Biological Effects of Stevia rebaudianum Induced by Carbon Ion Implantation

The biological effects during seed germination were investigated after the dry seeds of Stevia rebaudianum Bertoni were implanted with carbon ion beam of 75 keV and 10 14 ions/cm 2. The results showed that the germination rate of carbon ion implanted seeds was slightly higher than that of the control, but the survival rate of the treated seedlings, on the contrary, was lower than that of the control (P<0.02), while the height of the treated seedlings was significantly higher than that of the control (P<0.01). On the 4th day after germination, the leaf cell wall in the treated group was thick, some high electron_dense substance deposited in the enlarged plasmodesma; Cell membrane creased with high electron_dense granules deposited on it. The plasma membrane protruded towards cell wall, and the granules shifted via plasmodesma or deposited onto cell wall. These phenomena may be related to the conveyance of implanted ions across cell wall, or be related to the accumulation of callose. In addition, the implantation of carbon ions could increase the lamellae of the chloroplast and cause high development of the chloroplast which sometimes contained two plastid centers in an individual chloroplast. Also, the highly developed cristae, abundant mitochondria and typical crystalloid structure in microbody could be found. All these results indicated that the anabolic and catabolic activities in the seedlings implanted with carbon ions before germination were obviously more active than those in the controls.

Effects of Samarium on Liver and Kidney of Rats

Spraque-Dawley(SD)big rats with weaning weight of (195±15) g were randomly divided into 4 groups with 8 males and 8 females each group. One group drank de-ionized water served as control and also used for analysis with the background. The other three groups were cultured for five months by drinking de-ionized water with 3.0, 4.5 and 6.0 mg·L-1 Sm (NO3)3, respectively. Compared with the rats in control, it is found that the organs of the treated rats are apparently pathologically changed, such as liver swell, lung intumescence, peritoneum conglutination and hardness. Especially, in the high Sm group, the pathological percentage in liver and lung is up to 30% . The pathological changes in liver and lung show that rare earth Sm does hazard biological effects to animals. With increasing Sm concentration, the weight rate of organ/body has a tendency of increasing; the activity of superoxide dismutase (SOD) in liver and kidney decreases, but the maglonydiadehyde (MDA) concentration increases, indicating the abilities of anti-oxidation and the lipid per-oxi-dation inhibition degenerate, which leads to hard pathological changes in organs. Moreover, the relative weight rate of organ/body, the activity of SOD and the MDA concentration are remarkably lager in liver than in kidney and other organs, suggesting that the biological effect of Sm on liver is the greatest and Sm has a high affinity for liver.

Design of an experimental platform to investigate the effects of audible sounds on plant growth

An experimental platform was developed to investigate the effects of audible sound(20 Hz to 20 MHz)on plant growth promotion,which included a microcontroller-based embedded system for audible sound adjustment and analysis.The direct digital frequency synthesis(DDFS)method was used to generate various waveforms of sound in the platform.Soundproof glass and mufflers were used to reduce background noise.The developed system was tested on various plants,including hydroponic tomatoes,celery and mung bean.The testing results showed that the developed platform could produce pure tone and mixing audible sound with high stability and accuracy,make octave analysis of the sound under experimental environments,and the background noise in the testing chamber of the platform was lower than 55 dB(A)when the compression engine was working.The developed experimental platform has a great potential on facilitating scientific research on acoustic biology effects on plants and collecting real-time experimental data.