This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river chan...This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river channel was investigated with base diameter, top diameter, length, and decay class. To study relationship between in-stream LWD and adjacent riparian forest, species of each log of LWD in segment 1 was identified, and the riparian forest was examined by setting a 32m?4 m quadrat consisting of twelve 8m?m small quadrats. The results showed that, in segment 1, in-stream LWD loading was 1.733 m3/100m or 10.83 m3hm-2, and in segment 2, it was 1.709m3/100m or 21.36 m3hm-2. In-stream LWD in decay class III and IV were accounted for a high proportion, which was different from that in the broadleaved and Korean pine forest, and the possible reason might be different decomposing velocities due to different decomposing conditions. Logs of LWD in stream and living trees in riparian forest declined as diameter increased, and it was in a reverse J-shaped distribution except logs of LWD in segment 1 in the first diameter class. Volumes of LWD in stream and living trees in riparian forest increased as diameter increased, and it was in a typical J-shaped distribution. Loading and species component of in-stream LWD were correlative to status of riparian forest to a certain extent, and there also existed difference. Comparing the correlation and difference was helpful to study on dynamic of the riparian forest.展开更多
[ Objective] The aim of this study was to clone Class Ⅱ chitinase gene in Leymus chinensis grown in saline land in Heilongjiang Province and analyze its sequence, which provided a foundation for further study on the ...[ Objective] The aim of this study was to clone Class Ⅱ chitinase gene in Leymus chinensis grown in saline land in Heilongjiang Province and analyze its sequence, which provided a foundation for further study on the biological function and application of chitinasa gene. [ Method] cDNA library of Leymus chinensis leaves were constructed, and its DNA sequence was determined or analyzed, while the homology of chitinasa gene and amino acid sequence was compared with that in GenBank. [ Result] One full length cDNA fragment with length of 996 bp was cloned from cDNA library of Leymus chinensis leaves. The length of ORF was 768 bp encoding 225 amino acids （GenBank accession number： EU344908）. The encoding products lacked CBD and C-terminal extension region from the view of structure, but had structural characters of Class Ⅱ chitinase gene, which indicated that amino acid sequence had high homology compared with Class Ⅱ chitinase gene of rye and wheat. The constructed recombinant vector pQE-LcChi2 could express a protein of 27 kD through induction, which was consistent with the deduced encoding product of pQE-LcChi2 gene. [ Conclusion] LcChl2 gene is an expression gene, which can express in E. coll.展开更多
[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxyla...[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxylase （PEPCase） gene was introduced into wheat embryo callus by the agrobacterium-mediated transformation system, and then analyzed through successive selection with selective medium con- taing gygrornycin to detect the gene at the molecular level. [Result] The hyg-resistant plants were obtained, and GUS histochemical staining showed the leaf of resistant plants was stained dark blue. The target bands appeared in PCR analysis. [ Conclusion] Phosphoenolpyruvate Car- boxylase （PEPCase） gene has been primarily introduced into the recipient material.展开更多
[ Objective] The study was to compare the structural and moisture characteristics of leaf from the plantlets of three types of omamental lily（ Lilium brownii）. [ Method ] The paraffin sections of leaves of tested li...[ Objective] The study was to compare the structural and moisture characteristics of leaf from the plantlets of three types of omamental lily（ Lilium brownii）. [ Method ] The paraffin sections of leaves of tested lily varieties were prepared and then observed under microscope, and the stomatal characteristics and moisture characteristics of tested lily varieties were measured. I Resaltl All the three ornamental lily varieties show isobilateral leaf, single layer of epicuticula and lower epidermis, and no obvious differentiation of palisade tissue and spongy tissue; their stomata distribute in lower epidermis, and the guard cells are dumbbell-shaped; all of these matedais present high moisture. For the leaf sick- ness, midrib sickness and mesophyll tissue sickness, the order was determined to be oriental lily 〉 Lilium/ongiflorum 〉 Asian lily; of the three types of ornamental lily, Ulium Iongiflorum has the largest stomatai aperture and Asian lily has the smallest; focusing the water potential and moisture, the turn was Asian lily 〉 oriental lily 〉 Lilium Iong＇fflorum. [ Condusion] The study may facilitate the artificial regulation of the growth conditions of the plantlets of ornamental lily.展开更多
Objective: To study the relationship between alkaloids contents in Chinese traditional drug Yimu Cao (the dried aerial parts of Leonurus artemisia) and its growing environment. Methods: Samples of the drug and the soi...Objective: To study the relationship between alkaloids contents in Chinese traditional drug Yimu Cao (the dried aerial parts of Leonurus artemisia) and its growing environment. Methods: Samples of the drug and the soil at the growing site collected from 5 selected regions. Reference materials were checked and on-the-spot observations were carried out to investigate the growth environment. RP-HPLC was performed to determine the alkaloid contents in the drug. Results: Different regions had different environmental conditions, including climate, soil, vegetation, and so on. No matter barren or fertile the soil at the growing site was, the herb of L. artemisia could grow well, but the contents of alkaloid in the drug varied greatly. The drugs produced in 2 northern regions, where the soil is alkaline, had higher content of alkaloid (about 0.4%) than that produced in southern regions (0.1l%-0.2%), where the soil is acid. Conclusion: The contents of organic matters, effective phosphorus, quick-acting potassium, and the pH value of the growing site soil were the factors correlating with alkaloid contents in the drug, among which the pH value of soil was an important positively correlating factor. The alkaline soils in North benefit the accumulation of alkaloids more than the acid soils in South. The other probable elements affecting the alkaloid contents in Yimu Cao were climate and genetic factors.展开更多
Donor shortages for organ transplantations are a major clinical challenge worldwide. Potential risks that are inevitably encountered with traditional methods include complications, secondary injuries, and limited sour...Donor shortages for organ transplantations are a major clinical challenge worldwide. Potential risks that are inevitably encountered with traditional methods include complications, secondary injuries, and limited source donors. Three-dimensional （3D） printing technology holds the potential to solve these limitations; it can he used to rapidly manufacture personalized tissue engineering scaffolds, repair tissue defects in situ with cells, and even directly print tissue and organs. Such printed implants and organs not only perfectly match the patient＇s damaged tissue, hut can also have engineered material microstructures and cell arrangements to promote cell growth and differentiation. Thus, such implants allow the desired tissue repair to he achieved, and could eventually solve the donor-shortage problem. This review summarizes relevant studies and recent progress on four levels, introduces different types of biomedical materials, and discusses existing problems and development issues with 3D printing that are related to materials and to the construction of extracellular matrix in vitro for medical applications.展开更多
The hybrid functionally graded materials(FGM) of hydroxyapatite(HA), stainless steel 316L(SS316L) and carbon nanotubes(CNT) were synthesized for biomedical implants. Three different types of FGM were produced by the c...The hybrid functionally graded materials(FGM) of hydroxyapatite(HA), stainless steel 316L(SS316L) and carbon nanotubes(CNT) were synthesized for biomedical implants. Three different types of FGM were produced by the combination of SS316 L and CNT to reinforce HA in discrete layers of FGM. In the first type of FGM, concentration of SS316 L was varied from 10% to 40%(mass fraction) with an increment of 10% to reinforce micro HA. In the second type of FGM, 0.5%(mass fraction) functionalized CNT was added by maintaining the rest of composition as that of the first type of FGM. In the third type of FGM, mixture of micro and nano HA(mass ratio1:1) was used, keeping rest of composition similar to the second type of FGM. All types of FGM were subjected to uniaxial compaction and sintered by pressureless sintering technique at similar compaction and sintering parameters. The results show that the densification is enhanced with the addition of CNT and nanocrystalline HA in the FGM. Hardness and fracture toughness increase in both FGM reinforced with CNT, but the increase of the hardness and fracture toughness are more pronounced in FGM with micro and nanocrystalline HA.展开更多
A quantum well intermixing（QW1） investigation on double quantum well（DQW） structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing （RTA） was ca...A quantum well intermixing（QW1） investigation on double quantum well（DQW） structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing （RTA） was carried out by means of photoluminescence（PL）. The ion implantation was performed at the energy of 120 keV with the dose ranging from 1 × 10^11cm^-2 to 1× 10^14cm^-2. The RTA was performed at the temperature of 700 ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation（-1 × 10^11cm^-2） indicating that the implant vacancy distribution affects the QWl. When the ion dose is over - 1 × 10^12cm^-2, the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells.展开更多
Sedimentary TOC （total organic carbon）, TN （total nitrogen） and C/N （carbon/nitrogen） at selected sites of Lake Victoria basin have provided evidence of phytoplankton productivity, input of nitrates and allochth...Sedimentary TOC （total organic carbon）, TN （total nitrogen） and C/N （carbon/nitrogen） at selected sites of Lake Victoria basin have provided evidence of phytoplankton productivity, input of nitrates and allochthonous （land） plant materials/catchment destruction in the basin during the late Holocene period （last 4,000 years to present）. TOC and TN in the sediment cores were determined using EuroEA3000 Series Elemental Analyser and radiocarbon dating done using AMS （accelerator mass spectrometry） standard method. Results showed that TOC （13.45%-20.78%） and TN （1.07%-1.92%） values were higher at Napoleon Gulf from about 4,186 years before present （ca. 4,186 yr. BP） to present than at inlet of river Kagera （TOC： 3.27%-6.32% and TN： 0.30%-0.59%） from about 190 years before present （ca. 190 yr. BP） to present. Generally TOC and TN had a negative correlation （r = -0.37, p = 0.04, n = 32） at Napoleon Gulf in the last 4,186 years to present signifying that C/N ratios were governed mostly by phytoplankton productivity which markedly increased during some periods in the last 370 years to present possibly as a result of increased input of nitrates. However, the periods from about 4,186 years to 1,684 years before present （ca. 4,186 yr. BP to 1,684 yr. BP） and some periods between the last 370 years to present indicated increased input of allochthonous plant materials/catchment destruction. On overall, there was a positive correlation between C/N and TOC at inlet of river Kagera （r = 0.57, p = 0.01, n = 20） in the last 190 years to present possibly signifying that C/N ratios were governed mainly by input of allochthonous plant materials hence increased catchment destruction. Input of land plant materials （catchment destruction） along Kagera basin declined during some period after 1950 AD. However the most recent years have shown increased input of land plant materials （catchment destruction） in Kagera basin.展开更多
基金This paper was supported by the Chinese Academy of Sciences (KZCX2-406) and National Natural Science Foundation of China (NSFC39970123) and Changbai Mountain Open Research Station.
文摘This study was conducted in Erdaobaihe River passing through the broadleaved and Korean pine forest located on the north slope of Changbai Mountain. In-stream large woody debris (LWD) in two segments of the river channel was investigated with base diameter, top diameter, length, and decay class. To study relationship between in-stream LWD and adjacent riparian forest, species of each log of LWD in segment 1 was identified, and the riparian forest was examined by setting a 32m?4 m quadrat consisting of twelve 8m?m small quadrats. The results showed that, in segment 1, in-stream LWD loading was 1.733 m3/100m or 10.83 m3hm-2, and in segment 2, it was 1.709m3/100m or 21.36 m3hm-2. In-stream LWD in decay class III and IV were accounted for a high proportion, which was different from that in the broadleaved and Korean pine forest, and the possible reason might be different decomposing velocities due to different decomposing conditions. Logs of LWD in stream and living trees in riparian forest declined as diameter increased, and it was in a reverse J-shaped distribution except logs of LWD in segment 1 in the first diameter class. Volumes of LWD in stream and living trees in riparian forest increased as diameter increased, and it was in a typical J-shaped distribution. Loading and species component of in-stream LWD were correlative to status of riparian forest to a certain extent, and there also existed difference. Comparing the correlation and difference was helpful to study on dynamic of the riparian forest.
基金Supported by Science and Technology Research Project of Education Department of Liaoning Province(2008120)IntroducedTalent Start-up Fund Project of Dalian Nationalities University(20056209)~~
文摘[ Objective] The aim of this study was to clone Class Ⅱ chitinase gene in Leymus chinensis grown in saline land in Heilongjiang Province and analyze its sequence, which provided a foundation for further study on the biological function and application of chitinasa gene. [ Method] cDNA library of Leymus chinensis leaves were constructed, and its DNA sequence was determined or analyzed, while the homology of chitinasa gene and amino acid sequence was compared with that in GenBank. [ Result] One full length cDNA fragment with length of 996 bp was cloned from cDNA library of Leymus chinensis leaves. The length of ORF was 768 bp encoding 225 amino acids （GenBank accession number： EU344908）. The encoding products lacked CBD and C-terminal extension region from the view of structure, but had structural characters of Class Ⅱ chitinase gene, which indicated that amino acid sequence had high homology compared with Class Ⅱ chitinase gene of rye and wheat. The constructed recombinant vector pQE-LcChi2 could express a protein of 27 kD through induction, which was consistent with the deduced encoding product of pQE-LcChi2 gene. [ Conclusion] LcChl2 gene is an expression gene, which can express in E. coll.
文摘[ Objective] The aim of this study was to introduce Phosphoenolpyruvate Carboxylase （PEPCase） gene into common wheat Linyou 145. [ Method] With the material of common wheat Linyou 145, Phosphoenolpyruvate Carboxylase （PEPCase） gene was introduced into wheat embryo callus by the agrobacterium-mediated transformation system, and then analyzed through successive selection with selective medium con- taing gygrornycin to detect the gene at the molecular level. [Result] The hyg-resistant plants were obtained, and GUS histochemical staining showed the leaf of resistant plants was stained dark blue. The target bands appeared in PCR analysis. [ Conclusion] Phosphoenolpyruvate Car- boxylase （PEPCase） gene has been primarily introduced into the recipient material.
文摘[ Objective] The study was to compare the structural and moisture characteristics of leaf from the plantlets of three types of omamental lily（ Lilium brownii）. [ Method ] The paraffin sections of leaves of tested lily varieties were prepared and then observed under microscope, and the stomatal characteristics and moisture characteristics of tested lily varieties were measured. I Resaltl All the three ornamental lily varieties show isobilateral leaf, single layer of epicuticula and lower epidermis, and no obvious differentiation of palisade tissue and spongy tissue; their stomata distribute in lower epidermis, and the guard cells are dumbbell-shaped; all of these matedais present high moisture. For the leaf sick- ness, midrib sickness and mesophyll tissue sickness, the order was determined to be oriental lily 〉 Lilium/ongiflorum 〉 Asian lily; of the three types of ornamental lily, Ulium Iongiflorum has the largest stomatai aperture and Asian lily has the smallest; focusing the water potential and moisture, the turn was Asian lily 〉 oriental lily 〉 Lilium Iong＇fflorum. [ Condusion] The study may facilitate the artificial regulation of the growth conditions of the plantlets of ornamental lily.
文摘Objective: To study the relationship between alkaloids contents in Chinese traditional drug Yimu Cao (the dried aerial parts of Leonurus artemisia) and its growing environment. Methods: Samples of the drug and the soil at the growing site collected from 5 selected regions. Reference materials were checked and on-the-spot observations were carried out to investigate the growth environment. RP-HPLC was performed to determine the alkaloid contents in the drug. Results: Different regions had different environmental conditions, including climate, soil, vegetation, and so on. No matter barren or fertile the soil at the growing site was, the herb of L. artemisia could grow well, but the contents of alkaloid in the drug varied greatly. The drugs produced in 2 northern regions, where the soil is alkaline, had higher content of alkaloid (about 0.4%) than that produced in southern regions (0.1l%-0.2%), where the soil is acid. Conclusion: The contents of organic matters, effective phosphorus, quick-acting potassium, and the pH value of the growing site soil were the factors correlating with alkaloid contents in the drug, among which the pH value of soil was an important positively correlating factor. The alkaline soils in North benefit the accumulation of alkaloids more than the acid soils in South. The other probable elements affecting the alkaloid contents in Yimu Cao were climate and genetic factors.
文摘Donor shortages for organ transplantations are a major clinical challenge worldwide. Potential risks that are inevitably encountered with traditional methods include complications, secondary injuries, and limited source donors. Three-dimensional （3D） printing technology holds the potential to solve these limitations; it can he used to rapidly manufacture personalized tissue engineering scaffolds, repair tissue defects in situ with cells, and even directly print tissue and organs. Such printed implants and organs not only perfectly match the patient＇s damaged tissue, hut can also have engineered material microstructures and cell arrangements to promote cell growth and differentiation. Thus, such implants allow the desired tissue repair to he achieved, and could eventually solve the donor-shortage problem. This review summarizes relevant studies and recent progress on four levels, introduces different types of biomedical materials, and discusses existing problems and development issues with 3D printing that are related to materials and to the construction of extracellular matrix in vitro for medical applications.
基金GIK Institute for financial assistance and providing research facilitiessupported by the Basic Research program through the National Research Foundation of Korea (NRF) funded by Ministry, Science and Technology (MEST) (2011-0030058)
文摘The hybrid functionally graded materials(FGM) of hydroxyapatite(HA), stainless steel 316L(SS316L) and carbon nanotubes(CNT) were synthesized for biomedical implants. Three different types of FGM were produced by the combination of SS316 L and CNT to reinforce HA in discrete layers of FGM. In the first type of FGM, concentration of SS316 L was varied from 10% to 40%(mass fraction) with an increment of 10% to reinforce micro HA. In the second type of FGM, 0.5%(mass fraction) functionalized CNT was added by maintaining the rest of composition as that of the first type of FGM. In the third type of FGM, mixture of micro and nano HA(mass ratio1:1) was used, keeping rest of composition similar to the second type of FGM. All types of FGM were subjected to uniaxial compaction and sintered by pressureless sintering technique at similar compaction and sintering parameters. The results show that the densification is enhanced with the addition of CNT and nanocrystalline HA in the FGM. Hardness and fracture toughness increase in both FGM reinforced with CNT, but the increase of the hardness and fracture toughness are more pronounced in FGM with micro and nanocrystalline HA.
文摘A quantum well intermixing（QW1） investigation on double quantum well（DQW） structure with two different emitting wavelength caused by phosphorus ion implantation and following rapid thermal annealing （RTA） was carried out by means of photoluminescence（PL）. The ion implantation was performed at the energy of 120 keV with the dose ranging from 1 × 10^11cm^-2 to 1× 10^14cm^-2. The RTA was performed at the temperature of 700 ℃ for 30 s under pure nitrogen protection. The PL measurement implied that the band gap blue-shift from the upper well increases with the ion dose faster than that from lower well and the PL peaks from both QWs remained well separated under the lower dose implantation（-1 × 10^11cm^-2） indicating that the implant vacancy distribution affects the QWl. When the ion dose is over - 1 × 10^12cm^-2, the band gap blue-shift from both wells increases with the ion dose and finally the two peaks merge together as one peak indicating the ion implantation caused a total intermixing of both quantum wells.
文摘Sedimentary TOC （total organic carbon）, TN （total nitrogen） and C/N （carbon/nitrogen） at selected sites of Lake Victoria basin have provided evidence of phytoplankton productivity, input of nitrates and allochthonous （land） plant materials/catchment destruction in the basin during the late Holocene period （last 4,000 years to present）. TOC and TN in the sediment cores were determined using EuroEA3000 Series Elemental Analyser and radiocarbon dating done using AMS （accelerator mass spectrometry） standard method. Results showed that TOC （13.45%-20.78%） and TN （1.07%-1.92%） values were higher at Napoleon Gulf from about 4,186 years before present （ca. 4,186 yr. BP） to present than at inlet of river Kagera （TOC： 3.27%-6.32% and TN： 0.30%-0.59%） from about 190 years before present （ca. 190 yr. BP） to present. Generally TOC and TN had a negative correlation （r = -0.37, p = 0.04, n = 32） at Napoleon Gulf in the last 4,186 years to present signifying that C/N ratios were governed mostly by phytoplankton productivity which markedly increased during some periods in the last 370 years to present possibly as a result of increased input of nitrates. However, the periods from about 4,186 years to 1,684 years before present （ca. 4,186 yr. BP to 1,684 yr. BP） and some periods between the last 370 years to present indicated increased input of allochthonous plant materials/catchment destruction. On overall, there was a positive correlation between C/N and TOC at inlet of river Kagera （r = 0.57, p = 0.01, n = 20） in the last 190 years to present possibly signifying that C/N ratios were governed mainly by input of allochthonous plant materials hence increased catchment destruction. Input of land plant materials （catchment destruction） along Kagera basin declined during some period after 1950 AD. However the most recent years have shown increased input of land plant materials （catchment destruction） in Kagera basin.
