  
A. Kocyigit ◽  
A. Taskin
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Dietary Restriction ◽  
Room Temperature ◽  
Sperm Quality ◽  
Oxidative Status ◽  
Sulfhydryl Groups ◽  
Young Rats ◽  
Ad Libitum

The objective was to evaluate effects of dietary restriction on oxidative status and sperm parameters in rats exposed to long-term heat stress. Forty healthy Sprague-Dawley rats (2.5 months old) were equally allocated into 4 groups (with respect to diet and temperature): room temperature (22°C)-ad libitum; room temperature-dietary restriction (40%); high temperature (38°C)-ad libitum; and high temperature-dietary restriction. At the end of the 9th week, some oxidants (lipid hydroperoxide, total oxidant status, oxidative stress index) and some antioxidants (total antioxidant status, sulfhydryl groups, ceruloplasmin, paraoxonase and arylesterase activities) were measured in testicular tissues. In addition, concentration, motility, volume, abnormal sperm count, acrosome and membrane integrity of epididymal sperm were also evaluated. All data were analysed by 2-way ANOVA (P < 0.05). High temperature did not significantly affect most oxidative and antioxidative parameters (except for sulfhydryl groups and ceruloplasmin), yet it impaired all sperm values. Neither sperm values nor oxidative status, with the exception of sulfhydryl groups, ceruloplasmin and arylesterase in the testis tissue, were significantly affected by dietary restriction. We concluded that long-term heat stress did not significantly affect testicular oxidative status in young rats, although sperm were sensitive to heat stress. Furthermore, dietary restriction failed to improve sperm quality and oxidative status, except some individual antioxidant parameters in young rats exposed to long-term heat stress.

Development of a 300°C capable SiC based operational amplifier

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000305-000309 ◽  
Author(s):  
Vinayak Tilak ◽  
Cheng-Po Chen ◽  
Peter Losee ◽  
Emad Andarawis ◽  
Zachary Stum
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Operational Amplifier ◽  
Room Temperature ◽  
Open Loop ◽  
Common Source ◽  
Loop Gain ◽  
Long Term Stability ◽  
Silicon Silicon

Silicon carbide based ICs have the potential to operate at temperatures exceeding that of conventional semiconductors such as silicon. Silicon carbide (SiC) based MOSFETs and ICs were fabricated and measured at room temperature and 300°C. A common source amplifier was fabricated and tested at room temperature and high temperature. The gain at room temperature and high temperature was 7.6 and 6.8 respectively. A SiC MOSFET based operational amplifier was also fabricated and tested at room temperature and 300°C. The small signal open loop gain at 1kHz was 60 dB at room temperature and 57 dB at 300°C. Long term stability testing at 300°C of the MOSFET and common source amplifiers showed very little drift.

Sperm quality and oxidative status as affected by homogenization of liquid-stored boar semen diluted in short- and long-term extenders

2017 ◽  
Vol 179 ◽  
pp. 67-79 ◽  
Author(s):  
Mariana B. Menegat ◽  
Ana Paula G. Mellagi ◽  
Rafael C. Bortolin ◽  
Tila A. Menezes ◽  
Amanda R. Vargas ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Oxidative Status ◽  
Short And Long Term ◽  
Boar Semen

Heat - Stress Analysis and Structural Improvement of High Temperature Eutectic Fixed-Point Crucible

2011 ◽  
Vol 66-68 ◽  
pp. 516-523 ◽  
Author(s):  
Jian Hua Wang ◽  
Fei Liu ◽  
Tie Jun Wang ◽  
Li Gang Cai ◽  
Yong Sheng Zhao ◽  
...  
Keyword(s):  
Fixed Point ◽  
Heat Stress ◽  
High Temperature ◽  
Graphite Crucible ◽  
Long Term Stability ◽  
Finite Element Software ◽  
Structural Improvement ◽  
Two Measures ◽  
Transformation Stress

When the metal - carbon eutectic gets phase transition, the graphite crucible will be effect by the thermal stress and the phase transformation stress, which often make the crucible rupture, fail to achieve durability requirements, and then affect the research of high temperature eutectic fixed-point’s long-term stability and reproducibility. In order to improve the durability of crucible, the finite element software ANSYS and direct coupling method were used in this paper to analyze the heat-stress of Pt-C fixed-point crucible with sleeve (graphite sleeve) during the solidification. Based on the results of the simulation, we analyze the reasons of the breakdown of the crucible and propose two measures to improve the durability of crucible, which are adding graphite cloth or graphite foil between the crucible and the sleeve. Then we use ANSYS to analyze the two improved crucibles, and prove the effectiveness of these two measures.

Packaging Technology for High Temperature Capacitive Pressure Sensors

2010 ◽  
Vol 2010 (HITEC) ◽  
pp. 000367-000372 ◽  
Author(s):  
Liang-Yu Chen ◽  
Glenn M. Beheim ◽  
Roger D. Meredith
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Pressure Sensors ◽  
Differential Pressure ◽  
Capacitive Pressure Sensor ◽  
Packaging Technology ◽  
Parasitic Parameters ◽  
Term Performance

High temperature pressure sensors are critical sensing elements for the next generation of intelligent aerospace engine technology, as well as long-term exploration missions to Venus, where the surface temperature is 485°C. Various high temperature pressure sensors based on different sensing mechanisms are under development at the NASA Glenn Research Center. In order to test long-term performance and reliability of these sensors in a high temperature environment, and eventually commercialize these sensors, high temperature durable and long-term reliable packaging is essential. A prototype packaging technology for micro-sensors designated for applications in high temperature and high differential pressure environments has been developed and reported previously. Packaged high temperature silicon carbide pressure sensors have been successfully tested between room temperature and 500°C. This paper reports an improved version of this packaging technology and testing results of a packaged commercial Si capacitive pressure sensor at elevated temperatures. The parasitic parameters of the packaging are electrically characterized from room temperature to 500°C at 120Hz, 1kHz, 10kHz, and 100kHz. This packaging is primarily designed for high temperature capacitive pressure sensors, but it also applies to other high temperature sensors, especially those for high differential pressure environments.

Effect of dialysis of dog semen on sperm characteristics and some biochemical components of seminal plasma

2015 ◽  
Vol 18 (2) ◽  
pp. 447-448 ◽  
Author(s):  
R. Strzeżek ◽  
M. Koziorowska-Gilun ◽  
K. Kiełczewski ◽  
W. Kordan
Keyword(s):  
Molecular Weight ◽  
Seminal Plasma ◽  
Room Temperature ◽  
Sperm Quality ◽  
Biochemical Properties ◽  
Quality Parameters ◽  
Sperm Characteristics ◽  
Biochemical Components

AbstractThe aim of this study was to investigate the effect of dog semen dialysis on sperm characteristics and some biochemical components of seminal plasma. Whole ejaculates were dialyzed against Tris-citrate-fructose extender for a 5 h period at room temperature (using semi-permeable cellulose tubing of 12-14 kDa molecular weight cut-off). It has been demonstrated that the long-term dialysis of dog semen causes a significant decrease in sperm quality parameters and disrupts the biochemical properties of seminal plasma. This procedure requires further improvement.

scholarly journals Effect of long term heat stress and dietary restriction on the expression of small heat shock protein (sHSP) genes in rat liver tissue

2016 ◽  
Vol 32 (3) ◽  
pp. 161-161
Author(s):  
Faruk Bozkaya ◽  
Mehmet Osman Atlı ◽  
Aydin Guzeloglu ◽  
Seyit Ali Kayis ◽  
Mehmet Salih Kaya ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Rat Liver ◽  
Dietary Restriction ◽  
Liver Tissue ◽  
Small Heat Shock Protein

scholarly journals National Toxicology Program Experience With Dietary Restriction: Does the Manner in Which Reduced Body Weight Is Achieved Affect Tumor Incidence?

1998 ◽  
Vol 17 (2_suppl) ◽  
pp. 119-134 ◽  
Author(s):  
Joseph K. Haseman
Keyword(s):  
Body Weight ◽  
Dietary Restriction ◽  
Food Restriction ◽  
Control Groups ◽  
Reduced Body ◽  
Body Weights ◽  
Carcinogenic Effects ◽  
Ad Libitum ◽  
And Control

The increasing body weights and the associated increased tumor incidences observed in recent long-term rodent bioassays may adversely affect study sensitivity for detecting rodent carcinogenicity. For example, increasing body weights may result in reduced survival and fewer animals at risk for tumor development. Moreover, the increased control tumor incidences observed in the more recent studies make it more difficult to establish firm baseline values and to use historical control data in the overall evaluation of experimental results. Finally, if dosed animals are significantly lighter than controls within a given study, then it may be more difficult to detect carcinogenic effects for those tumor sites sensitive to body weight changes. One approach to deal with this problem is food restriction, and the recently completed NTP Dietary Restriction Study confirmed that reducing food intake can reduce background tumor rates in control animals. There was also a slight increase in survival (approximately 2 wk on average) in the food restricted animals. However, the experimental protocol that restricted food consumption in both dosed and control groups appeared to have reduced sensitivity for detecting carcinogenic effects relative to the standard NTP protocol. One important, but often overlooked, issue when considering dietary restriction is that tumor incidence profiles may differ for animals of equivalent body weight, depending upon how the reduced body weights were achieved. An evaluation of data from NTP long-term rodent studies and from the NTP Dietary Restriction Study indicates that food restricted animals show a significant reduction in a number of site-specific tumors relative to equivalently sized ad libitum-fed animals. These results suggest that a dietary restriction strategy that focuses on achieving similar body weights in dosed and control groups may produce false positive outcomes if substantially more food restriction is required for control groups than for dosed animals (e.g., if control animals must receive a moderate (15—20%) degree of food restriction to achieve body weights equivalent to those observed in ad libitum-fed dosed animals). Results from the NTP Dietary Restriction Study also demonstrate that a moderate (15—20%) food restriction protocol applied equally to dosed and control animals may produce false negative outcomes if the resulting body weights are substantially different in dosed and control groups. Alternative strategies for reducing body weights are briefly discussed, but at present it is unclear which strategy or combination of strategies will ultimately prove to be most effective for dealing with the problem of increasing body weights.

scholarly journals Pathophysiological Changes in Female Rats with Estrous Cycle Disorder Induced by Long-Term Heat Stress

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
GaiHong An ◽  
XueWei Chen ◽  
Chao Li ◽  
Li Zhang ◽  
MengFan Wei ◽  
...  
Keyword(s):  
Heat Stress ◽  
High Temperature ◽  
Estrous Cycle ◽  
Underlying Mechanism ◽  
Female Rats ◽  
Stable Model ◽  
Sprague Dawley ◽  
Pathological Characteristics ◽  
The Impact

High-temperature exposure is detrimental to women’s reproductive health; however, the impact caused by long-term high temperature is not comprehensive, and a stable model of estrous cycle disorder induced by a high temperature is yet lacking. Herein, we aimed to establish a stable and effective model of estrous cycle disorder in female rats induced by long-term heat stress to study its physiological and pathological characteristics and explore the underlying mechanism. In the present study, female Sprague-Dawley rats with normal estrous cycles were exposed to the temperature of 38±0.5°C, relative humidity (RH) of 55±5% (2 h/d, 1 time/d) hot cabin at more than 90 days. Consequently, after long-term heat stress, no difference was detected in body weight and rectal temperature, but the estrus cycle was prolonged, the uterine organ index was increased, pathological changes occurred, the increase latitude of stress hormones heat shock protein 70 (Hsp70) and corticosterone (CORT) decreased, estradiol (E2) and luteinizing hormone (LH) levels decreased, follicle stimulating hormone (FSH) and prolactin (Prl) levels increased, gonadotropin-releasing hormone (GnRH) and thyroid hormone (T4) showed no difference, and insulin (INS) decreased significantly. Moreover, the mRNA expression of the sex hormone receptor in the uterus and ovary was altered. Therefore, the estrous cycle disorder in female rats can be induced by regular heat stress for 90 days, which can be considered the pioneer method. Subsequently, prominent physiological and pathological characteristics and disruption in the hypothalamic-pituitary-gonadal (HPG) axis were noted.

Sign in / Sign up

Export Citation Format

Share Document