There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential...There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential or polynomial relationships between g-s and stomatal aperture were found when regression of g-s and stomatal aperture was established. Statistical analysis revealed that the relationship between g-s and stomatal aperture for high-light leaves was more significant than that of low-light leaves. A linear relationship between g-s and stomatal aperture existed in both positions 1 and 3 for both high- and low-light leaves. The stomatal density of the low-light leaves was much lower than that of the high-light leaves. The sensitivity of stomata to changing environment for high-light leaves was higher than that for low-light leaves, which may also relate to the higher stomatal density for the high-light leaves.展开更多
With the global promotion of LED lighting products, the health and safety of LED products has drawn wider attention. This paper systematically introduces the ergonomic evaluation (methods and indicators) svstem for ...With the global promotion of LED lighting products, the health and safety of LED products has drawn wider attention. This paper systematically introduces the ergonomic evaluation (methods and indicators) svstem for heahh and comfort which differs from the traditional manpowered physical detection, and sketches out the evaluation indicators and its industrialization prospect.展开更多
An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi'om both single nucl...An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi'om both single nucleotides and oligonucleotides, and were prepared in high yields of 81% to 91%. Alkyl modified aptamer AS1411s were synthesized using this method and the biological activity screening results demonstrated that alkylation at the 1^st P-S site on yielded stronger target protein binding capacity, greater growth suppression effects against K562 and HL-60 cell lines, and improved serum stability, as compared with AS1411. This modified aptamer may be useful in tumor detection and treatment.展开更多
Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have ...Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have been applied. Aptamers can bind to a wide range of targets that include small organic molecules, inorganic compounds, haptens and even whole cells with high binding affinity and specificity. Aptamers for a wide range of targets have been selected currently. In addition, aptamers are thermo stable and can also be regenerated easily within a few minutes denaturation, which makes them easy to store or handle. These advantages make aptamers extremely suitable for applications based on molecular recognition as analytical, diagnostic and therapeutic tools. In this review, the recent applications of aptamers for chemistry analysis, medicine and food security, along with the future trend will be discussed.展开更多
Here we report a dual-functionalized electrochemical substrate to trigger cancer cells release based on the supramolecular interaction between β-cyclodextrin (β-CD) and Fc on clinical trial II aptamer AS1411 funct...Here we report a dual-functionalized electrochemical substrate to trigger cancer cells release based on the supramolecular interaction between β-cyclodextrin (β-CD) and Fc on clinical trial II aptamer AS1411 functionalized graphene platform. On one hand, the host-guest interaction can be reversible electrochemically controlled to realize cancer cells capture/release, and 1-adamantylamine binding can further amplify this surface change by competing interaction with β-CD. On the other hand, the AS1411 aptamer and its complementary DNA (cDNA) also can be used as a switchable anchor for cell adhesion. Our work gives an example for label-free, multi-functionalized triggered cell release based on aptamer and β-CD/graphene-modified surface and this multi-ways for cell catch-and-release on graphene modified surface also provides their potential biomedical application.展开更多
Europium-doped gadolinium oxide (Gd2O3:Eu) nanoparticles have been synthesized, and then their surfaces have been conjugated with nucleolin- targeted AS1411 aptamer to form functionalized target-specific Gd2OB:EU ...Europium-doped gadolinium oxide (Gd2O3:Eu) nanoparticles have been synthesized, and then their surfaces have been conjugated with nucleolin- targeted AS1411 aptamer to form functionalized target-specific Gd2OB:EU nanoparticles (A-GdO:Eu nanoparticles). The A-GdO:Eu nanoparticles present strong fluorescence in the visible range, high magnetic susceptibility, X-ray attenuation and good biocompatibility. The A-GdO:Eu nanoparticles have been applied to test molecular expression of nucleolin highly expressed CL1-5 lung cancer cells under a confocal microscope. Fluorescence imaging clearly reveals that the nanoparticles can be applied as fluorescent tags for cancer-targeting molecular imaging. Furthermore, taking together their excellent T1 contrast and strong computed tomography (CT) signal, the A-GdO:Eu nanoparticles demonstrate a great capability for use as a dual modality contrast agent for CT and magnetic resonance (MR) molecular imaging. Animal experiments also show that the A-GdO:Eu nanoparticles are able to contrast the tissues of BALB/c mice using CT modality. Moreover, the obvious red fluorescence of A-GdO:Eu nanoparticles can be visualized in a tumor by the naked eye. Overall, our results demonstrate that the A-GdO:Eu nanoparticles can not only serve as new medical contrast agents but also as intraoperative fluorescence imaging probes for guided surgery in the near future.展开更多
One solid-state electrochemiluminescence (ECL) protein biosensor based on the competing reaction and substitute reaction between protein-to-DNA aptamer and DNA-to-DNA aptamer was proposed. Additionally, the biosenso...One solid-state electrochemiluminescence (ECL) protein biosensor based on the competing reaction and substitute reaction between protein-to-DNA aptamer and DNA-to-DNA aptamer was proposed. Additionally, the biosensor was based on ECL photo-quenching effect of ferrocene (Fc) to tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)2+). It was built up by modification of Au nanoparticles (AuNPs) and Ru(bpy)32+ on one Au electrode firstly, and then self-assembly of one special double-stranded DNA (dsDNA) onto the electrode. This dsDNA was prepared by hybridization of one Fc labeled molecular beacon single-stranded DNA(ssDNA) and one anti-thrombin aptamer ssDNA. Without the target protein, this Fc-dsDNA/Ru(bpy)2+- AuNPs/Au elec- trode trigged strong ECL signal, so we called it ECL "signal on" state. When thrombin was present in the sensing solution, the protein reacted with its aptamer from the Fc-dsDNA/Ru(bpy)3^2+-AuNPs/Au electrode. Then the left molecular beacon ssDNA on the electrode recovered to its normal stem-loop structure and consequently its Fc labeler was close enough to the electrode surface to quench the ECL signal from Ru(bpy)3^2+. It was in ECL "signal off" state. We measured the decrease in ECL intensity to sense the target protein. This was one endeavour to sense protein by using un-labeling target or probe strategy, which gave higher sensitivity and selectivity due to the better combination efficiency of protein and the un-labeled aptamer. 6.25 fmo/L thrombin was detected out,展开更多
Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populate...Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populated areas, the determination and monitoring of these OPs in food products and environment is of great importance. OPs are present in very small quantities and therefore, methods for their detection need to be highly sensitive and selective. Here, we aimed to develop a simple and selective aptamer-based colorimetric assay for the detection of omethoate, which is one of the commonly used OPs. The principle of the assay is that single-stranded DNA(ss DNA)-wrapped gold nanoparticles(Au NPs) are resistant to salt-induced aggregation. By employing an "artificial antibody" organophosphorous pesticide-binding aptamer(OBA) as the recognition element, aptamer-wrapped Au NPs(Au-apta) show high selectivity towards omethoate, resulting in the disconnection of aptamers from Au NPs and the aggregation of Au NPs. As there is a significant color change from the interparticle plasmon coupling during the aggregation of Au NPs, the established assay showed good linearity between 0.1 and 10 μmol/L, with a low detection limit of 0.1 μmol/L. Other OPs such as profenofos, phorate, and isocarbophos would not interfere with the detection of omethoate despite having similar structures. Thus, the colorimetric method shows potential for use in the detection of omethoate in real soil samples.展开更多
文摘There was heterogeneous distribution in stomatal conductance (g-s) and stomatal aperture for both high- and low-light leaves of Ligustrum sinense Lour. in four designated positions within a leaf. Linear or exponential or polynomial relationships between g-s and stomatal aperture were found when regression of g-s and stomatal aperture was established. Statistical analysis revealed that the relationship between g-s and stomatal aperture for high-light leaves was more significant than that of low-light leaves. A linear relationship between g-s and stomatal aperture existed in both positions 1 and 3 for both high- and low-light leaves. The stomatal density of the low-light leaves was much lower than that of the high-light leaves. The sensitivity of stomata to changing environment for high-light leaves was higher than that for low-light leaves, which may also relate to the higher stomatal density for the high-light leaves.
文摘With the global promotion of LED lighting products, the health and safety of LED products has drawn wider attention. This paper systematically introduces the ergonomic evaluation (methods and indicators) svstem for heahh and comfort which differs from the traditional manpowered physical detection, and sketches out the evaluation indicators and its industrialization prospect.
基金the Ministry of Science and Technology of China(Grant No.2012CB720604)National Natural Science Foundation of China(Grant No.21332010)
文摘An operationally simple and efficient method for the synthesis of a wide range of alkylated nucleotides under mild conditions was developed. This improved method furnishes alkylated nucleotides fi'om both single nucleotides and oligonucleotides, and were prepared in high yields of 81% to 91%. Alkyl modified aptamer AS1411s were synthesized using this method and the biological activity screening results demonstrated that alkylation at the 1^st P-S site on yielded stronger target protein binding capacity, greater growth suppression effects against K562 and HL-60 cell lines, and improved serum stability, as compared with AS1411. This modified aptamer may be useful in tumor detection and treatment.
基金supported by the 863 Project(2012AA022703,2015AA020502)the National Natural Science Foundation of China(61271056)
文摘Since aptamer and its in vitro selection process called SELEX were independently described by Ellington and Gold in 1990, extensive research has been undertaken and numerous isolated aptamers for various targets have been applied. Aptamers can bind to a wide range of targets that include small organic molecules, inorganic compounds, haptens and even whole cells with high binding affinity and specificity. Aptamers for a wide range of targets have been selected currently. In addition, aptamers are thermo stable and can also be regenerated easily within a few minutes denaturation, which makes them easy to store or handle. These advantages make aptamers extremely suitable for applications based on molecular recognition as analytical, diagnostic and therapeutic tools. In this review, the recent applications of aptamers for chemistry analysis, medicine and food security, along with the future trend will be discussed.
文摘Here we report a dual-functionalized electrochemical substrate to trigger cancer cells release based on the supramolecular interaction between β-cyclodextrin (β-CD) and Fc on clinical trial II aptamer AS1411 functionalized graphene platform. On one hand, the host-guest interaction can be reversible electrochemically controlled to realize cancer cells capture/release, and 1-adamantylamine binding can further amplify this surface change by competing interaction with β-CD. On the other hand, the AS1411 aptamer and its complementary DNA (cDNA) also can be used as a switchable anchor for cell adhesion. Our work gives an example for label-free, multi-functionalized triggered cell release based on aptamer and β-CD/graphene-modified surface and this multi-ways for cell catch-and-release on graphene modified surface also provides their potential biomedical application.
文摘Europium-doped gadolinium oxide (Gd2O3:Eu) nanoparticles have been synthesized, and then their surfaces have been conjugated with nucleolin- targeted AS1411 aptamer to form functionalized target-specific Gd2OB:EU nanoparticles (A-GdO:Eu nanoparticles). The A-GdO:Eu nanoparticles present strong fluorescence in the visible range, high magnetic susceptibility, X-ray attenuation and good biocompatibility. The A-GdO:Eu nanoparticles have been applied to test molecular expression of nucleolin highly expressed CL1-5 lung cancer cells under a confocal microscope. Fluorescence imaging clearly reveals that the nanoparticles can be applied as fluorescent tags for cancer-targeting molecular imaging. Furthermore, taking together their excellent T1 contrast and strong computed tomography (CT) signal, the A-GdO:Eu nanoparticles demonstrate a great capability for use as a dual modality contrast agent for CT and magnetic resonance (MR) molecular imaging. Animal experiments also show that the A-GdO:Eu nanoparticles are able to contrast the tissues of BALB/c mice using CT modality. Moreover, the obvious red fluorescence of A-GdO:Eu nanoparticles can be visualized in a tumor by the naked eye. Overall, our results demonstrate that the A-GdO:Eu nanoparticles can not only serve as new medical contrast agents but also as intraoperative fluorescence imaging probes for guided surgery in the near future.
文摘One solid-state electrochemiluminescence (ECL) protein biosensor based on the competing reaction and substitute reaction between protein-to-DNA aptamer and DNA-to-DNA aptamer was proposed. Additionally, the biosensor was based on ECL photo-quenching effect of ferrocene (Fc) to tris(2,2-bipyridyl)ruthenium(II) (Ru(bpy)2+). It was built up by modification of Au nanoparticles (AuNPs) and Ru(bpy)32+ on one Au electrode firstly, and then self-assembly of one special double-stranded DNA (dsDNA) onto the electrode. This dsDNA was prepared by hybridization of one Fc labeled molecular beacon single-stranded DNA(ssDNA) and one anti-thrombin aptamer ssDNA. Without the target protein, this Fc-dsDNA/Ru(bpy)2+- AuNPs/Au elec- trode trigged strong ECL signal, so we called it ECL "signal on" state. When thrombin was present in the sensing solution, the protein reacted with its aptamer from the Fc-dsDNA/Ru(bpy)3^2+-AuNPs/Au electrode. Then the left molecular beacon ssDNA on the electrode recovered to its normal stem-loop structure and consequently its Fc labeler was close enough to the electrode surface to quench the ECL signal from Ru(bpy)3^2+. It was in ECL "signal off" state. We measured the decrease in ECL intensity to sense the target protein. This was one endeavour to sense protein by using un-labeling target or probe strategy, which gave higher sensitivity and selectivity due to the better combination efficiency of protein and the un-labeled aptamer. 6.25 fmo/L thrombin was detected out,
基金supported by the National Natural Science Foundation of China(6137103921305067+5 种基金21105048)China Postdoctoral Science Foundation Funded Project(2012T50475)Science Foundation of Jiangsu Province(BK20130754)Ph D Fund of the Ministry of Education for Young Teachers(0133219120019)King Saud University(Distinguished Scientist Fellowship Program)Graduate Education Innovation Program of Nanjing University of Science and Technology and Chinese Academy of Sciences
文摘Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populated areas, the determination and monitoring of these OPs in food products and environment is of great importance. OPs are present in very small quantities and therefore, methods for their detection need to be highly sensitive and selective. Here, we aimed to develop a simple and selective aptamer-based colorimetric assay for the detection of omethoate, which is one of the commonly used OPs. The principle of the assay is that single-stranded DNA(ss DNA)-wrapped gold nanoparticles(Au NPs) are resistant to salt-induced aggregation. By employing an "artificial antibody" organophosphorous pesticide-binding aptamer(OBA) as the recognition element, aptamer-wrapped Au NPs(Au-apta) show high selectivity towards omethoate, resulting in the disconnection of aptamers from Au NPs and the aggregation of Au NPs. As there is a significant color change from the interparticle plasmon coupling during the aggregation of Au NPs, the established assay showed good linearity between 0.1 and 10 μmol/L, with a low detection limit of 0.1 μmol/L. Other OPs such as profenofos, phorate, and isocarbophos would not interfere with the detection of omethoate despite having similar structures. Thus, the colorimetric method shows potential for use in the detection of omethoate in real soil samples.