Nitric oxide (NO) is a highly reactive, labile gas produced by the enzymatic conversion of L-arginine by nitric oxide synthases NOS. In mammals, NO mediates multiple physiological processes from cardiovascular control...Nitric oxide (NO) is a highly reactive, labile gas produced by the enzymatic conversion of L-arginine by nitric oxide synthases NOS. In mammals, NO mediates multiple physiological processes from cardiovascular control to neural transmission. Three NOS isoforms neuronal, inducible and endothelial have been cloned, sequenced and characterized from several mammalian species. nNOS isoforms were characterized from adult grouper (Epinephelus coioides) by using RT-PCR with degenerate oligonucleotide primers designed against a portion of the mammalian NOS gene that codes for the calmodulin -binding region, this region was chosen because it is highly conserved among NOS sequences to date and is a functionally important region of NOS proteins. A partial gene sequence of 377 bp corresponding to mammalian nNOS is obtained. This sequence showed 82%-83%, 85%-93% homogeneity with that of mammalian and the other fish respectively. The deduced amino acid of E.coioides shows high identity with that of mammalian (92%-93%), and the other fish (93%-99%). Phylogenetic analysis of these sequences confirms the conserved nature of NOS, particularly of the calmodulin-binding domains.展开更多
A method is proposed to avoid complex computation in finding the region of interest （ROI） in a mammogram. In the method, the true negative region （TNR） definitely containing no microcalcification clusters （MCCs）...A method is proposed to avoid complex computation in finding the region of interest （ROI） in a mammogram. In the method, the true negative region （TNR） definitely containing no microcalcification clusters （MCCs） is screened out, thus obtaining ROIs, The strategy consists of three steps： （1） the mammogram is partitioned into a set of non-overlapping blocks with an equal size, and for each block, five statistical features are computed, （2） negative blocks are screened out by the threshold method through rough analyses, （3） the more accurate analysis is done by the cost-sensitive support vector machine to eliminate the block definitely containing no MCCs, Experimental results on real mammograms show that 81.71% of TNRs can be screened out by the proposed method.展开更多
Application of lime or gypsum is a common agricultural practice to ameliorate soils with low pH which prohibits crop production. Its integrated effect on soil properties in a red soil derived from Quaternary red clay ...Application of lime or gypsum is a common agricultural practice to ameliorate soils with low pH which prohibits crop production. Its integrated effect on soil properties in a red soil derived from Quaternary red clay in Southeast China is discussed in this paper. Application of gypsum in the topsoil without leaching raised soil pH and promoted the production of soil NH 4, but lime addition had a contrary effect. Generally, application of lime and/or gypsum has little effect on soil electrical properties. Gypsum had a little effect on soil exchange complex and its effect went down to 30 cm in depth. The effect of lime reached only to 5 cm below its application layer. With leaching, Ca transferred from top soil to subsoil and decreased exchangeable Al in subsoil. Gypsum application led to a sharp decrease in soil exchangeable Mg but had no effect on K.展开更多
In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to...In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P ＜ 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P ＜ 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r -- 0.8830, P ＜ 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system,microorganism and urease activities in the root zones were very important factors.展开更多
Nitrogen (N) losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated. Ammonia volatilization was determined by a micrometeorological method (ammonia samp...Nitrogen (N) losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated. Ammonia volatilization was determined by a micrometeorological method (ammonia sampler), total N loss was estimated by the 15N mass balance method, and denitrification loss was measured by the difference method (calculated from the difference between the total N loss and ammonia loss)and a direct method (measuring the emission of (N2+N2O)-15N ). Total ammonia losses from ammonium bicarbonate and urea in 33 days were 8.7% and 0.9% of the applied nitrogen, respectively. The corresponding total N losses were 21.6% and 29.5%. Apparent denitrification losses (by the difference method) were rather high, being 12.9% from ammonium bicarbonate and 28.6% from urea. However, no emission of (N2+N2O)-15N was detected using the direct method.展开更多
Limestone soil in karst areas is the product of weathering and carbonate rock dissolution in tropical and subtropical regions. Limestone soil in karst regions has a Ca-rich alkaline geochemical environment, but the ch...Limestone soil in karst areas is the product of weathering and carbonate rock dissolution in tropical and subtropical regions. Limestone soil in karst regions has a Ca-rich alkaline geochemical environment, but the characteristics of calcium speciation in limestone soil remain unclear. Here, to study changes in calcium speciation in soil across seasons in a karst area, different geomorphological positions and soil samples were collected from the Yaji karst experimental site. Using European Community Bureau of Reference （BCR） methods, we analyzed and discuss soil calcium speciation and seasonal migration characteristics. We found that total soil Ca content was 2.80-11.75 g kg^-1, with an average of 5.25±0.68 g kg^-1 （mean±SE）. The order of content of each Ca speciation is extractable-Ca〉reducible-Ca〉residual-Ca〉oxidizable-Ca. In addition to oxidizable-Ca, other Ca species had a positive correlation with total calcium. The calcium content and various forms of calcium content decreased gradually with changing season, but in addition to differences in residual calcium across seasons, total calcium and other forms of calcium across seasons were not different. Total calcium and different forms of calcium content were highest at sloped areas; slopes and other landforms were different but differences between plain, saddle and depression areas were not significant.展开更多
In this paper a finite element model is developed to study cytosolic calcium concen- tration distribution in astrocytes for a two-dimensional steady-state case in presence of excess buffer. The mathematical model of c...In this paper a finite element model is developed to study cytosolic calcium concen- tration distribution in astrocytes for a two-dimensional steady-state case in presence of excess buffer. The mathematical model of calcium diffusion in astrocytes leads to a boundary value problem involving elliptical partial differential equation. The model con- sists of reaction-diffusion phenomena, association and dissociation rates and buffer. A point source of calcium is incorporated in the model. Appropriate boundary conditions have been framed. Finite element method is employed to solve the problem. A MATLAB program has been developed for the entire problem and simulated to compute the numer- ical results. The numerical results have been used to plot calcium concentration profiles in astrocytes. The effect of ECTA, BAPTA and aCa influx on calcium concentration distribution in astrocytes is studied with the help of numerical results.展开更多
An ultraviolet （UV）-visible tunable photodetec- tor based on ZnO nanorod arrays （NAs）/perovskite hetero- junction solar cell structures is presented, in which the ZnO NAs are prepared using the hydrothermal method...An ultraviolet （UV）-visible tunable photodetec- tor based on ZnO nanorod arrays （NAs）/perovskite hetero- junction solar cell structures is presented, in which the ZnO NAs are prepared using the hydrothermal method and an- nealed in different atmospheres. Based on solar cell structure perovskite photodetectors, it exhibited highly repeatable and stable photoelectric response characteristics. In addition, the devices with ZnO NAs annealed in a vacuum showed a high responsivity of about 1014 cm Hz1/2 W-1 in the visible region, whereas the devices with ZnO NAs annealed in air exhib- Red good detectivity in the UV region, especially at around 350 nm. Furthermore, when the annealing atmosphere of the ZnO nanorods was changed from vacuum to air, the domi- nant detection region of the photodetectors was altered from the visible to the ultraviolet region. These results enable po- tential applications of the ZnO NAs/perovskite photodetec- tors in ultraviolet and visible regions.展开更多
文摘Nitric oxide (NO) is a highly reactive, labile gas produced by the enzymatic conversion of L-arginine by nitric oxide synthases NOS. In mammals, NO mediates multiple physiological processes from cardiovascular control to neural transmission. Three NOS isoforms neuronal, inducible and endothelial have been cloned, sequenced and characterized from several mammalian species. nNOS isoforms were characterized from adult grouper (Epinephelus coioides) by using RT-PCR with degenerate oligonucleotide primers designed against a portion of the mammalian NOS gene that codes for the calmodulin -binding region, this region was chosen because it is highly conserved among NOS sequences to date and is a functionally important region of NOS proteins. A partial gene sequence of 377 bp corresponding to mammalian nNOS is obtained. This sequence showed 82%-83%, 85%-93% homogeneity with that of mammalian and the other fish respectively. The deduced amino acid of E.coioides shows high identity with that of mammalian (92%-93%), and the other fish (93%-99%). Phylogenetic analysis of these sequences confirms the conserved nature of NOS, particularly of the calmodulin-binding domains.
文摘A method is proposed to avoid complex computation in finding the region of interest （ROI） in a mammogram. In the method, the true negative region （TNR） definitely containing no microcalcification clusters （MCCs） is screened out, thus obtaining ROIs, The strategy consists of three steps： （1） the mammogram is partitioned into a set of non-overlapping blocks with an equal size, and for each block, five statistical features are computed, （2） negative blocks are screened out by the threshold method through rough analyses, （3） the more accurate analysis is done by the cost-sensitive support vector machine to eliminate the block definitely containing no MCCs, Experimental results on real mammograms show that 81.71% of TNRs can be screened out by the proposed method.
文摘Application of lime or gypsum is a common agricultural practice to ameliorate soils with low pH which prohibits crop production. Its integrated effect on soil properties in a red soil derived from Quaternary red clay in Southeast China is discussed in this paper. Application of gypsum in the topsoil without leaching raised soil pH and promoted the production of soil NH 4, but lime addition had a contrary effect. Generally, application of lime and/or gypsum has little effect on soil electrical properties. Gypsum had a little effect on soil exchange complex and its effect went down to 30 cm in depth. The effect of lime reached only to 5 cm below its application layer. With leaching, Ca transferred from top soil to subsoil and decreased exchangeable Al in subsoil. Gypsum application led to a sharp decrease in soil exchangeable Mg but had no effect on K.
基金Project supported by the National Science Fund for Distinguished Young Scholars of China (No. 39925007)the Biotechnology section of INCO-DC under the 4th Framework Program of the European Commission(No. ERBIC18CT960059).
文摘In order to investigate the effects of microorganisms and their urease activities in macrophytic root zones on pollutant removal, four small-scale plots (SSPs) of vertical/reverse-vertical flow wetlands were set up to determine: a) the relationship between the abundance of microorganisms in the root zones and water purification efficiency; and b) the relationship between urease activities in the root zones and pollutant removal in a constructed wetland system. Total numbers of the microbial population (bacteria, fungi, and actinomyces) along with urease activities in the macrophytic root zones were determined. In addition, the relationships between microbial populations and urease activities as well as the wastewater purification efficiencies of total phosphorus (TP), total Kjeldahl nitrogen (TKN), biochemical oxygen demand in 5 days (BOD5), and chemical oxygen demand (COD) were also analyzed. The results showed that there was a highly significant positive correlation (r = 0.9772, P ＜ 0.01) between the number of bacteria in the root zones and BOD5 removal efficiency and a significant negative correlation (r = -0.9092, P ＜ 0.05) between the number of fungi and the removal efficiency of TKN. Meanwhile, there was a significant positive correlation (r -- 0.8830, P ＜ 0.05) between urease activities in the root zones and the removal efficiency of TKN. Thus, during wastewater treatment in a constructed wetland system,microorganism and urease activities in the root zones were very important factors.
文摘Nitrogen (N) losses from ammonium bicarbonate or urea applied to wheat and then followed immediately by irrigation were investigated. Ammonia volatilization was determined by a micrometeorological method (ammonia sampler), total N loss was estimated by the 15N mass balance method, and denitrification loss was measured by the difference method (calculated from the difference between the total N loss and ammonia loss)and a direct method (measuring the emission of (N2+N2O)-15N ). Total ammonia losses from ammonium bicarbonate and urea in 33 days were 8.7% and 0.9% of the applied nitrogen, respectively. The corresponding total N losses were 21.6% and 29.5%. Apparent denitrification losses (by the difference method) were rather high, being 12.9% from ammonium bicarbonate and 28.6% from urea. However, no emission of (N2+N2O)-15N was detected using the direct method.
基金Natural Scientific Foundation for Young Scientists of China(No.41402326)Natural Scientific Foundation for Young Scientists of Guangxi Zhuang Autonomous Region of China(No.2013GXNSFBA019217)+3 种基金the Natural Scientific Foundation of Guangxi Zhuang Autonomous Region of China(No.Guikehe14125008-2-1)the China Geological Survey(Nos.1212010911062,S-2010-KP03-07-02 and 12120113005300)the Ministry of Land and Resources(No.201211086-05)Institute of Karst Geology,CAGS(No.2012005)
文摘Limestone soil in karst areas is the product of weathering and carbonate rock dissolution in tropical and subtropical regions. Limestone soil in karst regions has a Ca-rich alkaline geochemical environment, but the characteristics of calcium speciation in limestone soil remain unclear. Here, to study changes in calcium speciation in soil across seasons in a karst area, different geomorphological positions and soil samples were collected from the Yaji karst experimental site. Using European Community Bureau of Reference （BCR） methods, we analyzed and discuss soil calcium speciation and seasonal migration characteristics. We found that total soil Ca content was 2.80-11.75 g kg^-1, with an average of 5.25±0.68 g kg^-1 （mean±SE）. The order of content of each Ca speciation is extractable-Ca〉reducible-Ca〉residual-Ca〉oxidizable-Ca. In addition to oxidizable-Ca, other Ca species had a positive correlation with total calcium. The calcium content and various forms of calcium content decreased gradually with changing season, but in addition to differences in residual calcium across seasons, total calcium and other forms of calcium across seasons were not different. Total calcium and different forms of calcium content were highest at sloped areas; slopes and other landforms were different but differences between plain, saddle and depression areas were not significant.
文摘In this paper a finite element model is developed to study cytosolic calcium concen- tration distribution in astrocytes for a two-dimensional steady-state case in presence of excess buffer. The mathematical model of calcium diffusion in astrocytes leads to a boundary value problem involving elliptical partial differential equation. The model con- sists of reaction-diffusion phenomena, association and dissociation rates and buffer. A point source of calcium is incorporated in the model. Appropriate boundary conditions have been framed. Finite element method is employed to solve the problem. A MATLAB program has been developed for the entire problem and simulated to compute the numer- ical results. The numerical results have been used to plot calcium concentration profiles in astrocytes. The effect of ECTA, BAPTA and aCa influx on calcium concentration distribution in astrocytes is studied with the help of numerical results.
基金supported by the National Nature Science Foundation of China (51372075)
文摘An ultraviolet （UV）-visible tunable photodetec- tor based on ZnO nanorod arrays （NAs）/perovskite hetero- junction solar cell structures is presented, in which the ZnO NAs are prepared using the hydrothermal method and an- nealed in different atmospheres. Based on solar cell structure perovskite photodetectors, it exhibited highly repeatable and stable photoelectric response characteristics. In addition, the devices with ZnO NAs annealed in a vacuum showed a high responsivity of about 1014 cm Hz1/2 W-1 in the visible region, whereas the devices with ZnO NAs annealed in air exhib- Red good detectivity in the UV region, especially at around 350 nm. Furthermore, when the annealing atmosphere of the ZnO nanorods was changed from vacuum to air, the domi- nant detection region of the photodetectors was altered from the visible to the ultraviolet region. These results enable po- tential applications of the ZnO NAs/perovskite photodetec- tors in ultraviolet and visible regions.
