Stellar Image Location with Maximum Correlation Procedure

The location method and accuracy analysis has become a very important subject in astrometry since the photoelectric technique was widely applied. The location methods of the stellar images observed with the slit micrometer are discussed in this paper, and a new estimation method called the maximum correlation procedure is presented. This procedure has already been used to process and analyze the observational data. Because of the ideal mathematical performance of the correlation function, the procedure provides us a good way to determine image locations. By means of simulated observations according to the theoretical analysis, we find that the locating accuracy and the limiting magnitude for this method is much higher than those of traditional locating method. For the observational data of about one thousand stars obtained with the Photoelectric Astrolabe at Yunnan Astronomical Observatory, the positional accuracy of a single star using the maximum correlation is improved by 0.045 arcsec over that with the median. The maximum correlation procedure has also increased the data reduction ability for faint star observations with very low signal to noise ratios.

VIP Potentiates Cholinergic Effects on the Mucociliary System in the Maxillary Sinus

The neuropeptide vasoactive intestinal polypeptide (VIP), which is found in a population of cholinergic parasympathetic neurons in the airways, has no effects per se on mucociliary activity. In order to test the hypothesis that VIP may modulate cholinergic regulation of the mucociliary system, VIP was infused intraarterially (8.4 pmol/kg/min), and the response to challenges with methacholine in the maxillary sinus of rabbits were recorded with a photoelectric technique. Occurrence of VIP-like immunoreactivity in the rabbit maxillary sinus, maxillary nerve, and sphenopalatine ganglion was investigated. Immunoreactivlty against VIP was found in nerve fibers in the subepithelial layer of the maxillary sinus and in numerous nerve cell bodies in the sphenopalatine ganglion. Infusion of VIP potentiated the mucociliary increase induced by methacholine. The mucociliary wave frequency change increased from 6.1% ± 1.7% to 13.3% ± 3.9% (0.01 μg/kg methacholine), from 11.6% ± 3.6% to 18.8% ± 2.2% (0.05 μg/kg) and from 17.0% ± 3.0% to 27.4% ± 3.6% (0.1 μg/kg). Both peak responses and response durations increased during infusions. In contrast, the vasodilating agent papaverine sulphate did not influence the mucociliary response to methacholine. The modulating effect of VIP on the mucociliary system, taken together with the morphologic observations, suggest that VIP may have a physiologic role in the regulation of the mucociliary system in the maxillary sinus.

Effects of Neuropeptides on Mucociliary Activity

The effects of four neuropeptides, vasoactive intestinal polypeptide, enkephalin, bombesin, and substance P, on mucociliary activity in the rabbit maxillary sinus were investigated in vivo. The peptides were administered via the feeding artery (arteria maxillaris), and the resulting effects were registered with a noninvasive photoelectric technique. The peptides were tested in the dose range 0.0001 to 10 μg/kg body weight. The following results were observed: 1) vasoactive intestinal polypeptide and enkephalin did not influence mucociliary activity; 2) bombesin had only a slight accelerating effect on the mucociliary activity at doses of 0.1 to 10 μg/kg; and 3) substance P markedly accelerated the mucociliary activity in a dose-dependent manner in the dose range 0.01 to 10 μg/kg, the maximal increase being about 50%. The effect of substance P was atropine-resistant, and probably acted directly on the mucosa.

Measurement of skin perfusion pressure by photoelectric technique– an aid to amputation level selection in arteriosclerotic disease

During a period of 14 months 60 amputations, 41 below-knee and 19 above-knee, were performed on 54 patients with gangrene of the lower limb. Wound healing was evaluated in 59 amputations. A newly introduced standardized photoelectric technique for measurement of the local skin perfusion pressure (SPP) was used preoperatively, the result of which served as a guide to the selection of the proper amputation level. An overall healing rate of 90 per cent was found. Sixty-eight per cent of the amputations were performed below-knee. The healing rates for individual SPP levels were identical to those obtained with the isotope washout technique. The standardized photoelectric technique is simple and rapid and gives only negligible discomfort to the patient allowing repeated measurements at different levels on the leg.