Phase imprinting enables the dynamic generation of superflow in bosonic atoms,effectively overcoming traditional limitations such as vortex number constraints and heating effects.However,the mechanisms underlying supe...Phase imprinting enables the dynamic generation of superflow in bosonic atoms,effectively overcoming traditional limitations such as vortex number constraints and heating effects.However,the mechanisms underlying superflow formation remain insufficiently understood.In this work,we reveal these mechanisms by studying the time evolution of the transferred total angular momentum and the quantized current throughout the phase imprinting process,achieved through numerically solving the time-dependent Schrodinger and Gross-Pitaevskii equations.We demonstrate that the Bose gas dynamically acquires angular momentum through the density depletion induced by the phase imprinting potential,whereas quantized currents emerge from azimuthal phase slips accompanied by complete density depletions.Regarding the impact of system parameters,such as interactions,we find that interactions hinder superflow formation,as the azimuthal density distribution becomes less susceptible to the phase imprinting potential.Our findings offer microscopic insights into the dynamic development of superflow during the phase imprinting process and provide valuable guidance for ongoing experimental efforts.展开更多
Genomic imprinting is the epigenetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner, and was first discovered in mammalian embryos. Recent studies have shown that it also occurs ...Genomic imprinting is the epigenetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner, and was first discovered in mammalian embryos. Recent studies have shown that it also occurs in developing plant seeds, and is now becoming a hot topic of biology of plant seed development. According to the previous studies on imprinted genes, imprinting mechanism and their roles in plant seed development, the current progress of genomic imprinting in plant seed development was summarized and possible strategies were proposed to deal with the problems, which could provide helpful information for further research.展开更多
Quantitative determination of tetracycline(TC)in environment and foods is of great importance,as excessive residues might have negative effects on human health and environmental risks.Herein,a selfpowered molecularly ...Quantitative determination of tetracycline(TC)in environment and foods is of great importance,as excessive residues might have negative effects on human health and environmental risks.Herein,a selfpowered molecularly imprinted photoelectrochemical(PEC)sensor based on the Zn O/C photoanode and the Fe-doped CuBi_(2)O_(4)(CBFO)photocathode is developed for the sensitive detection of TC.The photocathodic current can be amplified by the efficient electron transfer caused by the Fermi energy level gap between the photoanode and photocathode.Furthermore,molecularly imprinted polymers(MIPs)at photocathode can selectivity identify the TC templates and thus improve the specificity.Under the optimal conditions,the sensor has a linear range of 10^(-2)-1.0×10^(5) nmol/L,and a limit of detection(LOD)of 0.007 nmol/L(S/N=3).More crucially,the milk sample detection is carried out using the as-prepared sensor,and the outcome is satisfactory.The research gives us a novel sensing platform for quick and accurate antibiotic(like TC)in environment and food monitoring.展开更多
Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW...Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW)piglets,intrauterine growth restricted(IUGR)piglets have a different intestinal microbiota during their early life,which is related to maternal imprinting on intestinal microbial succession during gestation,at birth and via suckling.Imbalanced allocation of limited nutrients among fetuses during gestation could be one of the main causes for impaired intestinal development and microbiota colonization in neonatal IUGR piglets.In this review,we summarized the potential impact of maternal imprinting on the colonization of the intestinal microbiota in IUGR piglets,including maternal undernutrition,imbalanced allocation of nutrients among fetuses,as well as vertical microbial transmission from mother to offspring during gestation and lactation.At the same time,we give information about the current maternal nutritional strategies(mainly breastfeeding,probiotics and prebiotics)to help colonization of the advantageous intestinal microbiota for IUGR piglets.展开更多
A novel Ni（Ⅱ） ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPS） as a func...A novel Ni（Ⅱ） ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPS） as a functional monomer for the selective separation of Ni（Ⅱ） from aqueous solution. The sorbent showed good chemical and thermal stability. Kinetics studies indicated that the equilibrium adsorption was achieved within 10 min and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The maximum adsorption capacity of the ion-imprinted polymer towards Ni（Ⅱ） at the optimal p H of 7.0 was 66.22 mg·g^（-1）. The relative selectivity coefficients of the sorbent were 9.23, 15.71, 14.72 and 20.15 for Ni（Ⅱ）/Co（Ⅱ）, Ni（Ⅱ）/Cu（Ⅱ）, Ni（Ⅱ）/Zn（Ⅱ） and Ni（Ⅱ）/Pb（Ⅱ）, respectively. The adsorption isotherm fitted well with Langmuir isotherm model. The thermodynamic results indicated that the adsorption of Ni（Ⅱ） was a spontaneous and endothermic process. The sorbent showed good reusability evidenced by six cycles of adsorption/desorption experiments. The precision of this method is satisfactory. Thus, the prepared sorbent can be considered as a promising sorbent for selective separation of Ni（Ⅱ） in real water samples.展开更多
DEAR EDITOR,Genomic imprinting often results in parent-of-origin specific differential expression of maternally and paternally inherited alleles and plays an essential role in mammalian development and growth.Mammalia...DEAR EDITOR,Genomic imprinting often results in parent-of-origin specific differential expression of maternally and paternally inherited alleles and plays an essential role in mammalian development and growth.Mammalian genomic imprinting has primarily been studied in mice and humans,with only limited information available for pigs.To systematically characterize this phenomenon and evaluate imprinting status between different species,we investigated imprinted genes on a genome-wide scale in pig brain tissues.展开更多
ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm.Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination(...ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm.Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination(DAP), and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.展开更多
Computational strategies have been employed to investigate the influence of the nature of monomers and cross-linker in order to design three dimensional imprinted polymers with selective recognition sites for L-phenyl...Computational strategies have been employed to investigate the influence of the nature of monomers and cross-linker in order to design three dimensional imprinted polymers with selective recognition sites for L-phenylalanine benzyl ester(L-PABE)molecule.Here,computational chemistry methods were applied to screen the molar quantity of functional monomers that interact with one mole of the template molecule.Effects of the nature of functional monomer,cross-linker,and molar ratio were determined computationally using density functional calculations with B3LYP functional and generic 6-31G basis set.Methacrylic acid(MAA)and ethylene glycol dimethacrylate(EGDMA)were used as the functional monomer and crosslinking agent,respectively.L-PABE imprinted polymer layered on multiwalled carbon nanotube(MWCNT)and conventional bulk MIP were synthesised and characterized as well.To investigate the influence of pre-organization of binding sites on the selectivity of L-PABE,respective non-imprinted polymers were also synthesised.MWCNT-MIPs and MIPs exhibited the highest adsorption capacity towards L-PABE.The synthesized polymers revealed characteristic adsorption features and selectivity towards L-PABE in comparison with those of its enantiomer analogues.展开更多
L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with th...L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine. The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule, while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.展开更多
In this work,the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique.A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropylt...In this work,the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique.A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropyltriethoxysilane as functional monomer and tetraethyl orthosilicate as crosslinker.The SEM images indicated that the MIPs shell was successfully grafted onto the silica surface.The characteristics of the molecularly imprinted polymers such as capacity,selectivity and absorption dynamic were investigated by rebinding experiments.The results showed that the prepared MIPs had good imprinting effect and adsorption amount of quercetin.展开更多
G-enomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and mammal genomes and plays an essential role in mammalian development and growth. There are a number of genes ...G-enomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and mammal genomes and plays an essential role in mammalian development and growth. There are a number of genes in our genomes that are subject to genomic imprinting where one parent＇s copy of the gene is expressed while the other is silent. Silencing of one allele predetermines that any function ascribed to that gene are now dependant on the single active copy. Possession of only a single active allele can lead to deleterious health consequences in humans. If imprinted genes are crucial in mammalian development, one would also expect mutations in these genes to cause diseases. Since imprinting is an epigenetic mechanism, mistakes in maintaining epigenetic mark also cause imprinting disorders. Here we in this review focus on the current understanding of this unique genetic mechanism more than two decades after the first description of the imprinting phenomenon was given by McGrath and Solter. Although the possible molecular mechanisms by which imprinting is imposed and maintained are being identified, we have a long way to go in understanding the molecular mechanisms that regulate the expression of these oddly behaving genes, the function of imprinting and the evolution. Post genomic technologies might ultimately lead to a better understanding of the ＇imprinting effects＇.展开更多
Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual impr...Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual imprinting itself evolves. Theoretical work on polygynous mating systems predicts that females will evolve paternal imprinting, which means they learn to prefer phenotypes expressed by their fathers. In nature however, females of some species learn to prefer phenotypes expressed by their mothers instead. We used a dynamical systems model and tools from adaptive dynamics to study how sexual imprinting evolves in species with socially monogamous mating systems. We considered cases in which the target trait for imprinting is un- der viability selection but is not a reliable signal of paternal investment. Thus, the target trait signals the genetic benefits rather than the parental care benefits of mate choice. When mating is socially monogamous and there is some extra-pair patemity, we show that maternal imprinting can be favored over paternal imprinting. Counterintuitively, females often become choosier when selecting social partners in systems where extra-pair mating is more frequent. That is, females may be more selective when choosing social partners that will sire a smaller percentage of their offspring. Our results offer new testable hypotheses, and ad- vance our understanding of the mechanisms that drive the evolution of mate choice strategies in nature .展开更多
In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degra...In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degradation of a model pharmaceutical pollutant norfloxacin(NOR) by using MIPs were investigated.Various characterization methods were used to study the properties of MIPs,and it is suggested that the hydroxyl groups are the main adsorption sites for NOR.MIPs present better selective adsorption for NOR than its reference antibiotic sulfadiazine.The NOR adsorption data can be well fitted by Langmuir isotherm model and pseudosecond-order kinetic model.The optimum pH range for NOR adsorption is 7-10.In addition,the MIP-catalyzed Fenton-like system(MIPs/H_2O_2) exhibits remarkably faster removal rate for NOR than the case of γ-Fe_2O_3/H_2O_2.The result indicates that MIPs will be a good functional material in decontamination of pharmaceutical wastewaters since MIPs can be magnetically recycled after the treatment.展开更多
IntroductionOver the past few decades, molecular imprinting has been described as a technology for preparing ＂molecular doors＂ which can be matched to ＂template keys＂. It has been found to be a simple and effectiv...IntroductionOver the past few decades, molecular imprinting has been described as a technology for preparing ＂molecular doors＂ which can be matched to ＂template keys＂. It has been found to be a simple and effective approach to introduce specific recognition sites into synthetic polymers, namely, to create molecular imprinting polymers Remarkable features such as stability, ease of preparation and low cost, have made molecular imprinting polymers particularly attractive in chemical sensors, catalysis, drug delivery, and dedicated separations. Practical applications of molecular imprinting polymers require accessible sites, fast mass transfer, and quick binding. However, present techniques used to prepare molecular imprinting polymers most often result in materials exhibiting a high affinity and selectivity but a low capacity and poor site accessibility for the target molecules. It is also very difficult to remove the imprinted molecules located in these molecular imprinting polymers because the highly cross-linked structures do not allow the templates to move freely. To some extent, combining molecular imprinting technology with membrane separation and surface imprinting can overcome the shortcomings, such as mass transfer limitations and non-quantitative recovery of the template molecules seen for imprinted materials fabricated by conventional bulk methods. In that ease, it appears to us that molecular imprinting polymers with high surface area to volume ratios are particularly desirable for largescale applications. Eleetrospun nano and ultrafine fibrous membranes are the most suitable materials due to advantages such as： （1） large specific surfaces, providing relatively high imprinting sites per unit mass; （2） fine porous structures, resulting in the accessibility of imprinting sites and low diffusion resistance necessary for high efficiency; and （3） easy recoverability from practical operation or applicability for continuous usages. Therefore, in this work, we prepared a unique kind of imprinted material--molecularly imprinted fibrous membranes of poly （ acrylonitrile-co-acrylic acid） fabricated by means of an electrospinning process.展开更多
In this letter,N-acryloyl-3-aminophenylboronic acid（AAPBA） was synthesized and then examined as a new functional monomer for protein imprinting.It was allowed to be copolymerized with acrylamide to produce hemoglobi...In this letter,N-acryloyl-3-aminophenylboronic acid（AAPBA） was synthesized and then examined as a new functional monomer for protein imprinting.It was allowed to be copolymerized with acrylamide to produce hemoglobin- or lysozyme-imprinted hydrogels.In template rebinding tests,the imprinted gels showed significant increase in the specific binding with the increase of the AAPBA amounts in the prepolymerization recipes.These results indicate that AAPBA may be a useful functional monomer for its moderate interactions with protein molecules.展开更多
Firstly,we synthesized N-methacryloyl-histidine monomer and N-methacryloyl-histidine-Cu^2＋ complex（MAH-Cu^2＋）.Then the molecular imprinting polymers（MIP） has been prepared by surface grafting on uniform polystyr...Firstly,we synthesized N-methacryloyl-histidine monomer and N-methacryloyl-histidine-Cu^2＋ complex（MAH-Cu^2＋）.Then the molecular imprinting polymers（MIP） has been prepared by surface grafting on uniform polystyrene（PS） core using reversible addition-fragmentation transfer polymerization（RAFT） with MAH-Cu^2＋ as the functional monomer,methyl paraoxon as the template to simulate phosphodiesterase（PTE）.Finally,we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers（NIP） to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV spectrophotometry.The results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67×10^-5 mmol L^-1 min^-1,3.89-fold higher than MIP to the template analogue ethyl paraoxon,2.79-fold higher than NIP to the template methyl paraoxon.The KM,rm of MSP are also determined,and KM = 3.95×10^-4）mol/L,rm = 2.12μmol/ min.The MIP can be reused with only lose 7%of catalytic activity for four cycles.展开更多
Acrylamide was used as functional monomer to make high chiral selective molecule imprinting polymers against N-alpha-protected amino acid in polar solvent. The factor, which influence the efficiency of the polymer and...Acrylamide was used as functional monomer to make high chiral selective molecule imprinting polymers against N-alpha-protected amino acid in polar solvent. The factor, which influence the efficiency of the polymer and the mechanism of chiral recognition were investigated.展开更多
A new type of molecular imprinting stationary phase was prepared by using R- (+)-α -methylbenzy lamine as the print molecule. Experiments of high performance liquid chromatography show that the new stationary phase h...A new type of molecular imprinting stationary phase was prepared by using R- (+)-α -methylbenzy lamine as the print molecule. Experiments of high performance liquid chromatography show that the new stationary phase has high enantio-selectivity and discriminates (R, S) -(± )- α -methylbenzylamine successful ly with α value of 1. 67展开更多
To explore whether the imprinting status of IGF 2 in the malignant epithelial ovarian tumors is different from that in benign tumors, the target sequences (DNA and RNA) which contain a polymorphism site for ApaI res...To explore whether the imprinting status of IGF 2 in the malignant epithelial ovarian tumors is different from that in benign tumors, the target sequences (DNA and RNA) which contain a polymorphism site for ApaI restriction endonuclease digestion were amplified with PCR and RT PCR methods. Then the PCR/RT PCR products were digested by ApaI. The IGF 2 transcriptional pattern came out from the results of endonucleases digestion. Among the 36 cases of benign epithelial ovarian tumors, 20 were heterozygous for ApaI locus and all showed genomic imprinting. While in the malignant group, 22 were heterozygous for ApaI locus but six were found to lose imprinting. Significant differences existed between the two groups ( P <0.05). Loss of imprinting of IGF 2 may serve as a marker for differentiating the malignant ovarian cancers from the benign ones. In a new field of molecular genetics, our research provides an experimental basis for genetic diagnosis and treatment of the ovarian cancers.展开更多
As a novel technique, molecular imprinting technique are attracting more and more attention in recent years, due to its specific recognition function to im- printed molecules. This paper firstly introduced this techni...As a novel technique, molecular imprinting technique are attracting more and more attention in recent years, due to its specific recognition function to im- printed molecules. This paper firstly introduced this technique from its history, princi- ple, classification and methods, and then reviewed the application in food industry, and presented possible future research orientations.展开更多
基金supported by the National Natural Science Foundation of China(Grants Nos.12104406 and 12204105)the Natural Science Foundation Zhejiang Province,China(Grant No.ZCLMS25A0401)+1 种基金the Startup Grant of Zhejiang SciTech University(Grant No.21062338-Y)the Natural Science Foundation of Fujian Province,China(Grant No.2022J05116)。
文摘Phase imprinting enables the dynamic generation of superflow in bosonic atoms,effectively overcoming traditional limitations such as vortex number constraints and heating effects.However,the mechanisms underlying superflow formation remain insufficiently understood.In this work,we reveal these mechanisms by studying the time evolution of the transferred total angular momentum and the quantized current throughout the phase imprinting process,achieved through numerically solving the time-dependent Schrodinger and Gross-Pitaevskii equations.We demonstrate that the Bose gas dynamically acquires angular momentum through the density depletion induced by the phase imprinting potential,whereas quantized currents emerge from azimuthal phase slips accompanied by complete density depletions.Regarding the impact of system parameters,such as interactions,we find that interactions hinder superflow formation,as the azimuthal density distribution becomes less susceptible to the phase imprinting potential.Our findings offer microscopic insights into the dynamic development of superflow during the phase imprinting process and provide valuable guidance for ongoing experimental efforts.
基金Supported by National Natural Science Foundation of China(31660402)Industry Technological System Construction Project of Department of Agriculture of Yunnan ProvinceFund for Workstation of Academician Guan Chunyun from Department of Science and Technology of Yunnan Province~~
文摘Genomic imprinting is the epigenetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner, and was first discovered in mammalian embryos. Recent studies have shown that it also occurs in developing plant seeds, and is now becoming a hot topic of biology of plant seed development. According to the previous studies on imprinted genes, imprinting mechanism and their roles in plant seed development, the current progress of genomic imprinting in plant seed development was summarized and possible strategies were proposed to deal with the problems, which could provide helpful information for further research.
基金supported by the Fuxiaquan Collaborative Innovation Platform(No.K30001)Major Scientific Research Program for Young and Middle-aged Health Professionals of Fujian Province,China(No.2022ZQNZD007)Youth Innovation Technology Project of Higher School in Shandong Province(Food Nanotechnology Innovation Team)。
文摘Quantitative determination of tetracycline(TC)in environment and foods is of great importance,as excessive residues might have negative effects on human health and environmental risks.Herein,a selfpowered molecularly imprinted photoelectrochemical(PEC)sensor based on the Zn O/C photoanode and the Fe-doped CuBi_(2)O_(4)(CBFO)photocathode is developed for the sensitive detection of TC.The photocathodic current can be amplified by the efficient electron transfer caused by the Fermi energy level gap between the photoanode and photocathode.Furthermore,molecularly imprinted polymers(MIPs)at photocathode can selectivity identify the TC templates and thus improve the specificity.Under the optimal conditions,the sensor has a linear range of 10^(-2)-1.0×10^(5) nmol/L,and a limit of detection(LOD)of 0.007 nmol/L(S/N=3).More crucially,the milk sample detection is carried out using the as-prepared sensor,and the outcome is satisfactory.The research gives us a novel sensing platform for quick and accurate antibiotic(like TC)in environment and food monitoring.
基金supported by the Beijing Municipal Natural Science Foundation(S170001)the National Natural Science Foundation of China(31630074,31272449 and 31902170)+2 种基金the National Key Research and Development Program of China(2016YFD0500506 and 2018YDF0501002)the 111 Project(B16044)the Jinxinnong Animal Science Developmental Foundation.
文摘Early colonization of intestinal microbiota during the neonatal stage plays an important role on the development of intestinal immune system and nutrients absorption of the host.Compared to the normal birth weight(NBW)piglets,intrauterine growth restricted(IUGR)piglets have a different intestinal microbiota during their early life,which is related to maternal imprinting on intestinal microbial succession during gestation,at birth and via suckling.Imbalanced allocation of limited nutrients among fetuses during gestation could be one of the main causes for impaired intestinal development and microbiota colonization in neonatal IUGR piglets.In this review,we summarized the potential impact of maternal imprinting on the colonization of the intestinal microbiota in IUGR piglets,including maternal undernutrition,imbalanced allocation of nutrients among fetuses,as well as vertical microbial transmission from mother to offspring during gestation and lactation.At the same time,we give information about the current maternal nutritional strategies(mainly breastfeeding,probiotics and prebiotics)to help colonization of the advantageous intestinal microbiota for IUGR piglets.
文摘A novel Ni（Ⅱ） ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPS） as a functional monomer for the selective separation of Ni（Ⅱ） from aqueous solution. The sorbent showed good chemical and thermal stability. Kinetics studies indicated that the equilibrium adsorption was achieved within 10 min and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The maximum adsorption capacity of the ion-imprinted polymer towards Ni（Ⅱ） at the optimal p H of 7.0 was 66.22 mg·g^（-1）. The relative selectivity coefficients of the sorbent were 9.23, 15.71, 14.72 and 20.15 for Ni（Ⅱ）/Co（Ⅱ）, Ni（Ⅱ）/Cu（Ⅱ）, Ni（Ⅱ）/Zn（Ⅱ） and Ni（Ⅱ）/Pb（Ⅱ）, respectively. The adsorption isotherm fitted well with Langmuir isotherm model. The thermodynamic results indicated that the adsorption of Ni（Ⅱ） was a spontaneous and endothermic process. The sorbent showed good reusability evidenced by six cycles of adsorption/desorption experiments. The precision of this method is satisfactory. Thus, the prepared sorbent can be considered as a promising sorbent for selective separation of Ni（Ⅱ） in real water samples.
基金supported by the Ministry of Agriculture of China(2016ZX08009003-006)National Key R&D Program of China(2019YFA0110700)+1 种基金Science&Technology Department of Yunnan Province(2019HA003)Animal Branch of the Germplasm Bank of Wild Species,Chinese Academy of Sciences(Large Research Infrastructure Funding)。
文摘DEAR EDITOR,Genomic imprinting often results in parent-of-origin specific differential expression of maternally and paternally inherited alleles and plays an essential role in mammalian development and growth.Mammalian genomic imprinting has primarily been studied in mice and humans,with only limited information available for pigs.To systematically characterize this phenomenon and evaluate imprinting status between different species,we investigated imprinted genes on a genome-wide scale in pig brain tissues.
基金supported by the Fundamental Research Funds for the Central Universities (XDJK2013C023)the Chongqing Postdoctoral Science Foundation (Xm201344)+2 种基金the China Postdoctoral Science Foundation (2014M552303)the Research Fund for the Doctoral Program of Southwest University (SWU112037)the Research Fund for the Doctoral Program of Higher Education (2011182120011)
文摘ZAG2 has been identified as a maternally expressed imprinted gene in maize endosperm.Our study revealed that paternally inherited ZAG2 alleles were imprinted in maize endosperm and embryo at 14 days after pollination(DAP), and consistently imprinted in endosperm at 10, 12, 16, 18, 20, 22, 24, 26, and 28 DAP in reciprocal crosses between B73 and Mo17. ZAG2 alleles were also imprinted in reciprocal crosses between Zheng 58 and Chang7-2 and between Huang C and 178. ZAG2 alleles exhibited differential imprinting in hybrids of 178 × Huang C and B73 × Mo17, while in other hybrids ZAG2 alleles exhibited binary imprinting. The tissue-specific expression pattern of ZAG2 showed that ZAG2 was expressed at a high level in immature ears, suggesting that ZAG2 plays important roles in not only kernel but ear development.
文摘Computational strategies have been employed to investigate the influence of the nature of monomers and cross-linker in order to design three dimensional imprinted polymers with selective recognition sites for L-phenylalanine benzyl ester(L-PABE)molecule.Here,computational chemistry methods were applied to screen the molar quantity of functional monomers that interact with one mole of the template molecule.Effects of the nature of functional monomer,cross-linker,and molar ratio were determined computationally using density functional calculations with B3LYP functional and generic 6-31G basis set.Methacrylic acid(MAA)and ethylene glycol dimethacrylate(EGDMA)were used as the functional monomer and crosslinking agent,respectively.L-PABE imprinted polymer layered on multiwalled carbon nanotube(MWCNT)and conventional bulk MIP were synthesised and characterized as well.To investigate the influence of pre-organization of binding sites on the selectivity of L-PABE,respective non-imprinted polymers were also synthesised.MWCNT-MIPs and MIPs exhibited the highest adsorption capacity towards L-PABE.The synthesized polymers revealed characteristic adsorption features and selectivity towards L-PABE in comparison with those of its enantiomer analogues.
基金Research supported by The Analysis & Test Fund of Zhejiang Province.
文摘L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine. The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule, while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.
基金the National Science Foundation of China(Nos21175143 and 20905073)for the financial support of this work
文摘In this work,the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique.A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropyltriethoxysilane as functional monomer and tetraethyl orthosilicate as crosslinker.The SEM images indicated that the MIPs shell was successfully grafted onto the silica surface.The characteristics of the molecularly imprinted polymers such as capacity,selectivity and absorption dynamic were investigated by rebinding experiments.The results showed that the prepared MIPs had good imprinting effect and adsorption amount of quercetin.
文摘G-enomic imprinting is an epigenetic mechanism that produces functional differences between the paternal and mammal genomes and plays an essential role in mammalian development and growth. There are a number of genes in our genomes that are subject to genomic imprinting where one parent＇s copy of the gene is expressed while the other is silent. Silencing of one allele predetermines that any function ascribed to that gene are now dependant on the single active copy. Possession of only a single active allele can lead to deleterious health consequences in humans. If imprinted genes are crucial in mammalian development, one would also expect mutations in these genes to cause diseases. Since imprinting is an epigenetic mechanism, mistakes in maintaining epigenetic mark also cause imprinting disorders. Here we in this review focus on the current understanding of this unique genetic mechanism more than two decades after the first description of the imprinting phenomenon was given by McGrath and Solter. Although the possible molecular mechanisms by which imprinting is imposed and maintained are being identified, we have a long way to go in understanding the molecular mechanisms that regulate the expression of these oddly behaving genes, the function of imprinting and the evolution. Post genomic technologies might ultimately lead to a better understanding of the ＇imprinting effects＇.
文摘Sexual imprinting is a common mechanism of mate preference learning. It is thought to influence how traits evolve and in some cases to promote speciation. Recently there has been increasing interest in how sexual imprinting itself evolves. Theoretical work on polygynous mating systems predicts that females will evolve paternal imprinting, which means they learn to prefer phenotypes expressed by their fathers. In nature however, females of some species learn to prefer phenotypes expressed by their mothers instead. We used a dynamical systems model and tools from adaptive dynamics to study how sexual imprinting evolves in species with socially monogamous mating systems. We considered cases in which the target trait for imprinting is un- der viability selection but is not a reliable signal of paternal investment. Thus, the target trait signals the genetic benefits rather than the parental care benefits of mate choice. When mating is socially monogamous and there is some extra-pair patemity, we show that maternal imprinting can be favored over paternal imprinting. Counterintuitively, females often become choosier when selecting social partners in systems where extra-pair mating is more frequent. That is, females may be more selective when choosing social partners that will sire a smaller percentage of their offspring. Our results offer new testable hypotheses, and ad- vance our understanding of the mechanisms that drive the evolution of mate choice strategies in nature .
基金Supported by the National Natural Science Foundation of China(21407052)Key Project in the National Science&Technology Pillar Program during the Twelfth Five-year Plan Period(2012BAC02B04)+2 种基金Research Fund for the Doctoral Program of Higher Education of China(201201420087)SRF from ROCS and SEMthe Fundamental Research Funds for the Central Universities(2014QN144)
文摘In this study,a novel magnetically separable adsorbent,molecular imprinting magnetic γ-Fe_2O_3/crosslinked chitosan composites(MIPs),were prepared by a microemulsion process.Adsorption and Fenton-like oxidative degradation of a model pharmaceutical pollutant norfloxacin(NOR) by using MIPs were investigated.Various characterization methods were used to study the properties of MIPs,and it is suggested that the hydroxyl groups are the main adsorption sites for NOR.MIPs present better selective adsorption for NOR than its reference antibiotic sulfadiazine.The NOR adsorption data can be well fitted by Langmuir isotherm model and pseudosecond-order kinetic model.The optimum pH range for NOR adsorption is 7-10.In addition,the MIP-catalyzed Fenton-like system(MIPs/H_2O_2) exhibits remarkably faster removal rate for NOR than the case of γ-Fe_2O_3/H_2O_2.The result indicates that MIPs will be a good functional material in decontamination of pharmaceutical wastewaters since MIPs can be magnetically recycled after the treatment.
文摘IntroductionOver the past few decades, molecular imprinting has been described as a technology for preparing ＂molecular doors＂ which can be matched to ＂template keys＂. It has been found to be a simple and effective approach to introduce specific recognition sites into synthetic polymers, namely, to create molecular imprinting polymers Remarkable features such as stability, ease of preparation and low cost, have made molecular imprinting polymers particularly attractive in chemical sensors, catalysis, drug delivery, and dedicated separations. Practical applications of molecular imprinting polymers require accessible sites, fast mass transfer, and quick binding. However, present techniques used to prepare molecular imprinting polymers most often result in materials exhibiting a high affinity and selectivity but a low capacity and poor site accessibility for the target molecules. It is also very difficult to remove the imprinted molecules located in these molecular imprinting polymers because the highly cross-linked structures do not allow the templates to move freely. To some extent, combining molecular imprinting technology with membrane separation and surface imprinting can overcome the shortcomings, such as mass transfer limitations and non-quantitative recovery of the template molecules seen for imprinted materials fabricated by conventional bulk methods. In that ease, it appears to us that molecular imprinting polymers with high surface area to volume ratios are particularly desirable for largescale applications. Eleetrospun nano and ultrafine fibrous membranes are the most suitable materials due to advantages such as： （1） large specific surfaces, providing relatively high imprinting sites per unit mass; （2） fine porous structures, resulting in the accessibility of imprinting sites and low diffusion resistance necessary for high efficiency; and （3） easy recoverability from practical operation or applicability for continuous usages. Therefore, in this work, we prepared a unique kind of imprinted material--molecularly imprinted fibrous membranes of poly （ acrylonitrile-co-acrylic acid） fabricated by means of an electrospinning process.
基金supported by the National Natural Science Foundation of China(No.20574038)the Natural Science Foundation of Tianjin(No.09JCYBJC02900).
文摘In this letter,N-acryloyl-3-aminophenylboronic acid（AAPBA） was synthesized and then examined as a new functional monomer for protein imprinting.It was allowed to be copolymerized with acrylamide to produce hemoglobin- or lysozyme-imprinted hydrogels.In template rebinding tests,the imprinted gels showed significant increase in the specific binding with the increase of the AAPBA amounts in the prepolymerization recipes.These results indicate that AAPBA may be a useful functional monomer for its moderate interactions with protein molecules.
基金the support of the National Natural Science Foundation of China(No.50978138)
文摘Firstly,we synthesized N-methacryloyl-histidine monomer and N-methacryloyl-histidine-Cu^2＋ complex（MAH-Cu^2＋）.Then the molecular imprinting polymers（MIP） has been prepared by surface grafting on uniform polystyrene（PS） core using reversible addition-fragmentation transfer polymerization（RAFT） with MAH-Cu^2＋ as the functional monomer,methyl paraoxon as the template to simulate phosphodiesterase（PTE）.Finally,we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers（NIP） to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV spectrophotometry.The results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67×10^-5 mmol L^-1 min^-1,3.89-fold higher than MIP to the template analogue ethyl paraoxon,2.79-fold higher than NIP to the template methyl paraoxon.The KM,rm of MSP are also determined,and KM = 3.95×10^-4）mol/L,rm = 2.12μmol/ min.The MIP can be reused with only lose 7%of catalytic activity for four cycles.
文摘Acrylamide was used as functional monomer to make high chiral selective molecule imprinting polymers against N-alpha-protected amino acid in polar solvent. The factor, which influence the efficiency of the polymer and the mechanism of chiral recognition were investigated.
文摘A new type of molecular imprinting stationary phase was prepared by using R- (+)-α -methylbenzy lamine as the print molecule. Experiments of high performance liquid chromatography show that the new stationary phase has high enantio-selectivity and discriminates (R, S) -(± )- α -methylbenzylamine successful ly with α value of 1. 67
文摘To explore whether the imprinting status of IGF 2 in the malignant epithelial ovarian tumors is different from that in benign tumors, the target sequences (DNA and RNA) which contain a polymorphism site for ApaI restriction endonuclease digestion were amplified with PCR and RT PCR methods. Then the PCR/RT PCR products were digested by ApaI. The IGF 2 transcriptional pattern came out from the results of endonucleases digestion. Among the 36 cases of benign epithelial ovarian tumors, 20 were heterozygous for ApaI locus and all showed genomic imprinting. While in the malignant group, 22 were heterozygous for ApaI locus but six were found to lose imprinting. Significant differences existed between the two groups ( P <0.05). Loss of imprinting of IGF 2 may serve as a marker for differentiating the malignant ovarian cancers from the benign ones. In a new field of molecular genetics, our research provides an experimental basis for genetic diagnosis and treatment of the ovarian cancers.
文摘As a novel technique, molecular imprinting technique are attracting more and more attention in recent years, due to its specific recognition function to im- printed molecules. This paper firstly introduced this technique from its history, princi- ple, classification and methods, and then reviewed the application in food industry, and presented possible future research orientations.
