We report an improved strategy for conjugated polymer-based optical DNA detection with stem-loop structured DNA probes.The high sensitivity of conjugated polymer-based biosensors arises from light harvesting by the co...We report an improved strategy for conjugated polymer-based optical DNA detection with stem-loop structured DNA probes.The high sensitivity of conjugated polymer-based biosensors arises from light harvesting by the conjugated polymer and the related amplified fluorescent signal transduction either through quenching or through Fǒrster energy transfer) In our previous publication,we demonstrated that the coupling of magnetic particles to conjugated polymers significantly improves the selectivity of this class of DNA sensors.Here we further improved the selectivity by introducing both stem-loop structured capture probe and competition probe.We demonstrated further that this improved magnetically assisted DNA sensor can conveniently identify even a single-nucleotide mismatch in the target sequence.展开更多
Carboxylic acid-functionalized nano-sized magnetic composite polymers (COOH-NMPs) were synthesized and used for the preparation of the modified glassy carbon electrode, i.e., COOH-NMPs/GCE and DNA/COOH-NMPs/GCE. The e...Carboxylic acid-functionalized nano-sized magnetic composite polymers (COOH-NMPs) were synthesized and used for the preparation of the modified glassy carbon electrode, i.e., COOH-NMPs/GCE and DNA/COOH-NMPs/GCE. The electrochemical behaviors of melamine (MM) were investigated on COOH-NMPs/GCE by cyclic voltammetry (CV) in both cases of DNA in the solution and immobilized on the electrode surface. The electron transfer coefficient (a) and the rate constant (ks) kept unchanged in the absence and presence of DNA. Based on the electrochemical properties of the interaction of MM on the surface of the DNA/COOH-NMPs/GCE, a direct method for the determination of MM in liquid milk was established. The detection limit of this method was 2.0 ng·L﹣1, with average recoveries at 95.9% - 104.2% and RSD at 4.5% - 8.2%. The proposed method was provided to have a good accuracy, high stability and good reproducibility with a simple and environmental friendly process. 10 kinds of liquid milk samples bought from the market randomly were tested, and only 1 of them was found at relatively low level of MM residue with the amount of 0.12 ug·L﹣1.展开更多
Chromosomes, the longest molecular fiber that stores genetic information in eukaryotic cells, must be orderly packaged during mitosis for their proper segregation into daughter cells. Although the morphological change...Chromosomes, the longest molecular fiber that stores genetic information in eukaryotic cells, must be orderly packaged during mitosis for their proper segregation into daughter cells. Although the morphological changes of chromosomes during mitosis have been described in detail, how mitosis progression programs the transformation of seemingly amorphous and loose interphase .展开更多
The fabrication of precisely patterned polymers at the nanoscale is of critical importance.We have previously succeeded in creating various nanopatterned polymers with nanoscale resolution through the use of in situ a...The fabrication of precisely patterned polymers at the nanoscale is of critical importance.We have previously succeeded in creating various nanopatterned polymers with nanoscale resolution through the use of in situ atom transfer radical polymerization(ATRP)techniques on deoxyribonucleic acid(DNA)origami.However,separating nanopatterned polymers from the origami template without damaging the origami presents a significant challenge,thereby increasing costs and limiting the development of applications involving nanopatterned polymers.Here,we achieved spatially and temporally controlled release of DNA origami templates through photo-regulation by incorporating azobenzene-modified DNA into the initiator.Under UV exposure,azobenzene isomerization rapidly induces the disassociation of patterned polymers from the origami template at ambient temperatures,without damaging the DNA origami.Additionally,the released origami template can be reused as a template for the cyclic production of nanopatterned polymers.This method provides a pathway for the large-scale production of patterned polymers at reduced costs and facilitates dynamic control over the polymer-DNA complex,with potential applications in both the biomedical and chemical fields.展开更多
Decades of progress in the semiconductor industry has led to lithographically printed dimensions that are small enough that the positions of individual molecules and the stochastic variation in the number of photons h...Decades of progress in the semiconductor industry has led to lithographically printed dimensions that are small enough that the positions of individual molecules and the stochastic variation in the number of photons have a significant effect on the quality of photoresist patterns.These effects scale badly and will be more important as feature sizes continue to shrink.Selforganizing materials can provide regular patterns of molecules that have the potential to minimize stochastic effects.Some such reported materials are block copolymers,bottle brush polymers and DNA,all of which have been used as part of lithographic patterning.A key challenge for selforganizing materials is defect levels.The energy to rearrange has to be high enough that random defects aren’t created thermally but low enough that rearrangement into preferred domains can occur.All of the methods can generate accurate CDs based on the chemical composition of the material,but they all need some way to control the positions of the feature edges.There are methods for guiding the self-organization,but the final position is the sum of the guide pattern misalignment and the intrinsic alignment error of the self-organizing materials.Thus it can be worse than the positioning of the guide structures.Alignment and defect levels are thus two big challenges for manufacturing introduction of self-organizing materials.展开更多
Comprehensive Summary The chain effect of polymer is the kernel of the precise synthesis of complex polymer compounds and the development of polymer science.Nucleic acids,a special type of polyester,can form supramole...Comprehensive Summary The chain effect of polymer is the kernel of the precise synthesis of complex polymer compounds and the development of polymer science.Nucleic acids,a special type of polyester,can form supramolecular polymers via hydrogen bonds among corresponding bases.We focused on the precise control of polymer chains and proposed the concept of“nucleic acid-backboned chimeric polymers”(NCPs).There are three important elements of NCPs,namely nucleic acid backbone,side group and intra-/inter-chain weak interactions.In this review,we expound how to realize the construction of intelligent DNA structures through the regulation of these three elements and the applications of NCPs in various fields.展开更多
OBJECTIVE: To evaluate the long-term efficacy and safety of lamivudine therapy for the treatment of chronic hepatitis B and the clinical influence of emergence of tyrosine methionine aspartic acid (YMDD) motif mutatio...OBJECTIVE: To evaluate the long-term efficacy and safety of lamivudine therapy for the treatment of chronic hepatitis B and the clinical influence of emergence of tyrosine methionine aspartic acid (YMDD) motif mutation of hepatitis B virus (HBV). METHODS: This multicenter, double-blind, randomized, placebo controlled trial began in 1996. A total of 429 patients with HBsAg, HBeAg and HBV CNA positives were enrolled. They were randomized to receive either lamivudine 100 mg daily (n = 322) or placebo (n = 107) on 3 : 1 ratio for the first 12 weeks. Thereafter all patients were offered open label lamivudine treatment and assessed every 4 weeks for a total of 104 weeks. RESULTS: After 1 year treatment 72.7% patients (285/392) had a sustained serum HBV DNA response. HBV DNA continued to be substantially suppressed at the second year, except in patients with the emergence of YMDD mutation whose mean HBV DNA levels increased to 86 Meq/ml (bDNA assay) but were much more lower than that of pre-treatment baseline level. lamivudine therapy resulted in increased HBeAg loss and HBeAg/anti-HBe seroconversion, which were correlated with both baseline alanine transaminase (ALT) levels and also with duration of lamivudine treatment. HBeAg loss was achieved in 26.8% of patients with ALT > 1-fold upper limit of normal at 2 yeas and in 35.6% and 55.6% of patients with ALT > 2-fold upper limit of normal and ALT > 5-fold upper limit of normal, respectively. For HBeAg seroconversion, these figures were 17.4%, 22.2%, and 33.3% respectively. By the end of 2 years, ALT levels were remained in normal ranges in 50.3% whose ALT were abnormal before treatment, and in 83% whose ALT were mormal before treatment. YMDD mutation were developed in 49.7% of the patients. Their serum HBV DNA levels were slightly increased to bDNA median level 86 Meq/ml and 15% of the patients they were ALT exceeded baseline levels. Four patients clinically flared-up and recovered after stop treatment. The adverse drug reactions (ADRs) of lamivudine were mild to moderate, only two patients were reported as drug related severe ADR. CONCLUSION: Sustained HBV replication and clinical improvement could be obtained by the long-term lamivudine therapy with good tolerance and safety.展开更多
基金We greatly appreciate the support from National Natural Science Foundation （20404016, 60537030）；Shanghai Municipal Commission for Science and Technology （0452nm068, 03DZ14025）；the program for Shanghai Rising Star and Chinese Academy of Sciences.
文摘We report an improved strategy for conjugated polymer-based optical DNA detection with stem-loop structured DNA probes.The high sensitivity of conjugated polymer-based biosensors arises from light harvesting by the conjugated polymer and the related amplified fluorescent signal transduction either through quenching or through Fǒrster energy transfer) In our previous publication,we demonstrated that the coupling of magnetic particles to conjugated polymers significantly improves the selectivity of this class of DNA sensors.Here we further improved the selectivity by introducing both stem-loop structured capture probe and competition probe.We demonstrated further that this improved magnetically assisted DNA sensor can conveniently identify even a single-nucleotide mismatch in the target sequence.
文摘Carboxylic acid-functionalized nano-sized magnetic composite polymers (COOH-NMPs) were synthesized and used for the preparation of the modified glassy carbon electrode, i.e., COOH-NMPs/GCE and DNA/COOH-NMPs/GCE. The electrochemical behaviors of melamine (MM) were investigated on COOH-NMPs/GCE by cyclic voltammetry (CV) in both cases of DNA in the solution and immobilized on the electrode surface. The electron transfer coefficient (a) and the rate constant (ks) kept unchanged in the absence and presence of DNA. Based on the electrochemical properties of the interaction of MM on the surface of the DNA/COOH-NMPs/GCE, a direct method for the determination of MM in liquid milk was established. The detection limit of this method was 2.0 ng·L﹣1, with average recoveries at 95.9% - 104.2% and RSD at 4.5% - 8.2%. The proposed method was provided to have a good accuracy, high stability and good reproducibility with a simple and environmental friendly process. 10 kinds of liquid milk samples bought from the market randomly were tested, and only 1 of them was found at relatively low level of MM residue with the amount of 0.12 ug·L﹣1.
文摘Chromosomes, the longest molecular fiber that stores genetic information in eukaryotic cells, must be orderly packaged during mitosis for their proper segregation into daughter cells. Although the morphological changes of chromosomes during mitosis have been described in detail, how mitosis progression programs the transformation of seemingly amorphous and loose interphase .
基金supported by the National Key R&D Program of China(No.2021YFF200203)the Key R&D Program of Hubei Province(No.2021BAA168)+2 种基金the National Science Foundation of China(22077042)the Max Planck Partner Group.The authors are grateful to the Analytical and Testing Centre of HUST,Analytical and Testing Centre of the School of Chemistry and Chemical Engineering(HUST)Research Core Facilities for Life Science(HUST)for instrument support.
文摘The fabrication of precisely patterned polymers at the nanoscale is of critical importance.We have previously succeeded in creating various nanopatterned polymers with nanoscale resolution through the use of in situ atom transfer radical polymerization(ATRP)techniques on deoxyribonucleic acid(DNA)origami.However,separating nanopatterned polymers from the origami template without damaging the origami presents a significant challenge,thereby increasing costs and limiting the development of applications involving nanopatterned polymers.Here,we achieved spatially and temporally controlled release of DNA origami templates through photo-regulation by incorporating azobenzene-modified DNA into the initiator.Under UV exposure,azobenzene isomerization rapidly induces the disassociation of patterned polymers from the origami template at ambient temperatures,without damaging the DNA origami.Additionally,the released origami template can be reused as a template for the cyclic production of nanopatterned polymers.This method provides a pathway for the large-scale production of patterned polymers at reduced costs and facilitates dynamic control over the polymer-DNA complex,with potential applications in both the biomedical and chemical fields.
文摘Decades of progress in the semiconductor industry has led to lithographically printed dimensions that are small enough that the positions of individual molecules and the stochastic variation in the number of photons have a significant effect on the quality of photoresist patterns.These effects scale badly and will be more important as feature sizes continue to shrink.Selforganizing materials can provide regular patterns of molecules that have the potential to minimize stochastic effects.Some such reported materials are block copolymers,bottle brush polymers and DNA,all of which have been used as part of lithographic patterning.A key challenge for selforganizing materials is defect levels.The energy to rearrange has to be high enough that random defects aren’t created thermally but low enough that rearrangement into preferred domains can occur.All of the methods can generate accurate CDs based on the chemical composition of the material,but they all need some way to control the positions of the feature edges.There are methods for guiding the self-organization,but the final position is the sum of the guide pattern misalignment and the intrinsic alignment error of the self-organizing materials.Thus it can be worse than the positioning of the guide structures.Alignment and defect levels are thus two big challenges for manufacturing introduction of self-organizing materials.
基金the Institute of Chemistry CAS(C220200701)the National Natural Science Foundation of China(21890731,21873071,21821001,21534007,21971248,21890730)+2 种基金the National Basic Research Plan of China(2018YFA0208900)the Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)the Fundamental Research Funds for the Central Universities for financial support.
文摘Comprehensive Summary The chain effect of polymer is the kernel of the precise synthesis of complex polymer compounds and the development of polymer science.Nucleic acids,a special type of polyester,can form supramolecular polymers via hydrogen bonds among corresponding bases.We focused on the precise control of polymer chains and proposed the concept of“nucleic acid-backboned chimeric polymers”(NCPs).There are three important elements of NCPs,namely nucleic acid backbone,side group and intra-/inter-chain weak interactions.In this review,we expound how to realize the construction of intelligent DNA structures through the regulation of these three elements and the applications of NCPs in various fields.
文摘OBJECTIVE: To evaluate the long-term efficacy and safety of lamivudine therapy for the treatment of chronic hepatitis B and the clinical influence of emergence of tyrosine methionine aspartic acid (YMDD) motif mutation of hepatitis B virus (HBV). METHODS: This multicenter, double-blind, randomized, placebo controlled trial began in 1996. A total of 429 patients with HBsAg, HBeAg and HBV CNA positives were enrolled. They were randomized to receive either lamivudine 100 mg daily (n = 322) or placebo (n = 107) on 3 : 1 ratio for the first 12 weeks. Thereafter all patients were offered open label lamivudine treatment and assessed every 4 weeks for a total of 104 weeks. RESULTS: After 1 year treatment 72.7% patients (285/392) had a sustained serum HBV DNA response. HBV DNA continued to be substantially suppressed at the second year, except in patients with the emergence of YMDD mutation whose mean HBV DNA levels increased to 86 Meq/ml (bDNA assay) but were much more lower than that of pre-treatment baseline level. lamivudine therapy resulted in increased HBeAg loss and HBeAg/anti-HBe seroconversion, which were correlated with both baseline alanine transaminase (ALT) levels and also with duration of lamivudine treatment. HBeAg loss was achieved in 26.8% of patients with ALT > 1-fold upper limit of normal at 2 yeas and in 35.6% and 55.6% of patients with ALT > 2-fold upper limit of normal and ALT > 5-fold upper limit of normal, respectively. For HBeAg seroconversion, these figures were 17.4%, 22.2%, and 33.3% respectively. By the end of 2 years, ALT levels were remained in normal ranges in 50.3% whose ALT were abnormal before treatment, and in 83% whose ALT were mormal before treatment. YMDD mutation were developed in 49.7% of the patients. Their serum HBV DNA levels were slightly increased to bDNA median level 86 Meq/ml and 15% of the patients they were ALT exceeded baseline levels. Four patients clinically flared-up and recovered after stop treatment. The adverse drug reactions (ADRs) of lamivudine were mild to moderate, only two patients were reported as drug related severe ADR. CONCLUSION: Sustained HBV replication and clinical improvement could be obtained by the long-term lamivudine therapy with good tolerance and safety.
