[Study on effects of different habitat processing methods of Salviae Miltiorrhizae Radix et Rhizoma in rats with acute myocardial ischemia].

To investigate the effects of different habitat processing methods of Salviae Miltiorrhizae Radix et Rhizoma on acute myocardial ischemia induced by pituitrin in rats. In this experiment, the tail vein injection of pituitrin was used to induce acute myocardial ischemia in rats. Electrocardiograph(ECG) heart rate and ΔST changes were recorded, and the levels of creatine kinase isoenzyme(CK-MB), lactate dehydrogenase(LDH), superoxide dismutase(SOD) and malondialdehyde(MDA) in serum of rats were detected to comprehensively evaluate the effects of six processing methods of Salviae Miltiorrhizae Radix et Rhizoma on serum biochemical indexes of rats with acute myocardial injury. The ECG results showed that the Salviae Miltiorrhizae Radix et Rhizoma dried in a drying oven had a good effect on the improvement of heart rate and ΔST of electrocardiogram after ischemia, and all the other groups had some protective effects to different degrees. The results of biochemical indexes in serum of each group after ischemia showed that the activity of CK-MB decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in a drying oven after sweating and losing weight in a drying oven, high-dose group with drying in the shade and low-dose group with drying in the shade. The activity of LDH decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in the shade and low-dose group of drying in the shade. The activity of SOD increased most significantly in Salviae Miltiorrhizae Radix et Rhizoma low-dose group with drying in sun, low-dose group with drying in sun after sweating and losing weight in sun, and low-dose group with drying in a drying oven. The activity of MDA decreased most significantly in Salviae Miltiorrhizae Radix et Rhizoma low-dose group with drying in sun. The comprehensive scoring results showed that the highest score was obtained in Salviae Miltiorrhizae Radix et Rhizoma high-dose group with drying in the shade while the scores of other treatment groups were higher than that of the model group. It could be seen that the Salviae Miltiorrhizae Radix et Rhizoma dried in a drying oven had a good improvement effect on electrocardiograph indexes after acute myocardial injury, the Salviae Miltiorrhizae Radix et Rhizoma dried in the shade had a good improvement effect on serum myocardial enzymes after acute myocardial injury, and the other processing methods had a certain protective effect on myocardial injury. The six processing methods evaluated by pharmacodynamics showed that the Salviae Miltiorrhizae Radix et Rhizoma dried in the shade and dried in a drying oven had good efficacy.

Seed priming with chitosan improves maize germination and seedling growth in relation to physiological changes under low temperature stress.

Low temperature stress during germination and early seedling growth is an important constraint of global production of maize. The effects of seed priming with 0.25%, 0.50%, and 0.75% (w/v) chitosan solutions at 15 degrees C on the growth and physiological changes were investigated using two maize (Zea mays L.) inbred lines, HuangC (chilling-tolerant) and Mo17 (chilling-sensitive). While seed priming with chitosan had no significant effect on germination percentage under low temperature stress, it enhanced germination index, reduced the mean germination time (MGT), and increased shoot height, root length, and shoot and root dry weights in both maize lines. The decline of malondialdehyde (MDA) content and relative permeability of the plasma membrane and the increase of the concentrations of soluble sugars and proline, peroxidase (POD) activity, and catalase (CAT) activity were detected both in the chilling-sensitive and chilling-tolerant maize seedlings after priming with the three concentrations of chitosan. HuangC was less sensitive to responding to different concentrations of chitosan. Priming with 0.50% chitosan for about 60 approximately 64 h seemed to have the best effects. Thus, it suggests that seed priming with chitosan may improve the speed of germination of maize seed and benefit for seedling growth under low temperature stress.

Relationships between changes of kernel nutritive components and seed vigor during development stages of F1 seeds of sh2 sweet corn.

The changes of kernel nutritive components and seed vigor in F1 seeds of sh2 sweet corn during seed development stage were investigated and the relationships between them were analyzed by time series regression (TSR) analysis. The results show that total soluble sugar and reducing sugar contents gradually declined, while starch and soluble protein contents increased throughout the seed development stages. Germination percentage, energy of germination, germination index and vigor index gradually increased along with seed development and reached the highest levels at 38 d after pollination (DAP). The TSR showed that, during 14 to 42 DAP, total soluble sugar content was independent of the vigor parameters determined in present experiment, while the reducing sugar content had a significant effect on seed vigor. TSR equations between seed reducing sugar and seed vigor were also developed. There were negative correlations between the seed reducing sugar content and the germination percentage, energy of germination, germination index and vigor index, respectively. It is suggested that the seed germination, energy of germination, germination index and vigor index could be predicted by the content of reducing sugar in sweet corn seeds during seed development stages.

Efficiency and current in a correlated ratchet.

We present a detailed study of the transport and the efficiency of a ratchet system in a periodic potential in the presence of correlated noises. The current and the efficiency of the system are investigated. It is found that, when the potential is spatially symmetric, the correlation between the two noises can induce a net transport. The efficiency shows many interesting features as a function of the applied force, the noise intensity, the external load, etc. The efficiency can be maximized as a function of noise intensity (or temperature), which shows that the thermal fluctuation can facilitate the efficiency of energy transformation.

Correlated noise in a logistic growth model.

The logistic differential equation is used to analyze cancer cell population, in the presence of a correlated Gaussian white noise. We study the steady state properties of tumor cell growth and discuss the effects of the correlated noise. It is found that the degree of correlation of the noise can cause tumor cell extinction.

Efficiency optimization in a correlation ratchet with asymmetric unbiased fluctuations.

The efficiency of a Brownian particle moving in a periodic potential in the presence of asymmetric unbiased fluctuations is investigated. We found that even on the quasistatic limit there is a regime where the efficiency can be a peaked function of temperature, which proves that thermal fluctuations facilitate the efficiency of energy transformation, contradicting the earlier findings [H. Kamegawa et al., Phys. Rev. Lett. 80, 5251 (1998)]. It is also found that the mutual interplay between temporal asymmetry and spatial asymmetry may induce optimized efficiency at finite temperatures. The ratchet is not most efficient when it gives maximum current.