MicroRNAs (miRNAs) are a class of ～22 nt long endogenous non-coding RNAs that play important regulatory roles in diverse organisms. Up to now, little is known about the evolutionary properties of these crucial regula...MicroRNAs (miRNAs) are a class of ～22 nt long endogenous non-coding RNAs that play important regulatory roles in diverse organisms. Up to now, little is known about the evolutionary properties of these crucial regulators. Most miRNAs were thought to be phylogenetically conserved, but recently, a number of poorly-conserved miRNAs have been reported and miRNA innovation is shown to be an ongoing process. In this work, through the characterization of an miRNA super family, we studied the evolutionary patterns of miRNAs in vertebrates. Recently generated miRNAs seem to evolve rapidly during a certain period following their emergence. Multiple lineage-specific expansions were observed. Homolgous premiRNAs may produce mature products from the opposite stem arms following tandem duplications, which may have important contribution to miRNA innovation. Our observations of miRNAs' complicated evolutionary patterns support the notion that these key regulatory molecules may play very active roles in evolution.展开更多
The conformational interconversions of polymer chains have been of great interest as a basic scientific issue.Single-molecule force spectroscopy(SMFS)is a powerful tool for molecular manipulation,which enables experim...The conformational interconversions of polymer chains have been of great interest as a basic scientific issue.Single-molecule force spectroscopy(SMFS)is a powerful tool for molecular manipulation,which enables experimental studies on the single-chain behaviors of polymers.The SMFS results show that an individual polymer chain in a liquid environment may have similar properties to an ideal chain,which contradicts the traditional theoretical view.Herein,by taking into account the collisions of solvent molecules,the conformational interconversions of a single polymer chain in a liquid environment have been analyzed.The conformational interconversion frequency of a carbon-carbon bond of an alkane chain can be estimated by establishing the relationship between the internal rotation barriers of small molecules(monomers)and the corresponding macromolecules.Since the time scale of conformational interconversions of the polymer backbone is much shorter than that of SMFS experiments,most polymers with C-C backbones behave as ideal chains in liquid environments.展开更多
Quantum coherence,emerging from the"superposition"of quantum states,is widely used in various information processing tasks.Recently,the resource theory of multilevel quantum coherence is attracting substanti...Quantum coherence,emerging from the"superposition"of quantum states,is widely used in various information processing tasks.Recently,the resource theory of multilevel quantum coherence is attracting substantial attention.In this paper,we mainly study the transformations of resource pure states via free operations in the theoretical framework for multilevel coherence.We prove that any two multilevel coherent resource pure states can be interconverted with a nonzero probability via a completely positive and trace non-increasing k-coherence-preserving map.Meanwhile,we present the condition of the interconversions of two multilevel coherent resource pure states under k-coherence-preserving operations.In addition,we obtain that in the resource-theoretic framework of multilevel coherence,no resource state is isolated,that is,given a multilevel coherent pure state|ψ>,there exists another multilevel coherent pure state|Φ>and a k-coherence-preserving operation∧k,such that∧k(|Φ>)=|ψ>.展开更多
The relative conformer energies of glycine are evaluated by using a focal point analysis expressed as（HF→MP2→MP3→CCSD→CCSD（T））.The conformer abundances at various temperatures（298–500 K） are calculated base...The relative conformer energies of glycine are evaluated by using a focal point analysis expressed as（HF→MP2→MP3→CCSD→CCSD（T））.The conformer abundances at various temperatures（298–500 K） are calculated based on the relative energies and Boltzmann statistical thermostatistical analysis with and without considering internal hindered rotations.A comparison between the available Raman spectrum and the electron momentum spectrum confirms that the influence of rigid-rotor hindered rotation on the conformational proportions of glycine is considerable,especially for the IIIp structure.The conformational interconversions are discussed.It is found that with increasing temperature,the mole fraction of IIn keeps constant and Ip structure can convert into IVn and IIIp,leading to the decrease in the weight of Ip and the increase in the weights of IVn and IIIp conformers,which is in accordance with experimental observations.展开更多
Orchestrating conflicting polymerization mechanisms in a single polymerization process through one external stimulus is a prerequisite to achieve in-situ selective synthesis of different monomers. Here we report an el...Orchestrating conflicting polymerization mechanisms in a single polymerization process through one external stimulus is a prerequisite to achieve in-situ selective synthesis of different monomers. Here we report an electrochemically controlled mechanism transformation that enables selective activation of living cationic or radical polymerization via an alternating voltage and dual electrocatalysts. Using identical mixed-monomer condition, a variety of desired block copolymer structures, including diblock, multiblock, random, and tapered copolymers can be obtained by simply varying the periods or phases of the alternating potential. Moreover, merging this electro-interconverted polymerization with a flow-chemistry technique can streamline preparation of functional polymer materials with complex multiblock structure. This study would offer a new vision on large-scale electrochemical synthesis of sequence-defined polymers.展开更多
The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the sub...The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the subsequent fragmentation were studied using quantum chemical methods at the BHandHLYP/6311＋＋G（d,p） level of theory for optimized geometries and frequency calculations and at the QCISD/631G（d,p） level for the single point energy calculations. The rate coefficients were calculated for the temperature range 280-440 K by using the canonical transition state theory （TST）. For ozone addition to MVE, there are two different possibilities discussed on the basis of two different possible orientations for ozone attack. The results of the theoretical study indicate that although the synperiplanar-MVE is 7.11 kJ/mol more stable than the antiperiplanar-MVE, the antiperiplanar-MVE plays a more important role in formation of the primary ozonides because the primary ozonides formed from the ozone addition antiperiplanar-MVE are more stable and the energy barriers corresponding to transition states are lower. The intereonversion between the primary ozonides formed from the ozone addition to antiperiplanar-MVE is the most accessible compared with the transformations between other primary ozonides. The cleavage of the primary ozonides mainly leads to the formation of the CH2OO, which is in agreement with the experimental estimates. The calculated overall rate constant for the ozone-initiated reactions is 4.8× 10^-17 cm^3/（molecule.s） at 298.15 K, which agrees with the experimental value for ethyl vinyl ether.展开更多
Diabetes mellitus(DM)has emerged as a serious public health concern,due to the high morbidity and mortality resulted from its complications,such as diabetic nephropathy,diabetic cardiovascular complication,and diabeti...Diabetes mellitus(DM)has emerged as a serious public health concern,due to the high morbidity and mortality resulted from its complications,such as diabetic nephropathy,diabetic cardiovascular complication,and diabetic neuropathy,etc.In this study,we investigated the beneficial effects of sepia ink melanin(SIM)on hyperglycaemia and the restoration of diabetic symptoms in streptozotocin(STZ)-induced diabetic model mice.At first,the normal experimental mice were performed with intraperitoneal injection of STZ(40 mg(kg BW)^(−1))(BW,body weight)to attain diabetes and then were treated with different concentrations of SIM(120,240 and 480 mg(kg BW)^(−1))for four weeks.After treatment,significant decrease in gluconeogenesis were determined,accompanied by a notable increase in both glycolysis and oxidative enzyme activities in SIM-treated groups,such as liver marker enzymes in the serum and key antioxidant enzymes in liver.qPCR results revealed the transcriptional alterations in SIM-treated groups.SIM exposure increased the expression levels of several genes related to insulin transduction and PI3K/Akt pathway,including PI3K,Akt,Irs-2,and InsR.Meanwhile,expression levels of Dicarbonyl/l-xylulose reductase(Dcxr)and UDP-glucose dehydrogenase(Ugdh),which are in-volved in pentose-glucuronate interconversion pathway,were also elevated in SIM-treated groups.Furthermore,histological observation results indicated that nuclear deformation and organelle dissolution were improved,thus could enhance the liver function.These results demonstrated that SIM can be effective in ameliorating diabetic symptoms and improving disease management for diabetic patients.展开更多
Lead halide perovskite nanomaterials are among the forefront of developing materials for energy harvesting and light-emitting applications.Their unique defect tolerance,high photoluminescent quantum yields,and vast sy...Lead halide perovskite nanomaterials are among the forefront of developing materials for energy harvesting and light-emitting applications.Their unique defect tolerance,high photoluminescent quantum yields,and vast synthetic tunability make them attractive for many optoelectronic applications.In this review article,the broad synthetic toolbox of these materials is discussed,including how synthetic conditions can tune the optical properties and dimensionality of the resulting perovskite nanomaterial.Additionally,we discuss the brief history,current state,and bright future of these materials,in tune with their optoelectronic applications,namely in light-emitting diodes,lasing,photovoltaics,photon interconversion applications,and in photodetectors.展开更多
基金the National Natural Science Foundation of China (Grant Nos. 30625012, 60572086 and 60775002)National Basic Research Program of China (Grant No. 2004CB518605)
文摘MicroRNAs (miRNAs) are a class of ～22 nt long endogenous non-coding RNAs that play important regulatory roles in diverse organisms. Up to now, little is known about the evolutionary properties of these crucial regulators. Most miRNAs were thought to be phylogenetically conserved, but recently, a number of poorly-conserved miRNAs have been reported and miRNA innovation is shown to be an ongoing process. In this work, through the characterization of an miRNA super family, we studied the evolutionary patterns of miRNAs in vertebrates. Recently generated miRNAs seem to evolve rapidly during a certain period following their emergence. Multiple lineage-specific expansions were observed. Homolgous premiRNAs may produce mature products from the opposite stem arms following tandem duplications, which may have important contribution to miRNA innovation. Our observations of miRNAs' complicated evolutionary patterns support the notion that these key regulatory molecules may play very active roles in evolution.
基金This work was supported by the National Natural Science Foundation of China(No.22273079)the Natural Science Foundation of Sichuan Province,China(No.2022NSFSC1204)the Central Government Guiding Local Science and Technology Development Project of Sichuan Province,China(No.2022ZYD0043).
文摘The conformational interconversions of polymer chains have been of great interest as a basic scientific issue.Single-molecule force spectroscopy(SMFS)is a powerful tool for molecular manipulation,which enables experimental studies on the single-chain behaviors of polymers.The SMFS results show that an individual polymer chain in a liquid environment may have similar properties to an ideal chain,which contradicts the traditional theoretical view.Herein,by taking into account the collisions of solvent molecules,the conformational interconversions of a single polymer chain in a liquid environment have been analyzed.The conformational interconversion frequency of a carbon-carbon bond of an alkane chain can be estimated by establishing the relationship between the internal rotation barriers of small molecules(monomers)and the corresponding macromolecules.Since the time scale of conformational interconversions of the polymer backbone is much shorter than that of SMFS experiments,most polymers with C-C backbones behave as ideal chains in liquid environments.
基金supported by the National Natural Science Foundation of China(Grant No.12071110)the Hebei Natural Science Foundation of China(Grant Nos.A2020205014,and A2018205125)the Science and Technology Project of Hebei Education Department(Grant Nos.ZD2020167,and ZD2021066)。
文摘Quantum coherence,emerging from the"superposition"of quantum states,is widely used in various information processing tasks.Recently,the resource theory of multilevel quantum coherence is attracting substantial attention.In this paper,we mainly study the transformations of resource pure states via free operations in the theoretical framework for multilevel coherence.We prove that any two multilevel coherent resource pure states can be interconverted with a nonzero probability via a completely positive and trace non-increasing k-coherence-preserving map.Meanwhile,we present the condition of the interconversions of two multilevel coherent resource pure states under k-coherence-preserving operations.In addition,we obtain that in the resource-theoretic framework of multilevel coherence,no resource state is isolated,that is,given a multilevel coherent pure state|ψ>,there exists another multilevel coherent pure state|Φ>and a k-coherence-preserving operation∧k,such that∧k(|Φ>)=|ψ>.
基金Project supported by the Young Scientists Funds of the National Natural Science Foundation of China(Grant Nos.11404154 and 11304136)
文摘The relative conformer energies of glycine are evaluated by using a focal point analysis expressed as（HF→MP2→MP3→CCSD→CCSD（T））.The conformer abundances at various temperatures（298–500 K） are calculated based on the relative energies and Boltzmann statistical thermostatistical analysis with and without considering internal hindered rotations.A comparison between the available Raman spectrum and the electron momentum spectrum confirms that the influence of rigid-rotor hindered rotation on the conformational proportions of glycine is considerable,especially for the IIIp structure.The conformational interconversions are discussed.It is found that with increasing temperature,the mole fraction of IIn keeps constant and Ip structure can convert into IVn and IIIp,leading to the decrease in the weight of Ip and the increase in the weights of IVn and IIIp conformers,which is in accordance with experimental observations.
基金supported by the National Natural Science Foundation of China (21674022, 51703034)
文摘Orchestrating conflicting polymerization mechanisms in a single polymerization process through one external stimulus is a prerequisite to achieve in-situ selective synthesis of different monomers. Here we report an electrochemically controlled mechanism transformation that enables selective activation of living cationic or radical polymerization via an alternating voltage and dual electrocatalysts. Using identical mixed-monomer condition, a variety of desired block copolymer structures, including diblock, multiblock, random, and tapered copolymers can be obtained by simply varying the periods or phases of the alternating potential. Moreover, merging this electro-interconverted polymerization with a flow-chemistry technique can streamline preparation of functional polymer materials with complex multiblock structure. This study would offer a new vision on large-scale electrochemical synthesis of sequence-defined polymers.
文摘The interconversion between the two distinct isomers of methyl vinyl ether （MVE）, the formation of the primary ozonides from O3-initated reactions of MVE, the transformation between the primary ozonides, and the subsequent fragmentation were studied using quantum chemical methods at the BHandHLYP/6311＋＋G（d,p） level of theory for optimized geometries and frequency calculations and at the QCISD/631G（d,p） level for the single point energy calculations. The rate coefficients were calculated for the temperature range 280-440 K by using the canonical transition state theory （TST）. For ozone addition to MVE, there are two different possibilities discussed on the basis of two different possible orientations for ozone attack. The results of the theoretical study indicate that although the synperiplanar-MVE is 7.11 kJ/mol more stable than the antiperiplanar-MVE, the antiperiplanar-MVE plays a more important role in formation of the primary ozonides because the primary ozonides formed from the ozone addition antiperiplanar-MVE are more stable and the energy barriers corresponding to transition states are lower. The intereonversion between the primary ozonides formed from the ozone addition to antiperiplanar-MVE is the most accessible compared with the transformations between other primary ozonides. The cleavage of the primary ozonides mainly leads to the formation of the CH2OO, which is in agreement with the experimental estimates. The calculated overall rate constant for the ozone-initiated reactions is 4.8× 10^-17 cm^3/（molecule.s） at 298.15 K, which agrees with the experimental value for ethyl vinyl ether.
基金supported by the Natural Science Foundation of Zhejiang Province(No.LY18C190006)sponsored by K.C.Wong Magna Fund in Ningbo University.
文摘Diabetes mellitus(DM)has emerged as a serious public health concern,due to the high morbidity and mortality resulted from its complications,such as diabetic nephropathy,diabetic cardiovascular complication,and diabetic neuropathy,etc.In this study,we investigated the beneficial effects of sepia ink melanin(SIM)on hyperglycaemia and the restoration of diabetic symptoms in streptozotocin(STZ)-induced diabetic model mice.At first,the normal experimental mice were performed with intraperitoneal injection of STZ(40 mg(kg BW)^(−1))(BW,body weight)to attain diabetes and then were treated with different concentrations of SIM(120,240 and 480 mg(kg BW)^(−1))for four weeks.After treatment,significant decrease in gluconeogenesis were determined,accompanied by a notable increase in both glycolysis and oxidative enzyme activities in SIM-treated groups,such as liver marker enzymes in the serum and key antioxidant enzymes in liver.qPCR results revealed the transcriptional alterations in SIM-treated groups.SIM exposure increased the expression levels of several genes related to insulin transduction and PI3K/Akt pathway,including PI3K,Akt,Irs-2,and InsR.Meanwhile,expression levels of Dicarbonyl/l-xylulose reductase(Dcxr)and UDP-glucose dehydrogenase(Ugdh),which are in-volved in pentose-glucuronate interconversion pathway,were also elevated in SIM-treated groups.Furthermore,histological observation results indicated that nuclear deformation and organelle dissolution were improved,thus could enhance the liver function.These results demonstrated that SIM can be effective in ameliorating diabetic symptoms and improving disease management for diabetic patients.
文摘Lead halide perovskite nanomaterials are among the forefront of developing materials for energy harvesting and light-emitting applications.Their unique defect tolerance,high photoluminescent quantum yields,and vast synthetic tunability make them attractive for many optoelectronic applications.In this review article,the broad synthetic toolbox of these materials is discussed,including how synthetic conditions can tune the optical properties and dimensionality of the resulting perovskite nanomaterial.Additionally,we discuss the brief history,current state,and bright future of these materials,in tune with their optoelectronic applications,namely in light-emitting diodes,lasing,photovoltaics,photon interconversion applications,and in photodetectors.
