Compared with the measureable but limited K isotope variation in geological samples,biological samples have much larger variations in δ^41 values：from-1.3‰ to＋1.1‰ relative to the international K standard NIST SR...Compared with the measureable but limited K isotope variation in geological samples,biological samples have much larger variations in δ^41 values：from-1.3‰ to＋1.1‰ relative to the international K standard NIST SRM 3141a.Notably,higher plants generally have δ^41 values that are lower than igneous rocks,whereas sea plants（algae）have δ^41 values that are higher than seawater;the range in δ^41K values of plants encompasses the δ^41 values of both igneous rocks and seawater.Plant cells utilize different K uptake mechanisms in response to highand low-K conditions.In a low-K environment,plant cells use energy-consuming ion pumps for active uptake of K;plant cells in high-K environments use non-energy-consuming ion channels.Based on these facts and on K isotope data from sea and land plants,it is hypothesized that the different K uptake mechanisms are accompanied by distinct K isotope fractionation behaviors or vital effects.The enrichment of light K isotopes in terrestrial plants could be attributed to preferential transport of isotopically light K in the energy-consuming active uptake process by K ion pumps in the membranes of plant root cells.On the other hand,the enrichment of heavy K isotopes in algae may be caused by a combination of the lack of K isotope fractionation during K uptake from seawater via ion channels and the preferential efflux of light K isotopes across the cell membrane back to the seawater.The large variation of K isotope compositions in biological samples therefore may reflect the diversity of isotopic vital effects for K in organisms,which implies the great potential of K isotopes in biogeochemical studies.展开更多
The polarization and absorption principle of corona virus in the electric field is presented. It is expressed by the mathematic differential equation based on the physical model. According to the parameters of the dip...The polarization and absorption principle of corona virus in the electric field is presented. It is expressed by the mathematic differential equation based on the physical model. According to the parameters of the dipole moment of virus, the electric field force exerted by the external electric field can be calculated. According to the parameters of size, mass and elastic modular, etc., the moment of inertia of virus can be calculated. According to the viscosity of tissues, the resistant force when virus rotates can be calculated. According to the balance condition of relaxation polarization, when the drive force equals to the resistant force, the rotating or swaying frequency of virus can be calculated. According to the heat producing condition such as friction, the temperature rising of virus can be calculated. When the temperature exceeds a certain threshold, virus would be inactivated. Through the calculation, it is found that the movement type of the virus depends on the intensity and frequency of the external electric field, which are the effects of "intensity widows" and "frequency windows". It also gives approximate calculation of the temperature rising of the virus according to this model. The vitro experiment confirms the reasonability of this model. The electric fields of different densities of a certain frequency are applied to the solution of avian infectious bronchitis virus. Through the toxicity experiment of the SPF chicken embryo, it is found that the toxicity is decreased exceedingly with a certain intensity of the applied voltage. EID50 decreases from 6.70/0.2 mL to 2.66/0.2 mL. It is proved that the avian infectious bronchitis virus can be inactivated with a certain low frequency and low-density electric field.展开更多
The data of d ieleclric properties of hum an tissues m ably com es from an in al tissues or hum an corpse at present U p to now, there has not been a report of dielectric properties of human living liver. This paper ...The data of d ieleclric properties of hum an tissues m ably com es from an in al tissues or hum an corpse at present U p to now, there has not been a report of dielectric properties of human living liver. This paper aims to studying the dielectric properties of hum an living liver and corn paring the results with those of an in al living liver as well as the human non-livhg liver. In vitro measurements of living and non-living livers from human and rabbitare shown in the range of 10 Hz to 100 MHz. Analysis of the conductivity, perm ittivity and characteristic param eters from the data were made. The conductivity of three kinds of liver were markedly different at low frequency： 0.06 S/m （living rabbit liver）, 0.13 S/m （living hum an liver） and 0.24 S/m （non-living hum an liver）; The Cole param eters that best characterize the liver of hum an and rabbit are RO, fc1,△R I and R ∞ ;The Cole param eters that best characterize the living and non-living liver ofhum an are RO, fc1,△R I,△R2 and R ∞. In conclusion,we can＇t substitute the dielectric properties of anin al or hum an corpse liver for the living human liver. The results suggest that the study on the dielectric properties of living hum an tissues has great sign ificance.展开更多
基金supported by"1000-talent Program"of China,and National Science Foundation of China(Grant No.41622301)to WL
文摘Compared with the measureable but limited K isotope variation in geological samples,biological samples have much larger variations in δ^41 values：from-1.3‰ to＋1.1‰ relative to the international K standard NIST SRM 3141a.Notably,higher plants generally have δ^41 values that are lower than igneous rocks,whereas sea plants（algae）have δ^41 values that are higher than seawater;the range in δ^41K values of plants encompasses the δ^41 values of both igneous rocks and seawater.Plant cells utilize different K uptake mechanisms in response to highand low-K conditions.In a low-K environment,plant cells use energy-consuming ion pumps for active uptake of K;plant cells in high-K environments use non-energy-consuming ion channels.Based on these facts and on K isotope data from sea and land plants,it is hypothesized that the different K uptake mechanisms are accompanied by distinct K isotope fractionation behaviors or vital effects.The enrichment of light K isotopes in terrestrial plants could be attributed to preferential transport of isotopically light K in the energy-consuming active uptake process by K ion pumps in the membranes of plant root cells.On the other hand,the enrichment of heavy K isotopes in algae may be caused by a combination of the lack of K isotope fractionation during K uptake from seawater via ion channels and the preferential efflux of light K isotopes across the cell membrane back to the seawater.The large variation of K isotope compositions in biological samples therefore may reflect the diversity of isotopic vital effects for K in organisms,which implies the great potential of K isotopes in biogeochemical studies.
基金the National Natural Science Foundation of China (Grant No.50477007)
文摘The polarization and absorption principle of corona virus in the electric field is presented. It is expressed by the mathematic differential equation based on the physical model. According to the parameters of the dipole moment of virus, the electric field force exerted by the external electric field can be calculated. According to the parameters of size, mass and elastic modular, etc., the moment of inertia of virus can be calculated. According to the viscosity of tissues, the resistant force when virus rotates can be calculated. According to the balance condition of relaxation polarization, when the drive force equals to the resistant force, the rotating or swaying frequency of virus can be calculated. According to the heat producing condition such as friction, the temperature rising of virus can be calculated. When the temperature exceeds a certain threshold, virus would be inactivated. Through the calculation, it is found that the movement type of the virus depends on the intensity and frequency of the external electric field, which are the effects of "intensity widows" and "frequency windows". It also gives approximate calculation of the temperature rising of the virus according to this model. The vitro experiment confirms the reasonability of this model. The electric fields of different densities of a certain frequency are applied to the solution of avian infectious bronchitis virus. Through the toxicity experiment of the SPF chicken embryo, it is found that the toxicity is decreased exceedingly with a certain intensity of the applied voltage. EID50 decreases from 6.70/0.2 mL to 2.66/0.2 mL. It is proved that the avian infectious bronchitis virus can be inactivated with a certain low frequency and low-density electric field.
基金National Natural Science Foundation of the People's Republic of Chinagrant number:50937005 and 61071033
文摘The data of d ieleclric properties of hum an tissues m ably com es from an in al tissues or hum an corpse at present U p to now, there has not been a report of dielectric properties of human living liver. This paper aims to studying the dielectric properties of hum an living liver and corn paring the results with those of an in al living liver as well as the human non-livhg liver. In vitro measurements of living and non-living livers from human and rabbitare shown in the range of 10 Hz to 100 MHz. Analysis of the conductivity, perm ittivity and characteristic param eters from the data were made. The conductivity of three kinds of liver were markedly different at low frequency： 0.06 S/m （living rabbit liver）, 0.13 S/m （living hum an liver） and 0.24 S/m （non-living hum an liver）; The Cole param eters that best characterize the liver of hum an and rabbit are RO, fc1,△R I and R ∞ ;The Cole param eters that best characterize the living and non-living liver ofhum an are RO, fc1,△R I,△R2 and R ∞. In conclusion,we can＇t substitute the dielectric properties of anin al or hum an corpse liver for the living human liver. The results suggest that the study on the dielectric properties of living hum an tissues has great sign ificance.
