The female inflorescence,or ear,of maize develops no branch meristem(BM),which differs from the male inforescence,or tassel.While the mutations of some well documented genes,such as fea2/3/4 and ramosa1/2/3,can cause ...The female inflorescence,or ear,of maize develops no branch meristem(BM),which differs from the male inforescence,or tassel.While the mutations of some well documented genes,such as fea2/3/4 and ramosa1/2/3,can cause the branched architecture of ears in maize,such mutations also change the normal phenotypic performance of the tassels.In the present study,a natural maize mutant with branched ears,named branched ear1(be1),was characterized.be1 shows several branched ears at the base of the central ear with unchanged architecture of the tassels.Besides,both the branched and central ears of be1 possess regularly arranged kerels.The phenotypic characteristics of be1 differ completely from those reported mutants of fasciated ears or RAMOSA-like ears in maize.An SEM survey at the very early development stage showed that meristems with three protrusions,similar to the BM in tassels,were present during the development of the branched ears in be1.Gene mapping and sequence alignment suggested that TEOSINTE BRANCHED1(TB1)was the candidate gene of BE1.Further verification showed that a be1-specific 31 bp deletion at the downstream of BE1 led to statistically reduced expression of this gene in the immature ear,which serves as the potential causal reason for the branched ears of be1.CRISPR/Cas9-based gene editing downstream of TB1 complemented the phenotypic architecture of branched ears,suggesting that TB1 was the target of BE1,and it was named as Zm TB1be1.The results of the present study implied a novel function of TB1 in female inforescence development,rather than shaping the plant architecture in maize.Meanwhile,further functional dissection of ZmTB1be1might shed new light on TB1,the most famous domestication related gene in maize.展开更多
Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving t...Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.展开更多
Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry plat...Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry platform for the continuous microflow synthesis of bottlebrush block copolymers(BBCPs)using a grafting-through method.This involves performing ring-opening metathesis polymerization(ROMP)of two different macromonomers within two microfluidic reactors connected in series.The microflow environment allows for complete monomer conversion within a few tens of seconds,benefiting from the superior mixing efficiency achieved in Z-shaped channels as indicated by both theoretical simulations and experimental results.Consequently,a library of well-defined BBCPs of up to 528 distinct samples can be produced within one day through automation of the continuous procedure,while keeping precise control on degree of polymerization(DP<4)and polydispersity indices(PDI<1.2).The synthetic method is generally applicable to different macromonomers with different compositions and contour lengths,yielding libraries of branched block copolymers with great diversity in physiochemical properties and chain architectures.This work presents a powerful platform for high-throughput production of branched copolymers,significantly lowering the costs of the materials for real applications.展开更多
Along with the surge of unearthed medical literature and cultural relics in recent years,a network of channels in the system of medical conduit vessels(meridians) during the early Western Han dynasty has become much c...Along with the surge of unearthed medical literature and cultural relics in recent years,a network of channels in the system of medical conduit vessels(meridians) during the early Western Han dynasty has become much clearer gradually.In it,the increasing number of channel branches,network vessels and needle insertion holes(acupoints) is an important feature of the development of channel medicine during the Western Han dynasty.This is not only a reflection of the expanding requirements of the theoretical system of the main trunk channels and other vessels,but also an inevitable result of the continuous enrichment and accumulation of clinical experience.This article integrates the information about channel branches,network vessels,inscriptions,dots and further relics on the Tianhui(天回) Lacquered Meridian Figurine to compare the unearthed literature of the channel genre with the transmitted classical literature about acupuncture.The “Heart-Regulated Channel” in Medical Manuscripts on Bamboo Slips from Tianhui(《天回医简》) serves as an example to explain the occurrence,development and changes of the channel branches and network vessels in the early system of medical channels.展开更多
Developing accurate and sensitive DNA methyltransferase(MTase) analysis methods is essential for early clinical diagnosis and development of antimicrobial drug targets. In this work, by coupling WO_(3-x) dotsencapsula...Developing accurate and sensitive DNA methyltransferase(MTase) analysis methods is essential for early clinical diagnosis and development of antimicrobial drug targets. In this work, by coupling WO_(3-x) dotsencapsulated metal-organic frameworks(MOFs) as co-reactants and terminal deoxynucleotidyl transferase(Td T)-mediated template-free branched polymerization, a dual signal-amplified electrochemiluminescent(ECL) biosensor was constructed to detect DNA adenine methylation(Dam) MTase. The employment of WO_(3-x) dots-encapsulated MOFs(i.e., NH_(2)-UIO66@WO_(3-x) ) was not only beneficial for biomolecule conjugation because of the abundant amino groups but also led to a 7-fold enhanced ECL response due to the increased loading of WO_(3-x). Moreover, Td T-mediated template-free branched polymerization promoted the capture of ECL emitters on the electrode surface, achieving 20-fold enhanced signal amplification. The presented ECL biosensor demonstrated a low detection limit of 2.4 × 10^(-4)U/m L, and displayed high reliability for the detection of Dam MTase in both spiked human serum and E. coli cell samples, and for the screening of potential inhibitors. This study opens a new avenue for designing a dual signal amplificationbased ECL bioassay for Dam MTase and screening inhibitors in the fields of clinical diagnosis and drug development.展开更多
Highly branched poly(β-amino ester)s(HPAEs)have emerged as a safe and efficient type of non-viral gene delivery vectors.However,the presence of inactive terminal secondary amine groups compromises their gene transfec...Highly branched poly(β-amino ester)s(HPAEs)have emerged as a safe and efficient type of non-viral gene delivery vectors.However,the presence of inactive terminal secondary amine groups compromises their gene transfection capability.In this study,HPAEs with similar topological structures and chemical compositions but varying numbers of terminal secondary 4-amino-1-butanol(S4)and secondary/tertiary 3-morpholinopropylamine(MPA)groups were synthesized.The results demonstrate that an increased number of secondary/tertiary MPA groups in-situ significantly enhances the DNA binding capability of HPAEs,leading to the formation of smaller HPAE/DNA polyplexes with higher zeta potential,ultimately resulting in superior gene transfection efficiency in bladder epithelial cells.This study establishes a sim-ple yet effective strategy to maximize the gene transfection potency of HPAEs by converting the inactive terminal groups in-situ without the need for complex modifications to their topological structure and chemical composition.展开更多
The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, ...The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.展开更多
Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the feedstock.Thermal pretreatment of biomass could induce d...Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the feedstock.Thermal pretreatment of biomass could induce dehydration and/or aromatization to change the structure of cellulose/hemicellulose.This might interfere with evolution of structures of AC,which was investigated herein via thermal pretreatment of willow branch(WB)from 200 to 360℃and the subsequent activation with ZnCl_(2) at 550℃.The results showed that thermal pretreatment at 360℃(WB-360)could lead to substantial pyrolysis to form biochar,with a yield of 31.9%,accompanying with nearly complete destruction of cellulose crystals and remarkably enhanced aromatic degree.However,cellulose residual in WB-360 could still be activated to form AC-360 with specific surface area of 1837.9 m~2·g^(-1),which was lower than that in AC from activation of untreated WB(AC-blank,2077.8 m~2·g^(-1)).Nonetheless,the AC-200 from activation of WB-200 had more developed pores(2113.9 m~2·g^(-1))and superior capability for adsorption of phenol,due to increased permeability of ZnCl_(2) to the largely intact cellulose structure in WB-200.The thermal pretreatment did increase diameters of micropores of AC but reduced the overall yield of AC(26.8%for AC-blank versus 18.0%for AC-360),resulting from accelerated cracking but reduced intensity of condensation.In-situ infrared characterization of the activation showed that ZnCl_(2) mainly catalyzed dehydration,dehydrogenation,condensation,and aromatization but not cracking,suppressing the formation of derivatives of cellulose and lignin in bio-oil.The thermal pretreatment formed phenolic-OH and C=O with higher chemical innerness,which changed the reaction network in activation,shifting morphology of fibrous structures in AC-blank to“melting surface”in AC-200 or AC-280.展开更多
[Objective] The study was carried out in order to find out the best method of rapid cutting rooting of Syriga microphylla with tender branches.[Method] Effect of rooting reagent with different concentrations on the ra...[Objective] The study was carried out in order to find out the best method of rapid cutting rooting of Syriga microphylla with tender branches.[Method] Effect of rooting reagent with different concentrations on the rapid cutting rooting of Syriga microphylla with tender branches was studied in our paper.[Result] There was great difference between cuttings with auxin and without auxin.[Conclusion] Tender branches treated by 90 mg/L indole butyric acid（IBA）had the best cutting rooting.展开更多
To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratio...To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratios, branched fracture opening time and injection sequence of proppants in varied particle sizes. The results show that the settled proppant height increases and the placement length decreases in main fractures as the fracturing fluid diverts gradually to the branched fractures at different positions. The flow rate in branched fractures is the main factor affecting their filling. The diverion to branched fractures leads to low flow rate and poor filling of far-wellbore branched fractures. The inclined fracture wall exerts a frictional force on the proppant to slow its settlement, thus enhancing the vertical proppant distribution in the fracture. The increase of sand ratio can improve the filling of near-wellbore main fracture and far-wellbore branched fracture and also increase the settled proppant height in main fracture. Due to the limitation of fracture height, when the sand ratio increases to a certain level, the increment of fracture filling decreases. When branched fracture is always open(or extends continuously), the supporting effect on the branched fractures is the best, but the proppant placement length within the main fractures is shorter. The fractures support effect is better when it is first closed and then opened(or extends in late stage) than when it is first opened and then closed(or extends in early stage). Injecting proppants with different particle sizes in a specific sequence can improve the placement lengths of main fracture and branched fracture. Injection of proppants in an ascending order of particle size improves the near-wellbore fracture filling, to a better extent than that in a descending order of particle size.展开更多
Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of ...Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of liver cancer cells in vitro,and are essential for lymphocyte proliferation and dendritic cell maturation.In patients with advanced chronic liver disease,BCAA concentrations are low,whereas the concentrations of aromatic amino acids such as phenylalanine and tyrosine are high,conditions that may be closely associated with hepatic encephalopathy and the prognosis of these patients.Based on these basic observations,patients with advanced chronic liver disease have been treated clinically with BCAA-rich medicines,with positive effects.展开更多
ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distr...ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that： The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different.展开更多
Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the labo...Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.展开更多
The structure-property characteristics of a series of newly synthesized intramolecular charge- transfer （ICT） compounds, single-branch monomer with triphenylmethane as electron donor and 2,1,3-benzothiadiazole as ac...The structure-property characteristics of a series of newly synthesized intramolecular charge- transfer （ICT） compounds, single-branch monomer with triphenylmethane as electron donor and 2,1,3-benzothiadiazole as acceptor, the corresponding two-branch dimer and three- branch trimer, have been investigated by means of steady-state and femtosecond time- resolved stimulated emission fluorescence depletion （FS TR-SEP FD） techniques in different polar solvents. The TD-DFT calculations are further performed to explain the observed ICT properties. The interpretation of the experimental results is based on the comparative studies of the series of compounds which have increased amount of identical branch moiety. The similarity of the absorption and fluorescence spectra as well as strong solvent-dependence of the spectral properties for the three compounds reveal that the excited state of the dimer and trimer are nearly the same with that of the monomer, which may localize on one branch. It is found that polar excited state emerged through multidimensional intramolecular charge transfer from the donating moiety to the acceptor upon excitation, and quickly relaxed to one branch before emission. Even so, the red-shift in the absorption and emission spectra and decreased fluorescence radiative lifetime with respect to their monomer counterpart still suggest some extent delocalization of excited state in the dimer and trimer upon excitation. The similar behavior of their excited ICT state is demonstrated by FS TR-SEP FD measurements, and shows that the trimer has the largest charge-separate extent in all studied three samples. Finally, steady-state excitation anisotropy measurements has further been carried out to estimate the nature of the optical excitation and the mechanism of energy redistribution among the branches, where no plateau through the ICT band suggests the intramolecular excitation transfer process between the branches in dimer and trimer.展开更多
By making use of Thiele-type bivariate branched continued fractions and Sumelson inverse,we construct a few kinds of bivariate vector valued rational interpolonts (BVRIs) over rectangular grids and find out certain re...By making use of Thiele-type bivariate branched continued fractions and Sumelson inverse,we construct a few kinds of bivariate vector valued rational interpolonts (BVRIs) over rectangular grids and find out certain relations among these BVRIs such as boundary identity and duality.展开更多
Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In th...Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In this work,we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes(NBNTs)for LIBs.The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAhg-1 at a current density of 0.1 Ag-1,and was able to maintain a stable reversible discharge capacity of 1109 mAhg-1 at a current density of 0.5 Ag-1 with coulombic efficiency reaching almost 100% for 200 cycles.The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks,the incorporation of nitrogen doping,and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.展开更多
Raising the in situ decomposition rate of natural gas hydrate and increasing the decomposition contact area are two main ways to raise the productivity of hydrate. An exploitation technique based on large borehole wit...Raising the in situ decomposition rate of natural gas hydrate and increasing the decomposition contact area are two main ways to raise the productivity of hydrate. An exploitation technique based on large borehole with multi-lateral branches (LB & MB) was proposed in this paper. This technique is mainly intended for the clayey silt hydrate reservoir in the South China Sea, and its main purpose is to alleviate the sand output from formation for maintaining the stability of the reservoir and to greatly increase the gas productivity of the reservoir. In this paper, the following aspects were mainly expounded: definition of the basic geometric parameters for layout of multi-lateral branches in clayey silt hydrate reservoir, simulation of the stimulation effect of a typical well profile with two branches, and prediction and simulation of the reservoir failure risk in a well profile with eight branches. The results show that the LB & MB effectively improves the flow field in the formation, raises the productivity of the reservoir and may also help to decrease the produced water-gas ratio (WGR). When the lateral branches spacing is too small, the failure zones around adjacent lateral branches overlap each other, possibly causing reservoir failure in a larger range. Therefore, the geometric parameters of multi-lateral branches depend on the dual control of the productivity and geotechnical risk factor of reservoir. Further study is being carried out, so as to obtain the optimal combination of parameters of multi-lateral branches.展开更多
Owing to the dramatically enhanced charge-mass transport and abundant electrochemically active sites,transition metal compound electrodes are increasingly attractive for achieving high-performance supercapacitors(SCs)...Owing to the dramatically enhanced charge-mass transport and abundant electrochemically active sites,transition metal compound electrodes are increasingly attractive for achieving high-performance supercapacitors(SCs).Here,we report the fabrication of nickel foam supported three-dimensional(3 D)branched nickel-cobalt phosphides@tri-metal cobalt-nickel-molybdenum phosphides core/shell nanowire heterostructures(denoted as NiCo-P@CoNiMo-P)as high-performance electrode materials for hybrid supercapacitors.The presence of multiple valences of the cations in such NiCo-P@CoNiMo-P enables rich redox reactions and promoted synergy effects.Benefiting from their collective effects,the resulting electrode demonstrates high specific capacity of 1366 C g^(-1) at 2 A g^(-1)(2.03 C cm^(-2) at2 mA cm^(-2))and 922 C g^(-1) at 10 A g^(-1),as well as good cycling stability(retaining~94%of the initial capacity after 6000 cycles at 15 A g^(-1)).A hybrid SC using the NiCo-P@CoNiMo-P as the positive electrode and N-doped rGOs as the negative electrode exhibits a high energy density of 81.4 Wh kg^(-1) at a power density of 1213 W kg^(-1) and a capacity retention of 132%even after 6000 cycles at 10 A g^(-1).Our findings can facilitate the material design for boosting the performance of transition metal compounds based materials for fast energy storage.展开更多
Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene trans...Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene transfection performance have not yet been explored.Here,using triacrylate(B3)and diamine(B4)as the branching monomers,a series of HPAEs were synthesized via the"A2+B3+C2"and"A2+B4+C2"strategies,respectively.Results show that the branching strategy plays a pivotal role in dictating the physiological properties of the HPAE/DNA polyplexes and thus leads to obviously different cell viability and transfection efficiency.Comparatively,HPAEs synthesized via the"A2+B3+C2"branching strategy are more favorable for DNA transfection than that synthesized via the"A2+B4+C2"strategy.This study may provide new insights into the development of HPAEs based non-viral DNA delivery system.展开更多
A series of hyperbranched polyurethane-benzyltetrazoles （H-PBTZs） with different linkage structures were synthesized via the polycondensation of hexamethylenediisocyanate as an A2 type monomer with （4-（1H-tetrazol...A series of hyperbranched polyurethane-benzyltetrazoles （H-PBTZs） with different linkage structures were synthesized via the polycondensation of hexamethylenediisocyanate as an A2 type monomer with （4-（1H-tetrazol-5- yl）benzyl）-diethanolamine （TBDEA） as a BB＇2 type monomer in the absence of catalyst at different temperatures. The FTIR, and 13C and 1H-NMR spectroscopy were used to characterize the molecular structures of TBDEA and H-PBTZs as well as the counterpart linear polyurethane-benzyltetrazole （L-PBTZ）. The molecular composition was determined by the reaction selectivity that the isocyanate group reacted with the hydroxyl group in diethanolamine segment or the active hydrogen atom on tetrazole ring. Raising reaction temperature was propitious to the reaction of isocyanate group with the active hydrogen atom on tetrazole ring. The degrees of branching （DB） for H-PBTZs obtained from the 1H-NMR spectra increased with raising reaction temperature. The wider molecular weight distribution of 1.7-2.9 for H-PBTZs was obtained via GPC analysis. TGA results showed that H-PBTZs had high thermal stability compared with L-PBTZ.展开更多
基金supported by the Special Key Project for Technological Innovation and Application Development in Chongqing,China(CSTB2022TIAD-KPX0011)the Special Fund for Youth Team of the Southwest Universities,China(SWU-XJPY202306)+1 种基金the Natural Science Foundation of Chongqing,China(cstc2021jcyj-msxmX0583)the Fundamental Research Funds for the Central Universities of Southwest University,China(S202210635326)。
文摘The female inflorescence,or ear,of maize develops no branch meristem(BM),which differs from the male inforescence,or tassel.While the mutations of some well documented genes,such as fea2/3/4 and ramosa1/2/3,can cause the branched architecture of ears in maize,such mutations also change the normal phenotypic performance of the tassels.In the present study,a natural maize mutant with branched ears,named branched ear1(be1),was characterized.be1 shows several branched ears at the base of the central ear with unchanged architecture of the tassels.Besides,both the branched and central ears of be1 possess regularly arranged kerels.The phenotypic characteristics of be1 differ completely from those reported mutants of fasciated ears or RAMOSA-like ears in maize.An SEM survey at the very early development stage showed that meristems with three protrusions,similar to the BM in tassels,were present during the development of the branched ears in be1.Gene mapping and sequence alignment suggested that TEOSINTE BRANCHED1(TB1)was the candidate gene of BE1.Further verification showed that a be1-specific 31 bp deletion at the downstream of BE1 led to statistically reduced expression of this gene in the immature ear,which serves as the potential causal reason for the branched ears of be1.CRISPR/Cas9-based gene editing downstream of TB1 complemented the phenotypic architecture of branched ears,suggesting that TB1 was the target of BE1,and it was named as Zm TB1be1.The results of the present study implied a novel function of TB1 in female inforescence development,rather than shaping the plant architecture in maize.Meanwhile,further functional dissection of ZmTB1be1might shed new light on TB1,the most famous domestication related gene in maize.
基金supported by the National Natural Science Foundation of China(No.U23B6011)the Jilin Provincial Science and Technology Department Program(No.20230101347JC)。
文摘Mechanochromic polyolefins represent a novel class of functionalized polyolefins,which still remains significant challenges.Pd(II)-catalyzed coordination-insertion copolymerization is a feasible method for achieving this kind of polymers,yet with linear microstructures.Ringopening metathesis polymerization(ROMP)offers another promising avenue for affording functionalized polyolefins.This method exhibits high polar group tolerance and the ability to precisely regulate polymer branches.In this study,we report the method for producing mechanochromic branched polyethylenes via ROMP.By employing the terpolymerization of a well-designed monomer containing the mechanochromic group,NB-ABF,with cyclooctene(COE)and long-chain 5-hexylcyclooctene(COE-C6),following by hydrogenation process,we synthesized a range of functionalized branched polyethylenes characterized by varied branching density and polar monomer incorporation.These polymers bear a structural resemblance to functionalized ethylene-octene copolymers.After crosslinking,mechanochromophores are generated,and mechanochromism is achieved in uniaxial tensile testing.A comprehensive assessment reveals that both the incorporation of polar monomers and variations in branching density significantly influence their mechanical properties.Notably,upon stretching,these materials display pronounced visible color change,confirming the successful development of mechanochromic branched polyethylenes.
基金financially supported by the National Natural Science Foundation of China(No.22071176)。
文摘Cutting-edge research has primarily focused on flow synthesis of linear block copolymers,lacking the ability for manipulating chain architectures for more extensive applications.Herein,we develop a flow chemistry platform for the continuous microflow synthesis of bottlebrush block copolymers(BBCPs)using a grafting-through method.This involves performing ring-opening metathesis polymerization(ROMP)of two different macromonomers within two microfluidic reactors connected in series.The microflow environment allows for complete monomer conversion within a few tens of seconds,benefiting from the superior mixing efficiency achieved in Z-shaped channels as indicated by both theoretical simulations and experimental results.Consequently,a library of well-defined BBCPs of up to 528 distinct samples can be produced within one day through automation of the continuous procedure,while keeping precise control on degree of polymerization(DP<4)and polydispersity indices(PDI<1.2).The synthetic method is generally applicable to different macromonomers with different compositions and contour lengths,yielding libraries of branched block copolymers with great diversity in physiochemical properties and chain architectures.This work presents a powerful platform for high-throughput production of branched copolymers,significantly lowering the costs of the materials for real applications.
基金one of the stage results of the Science and Technology Innovation Project (CI2021A00413) of the China Academy of Traditional Chinese Medicine。
文摘Along with the surge of unearthed medical literature and cultural relics in recent years,a network of channels in the system of medical conduit vessels(meridians) during the early Western Han dynasty has become much clearer gradually.In it,the increasing number of channel branches,network vessels and needle insertion holes(acupoints) is an important feature of the development of channel medicine during the Western Han dynasty.This is not only a reflection of the expanding requirements of the theoretical system of the main trunk channels and other vessels,but also an inevitable result of the continuous enrichment and accumulation of clinical experience.This article integrates the information about channel branches,network vessels,inscriptions,dots and further relics on the Tianhui(天回) Lacquered Meridian Figurine to compare the unearthed literature of the channel genre with the transmitted classical literature about acupuncture.The “Heart-Regulated Channel” in Medical Manuscripts on Bamboo Slips from Tianhui(《天回医简》) serves as an example to explain the occurrence,development and changes of the channel branches and network vessels in the early system of medical channels.
基金supported by the National Natural Science Foundation of China (Nos.22074015 and 22174014)。
文摘Developing accurate and sensitive DNA methyltransferase(MTase) analysis methods is essential for early clinical diagnosis and development of antimicrobial drug targets. In this work, by coupling WO_(3-x) dotsencapsulated metal-organic frameworks(MOFs) as co-reactants and terminal deoxynucleotidyl transferase(Td T)-mediated template-free branched polymerization, a dual signal-amplified electrochemiluminescent(ECL) biosensor was constructed to detect DNA adenine methylation(Dam) MTase. The employment of WO_(3-x) dots-encapsulated MOFs(i.e., NH_(2)-UIO66@WO_(3-x) ) was not only beneficial for biomolecule conjugation because of the abundant amino groups but also led to a 7-fold enhanced ECL response due to the increased loading of WO_(3-x). Moreover, Td T-mediated template-free branched polymerization promoted the capture of ECL emitters on the electrode surface, achieving 20-fold enhanced signal amplification. The presented ECL biosensor demonstrated a low detection limit of 2.4 × 10^(-4)U/m L, and displayed high reliability for the detection of Dam MTase in both spiked human serum and E. coli cell samples, and for the screening of potential inhibitors. This study opens a new avenue for designing a dual signal amplificationbased ECL bioassay for Dam MTase and screening inhibitors in the fields of clinical diagnosis and drug development.
基金funded by the National Natural Science Foundation of China(NSFC,No.51903202)the Key R&D Program of Shaanxi Province(No.2020GXLH-Y-016)+2 种基金the Natural Science Foundation of Shaanxi Province(No.2020JM-055)the Fundamental Re-search Funds for the Central Universities(No.xtr042019020)the Young Talents Support Plan of Xi’an Jiaotong University(No.HG6J002).
文摘Highly branched poly(β-amino ester)s(HPAEs)have emerged as a safe and efficient type of non-viral gene delivery vectors.However,the presence of inactive terminal secondary amine groups compromises their gene transfection capability.In this study,HPAEs with similar topological structures and chemical compositions but varying numbers of terminal secondary 4-amino-1-butanol(S4)and secondary/tertiary 3-morpholinopropylamine(MPA)groups were synthesized.The results demonstrate that an increased number of secondary/tertiary MPA groups in-situ significantly enhances the DNA binding capability of HPAEs,leading to the formation of smaller HPAE/DNA polyplexes with higher zeta potential,ultimately resulting in superior gene transfection efficiency in bladder epithelial cells.This study establishes a sim-ple yet effective strategy to maximize the gene transfection potency of HPAEs by converting the inactive terminal groups in-situ without the need for complex modifications to their topological structure and chemical composition.
文摘The catalysis of olefin polymerization through the chain-walking process is a subject of great interest. In this contribution, the successful synthesis of a Brookhart-type unsymmetrical α-diimine nickel catalyst Ni, which contains both dibenzhydryl and phenyl groups, was determined by X-ray crystallography. The compound has a pseudo-tetrahedral geometry at the Ni center, showing pseudo-C2-symmetry. Upon activation with modified methylaluminoxane (MMAO), Ni1 exhibits high catalytic activity up to 1.02 × 107 g PE (mol Ni h)−1 toward ethylene polymerization, enabling the synthesis of high molecular weight branched polyethylene. The molecular weights and branching densities could be tuned over a very wide range. The polymerization results indicated the possibility of precise microstructure control, depending on the polymerization temperature. The branching densities were decreased with increasing the polymerization temperature.
基金supported by the National Natural Science Foundation of China(52276195)Program for Supporting Innovative Research from Jinan(202228072)Program of Agricultural Development from Shandong(SD2019NJ015)。
文摘Development of pore structures of activated carbon(AC)from activation of biomass with ZnCl_(2) relies on content and structure of cellulose/hemicellulose in the feedstock.Thermal pretreatment of biomass could induce dehydration and/or aromatization to change the structure of cellulose/hemicellulose.This might interfere with evolution of structures of AC,which was investigated herein via thermal pretreatment of willow branch(WB)from 200 to 360℃and the subsequent activation with ZnCl_(2) at 550℃.The results showed that thermal pretreatment at 360℃(WB-360)could lead to substantial pyrolysis to form biochar,with a yield of 31.9%,accompanying with nearly complete destruction of cellulose crystals and remarkably enhanced aromatic degree.However,cellulose residual in WB-360 could still be activated to form AC-360 with specific surface area of 1837.9 m~2·g^(-1),which was lower than that in AC from activation of untreated WB(AC-blank,2077.8 m~2·g^(-1)).Nonetheless,the AC-200 from activation of WB-200 had more developed pores(2113.9 m~2·g^(-1))and superior capability for adsorption of phenol,due to increased permeability of ZnCl_(2) to the largely intact cellulose structure in WB-200.The thermal pretreatment did increase diameters of micropores of AC but reduced the overall yield of AC(26.8%for AC-blank versus 18.0%for AC-360),resulting from accelerated cracking but reduced intensity of condensation.In-situ infrared characterization of the activation showed that ZnCl_(2) mainly catalyzed dehydration,dehydrogenation,condensation,and aromatization but not cracking,suppressing the formation of derivatives of cellulose and lignin in bio-oil.The thermal pretreatment formed phenolic-OH and C=O with higher chemical innerness,which changed the reaction network in activation,shifting morphology of fibrous structures in AC-blank to“melting surface”in AC-200 or AC-280.
基金Supported by Scientific Research Project of Jilin Education Department([2010]number450)~~
文摘[Objective] The study was carried out in order to find out the best method of rapid cutting rooting of Syriga microphylla with tender branches.[Method] Effect of rooting reagent with different concentrations on the rapid cutting rooting of Syriga microphylla with tender branches was studied in our paper.[Result] There was great difference between cuttings with auxin and without auxin.[Conclusion] Tender branches treated by 90 mg/L indole butyric acid（IBA）had the best cutting rooting.
基金Supported by the National Natural Science Foundation of China (52074332,52204024)Outstanding Youth Foundation of Shandong Province (ZR2020YQ36)China Postdoctoral Science Foundation (M710225)。
文摘To further clarify the proppant transport and placement law in multi-branched fractures induced by volume fracturing, proppant transport simulation experiments were performed with different fracture shapes, sand ratios, branched fracture opening time and injection sequence of proppants in varied particle sizes. The results show that the settled proppant height increases and the placement length decreases in main fractures as the fracturing fluid diverts gradually to the branched fractures at different positions. The flow rate in branched fractures is the main factor affecting their filling. The diverion to branched fractures leads to low flow rate and poor filling of far-wellbore branched fractures. The inclined fracture wall exerts a frictional force on the proppant to slow its settlement, thus enhancing the vertical proppant distribution in the fracture. The increase of sand ratio can improve the filling of near-wellbore main fracture and far-wellbore branched fracture and also increase the settled proppant height in main fracture. Due to the limitation of fracture height, when the sand ratio increases to a certain level, the increment of fracture filling decreases. When branched fracture is always open(or extends continuously), the supporting effect on the branched fractures is the best, but the proppant placement length within the main fractures is shorter. The fractures support effect is better when it is first closed and then opened(or extends in late stage) than when it is first opened and then closed(or extends in early stage). Injecting proppants with different particle sizes in a specific sequence can improve the placement lengths of main fracture and branched fracture. Injection of proppants in an ascending order of particle size improves the near-wellbore fracture filling, to a better extent than that in a descending order of particle size.
文摘Branched chain amino acids(BCAAs)have been shown to affect gene expression,protein metabolism,apoptosis and regeneration of hepatocytes,and insulin resistance.They have also been shown to inhibit the proliferation of liver cancer cells in vitro,and are essential for lymphocyte proliferation and dendritic cell maturation.In patients with advanced chronic liver disease,BCAA concentrations are low,whereas the concentrations of aromatic amino acids such as phenylalanine and tyrosine are high,conditions that may be closely associated with hepatic encephalopathy and the prognosis of these patients.Based on these basic observations,patients with advanced chronic liver disease have been treated clinically with BCAA-rich medicines,with positive effects.
基金Supported by National Department Public Benefit Research Foundation(201304701-4)Science and Technology Planning Program of Xinjiang Uygur Autonomous RegionXinjiang Uygur Autonomous Region Fruit Major Subjects~~
文摘ObjectiveThe thesis aims at investigating the distribution and structural characteristics of various branches in canopy of Korla fragrant pear. MethodStatistic work and analysis were conducted on the numbers and distribution characteristics of various branches in each cubic lattice by using the canopy cellular method. ResultThe results showed that： The total number of scaffold branches of evacuation layered tree shape was 97, which mainly distributed in the lower layer and middle part of the canopy; the total number of scaffold branches of open-center tree shape was 94, which mainly distributed in the lower layer and middle part of the canopy. The total number of annual branches of evacuation layered tree shape was 3 920, which mainly distributed in the middle layer and outer part of the canopy; and the total number of annual branches of the open-center tree shape was 3 183, which mainly distributed in middle layer and outer part of the canopy. The total number of perennial branches of evacuation layered tree shape was 2 184, which mainly distributed in lower layer and outer part of the canopy; the total number of perennial branches of open-center tree shape was 1 444, which mainly distributed in middle layer and outer part of the canopy. ConclusionThe total number and the distribution positions of scaffold branches in the canopy of each tree shape were basically the same. The total numbers of annual branches of the two kinds of tree shapes were different, but the distribution positions were basically the same. The total numbers and the distribution positions of perennial branches in the canopy of the two kinds of tree shapes were different.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.YX2010-20)the National Natural Science Foundation of China(No.31570708,No.30901162)the Open Projects Foundation of Key Laboratory of Soil and Water Conservation&Desertification Combat(Beijing Forestry University),Ministry of Education of China(No.201002)
文摘Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.
基金We sincerely thank Prof. Yong-fang Li for providing the samples. S. Vdovi5 thanks CAS for support through a CAS Research Fellowship for International Young Researchers. This work was supported by National Natural Science Foundation of China, the Chinese Academy of Sciences, and the State Key Project for Fundamental Research.
文摘The structure-property characteristics of a series of newly synthesized intramolecular charge- transfer （ICT） compounds, single-branch monomer with triphenylmethane as electron donor and 2,1,3-benzothiadiazole as acceptor, the corresponding two-branch dimer and three- branch trimer, have been investigated by means of steady-state and femtosecond time- resolved stimulated emission fluorescence depletion （FS TR-SEP FD） techniques in different polar solvents. The TD-DFT calculations are further performed to explain the observed ICT properties. The interpretation of the experimental results is based on the comparative studies of the series of compounds which have increased amount of identical branch moiety. The similarity of the absorption and fluorescence spectra as well as strong solvent-dependence of the spectral properties for the three compounds reveal that the excited state of the dimer and trimer are nearly the same with that of the monomer, which may localize on one branch. It is found that polar excited state emerged through multidimensional intramolecular charge transfer from the donating moiety to the acceptor upon excitation, and quickly relaxed to one branch before emission. Even so, the red-shift in the absorption and emission spectra and decreased fluorescence radiative lifetime with respect to their monomer counterpart still suggest some extent delocalization of excited state in the dimer and trimer upon excitation. The similar behavior of their excited ICT state is demonstrated by FS TR-SEP FD measurements, and shows that the trimer has the largest charge-separate extent in all studied three samples. Finally, steady-state excitation anisotropy measurements has further been carried out to estimate the nature of the optical excitation and the mechanism of energy redistribution among the branches, where no plateau through the ICT band suggests the intramolecular excitation transfer process between the branches in dimer and trimer.
基金Supported by the National Natural Science Foundation of China.
文摘By making use of Thiele-type bivariate branched continued fractions and Sumelson inverse,we construct a few kinds of bivariate vector valued rational interpolonts (BVRIs) over rectangular grids and find out certain relations among these BVRIs such as boundary identity and duality.
基金financially supported by the Natural Science Foundation of Anhui Province(KJ2018A0534)the research fund of Anhui Science and Technology University(ZRC2014402)+1 种基金Materials Science and Engineering Key Discipline Foundation(AKZDXK2015A01)the Deanship of Scientific Research at King Saud University for its funding of this research through the Research Group Project No.Prolific Research Group No.1436-011
文摘Lithium-ion batteries(LIBs) are considered new generation of large-scale energy-storage devices.However,LIBs suffer from a lack of desirable anode materials with excellent specific capacity and cycling stability.In this work,we design a novel hierarchical structure constructed by encapsulating cobalt sulfide nanowires within nitrogen-doped porous branched carbon nanotubes(NBNTs)for LIBs.The unique hierarchical Co9S8@NBNT electrode displayed a reversible specific capacity of 1310 mAhg-1 at a current density of 0.1 Ag-1,and was able to maintain a stable reversible discharge capacity of 1109 mAhg-1 at a current density of 0.5 Ag-1 with coulombic efficiency reaching almost 100% for 200 cycles.The excellent rate and cycling capabilities can be ascribed to the hierarchical porosity of the one-dimensional Co9S8@NBNT internetworks,the incorporation of nitrogen doping,and the carbon nanotube confinement of the active cobalt sulfide nanowires offering a proximate electron pathway for the isolated nanoparticles and shielding of the cobalt sulfide nanowires from pulverization over long cycling periods.
基金This research was supported by Project of Distinguished Experts of Taishan Scholars (ts201712079)Youth Foundation of National Natural Science Foundation of China (41606078)+1 种基金Open Foundation of Pilot National Laboratory for Marine Science and Technology (QNLM2016ORP0207)Marine Geological Survey Program (DD20190231). Anonymous reviewers and Dr. Hao Zi-guo and Dr. Yang Yan were grateful for their constructive suggestions on the manuscript.
文摘Raising the in situ decomposition rate of natural gas hydrate and increasing the decomposition contact area are two main ways to raise the productivity of hydrate. An exploitation technique based on large borehole with multi-lateral branches (LB & MB) was proposed in this paper. This technique is mainly intended for the clayey silt hydrate reservoir in the South China Sea, and its main purpose is to alleviate the sand output from formation for maintaining the stability of the reservoir and to greatly increase the gas productivity of the reservoir. In this paper, the following aspects were mainly expounded: definition of the basic geometric parameters for layout of multi-lateral branches in clayey silt hydrate reservoir, simulation of the stimulation effect of a typical well profile with two branches, and prediction and simulation of the reservoir failure risk in a well profile with eight branches. The results show that the LB & MB effectively improves the flow field in the formation, raises the productivity of the reservoir and may also help to decrease the produced water-gas ratio (WGR). When the lateral branches spacing is too small, the failure zones around adjacent lateral branches overlap each other, possibly causing reservoir failure in a larger range. Therefore, the geometric parameters of multi-lateral branches depend on the dual control of the productivity and geotechnical risk factor of reservoir. Further study is being carried out, so as to obtain the optimal combination of parameters of multi-lateral branches.
基金supported by the National Natural Science Foundation of China(Grants Nos.52072323 and 51872098)the Leading Project Foundation of Science Department of Fujian Province(Grants No.2018H0034)+1 种基金the“Double-First Class”Foundation of Materials and Intelligent Manufacturing Discipline of Xiamen Universitythe financial support from the Opening Project of National Joint Engineering Research Center for Abrasion Control and Molding of Metal Materials,&Henan Key Laboratory of High-temperature Structural and Functional Materials,Henan University of Science and Technology(Grants No.HKDNM2019013)。
文摘Owing to the dramatically enhanced charge-mass transport and abundant electrochemically active sites,transition metal compound electrodes are increasingly attractive for achieving high-performance supercapacitors(SCs).Here,we report the fabrication of nickel foam supported three-dimensional(3 D)branched nickel-cobalt phosphides@tri-metal cobalt-nickel-molybdenum phosphides core/shell nanowire heterostructures(denoted as NiCo-P@CoNiMo-P)as high-performance electrode materials for hybrid supercapacitors.The presence of multiple valences of the cations in such NiCo-P@CoNiMo-P enables rich redox reactions and promoted synergy effects.Benefiting from their collective effects,the resulting electrode demonstrates high specific capacity of 1366 C g^(-1) at 2 A g^(-1)(2.03 C cm^(-2) at2 mA cm^(-2))and 922 C g^(-1) at 10 A g^(-1),as well as good cycling stability(retaining~94%of the initial capacity after 6000 cycles at 15 A g^(-1)).A hybrid SC using the NiCo-P@CoNiMo-P as the positive electrode and N-doped rGOs as the negative electrode exhibits a high energy density of 81.4 Wh kg^(-1) at a power density of 1213 W kg^(-1) and a capacity retention of 132%even after 6000 cycles at 10 A g^(-1).Our findings can facilitate the material design for boosting the performance of transition metal compounds based materials for fast energy storage.
基金This work was financially supported by Science Foundation Ireland(SFI)Principal Investigator Program(No.13/IA/1962)the National Natural Science Foundation of China(Nos.51873179,51903202),and University College Dublin。
文摘Highly branched poiy(β-amino ester)s(HPAEs)have emerged as one type of the most viable non-viral gene delivery vectors,both in vitro and in viva.However,the effects of different branching strategies on the gene transfection performance have not yet been explored.Here,using triacrylate(B3)and diamine(B4)as the branching monomers,a series of HPAEs were synthesized via the"A2+B3+C2"and"A2+B4+C2"strategies,respectively.Results show that the branching strategy plays a pivotal role in dictating the physiological properties of the HPAE/DNA polyplexes and thus leads to obviously different cell viability and transfection efficiency.Comparatively,HPAEs synthesized via the"A2+B3+C2"branching strategy are more favorable for DNA transfection than that synthesized via the"A2+B4+C2"strategy.This study may provide new insights into the development of HPAEs based non-viral DNA delivery system.
基金financially supported by the National Natural Science Foundation of China(Nos.50633010 and 50973100)
文摘A series of hyperbranched polyurethane-benzyltetrazoles （H-PBTZs） with different linkage structures were synthesized via the polycondensation of hexamethylenediisocyanate as an A2 type monomer with （4-（1H-tetrazol-5- yl）benzyl）-diethanolamine （TBDEA） as a BB＇2 type monomer in the absence of catalyst at different temperatures. The FTIR, and 13C and 1H-NMR spectroscopy were used to characterize the molecular structures of TBDEA and H-PBTZs as well as the counterpart linear polyurethane-benzyltetrazole （L-PBTZ）. The molecular composition was determined by the reaction selectivity that the isocyanate group reacted with the hydroxyl group in diethanolamine segment or the active hydrogen atom on tetrazole ring. Raising reaction temperature was propitious to the reaction of isocyanate group with the active hydrogen atom on tetrazole ring. The degrees of branching （DB） for H-PBTZs obtained from the 1H-NMR spectra increased with raising reaction temperature. The wider molecular weight distribution of 1.7-2.9 for H-PBTZs was obtained via GPC analysis. TGA results showed that H-PBTZs had high thermal stability compared with L-PBTZ.
