[Analysis on possibilities of multi-spectral data for quantitative retrieving soil nutrition element contents].

Models for predicting soil nutrition elements content were established by regression methods. The data source was simulated multi-spectral data from reflectance spectra measured under laboratory condition. First, the reflectance spectra were resampled to the corresponding bands of multi-spectral sensors (TM and ASTER) according to their reflectance response functions. Then, the experiential models were established between measured spectra, simulated reflectance spectra (TM and ASTER) and soil nutrition element contents by stepwise multiple linear regression (SMLR) and partial least square regression (PLSR) methods. Precision of these models was tested by validation soil samples. Compared with models established by measured spectra, precision of simulated spectra models is slightly affected by spectral resolution. Simulated spectra models give good results for nitrogen (R = 0.89), phosphor (R = 0.79), and potassium (R = 0.68). The selected band range of SMLR models for soil N, P, and K are 2 000 to 2 300 nm, 1 650 to 1 800 nm and 600 to 800 nm respectively. The coefficients of PLSR models show that near infrared (NIR) band is more sensitive to nitrogen and phosphor than visible (VIS) band, while VIS is better for potassium. Good prediction performance indicates theoretically the future possibilities of multivariate calibration for soil nutrition element concentrations by multi-spectral remotely sensed images and bands character of sensors should be considered well because different element has different response.

New electrocardiographic criteria for identifying the culprit artery in inferior wall acute myocardial infarction-usefulness of T-wave amplitude ratio in leads II/III and T-wave polarity in the right V5 lead.

ST-segment elevations in the right ventricular lead and those greater in lead III than in lead II strongly suggest that right, rather than left circumflex, coronary arterial occlusion occurs in acute myocardial infarction in the inferior wall. Our study demonstrated that, in the very early stages of infarction, a T-wave amplitude that is greater in lead III than in lead II and an upright or positive biphasic T wave in lead V(5)R are just as predictive as ST-segment changes and are often easier to measure.

[Mid- to long-term effects of delayed percutaneous coronary intervention on left ventricular function and prognosis in patients with acute myocardial infarction].

OBJECTIVE: To investigate the mid- to long-term effects of delayed percutaneous coronary intervention (PCI) on the left ventricular function and clinical outcome of patients with acute myocardial infarction (AMI). METHODS: PCI (including percutaneous transluminal coronary angioplasty and stenting) was performed in 42 patients within 1 to 2 weeks following the onset of AMI (PCI group), with another 31 patients who were admitted within the same period to receive medication for AMI serving as the control group. The patients in both groups were observed for comparison of the occurrence of reinfarction and angina, mortality at 1 and 6 months, and findings by ultrasound cardiograms (UCG). RESULTS: In PCI group, the left ventricular function were obviously improved as compared with the control group (P<0.01) 1 month after the onset of AMI, showing greater improvement at 6 months (P<0.01). No death or reinfarction occurred in the PCI group, with only 1 patients experiencing angina 5 months after PCI. In control group, death occurred in 2 cases, reinfarction in 1 case, recurrent angina in 4 cases (include 2 cases of early postinfarction angina). CONCLUSION: Delayed PCI may significantly improve the prognosis of patients with AMI and prolong their survival without cardiovascular accidents and ameliorate their left ventricular functions, with high success rate of the operation.