This study investigated the role of prostaglandins (PGs) and leukotrieres (LTs) in hypoxic pulmonary vasoconstriction (HPV) and in cigarette smoking-induced changes in hemodynamics and HPV in Wistar rats. Selective LTD4-LTE4 receptor antagonist LY-171883 (LY) inhibited HPV by 71.8%, while cyclooxygenase inhibitor indomethacin (IND) augmented HPV. The results indicate that LTs mediate HPV in Wistar rats. Smoking increased the level of TXB2 over control by 143.6% in plasma and 69.2% in lung tissue, concomitantly, pulmonary and systemic vascular resistance (PVR and SVR) were increased by 38.7% and 46.7%, respectively. Both LY and IND prevented the smoking-induced increase of PVR and SVR. After smoking HPV increased twofold. The increase of HPV was abolished by LY, but not by IND. Our results suggest that smoking leads to pulmonary and systemic vasoconstriction partly mediated by TXA2 and LTs; smoking also leads to an augmentation of HPV, and LTs play an important role in it.

To investigate the effects of prostaglandins (PGs) and leukotrienes (LTs) on hypoxic pulmonary vasoconstriction (HPV), in vivo rats experiment and in vitro perfused lung experiment were conducted. The effect of hypoxia on hemodynamics, concentrations of TXB2 and 6-keto-PGF1 alpha in serum and lung tissue during hypoxia and effects of PGs and LTs on HPV were observed. The results showed that pulmonary arterial pressure (Ppa) and pulmonary vascular resistance were increased during hypoxia, but cardiac output and systemic arterial pressure were decreased. There were increases of the concentrations of TXB2 and 6-keto-PGF1 alpha and their ratio in serum and lung tissue during hypoxia. After use of cyclooxygenase inhibitor (indomethacin) in vivo and in vitro, HPV was augmented respectively, but after use of lipoxygenase inhibitor (diethylcorbamazine) or leukotriene receptor blocker (LY-171883), HPV was attenuated. It was suggested that LTs mediated pulmonary vasoconstriction, PGs inhibited pulmonary vasoconstriction and they played a modulating role during hypoxia.

This study assesses the impact of sensor number and placement on the energy needed to condition a typical office using several likely variants of an underfloor air distribution system (UFAD). The study uses an empirical-based room stratification model developed from full-scale tests of UFAD systems. Annual energy consumption is calculated for an interior zone using outside air temperature bin data. The comfort criteria are taken from ASHRAE standard 55-92. The simulations indicate that there are benefits derived from using more than one temperature sensor to control conditions in the occupied zone of a room. Among these are: 1. By adjusting both supply air temperature and volume to maintain the maximum allowable thermal gradient in the occupied (lower) part of the room, an optimal supply air condition can reduce energy use (relative to the best arrangement of a single sensor) while maintaining comfort; 2. Discomfort caused by stratification can be detected by having one of the sensors located at foot level; 3. For the simulated UFAD interior zone of a typical office building in Sacramento, an overall energy saving of 8%/24% (VAV/CAV respectively) can be achieved when two sensors as opposed to one are used to control room conditions.

Ambient intelligence has the potential to profoundly affect future building operations. Recent breakthroughs in wireless sensor network technology will permit 1) highly flexible location of sensors and actuators, 2) increased numbers and types of sensors informing more highly distributed control systems, 3) occupants’ involvement in control loops, 4) demand responsive electricity management, 5) integration among now-separate building systems, and 6) the adoption of mixed-mode and other new types of air conditioning systems that require more sensor information to operate efficiently. This chapter describes the issues with current building automation technology, assesses how some applications of wireless sensor technology can increase the quality of control and improve energy efficiency, and suggests opportunities for future development.