Radial Pressure Pulse and Heart Rate Variability in Normotensive and Hypertensive Subjects

Objectives: The characteristics of the right/left radial pressure pulse (RPP) at the six diagnosis positions in Chinese medicine are not well documented. The purpose of this study is to investigate the spectral energy and augmentation index (AI) of bilateral RPP at the six diagnosis positions and heart rate variability (HRV) in the normotensives, hypertensives without heart dysfunction (HTN-N), and hypertensives with mild diastolic dysfunction (HTN-A). Design: One hundred and thirty-eight (138) subjects were enrolled in this study. All subjects underwent measurements of brachial arterial blood pressure and RPP of both wrists while seated, and the supine measurement of HRV. AI and spectral energy of RPP as well as HRV were analyzed. Results: The low-frequency component, the spectral HRV parameter, was significantly reduced in HTN-A compared with that in the normotensive group. Radial AI of the six diagnosis positions in HTN-N was significantly higher compared with that in the normotensive group or HTN-A. At the six diagnosis positions, the spectral energy of 0-10 Hz (SE(0-10Hz)) in both hypertensive groups and 10-50 Hz (SE(10-50Hz)) in the HTN-A group were significantly higher compared with those in the normotensive group. SE(10-50Hz) at right Chy, left Chun, and left Guan in the HTN-N group were higher than those in the normotensive group. Within each group, there was a significant difference in the energy proportion, 10-50Hz% (EP(10-50Hz%)), between the six positions and a significant reduction only at the left Chun position in both hypertensive groups compared to that in the normotensive group. Conclusions: It is concluded that the EP(10-50Hz%) revealed the specific characteristics of RPP and significantly varied at the six positions, and the left Chun position, the position to detect the heart diseases in Chinese medicine, is qualified to discriminate the differences between the normotensive and hypertensive patients

The decline of porcine sperm motility by geldanamycin, a specific inhibitor of heat-shock protein 90 (HSP90)

Sperm motility is an important parameter for fertility. The molecular mechanisms of mammalian sperm motility are still largely undefined. Our previous observations suggested that heat shock protein 90 (HSP90) may be associated with porcine sperm motility. The aim of the present study was to further characterize the plausible novel function of HSP90 on sperm motility. Semen from normal, sexually mature boars with sperm motility higher than 80% was used. An HSP90-specific inhibitor, geldanamycin (GA), was added to diluted semen at 0.5, 1.0, 2.5 or 5.0 mu g/mL, and the semen was then incubated at 37 degrees C for 15, 30, 45 or 60 min. Sperm motility was determined by using computer-assisted semen analyzer at the end of incubation. The results indicated that GA significantly reduced sperm motility in a dose and time dependent manner. Moreover, incubation of semen with 5.0 mu g/mL GA for 15 min completely stopped sperm motility. To test the reversibility of the GA effect on sperm motility, GA was removed after 30 min incubation and was replaced with fresh extender alone or with extender plus 5 mM caffeine, then incubated for another 15, 30, 45 or 60 min. The results showed that simply removing GA did not reverse the inhibitory effect on sperm motility, while adding caffeine partially reversed this inhibitory effect. However, the effect of 2.5 or 5.0 mu g/mL GA was not reversed by caffeine. Considering the specificity of GA targeting to HSP90, the above observations suggested that HSP90 may play a crucial role in regulating porcine sperm motility. (C) 2000 by Elsevier Science

Temperature variation at the low-latitude regions of East Asia recorded by tree rings during the past six centuries

The understanding of past millennium climate change is very important. Due to the lack of continuously annual resolution records, the temperature characteristics in the low-latitude regions of East Asia (LLREA) during past several centuries are still unknown. Using tree-ring width chronology from Taiwan, an island located in the western Pacific region and in southeastern China, February-October mean temperature from 1380 to 2007 AD was reconstructed. Spatial correlation analysis indicated that the reconstructed temperature could represent the sea-land temperature change in LLREA. During the past six centuries, both the warmest intervals and the largest variability of temperature appeared in the twentieth century. This is probably related to human activities. Temperature in LLREA provided good contrast with temperature changes in the Tibet Plateau and elsewhere in the Northern Hemisphere. The LLREA entered into the Little Ice Age around the year of 1450, approximately 100 years earlier than the Tibet Plateau. The 10-year cycle contained in the reconstructed temperature is close to the 11-year period of solar activity, which revealed there was a certain relationship between them. The temperature in LLREA significantly correlated with solar activity at the decadal to centennial scales. The strong/weak solar irradiance corresponded to the great/small temperature variability

Blasius and Sakiadis problems in nanofluids

The classical problems of forced convection boundary layer flow and heat transfer past a semi-infinite static flat plate (Blasius problem) and past a moving semi-infinite flat plate (Sakiadis problem) using nanofluids are theoretically studied. The similarity equations are solved numerically for three types of metallic or nonmetallic nanoparticles such as copper (Cu), alumina (Al2O3), and titania (TiO2) in the base fluid of water with the Prandtl number Pr = 6.2 to investigate the effect of the solid volume fraction parameter φ of the nanofluids. Also, the case of conventional or regular fluid (φ = 0) with Pr = 0.7 is considered for comparison with known results from the open literature. The comparison shows excellent agreement. The skin friction coefficient, Nusselt number, and the velocity and temperature profiles are presented and discussed in detail. It is found that the solid volume fraction affects the fluid flow and heat transfer characteristics