[Effect evaluation of optical magnification errors for coded aperture spectrometer].

In the present paper, we simulated the system optical magnification error's influence on the quality of reconstructed image, analyzed the variant of the coded aperture with different optical magnification, then proposed an accurate curve of image quality and optical magnification in 128 x 128 code template, which provide important references for the design and development of push-broom coded aperture spectrometer.

[Imaging quality evaluation of computational imaging spectrometry].

As a novel imaging spectrometry, computational imaging spectrometry (CIS) has the advantages of high throughput, snapshot imaging etc. However, there is little research on imaging quality evaluation of CIS system. In the present paper, a quantitive evaluation method for imaging quality of CIS system was presented. ISO 12233 chart was used as the objective source, and then imaging and reconstruction of the spatial-spectral information was provided. Calculating modulation transfer functions (MTFs) for the reconstructed images was considered as the criterion of the imaging quality evaluation of CIS system. The result shows that MTFs for single-frame sampling decrease rapidly with the aliasing spectral number increasing. When the number of the aliasing spectra is 9, MTF for the reconstructed image decreases by 50% compared to the original scene. This work helps better understand the pros and cons of CIS system and arrange the aliasing spectral number reasonably to reconstruct the object scene precisely.

[Atropine treatment of hypoxic bradycardia accelerated the occurrence of cardiac arrest].

OBJECTIVE: To explore the therapeutic effects of atropine for hypoxic bradycardia during the occurrence of cardiac arrest. METHODS: Sixty-four adult New Zealand rabbits were selected and allocated randomly into 2 groups: instant resuscitation group and 8-minute resuscitation group. Each animal was anesthetized by an intravenous injection of sodium pentobarbital and intubated through tracheostomy. The tracheostomy tube was then clamped off to induce acute hypoxia. At soon as heart rate (HR) decreased to a half of basic-heart-rate, either atropine 50 µg/kg or 0.9% normal saline as control was randomly administered intravenously. In instant resuscitation group (group T1), the tracheostomy tube was unclamped and cardiopulmonary resuscitation (CPR) initiated for the occurrence of cardiac arrest (MAP < 10 mm Hg). In 8-minute resuscitation group (group T2), the tracheostomy tube was clamped for 8 minutes and then CPR initiated. The statistical data were analyzed by SPSS 10.0. All data were reported as x(-) ± s. T test was used to compare the means of cardiac arrest time between two groups, one-way ANONA to compare HR & mean arterial pressure (MAP) and Fisher's exact probabilities test to compare the survival rates between two groups. A value of P < 0.05 was considered statistically significant. RESULTS: The heart rate of atropine treated group was higher than that of normal saline group for about 90 minutes post-dosing. In atropine group, the MAP decrease was significantly faster than that of normal saline group (P < 0.01). Most importantly, after the clamping of tracheostomy tube, the average time of cardiac arrest occurred at (335.43 ± 43.25) s in atropine group versus (371 ± 55) s in normal saline group (P = 0.006). CONCLUSION: Although atropine treatment of severe hypoxic bradycardia improves the decrease of HR for a short time, it decreases MAP and accelerates the occurrence of cardiac arrest result from acute hypoxia. But the mortality rate is not improved by the treatment of atropine.