This paper reports the cloning and expression analysis of a high-affinity nitrate transporter inwheat ( Triticurn aestivurn L.). A full-length cDNA, TaNRT2.3(accession number AY053452), was isolatedfrom NO3--induced r...This paper reports the cloning and expression analysis of a high-affinity nitrate transporter inwheat ( Triticurn aestivurn L.). A full-length cDNA, TaNRT2.3(accession number AY053452), was isolatedfrom NO3--induced roots of wheat. The cDNA encodes a polypeptide with 507 amino acids and 12transmembrane domains, belongs to nitrate/nitrite porter (NNP) family within the major facilitator superfamily(MFS), and is closely related to other NRT2 proteins from plants. The expressions of TaNtTT2 genes inwheat tissues were analyzed using Northern blot, results indicated that TaNRT2 were induced specificallyin roots but not in shoots in response to both low (5-200 μmol/L) and high (2.0 retool/L) concentrationsof NO^-. TaNRT2transcripts were undetectable in N-deprived or NH4^+grown plant roots. The significantcorrelation between the time course of TaNtTT2transcription accumulation in the roots of wheat plantsgrown in 0.2 mmol/L NO3- and the time course of the nitrate uptake rates by wheat plants grown under thesame conditions suggested that TaNtTT2 played an important role in high-affinity NO3-uptake. Using thesplit root system, we found that supplying NO3- to one part of the roots induced the expression of TaNtTT2in the other part not supplied with NO3- or supplied with NH4^+, which implied that N cycling within plantsacted as a regulatory signal for N uptake.展开更多
reconstituted embryos were produced by nuclear transplantation using bovine ear fibroblasts at G 0 or non-G 0 stage as donor nuclei and oocytes collected from superovulated multiparous or young rabbits as recipi...reconstituted embryos were produced by nuclear transplantation using bovine ear fibroblasts at G 0 or non-G 0 stage as donor nuclei and oocytes collected from superovulated multiparous or young rabbits as recipients. After cultivation in two kinds of medium M199+10%FBS or RD+10%FBS, 112 of them developed to 2-cell stage (62.2%) and 26 to morula stage (14.4%) and 20 of them eventually developed to blastocyst stage (11.1%). There is no significant difference for the cleavage rates in two groups of reconstituted embryos derived from G 0 -stage and non-G 0 stage donor cells respectively. However, G 0-stage donor cells could result in higher rate of 8-cell16-cell stage embryos significantly (P<0.05), as well as higher rate of blastocysts (P<0.01). It seems that using two different culture systems had no significant effects on the cleavage rate, morula rate or blastocyst rate (P>0.05).展开更多
It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) ...It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) locate on 1RS, and the high P efficiency of Lovrin No.10 is from 1RS? To test thishypothesis, we investigated the P use efficiency (PUE) of a doubled haploid (DH) population with 61 linesderived from anther culture of F1 hybrid between Lovrin No.10 and phosphorus uptake inefficient genotypeChinese Spring to see whether PUE differs between DH line with and without 1RS/1BL translocation.Acidic polyacrylamide-gel electrophoresis (A-PAGE) of gliadin and genomic DNA in situ hybridization (GISH)were employed to discriminate 1RS/1BL translocation DH lines from the normal 1B DH lines. Among the61 DH lines investigated, A-PAGE analysis showed that 34 lines contained the 1RS/1BL translocationchromosome, which was characterized by the presence of a 1RS-specific Sec- 1 marker bands. Furtherverification with GISH proved that 33 in the 34 lines contained a pair of homozygous 1RS/1BL transloca-tion chromosomes, only one line was a 1RS/1BL monosomic line. A field experiment was carried out on Pdeficient soil to investigate grain yield, biomass, numbers of spikes per plant (SPP), P uptake efficiency(PUpE), and P utilization efficiency (PUtE) of the DH lines and their parents under -P (nil P applied) and +P(60 kg P/hm2 applied) at maturity. Results showed soil P deficiency decreased the values of the first fourtraits in Lovrin No.10, but were more severe for Chinese Spring. Lovrin No.10 had higher values of all theabove tested traits at both -P and +P than Chinese Spring did, but had similar PUtE with Chinese Spring.These five traits segregated, and differed greatly among DH lines under both -P and +P conditions.Although the variations among DH lines exceeded the difference between the two parents, the averagevalues of the DH lines were between the two parents. The average of the above five traits, and P deficiencytolerance (PDT) (measured by relative grain yield of -P/+P) were not different between the DH lines withand without 1RS/1BL translocation. This indicated that there was no association between 1RS and PUEand PDT in Lovrin No.10, and 1RS may not have P efficient gene(s). Therefore, in the offspring of LovrinNo.10, it is possible to combine high PUE and PDT with good quality without the negative effect of 1RS onflour quality.展开更多
This paper introduces a novel technique for object detection using genetic algorithms and morphological processing. The method employs a kind of object oriented structure element, which is derived by genetic algorithm...This paper introduces a novel technique for object detection using genetic algorithms and morphological processing. The method employs a kind of object oriented structure element, which is derived by genetic algorithms. The population of morphological filters is iteratively evaluated according to a statistical performance index corresponding to object extraction ability, and evolves into an optimal structuring element using the evolution principles of genetic search. Experimental results of road extraction from high resolution satellite images are presented to illustrate the merit and feasibility of the proposed method.展开更多
Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotech- nology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on ...Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotech- nology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on atomic force microscopy (AFM). Precise manipulation has been realized including varied manipulating modes such as “cutting”, “pushing”, “folding”, “kneading”, “picking up”, “dipping”, etc. The cutting accuracy is dominated by the size of the AFM tip, which is usually 10nm or less. Single DNA fragments can be cut and picked up and then amplified by single molecule PCR. Thus positioning isolation and sequencing can be performed.展开更多
Since convective boiling or highly subcooled single-phase forced convection in micro-channels is an effective cooling mechanism with a wide range of applications, more experimental and theoretical studies are re- quir...Since convective boiling or highly subcooled single-phase forced convection in micro-channels is an effective cooling mechanism with a wide range of applications, more experimental and theoretical studies are re- quired to explain and verify the forced convection heat transfer phenomenon in narrow channels. In this experimental study, we model the convective boiling behavior of water with low latent heat substance Freon 113 (R-113), with the purpose of saving power consumption and visualizing experiments. Both heat transfer and pressure drop characteris- tics were measured in subcooled and saturated concentric narrow gap forced convection boiling. Data were obtained to qualitatively identify the effects of gap size, pressure, flow rate and wall superheat on boiling regimes and the tran- sition between various regimes. Some significant differences from unconfined forced convection boiling were found, and also, the flow patterns in narrow vertical annulus tubes have been studied quantitatively.展开更多
Silicon deep etching technique is the key fabrication step in the development of MEMS. The mask selectivity and the lateral etching control are the two primary factors that decide the result of deep etching process. T...Silicon deep etching technique is the key fabrication step in the development of MEMS. The mask selectivity and the lateral etching control are the two primary factors that decide the result of deep etching process. These two factors are studied in this paper. The experimental results show that the higher selectivity can be gotten when F - gas is used as etching gas and Al is introduced as mask layer. The lateral etching problems can be solved by adjusting the etching condition, such as increasing the RF power, changing the gas composition and flow volume of etching machine.展开更多
Since the start of the construction project supervision system pilot, construction project supervision has played a huge role in construction projects;at the same time, the role of the supervision unit cannot be separ...Since the start of the construction project supervision system pilot, construction project supervision has played a huge role in construction projects;at the same time, the role of the supervision unit cannot be separated from the effective management of the construction unit. Engineering supervision is a kind of paid engineering consulting service, and the management of supervision costs is an important subject for construction units to strengthen the management of supervision units. Based on practical data and management experience, the article analyzes and studies the supervision cost management, aiming to improve the management level of the construction unit to the supervision unit.展开更多
Atomic force micriscope (AFM)-based dip-pen nanolithography (DPN) is an emerging approach for con-structing nanostructures on material surfaces such as gold, silicon and silicon oxide. Although DPN is a powerful tech-...Atomic force micriscope (AFM)-based dip-pen nanolithography (DPN) is an emerging approach for con-structing nanostructures on material surfaces such as gold, silicon and silicon oxide. Although DPN is a powerful tech-nique, it has not shown its ability of direct-writing and pat-terning of nanostructures on surfaces of soft materials, for example biomacromolecules. Direct depositing on soft sur-faces becomes possible with the introduction of a com-bined-dynamic mode DPN rather than mostly used contact mode DPN or tapping mode DPN. In this report, the com-bined dynamic mode DPN is used for direct depositing pro-tein ink on DNA molecules at the nanometer scale.展开更多
文摘This paper reports the cloning and expression analysis of a high-affinity nitrate transporter inwheat ( Triticurn aestivurn L.). A full-length cDNA, TaNRT2.3(accession number AY053452), was isolatedfrom NO3--induced roots of wheat. The cDNA encodes a polypeptide with 507 amino acids and 12transmembrane domains, belongs to nitrate/nitrite porter (NNP) family within the major facilitator superfamily(MFS), and is closely related to other NRT2 proteins from plants. The expressions of TaNtTT2 genes inwheat tissues were analyzed using Northern blot, results indicated that TaNRT2 were induced specificallyin roots but not in shoots in response to both low (5-200 μmol/L) and high (2.0 retool/L) concentrationsof NO^-. TaNRT2transcripts were undetectable in N-deprived or NH4^+grown plant roots. The significantcorrelation between the time course of TaNtTT2transcription accumulation in the roots of wheat plantsgrown in 0.2 mmol/L NO3- and the time course of the nitrate uptake rates by wheat plants grown under thesame conditions suggested that TaNtTT2 played an important role in high-affinity NO3-uptake. Using thesplit root system, we found that supplying NO3- to one part of the roots induced the expression of TaNtTT2in the other part not supplied with NO3- or supplied with NH4^+, which implied that N cycling within plantsacted as a regulatory signal for N uptake.
基金The research was supported by a Key Project of the“Tenth Five-Year”Science&Technology Development Plan(01606006)from Natural Science Foundation of Anhui Province,China.
文摘reconstituted embryos were produced by nuclear transplantation using bovine ear fibroblasts at G 0 or non-G 0 stage as donor nuclei and oocytes collected from superovulated multiparous or young rabbits as recipients. After cultivation in two kinds of medium M199+10%FBS or RD+10%FBS, 112 of them developed to 2-cell stage (62.2%) and 26 to morula stage (14.4%) and 20 of them eventually developed to blastocyst stage (11.1%). There is no significant difference for the cleavage rates in two groups of reconstituted embryos derived from G 0 -stage and non-G 0 stage donor cells respectively. However, G 0-stage donor cells could result in higher rate of 8-cell16-cell stage embryos significantly (P<0.05), as well as higher rate of blastocysts (P<0.01). It seems that using two different culture systems had no significant effects on the cleavage rate, morula rate or blastocyst rate (P>0.05).
文摘It is reported that chromosome 1 R of rye (Secale cereale L) convey phosphorus use efficientgene (s), and 1RS/1BL translocation genotype Lovrin No. 10 is P use efficient. So we hypothesized whetherP efficient gene(s) locate on 1RS, and the high P efficiency of Lovrin No.10 is from 1RS? To test thishypothesis, we investigated the P use efficiency (PUE) of a doubled haploid (DH) population with 61 linesderived from anther culture of F1 hybrid between Lovrin No.10 and phosphorus uptake inefficient genotypeChinese Spring to see whether PUE differs between DH line with and without 1RS/1BL translocation.Acidic polyacrylamide-gel electrophoresis (A-PAGE) of gliadin and genomic DNA in situ hybridization (GISH)were employed to discriminate 1RS/1BL translocation DH lines from the normal 1B DH lines. Among the61 DH lines investigated, A-PAGE analysis showed that 34 lines contained the 1RS/1BL translocationchromosome, which was characterized by the presence of a 1RS-specific Sec- 1 marker bands. Furtherverification with GISH proved that 33 in the 34 lines contained a pair of homozygous 1RS/1BL transloca-tion chromosomes, only one line was a 1RS/1BL monosomic line. A field experiment was carried out on Pdeficient soil to investigate grain yield, biomass, numbers of spikes per plant (SPP), P uptake efficiency(PUpE), and P utilization efficiency (PUtE) of the DH lines and their parents under -P (nil P applied) and +P(60 kg P/hm2 applied) at maturity. Results showed soil P deficiency decreased the values of the first fourtraits in Lovrin No.10, but were more severe for Chinese Spring. Lovrin No.10 had higher values of all theabove tested traits at both -P and +P than Chinese Spring did, but had similar PUtE with Chinese Spring.These five traits segregated, and differed greatly among DH lines under both -P and +P conditions.Although the variations among DH lines exceeded the difference between the two parents, the averagevalues of the DH lines were between the two parents. The average of the above five traits, and P deficiencytolerance (PDT) (measured by relative grain yield of -P/+P) were not different between the DH lines withand without 1RS/1BL translocation. This indicated that there was no association between 1RS and PUEand PDT in Lovrin No.10, and 1RS may not have P efficient gene(s). Therefore, in the offspring of LovrinNo.10, it is possible to combine high PUE and PDT with good quality without the negative effect of 1RS onflour quality.
文摘This paper introduces a novel technique for object detection using genetic algorithms and morphological processing. The method employs a kind of object oriented structure element, which is derived by genetic algorithms. The population of morphological filters is iteratively evaluated according to a statistical performance index corresponding to object extraction ability, and evolves into an optimal structuring element using the evolution principles of genetic search. Experimental results of road extraction from high resolution satellite images are presented to illustrate the merit and feasibility of the proposed method.
文摘Nano-manipulation of single atoms and molecules is a critical technique in nanoscience and nanotech- nology. This review paper will focus on the recent development of the manipulation of single DNA molecules based on atomic force microscopy (AFM). Precise manipulation has been realized including varied manipulating modes such as “cutting”, “pushing”, “folding”, “kneading”, “picking up”, “dipping”, etc. The cutting accuracy is dominated by the size of the AFM tip, which is usually 10nm or less. Single DNA fragments can be cut and picked up and then amplified by single molecule PCR. Thus positioning isolation and sequencing can be performed.
基金Supported by the 973 Project of China (G1999022308) and the Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-SW-L05)
文摘Since convective boiling or highly subcooled single-phase forced convection in micro-channels is an effective cooling mechanism with a wide range of applications, more experimental and theoretical studies are re- quired to explain and verify the forced convection heat transfer phenomenon in narrow channels. In this experimental study, we model the convective boiling behavior of water with low latent heat substance Freon 113 (R-113), with the purpose of saving power consumption and visualizing experiments. Both heat transfer and pressure drop characteris- tics were measured in subcooled and saturated concentric narrow gap forced convection boiling. Data were obtained to qualitatively identify the effects of gap size, pressure, flow rate and wall superheat on boiling regimes and the tran- sition between various regimes. Some significant differences from unconfined forced convection boiling were found, and also, the flow patterns in narrow vertical annulus tubes have been studied quantitatively.
文摘Silicon deep etching technique is the key fabrication step in the development of MEMS. The mask selectivity and the lateral etching control are the two primary factors that decide the result of deep etching process. These two factors are studied in this paper. The experimental results show that the higher selectivity can be gotten when F - gas is used as etching gas and Al is introduced as mask layer. The lateral etching problems can be solved by adjusting the etching condition, such as increasing the RF power, changing the gas composition and flow volume of etching machine.
文摘Since the start of the construction project supervision system pilot, construction project supervision has played a huge role in construction projects;at the same time, the role of the supervision unit cannot be separated from the effective management of the construction unit. Engineering supervision is a kind of paid engineering consulting service, and the management of supervision costs is an important subject for construction units to strengthen the management of supervision units. Based on practical data and management experience, the article analyzes and studies the supervision cost management, aiming to improve the management level of the construction unit to the supervision unit.
文摘Atomic force micriscope (AFM)-based dip-pen nanolithography (DPN) is an emerging approach for con-structing nanostructures on material surfaces such as gold, silicon and silicon oxide. Although DPN is a powerful tech-nique, it has not shown its ability of direct-writing and pat-terning of nanostructures on surfaces of soft materials, for example biomacromolecules. Direct depositing on soft sur-faces becomes possible with the introduction of a com-bined-dynamic mode DPN rather than mostly used contact mode DPN or tapping mode DPN. In this report, the com-bined dynamic mode DPN is used for direct depositing pro-tein ink on DNA molecules at the nanometer scale.
