Atmospheric-Pressure Plasma Essay Example | Topics and Well Written Essays - 1500 words

Atmospheric-Pressure Plasma - Essay Example However, the mechanism of regeneration of tissues through the short-time plasma exposure has not been explicitly revealed as yet in spite of its increased practical application. In order to improve the situation, it may be important to clarify the mechanism from multilateral standpoints including plasma science and engineering, molecular biology, and biochemistry. Therefore, we conducted a basic experiment on the direct irradiation of cells by using micro-spot atmospheric-pressure plasma source, which is hardly harmful to the living bodies both thermally and electromagnetically. In this experiment, murine fibroblast cell line (NIH3T3), which is usually used for cell experiments, was used and effect of plasma on the culture cells was considered. As a result of the experiment, it was revealed that cell multiplication is activated by plasma exposure. In response to the result, we considered factors related to the multiplication. Although there are many factors involved in the cell multi plication, we particularly focused on neoangiogenesis and NO production, and considered vascular endothelial growth factor (VEGF) and acidic fibroblast growth factor (bFGF). Schematic diagram of the experimental apparatus is shown in Fig 1. The apparatus comprised a coaxial structure with tungsten electrodes employed in a glass capillary (internal diameter of plasma genesis region: 8 mm, internal diameter of the tip: 1 mm) with cylindrical electrodes on the exterior. High voltage for plasma generation was generated by externally-controlled high-voltage power supply device. Plasma generation conditions were: applied voltage: 5-9 kV; frequency: 1-3 kHz; helium (He) gas flow rate: 1 L/min; and plasma exposure time: 1-100 sec. It was found in the earlier studies that NO gas is not generated by this apparatus. In the experiment, a culture containing 1 x 105 murine fibroblast cell lines (NIH3T3) was set in a 12-hole culture vessel. It was cultured for 24 hours in a CO2 incubator (culture conditions: temperature: 37 deg. C and CO2 gas concentration: 5%). The medium was replaced with serum-free medium. The unprocessed specimens (control), those processed with He gas flow and others exposed to plasma were compared. Processing time for each specimen group was 1, 10 and 100 sec, respectively. They were cultured for 24 hours in CO2 incubator after plasma exposure and then cell forms were observed with optical microscope. Afterwards, only live cells of NIH3T3 cell line attached to the bottom face of the culture vessel were peeled off by trypsin treatment and the number of cells under each condition was counted, followed by consideration of multiplication rate changes among the conditions. In addition to that, they were continuously cultured for 7 days in NIH3T3 cell line. Differences in the cell multiplication curves of specimens exposed to plasma for 90 sec per day and those processed with He gas flow were also considered. With this experiment, we considered the effects o f plasma exposure on cell multiplication based on both the trends of exposure time-dependent cell multiplication and the effects of plasma exposure on cell multiplication. Fig 2 shows cells exposed to the plasma. Culture medium thickness was 6 mm. Plasma was radiated from capillary of 1 mm diameter to cells adhering to 6 cm2 base area at a flow rate of 1 L/min.  

Maurya's Understanding of the Relationship between God, Humans and Essay

Maurya's Understanding of the Relationship between God, Humans and Nature - Essay Example It brings out a  clear  faith  of human beings on their  religion  and God on the various aspects of nature and Gods plans and outcomes that they cannot  control. We can  identify  this  faith  in religion and  fear  of nature when Maurya makes a  remark  of desperation saying, â€Å"God spare us, and we'll not see him again. He  has gone  now, and when the  black  night is falling I'll have no son left me in the world† (Synge, 2008). It  further  demonstrates the interdependence of humans on their  religion  and  nature  for survival even though the various fates that may befall them. They depend upon the sea for food for survival and of Gods  control  and protection against the various risk fatalities that face them. God’s role in Maurya’s  life In the play, Maurya depicts continual faith in God to be her  protector. This is to protect both her and men in her family. She believes in the  overall  power   and  control  of God over all people and nature. She acknowledges the fact that all humans and  nature  are God’s creations and that they are  different  entities functioning independently and affecting each other. Additionally, she believes that a human can affect the functioning and  state  of nature and vice versa. As such, people live in  dread  of the harsh possibilities that the sea holds against them that they can neither control nor predict. They, therefore,  opt  for God's  protection  and put faith in their religions to help them cope with such fears. Even after losing all the other men in her family to the sea with the same faith, Maurya still believes in prayer. This shows the need for  religion  and  faith  in dealing with what one cannot  control  that instills fear. Maurya holds her  faith  for fear of her remaining son’s life until the time when he  too  escaped from her by nature, and she makes peace with God, her faith and fear of the unknown fatalities of nature. This is evident in the  remark  that â€Å"They are all  dead  now there is nothing else greater the  sea  can do to me† (Synge, 2008). Nature’s role in Maurya’s  life It is ironical that Maurya fears the same  sea  that she mainly depends on for daily food. Her life is full of constant fear for the lives of the men in her family against the sea that feeds them (Synge, 2008). Though she acknowledges the fact that the sea and the winds are what  provide  them with food and  transport, she lives in the  constant  risks they pose to her family. Over the years, she has lost many men to the sea, but their  dependency  on the same  sea  for life leads them to  accept  such risks and their fates to the  sea  to ensure they are able to  maintain  life. She finds herself to be helpless to the fatalities of the  sea  to her family as one by one escape from her. As a result, they  accept  the deaths of those taken by the  sea  and continue on with their fishing activities with  faith  in their  religion  for protection against facing the same fates. Maurya’s acceptance of god and natures roles of death in her life is evident in Mauryas response to Bartley when she says, â€Å"†¦and I, an old woman looking for the grave?† (Synge, 2008). This shows her acceptance of death. Towards the end of the play, Maurya accepts the sad fact that all humans must  die  at one time or another through various means.  She accepts that her lost  family  is now  together  in accordance to her religious faith and further prays for the protection of the still living