Biology is governed by macromolecular interactions,perturbation of which often lies at the heart of disease.Most therapeutic drugs,whether they are small molecules or biologics,exert their effects through impeding suc...Biology is governed by macromolecular interactions,perturbation of which often lies at the heart of disease.Most therapeutic drugs,whether they are small molecules or biologics,exert their effects through impeding such interactions,whether they are of an enzyme with its substrate or a ligand with its receptor.Conversely,a handful of approved drugs and a larger number of candidates in development have the opposite effect:They either activate or inhibit a biological output by stabilizing a preexisting complex through reducing the rate at which its components dissociate(koff).展开更多
Natural endogenous materials(NEMs),such as cell and cell derivatives,polysaccharide,protein and peptide,and nucleic acid-derived vectors,often exhibit biocompatibility,biodegradability and natural homing ability,which...Natural endogenous materials(NEMs),such as cell and cell derivatives,polysaccharide,protein and peptide,and nucleic acid-derived vectors,often exhibit biocompatibility,biodegradability and natural homing ability,which can minimize adverse reactions in vivo and have the potential to improve drug delivery efficacy.Currently,a variety of drug delivery systems(DDSs)based on NEMs have been constructed for macromolecules to address the challenges posed by their inherent large size,intricate structure,low permeability,and susceptibility to harsh environments.The aim of this article is to provide a comprehensive overview of various delivery strategies that predominantly utilize NEMs as carriers for macromolecular delivery.By thoroughly discussing the pros and cons of NEM-based DDSs,we hope to provide valuable insights into future innovations in pharmaceutical science,with a focus on improving therapeutic outcomes through advanced drug formulations.展开更多
AIM:To investigate whether curcumin could attenuate nuclear factor(NF)-κB p65 expression and macromolecular leakage in the gastric mucosa of Helicobacter pylori(H.pylori)-infected rats.METHODS:Twenty-five male Spragu...AIM:To investigate whether curcumin could attenuate nuclear factor(NF)-κB p65 expression and macromolecular leakage in the gastric mucosa of Helicobacter pylori(H.pylori)-infected rats.METHODS:Twenty-five male Sprague-Dawley rats were equally divided into five groups:control rats(Control),control rats supplemented with 600 mg/kg curcumin,H.pylori-infected rats(Hp),H.pylori-infected rats supplemented with 200 mg/kg curcumin(Hp + curIn H.pylori-infected groups,rats were inoculated with H.pylori suspension twice a day at an interval of 4 h for 3 d.Two weeks later,200 or 600 mg/kg curcumin was given once daily to curcuminsupplemented groups for 7 d.On the day of the experiment,macromolecular leakage in gastric mucosa was examined by intravital fluorescence microscopy.The stomach tissue was removed to examine NF-κB p65 expression in gastric epithelial cells by immunohistochemistry.RESULTS:The expression of NF-κB p65 in gastric epithelial cells and the macromolecular leakage from gastric mucosal microcirculation significantly increased in the Hp group compared with the Control group.The percentages of NF-κB p65 immunoreactive cells in Control and Hp groups were 10.72% ± 2.10% vs 16.02% ± 2.98%,P = 0.004,respectively.The percentages of macromolecular leakage in Control and Hp groups were 10.69% ± 1.43% vs 15.41% ± 2.83%,P = 0.001,respectively.Curcumin supplementation in Hp + cur-CONCLUSION:H.pylori-induced gastric inflammation in rats is associated with increased NF-κB activation and macromolecular leakage which can be reduced by curcumin supplementation.展开更多
Beamline BL17 U1 at Shanghai Synchrotron Radiation Facility is an energy-tunable macromolecular crystallography beamline that has been in user operation since 2009. Growing demand from the user community for a small b...Beamline BL17 U1 at Shanghai Synchrotron Radiation Facility is an energy-tunable macromolecular crystallography beamline that has been in user operation since 2009. Growing demand from the user community for a small beam and related experimental methods have motivated upgrades of the devices in the endstation.Minibeam modes have already been developed for operation. A self-integrated diffractometer reduces the sphere of confusion of the rotatory axis to 1μm. The new diffractometer is equipped with an upgraded on-axis viewing system that can improve the resolving power. Additionally,the area detector was also upgraded to the newest generation of detectors, the EIGER X 16 M, which can collect data at 133 Hz. After these upgrades, the endstation became virtually new. This paper covers the upgrade of the endstation devices and gives the first data collection results.展开更多
The structural evolution of tectonically deformed coals （TDC） with different deformational mechanisms and different deformational intensities are investigated in depth through X-ray diffraction （XRD） analysis on 3...The structural evolution of tectonically deformed coals （TDC） with different deformational mechanisms and different deformational intensities are investigated in depth through X-ray diffraction （XRD） analysis on 31 samples of different metamorphic grades （R ： 0.7%-3.1%） collected from the Huaibei coalfield. The results indicated that there are different evolution characteristics between the ductile and brittle deformational coals with increasing of metamorphism and deformation. On the one hand, with the increase of metamorphism, the atomic plane spacing （d002） is decreasing at step velocity, the stacking of the BSU layer （Lc） is increasing at first and then decreasing, but the extension of the BSU layer （La） and the ratio of La/Lc are decreasing initially and then increasing. On the other hand, for the brittle deformational coal, d002 is increasing initially and then decreasing, which causes an inversion of the variation of Lc and La under the lower-middle or higher-middle metamorphism grade when the deformational intensity was increasing. In contrast, in the ductile deformational coals, d002 decreased initially and then increased, and the value of L~ decreased with the increase of deformational intensity. But the value of La increased under the lower-middle metamorphism grade and increased at first and then decreased under the higher-middle metamorphism grade. We conclude that the degradation and polycondensation of TDC macromolecular structure can be obviously impacted during the ductile deformational process, because the increase and accumulation of unit dislocation perhaps transforms the stress into strain energy. Meanwhile, the brittle deformation can transform the stress into frictional heat energy, and promote the metamorphism and degradation as well. It can be concluded that deformation is more important than metamorphism to the differential evolution of the ductile and brittle deformational coals.展开更多
A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization. At first, polydiene-stannum chloride （PD-SnCl3） was prepared by the reactio...A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization. At first, polydiene-stannum chloride （PD-SnCl3） was prepared by the reaction of n-butyl-Li （n-BuLi）, stannic chloride （SnCl4） and diene. Then PD-SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators. The result suggested that the initiators had a remarkable yield by GPC, nearly 90%. By using these multifunctional macromolecular initiators, styrene and butadiene were effectively polymefized via anionic polymerization, which gave birth to novel miktoarm star copolymers. The relative molecular weight and polydispersity index, microstructure contents, copolymerization components, glass transition temperature （Tg） and morphology of the miktoarm star copolymers were investigated by GPC-UV, ~H NMR, DSC and TEM, respectively. 2009 Xing Ying Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
In this paper, we review our recent progress in the synthesis and application of styryl-capped polypropylene （PP-t- St）, an excellent reactive polyolefin that is both convenient and efficient in synthesis and facile...In this paper, we review our recent progress in the synthesis and application of styryl-capped polypropylene （PP-t- St）, an excellent reactive polyolefin that is both convenient and efficient in synthesis and facile and versatile in application for preparing advanced polypropylene materials via macromolecular engineering. The synthesis of PP-t-St is made possible by a unique chain transfer reaction coordinated by a bis-styrenic molecule, such as 1,4-divinylbenzene （DVB） and 1,2-bis（4- vinylphenyl）ethane （BVPE）, and hydrogen in typical C2-symmetric metallocene （e.g. rac-Me2Si（2-Me-4-Ph-Ind）2ZrC12, in association with methylaluminocene, MAO） catalyzed propylene polymerization. The regio-selective 2,1- insertion of the styrenic double bond in DVB or BVPE into the overwhelmingly 1,2-fashioned Zr-PP propagating chain enables substantial dormancy of the catalyst active site, which triggers selective hydrogen chain transfer that, with the formed Zr-H species ultimately saturated by the insertion of propylene monomer, results in an exclusive capping of the afforded PP chains by styryl group at the termination end. With a highly reactive styryl group at chain end, PP-t-St has been used as a facile building block in PP macromolecular engineering together with the employment of state-of-the-art synthetic polymer chemistry to fabricate broad types of new polypropylene architectures.展开更多
Dodecyl-benzophenone（DBP） and hexadecoxyl-benzophenone（HDBP） as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTI...Dodecyl-benzophenone（DBP） and hexadecoxyl-benzophenone（HDBP） as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTIR spectroscopy. The UV-Vis absorption spectra of DBP and HDBP, propitious to photopolymerization under a commercial mercury UV bulb are centered at 345 and 335 nm, respectively. HDBP has higher extinction coefficient than DBP, but lower photoinitiating efficiency. Their photoinitiating performances for EB605, a bisphenol A epoxy acrylate with 40%（mass fraction） tripropyleneglycol diacrylate （TPGDA）, resin consisting of bisphenol A epoxy acrylate and tripropyleneglycol diacrylate in the presence of triethanolamine as a coinitiator were investigated by photo-differential scanning calorimetry（photo-DSC）. DBP initiates the curing of acrylate more efficiently than HDBP, showing higher photopolymerization rate and unsaturation conversion, resulted from the poor compatibility of HDBP with the resin. The photoinitiating activity of DBP to epoxy acrylate resin is even higher than that of BP at lower loadings.展开更多
A new macromolecular surface modifier, a copolymer of lauryl methacrylate （LMA） and poly（ethylene glycol） methyl methacrylate （PEGMA）, was synthesized through free radical polymerization. The copolymer was chara...A new macromolecular surface modifier, a copolymer of lauryl methacrylate （LMA） and poly（ethylene glycol） methyl methacrylate （PEGMA）, was synthesized through free radical polymerization. The copolymer was characterized by nuclear magnetic resonance spectrum （lH-NMR） and thermogravimetric analysis （TGA）. The copolymer was used to blend with polyethylene. The binary blends have been characterized by attenuated total reflection/Fourier transform infrared （ATR- FTIR）, contact-angle measurements （CDA） and scanning electron microscopy （SEM）. The results indicated that poly（ethylene glycol） methyl methacrylate-co-lauryl methacrylate （PEGMA-co-LMA） could diffuse preferably onto the surface of the polyethylene （PE） film, and thus can be used as an efficient surface modifier for PE.展开更多
Adsorption kinetics of the interaction between Pt, Pd and Rh(defined here as platinum group elements, PGEs)ions and macromolecular organic compounds(MOCs,>10 kDa), including humic acid, carrageenan and bovine serum...Adsorption kinetics of the interaction between Pt, Pd and Rh(defined here as platinum group elements, PGEs)ions and macromolecular organic compounds(MOCs,>10 kDa), including humic acid, carrageenan and bovine serum albumin, and different cutoff fractions of natural organic matter(>1 kDa and >3 kDa) obtained from seawater using centrifugal ultrafiltration devices were investigated. For a given element, all the adsorption kinetics did not reach equilibrium except the interaction between Pt and >1 kDa cutoff, and between Pd and humic acid.For all the tested MOCs, the adsorption kinetics could be divided into two stages, a rapid adsorption process in the first 8 h and the desorption stage after the first 8 h until the equilibrium. The change trend of partition coefficient(log10Kd) values with experiment time was consistent with that of the kinetic curves. However, in the interaction between PGE ions and natural dissolved organic matter(NDOM), an obvious difference in the change trends of log10Kd and kinetic curves was observed. It indicated that the partition behavior of PGE ions interacting with NDOM in seawater was a combined effect of different organic constituents. The adsorption and log10Kd of PGEs in the >1 kDa NDOM fraction were higher and more stable than those in the >3 kDa NDOM fraction. The results also indicated that the 1–3 kDa NDOM may dominate the interaction between PGEs ions and NDOM. Moreover, no kinetic model could perfectly simulate the adsorption process. It indicated that the colloidal struction and morphology of MOCs or NDOM in seawater might be inhomogeneous. Hence, the interaction between PGE ions and organic matter in seawater was a complicated process and needs further research.展开更多
A new unsteady three-dimensional convective-diffusive mathematical model for the transportation of macromolecules and water across the arterial wall was proposed . After the formation of leaky junctions due to the mit...A new unsteady three-dimensional convective-diffusive mathematical model for the transportation of macromolecules and water across the arterial wall was proposed . After the formation of leaky junctions due to the mitosis of endothelial cell of the arterial wall, the macromolecular transport happens surrounding the leaky cells. The arterial wall was divided into four layers: the endothelial layer, the subendothelial intima, the internal elastic lamina and the media for the convenience of research. The time-dependent concentration growth,the effect of the shape of endothelial cell and the effect of physiological parameters were analyzed. The analytical solution of velocity field and pressure field of water flow across the arterial wall were obtained; and concentration distribution of three macromolecules ; LDL,HRP and Albumin, were calculated with numerical simulation method. The new theory predicts, the maximum and distribution areas of time dependent concentration with round shape endothelial cell are both larger than that with ellipse-shape endothelial cell. The model also predicts the concentration growth is much alike that of a two-dimensional model and it shows that the concentration reaches its peak at the leaky junction where atherosclerotic formation frequently occurs and falls down rapidly in a limited area beginning from its earlier time growth to the state when macromolecular transfer approaches steadily. These predictions of the new model are in agreement with the experimental observation for the growth and concentration distribution of LDL and Albumin.展开更多
With Bowytis cinerea and its extracellular macromolecular toxins as the test materials, 30 speiees of plants belonging to 29 genera and 21 families were selected as the test plants to observe the infectivity of B. dne...With Bowytis cinerea and its extracellular macromolecular toxins as the test materials, 30 speiees of plants belonging to 29 genera and 21 families were selected as the test plants to observe the infectivity of B. dnerea and damage status of macromolecular toxins secreted by B. cinerea on plants. The resulsts showed that 17 species of plants were beth infected by B. cinerea and damaged by toxins, accounting for 56.7% of the total plants. Two species of plants could be neither infected by B. cinerea nor damaged by toxins. The study provided the reference for further understanding of pathogenic mechanism of plant pathogenic fungi toxins.展开更多
DTPA was covalently conjugated to the copolymer of L lysine and L tyrosine, then transchelated with Gd EDTA,the resultant polymer chelates were further reacted with 6 O bromoacetyl D galacto...DTPA was covalently conjugated to the copolymer of L lysine and L tyrosine, then transchelated with Gd EDTA,the resultant polymer chelates were further reacted with 6 O bromoacetyl D galactose or methyl lactobionyloxyacetate to give PLT(Gd DTPA) with galactose moiety as liver targeting group.These macromolecular MRI contrast agents were characterized by means of FT IR, ICP AES, elementary analyses and UV Vis spectrophotometry. Their in vitro relaxivity and liver targeting property in mice were also investigated.展开更多
Uveitis is a sophisticated syndrome showing a high relevance with reactive oxygen species(ROS).Herein,an ROS-responsive PEGylated polypeptide based macromolecular prodrug of herbaceous antioxidant ethyl caffeate(EC)is...Uveitis is a sophisticated syndrome showing a high relevance with reactive oxygen species(ROS).Herein,an ROS-responsive PEGylated polypeptide based macromolecular prodrug of herbaceous antioxidant ethyl caffeate(EC)is designed via phenylboronic esters with improved solubility for the alleviation of uveitis.The antioxidative 4-hydroxybenzyl alcohol(HBA)and EC can be released from the macromolecular EC prodrug under the stimulation of ROS,which can effectively protect cells against oxidative stress-induced injury in an ROS-depletion way.The antioxidative and protective effects of the macromolecular EC prodrug in vivo are further verified in a uveitis mouse model.Overall,this work not only provides a handy method to synthesize a phenylboronic ester-bearing EC prodrug which is highly sensitive to pathological ROS,but also depicts a promising future to apply macromolecular antioxidative prodrugs in the treatment of uveitis as well as other ROS-related diseases.展开更多
Fourier transform infrared imaging(FTIRI)was used to examine the depth-dependent content variations of macromolcular components,ollagen and protooglycan(PG),in osteoarthritic and healthy cartilages.Dried 6 pmm thick s...Fourier transform infrared imaging(FTIRI)was used to examine the depth-dependent content variations of macromolcular components,ollagen and protooglycan(PG),in osteoarthritic and healthy cartilages.Dried 6 pmm thick sections of canine knee cartilages were imaged at 6.25 pμrm pixel-size in FTIRI.By analyzing the infrared(IR)images and spectra,the depth dependence of characteristic band(sugar)intensity of PG show obvious difference bet ween the cartilage sections of(OA)and bealth.The result confimns that PG content decreases in the ostcoarthritic cartilage.However,no clear change occurs to collagen,suggesting that the OA influences little on the collagen content at early stage of OA.This observation will be helpful to further understand PG loss associated with pathological conditions in OA,and demonstrates that FIIRI has the po-tential to become an important analytical tool to identify early clinical signs of tissue degna-dation,such as PG loss even collagen disruption.展开更多
Cellulose diacetate(CDA)can be melt processed to produce numerous and widely-used plastic products.However,due to the high glass transition temperature(Tg)of CDA,the addition of up to 30 wt%of micromolecular plasticiz...Cellulose diacetate(CDA)can be melt processed to produce numerous and widely-used plastic products.However,due to the high glass transition temperature(Tg)of CDA,the addition of up to 30 wt%of micromolecular plasticizers is indispensable,which significantly reduces the dimensional stability and raises safety concerns from the migration of plasticizers.In this work,a series of CDA-graft poly(lactic acid)(CDA-g-PLA)copolymers were synthesized by ring-opening polymerization of lactide onto the hydroxyI groups of CDA.The resultant CDA-g-PLA copolymers possess adjustable degrees of substitution(DSpua)and side chain length(DPpLa)by controlling the reaction time and feed ratio.The Tgs and thermal flow temperatures(Ts)of CDA-g-PLA strongly depend on DPpA such as the Tgs decrease linearly with the increase of DPA.The CDA-g-PLA copolymers with the DPLA of 3-9 can be directly processed to transparent plastics by melt processing without any external plasticizers,because of their low Tfs of 170-215℃.More impressively.the CDA-g PLA can act as the macromolecular plasticizer.The obtained CDA/CDA-g-PLA has higher storage modulus,flexural modulus and Young's modulus than the commercial CDA plasticized with triethyl citrate.In addition,the CDA/CDA-g PLA exhibits high dimensional stabilty and anti-migration property.During a long term treatment at 80℃ and 60%humidity,the CDA/CDA-g-PLA can retain the initial shape.Therefore,this work not only proposes a facile method for achieving a direct thermoplastic processing of CDA,but also provides a macromolecular plasticizer for CDA to make lightweight,stable and safer biobased thermoplastics.展开更多
Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility has been relocated,upgraded,and given a new ID(BL02U1).It now delivers X-rays in the energy range of 6–16 keV,with a focus...Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility has been relocated,upgraded,and given a new ID(BL02U1).It now delivers X-rays in the energy range of 6–16 keV,with a focused beam of 11.6μm×4.8μm and photon flux greater than 1012 phs/s.The high credibility and stability of the beam and good timing synchronization of the equipment significantly improve the experimental efficiency.Since June 2021,when it officially opened to users,over 4200 h of beamtime have been provided to over 200 research groups to collect data at the beamline.Its good performance and stable operation have led to the resolution of several structures based on data collected at the beamline.展开更多
Objective:To investigate the anti-tumor effect of macromolecular fractions of fresh gecko (M-AG) in vivo and their differentiation-inducing activity in Bel-7402 cells in vitro.Methods:An H22 hepatocarcinoma-bearing mo...Objective:To investigate the anti-tumor effect of macromolecular fractions of fresh gecko (M-AG) in vivo and their differentiation-inducing activity in Bel-7402 cells in vitro.Methods:An H22 hepatocarcinoma-bearing mouse model was used to evaluate the anti-tumor activity of M-AG samples.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was applied to analyze cell viability.Cell morphology was observed by phase contrast microscopy.The quantity of the alpha-fetoprotein was detected by a radioimmunoassay.Chromatometry was used to assay the albumin quantity.Activities of alkaline phosphatase and γ-glutamyl trans-peptidase were measured by biochemical methods.Finally,western blotting was applied to assess proteins in the mitogen-activated protein kinase (MAPK) signaling pathway.Results:Macromolecular fractions of fresh gecko exerted a significant anti-tumor effect in mice.The inhibition rate of tumor growth was 63% in the moderate M-AG dose group.Cells treated with M-AG displayed a differentiated state.The treatment lowered alphafetoprotein secretion and significantly decreased the activities of γ-glutamyl trans-peptidase and alkaline phosphatase in Bel-7402 cells.In contrast,M-AG increased the amount of albumin in the cell culture medium.All biochemical indices demonstrated that M-AG induced Bel7402 cell differentiation.Western blotting showed no changes in the quantities of extracellular signal-regulated kinase (ERK) 1/2,p38MAPK,or c-Jun N-terminal protein kinase 1/2.However,M-AG significantly activated the phosphorylation of ERK1/2 in a dose-dependent manner.In addition,M-AG had no significant influence on the expression of nuclear factor-kappa B.Conclusion:Macromolecular fractions of fresh gecko has an anti-tumor activity in H22 hepatocarcinoma-bearing mice in vivo and inhibits Bel-7402 cell proliferation in vitro by inducing cell differentiation related to activation of ERK1/2.展开更多
A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary fl...A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary flow is time-dependent in the aortic arch. The concentration of macromolecule concentrates at the region of sharp curve, and the wall concentration at the outer part is higher than that at the inner part. Atherosclerosis and thrombosis are prone to develop in such regions with sharp flow.展开更多
文摘Biology is governed by macromolecular interactions,perturbation of which often lies at the heart of disease.Most therapeutic drugs,whether they are small molecules or biologics,exert their effects through impeding such interactions,whether they are of an enzyme with its substrate or a ligand with its receptor.Conversely,a handful of approved drugs and a larger number of candidates in development have the opposite effect:They either activate or inhibit a biological output by stabilizing a preexisting complex through reducing the rate at which its components dissociate(koff).
基金supported by the National Natural Science Foundation of China(No.82273884)。
文摘Natural endogenous materials(NEMs),such as cell and cell derivatives,polysaccharide,protein and peptide,and nucleic acid-derived vectors,often exhibit biocompatibility,biodegradability and natural homing ability,which can minimize adverse reactions in vivo and have the potential to improve drug delivery efficacy.Currently,a variety of drug delivery systems(DDSs)based on NEMs have been constructed for macromolecules to address the challenges posed by their inherent large size,intricate structure,low permeability,and susceptibility to harsh environments.The aim of this article is to provide a comprehensive overview of various delivery strategies that predominantly utilize NEMs as carriers for macromolecular delivery.By thoroughly discussing the pros and cons of NEM-based DDSs,we hope to provide valuable insights into future innovations in pharmaceutical science,with a focus on improving therapeutic outcomes through advanced drug formulations.
基金Supported by Thailand Research fund (code RMU 4980032)Graduate Thesis Grant,Graduate School,Chulalongkorn University,Thailand
文摘AIM:To investigate whether curcumin could attenuate nuclear factor(NF)-κB p65 expression and macromolecular leakage in the gastric mucosa of Helicobacter pylori(H.pylori)-infected rats.METHODS:Twenty-five male Sprague-Dawley rats were equally divided into five groups:control rats(Control),control rats supplemented with 600 mg/kg curcumin,H.pylori-infected rats(Hp),H.pylori-infected rats supplemented with 200 mg/kg curcumin(Hp + curIn H.pylori-infected groups,rats were inoculated with H.pylori suspension twice a day at an interval of 4 h for 3 d.Two weeks later,200 or 600 mg/kg curcumin was given once daily to curcuminsupplemented groups for 7 d.On the day of the experiment,macromolecular leakage in gastric mucosa was examined by intravital fluorescence microscopy.The stomach tissue was removed to examine NF-κB p65 expression in gastric epithelial cells by immunohistochemistry.RESULTS:The expression of NF-κB p65 in gastric epithelial cells and the macromolecular leakage from gastric mucosal microcirculation significantly increased in the Hp group compared with the Control group.The percentages of NF-κB p65 immunoreactive cells in Control and Hp groups were 10.72% ± 2.10% vs 16.02% ± 2.98%,P = 0.004,respectively.The percentages of macromolecular leakage in Control and Hp groups were 10.69% ± 1.43% vs 15.41% ± 2.83%,P = 0.001,respectively.Curcumin supplementation in Hp + cur-CONCLUSION:H.pylori-induced gastric inflammation in rats is associated with increased NF-κB activation and macromolecular leakage which can be reduced by curcumin supplementation.
基金supported by the Maintenance and Renovation Project for the major infrastructure of the Chinese Academy of Sciencesthe Operation Project of SSRF
文摘Beamline BL17 U1 at Shanghai Synchrotron Radiation Facility is an energy-tunable macromolecular crystallography beamline that has been in user operation since 2009. Growing demand from the user community for a small beam and related experimental methods have motivated upgrades of the devices in the endstation.Minibeam modes have already been developed for operation. A self-integrated diffractometer reduces the sphere of confusion of the rotatory axis to 1μm. The new diffractometer is equipped with an upgraded on-axis viewing system that can improve the resolving power. Additionally,the area detector was also upgraded to the newest generation of detectors, the EIGER X 16 M, which can collect data at 133 Hz. After these upgrades, the endstation became virtually new. This paper covers the upgrade of the endstation devices and gives the first data collection results.
基金supported by the National Natural Science Foundation of China(Grant Nos.41030422, 40972131,40772135 and 41202120)the National Basic Research Program of China(Grant Nos.2009CB219601 and 2006CB202201)the China Postdoctoral Science Foundation Funded Project(2012M510590)
文摘The structural evolution of tectonically deformed coals （TDC） with different deformational mechanisms and different deformational intensities are investigated in depth through X-ray diffraction （XRD） analysis on 31 samples of different metamorphic grades （R ： 0.7%-3.1%） collected from the Huaibei coalfield. The results indicated that there are different evolution characteristics between the ductile and brittle deformational coals with increasing of metamorphism and deformation. On the one hand, with the increase of metamorphism, the atomic plane spacing （d002） is decreasing at step velocity, the stacking of the BSU layer （Lc） is increasing at first and then decreasing, but the extension of the BSU layer （La） and the ratio of La/Lc are decreasing initially and then increasing. On the other hand, for the brittle deformational coal, d002 is increasing initially and then decreasing, which causes an inversion of the variation of Lc and La under the lower-middle or higher-middle metamorphism grade when the deformational intensity was increasing. In contrast, in the ductile deformational coals, d002 decreased initially and then increased, and the value of L~ decreased with the increase of deformational intensity. But the value of La increased under the lower-middle metamorphism grade and increased at first and then decreased under the higher-middle metamorphism grade. We conclude that the degradation and polycondensation of TDC macromolecular structure can be obviously impacted during the ductile deformational process, because the increase and accumulation of unit dislocation perhaps transforms the stress into strain energy. Meanwhile, the brittle deformation can transform the stress into frictional heat energy, and promote the metamorphism and degradation as well. It can be concluded that deformation is more important than metamorphism to the differential evolution of the ductile and brittle deformational coals.
基金supported by National Natural Science Foundation of China(No.50573005)
文摘A new kind of multifunctional macromolecular initiator with Sn-C bonds and polydiene arms was synthesized by living anionic polymerization. At first, polydiene-stannum chloride （PD-SnCl3） was prepared by the reaction of n-butyl-Li （n-BuLi）, stannic chloride （SnCl4） and diene. Then PD-SnCl3 was used to react with the dilithium initiator to prepare the multifunctional organic macromolecular initiators. The result suggested that the initiators had a remarkable yield by GPC, nearly 90%. By using these multifunctional macromolecular initiators, styrene and butadiene were effectively polymefized via anionic polymerization, which gave birth to novel miktoarm star copolymers. The relative molecular weight and polydispersity index, microstructure contents, copolymerization components, glass transition temperature （Tg） and morphology of the miktoarm star copolymers were investigated by GPC-UV, ~H NMR, DSC and TEM, respectively. 2009 Xing Ying Zhang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金supported by the National Natural Science Foundation of China (Nos. 20734002, 51103163,51003106 and 51003105)Chinese Academy of Sciences (Directional key project on high performance polypropylene alloy resin development)
文摘In this paper, we review our recent progress in the synthesis and application of styryl-capped polypropylene （PP-t- St）, an excellent reactive polyolefin that is both convenient and efficient in synthesis and facile and versatile in application for preparing advanced polypropylene materials via macromolecular engineering. The synthesis of PP-t-St is made possible by a unique chain transfer reaction coordinated by a bis-styrenic molecule, such as 1,4-divinylbenzene （DVB） and 1,2-bis（4- vinylphenyl）ethane （BVPE）, and hydrogen in typical C2-symmetric metallocene （e.g. rac-Me2Si（2-Me-4-Ph-Ind）2ZrC12, in association with methylaluminocene, MAO） catalyzed propylene polymerization. The regio-selective 2,1- insertion of the styrenic double bond in DVB or BVPE into the overwhelmingly 1,2-fashioned Zr-PP propagating chain enables substantial dormancy of the catalyst active site, which triggers selective hydrogen chain transfer that, with the formed Zr-H species ultimately saturated by the insertion of propylene monomer, results in an exclusive capping of the afforded PP chains by styryl group at the termination end. With a highly reactive styryl group at chain end, PP-t-St has been used as a facile building block in PP macromolecular engineering together with the employment of state-of-the-art synthetic polymer chemistry to fabricate broad types of new polypropylene architectures.
基金Supported by the National Natural Science Foundation of China(No50973100)
文摘Dodecyl-benzophenone（DBP） and hexadecoxyl-benzophenone（HDBP） as type 11 photoinitiators used for radical photopolymerization systems were synthesized by Friedel-Crafts reaction, and characterized by 1H NMR and FTIR spectroscopy. The UV-Vis absorption spectra of DBP and HDBP, propitious to photopolymerization under a commercial mercury UV bulb are centered at 345 and 335 nm, respectively. HDBP has higher extinction coefficient than DBP, but lower photoinitiating efficiency. Their photoinitiating performances for EB605, a bisphenol A epoxy acrylate with 40%（mass fraction） tripropyleneglycol diacrylate （TPGDA）, resin consisting of bisphenol A epoxy acrylate and tripropyleneglycol diacrylate in the presence of triethanolamine as a coinitiator were investigated by photo-differential scanning calorimetry（photo-DSC）. DBP initiates the curing of acrylate more efficiently than HDBP, showing higher photopolymerization rate and unsaturation conversion, resulted from the poor compatibility of HDBP with the resin. The photoinitiating activity of DBP to epoxy acrylate resin is even higher than that of BP at lower loadings.
基金supported by the National Natural Science Foundation of China (Nos. 51173214, J1103305)Department of Education of Guangdong Province (2012KJCX0005)Science and Technology Bureau of Guangzhou
文摘A new macromolecular surface modifier, a copolymer of lauryl methacrylate （LMA） and poly（ethylene glycol） methyl methacrylate （PEGMA）, was synthesized through free radical polymerization. The copolymer was characterized by nuclear magnetic resonance spectrum （lH-NMR） and thermogravimetric analysis （TGA）. The copolymer was used to blend with polyethylene. The binary blends have been characterized by attenuated total reflection/Fourier transform infrared （ATR- FTIR）, contact-angle measurements （CDA） and scanning electron microscopy （SEM）. The results indicated that poly（ethylene glycol） methyl methacrylate-co-lauryl methacrylate （PEGMA-co-LMA） could diffuse preferably onto the surface of the polyethylene （PE） film, and thus can be used as an efficient surface modifier for PE.
基金The National Natural Science Foundation of China under contract No.41376083the Strategic Priority Research Program of the Chinese Academy of Sciences under contract No.XDA23050303
文摘Adsorption kinetics of the interaction between Pt, Pd and Rh(defined here as platinum group elements, PGEs)ions and macromolecular organic compounds(MOCs,>10 kDa), including humic acid, carrageenan and bovine serum albumin, and different cutoff fractions of natural organic matter(>1 kDa and >3 kDa) obtained from seawater using centrifugal ultrafiltration devices were investigated. For a given element, all the adsorption kinetics did not reach equilibrium except the interaction between Pt and >1 kDa cutoff, and between Pd and humic acid.For all the tested MOCs, the adsorption kinetics could be divided into two stages, a rapid adsorption process in the first 8 h and the desorption stage after the first 8 h until the equilibrium. The change trend of partition coefficient(log10Kd) values with experiment time was consistent with that of the kinetic curves. However, in the interaction between PGE ions and natural dissolved organic matter(NDOM), an obvious difference in the change trends of log10Kd and kinetic curves was observed. It indicated that the partition behavior of PGE ions interacting with NDOM in seawater was a combined effect of different organic constituents. The adsorption and log10Kd of PGEs in the >1 kDa NDOM fraction were higher and more stable than those in the >3 kDa NDOM fraction. The results also indicated that the 1–3 kDa NDOM may dominate the interaction between PGEs ions and NDOM. Moreover, no kinetic model could perfectly simulate the adsorption process. It indicated that the colloidal struction and morphology of MOCs or NDOM in seawater might be inhomogeneous. Hence, the interaction between PGE ions and organic matter in seawater was a complicated process and needs further research.
文摘A new unsteady three-dimensional convective-diffusive mathematical model for the transportation of macromolecules and water across the arterial wall was proposed . After the formation of leaky junctions due to the mitosis of endothelial cell of the arterial wall, the macromolecular transport happens surrounding the leaky cells. The arterial wall was divided into four layers: the endothelial layer, the subendothelial intima, the internal elastic lamina and the media for the convenience of research. The time-dependent concentration growth,the effect of the shape of endothelial cell and the effect of physiological parameters were analyzed. The analytical solution of velocity field and pressure field of water flow across the arterial wall were obtained; and concentration distribution of three macromolecules ; LDL,HRP and Albumin, were calculated with numerical simulation method. The new theory predicts, the maximum and distribution areas of time dependent concentration with round shape endothelial cell are both larger than that with ellipse-shape endothelial cell. The model also predicts the concentration growth is much alike that of a two-dimensional model and it shows that the concentration reaches its peak at the leaky junction where atherosclerotic formation frequently occurs and falls down rapidly in a limited area beginning from its earlier time growth to the state when macromolecular transfer approaches steadily. These predictions of the new model are in agreement with the experimental observation for the growth and concentration distribution of LDL and Albumin.
基金the financial support of the National Natural Science Foundation of China(Nos.20806013, 20923006)the National Key Technology R&D Program(No. 2011BAE07B08)
文摘Received 26 September 2012 Received in revised form 18 December 20 Accepted 1 January 2013 Available online 4 February 2013
基金Supported by National Natural Science Foundation of China(31260062,30860121)Talent Introduction Project of Kunming University(YJL11017)
文摘With Bowytis cinerea and its extracellular macromolecular toxins as the test materials, 30 speiees of plants belonging to 29 genera and 21 families were selected as the test plants to observe the infectivity of B. dnerea and damage status of macromolecular toxins secreted by B. cinerea on plants. The resulsts showed that 17 species of plants were beth infected by B. cinerea and damaged by toxins, accounting for 56.7% of the total plants. Two species of plants could be neither infected by B. cinerea nor damaged by toxins. The study provided the reference for further understanding of pathogenic mechanism of plant pathogenic fungi toxins.
文摘DTPA was covalently conjugated to the copolymer of L lysine and L tyrosine, then transchelated with Gd EDTA,the resultant polymer chelates were further reacted with 6 O bromoacetyl D galactose or methyl lactobionyloxyacetate to give PLT(Gd DTPA) with galactose moiety as liver targeting group.These macromolecular MRI contrast agents were characterized by means of FT IR, ICP AES, elementary analyses and UV Vis spectrophotometry. Their in vitro relaxivity and liver targeting property in mice were also investigated.
基金financially supported by National Key Research and Development Project (No. 2020YFE0204400)
文摘Uveitis is a sophisticated syndrome showing a high relevance with reactive oxygen species(ROS).Herein,an ROS-responsive PEGylated polypeptide based macromolecular prodrug of herbaceous antioxidant ethyl caffeate(EC)is designed via phenylboronic esters with improved solubility for the alleviation of uveitis.The antioxidative 4-hydroxybenzyl alcohol(HBA)and EC can be released from the macromolecular EC prodrug under the stimulation of ROS,which can effectively protect cells against oxidative stress-induced injury in an ROS-depletion way.The antioxidative and protective effects of the macromolecular EC prodrug in vivo are further verified in a uveitis mouse model.Overall,this work not only provides a handy method to synthesize a phenylboronic ester-bearing EC prodrug which is highly sensitive to pathological ROS,but also depicts a promising future to apply macromolecular antioxidative prodrugs in the treatment of uveitis as well as other ROS-related diseases.
基金The authors are grateful to the National Institutes of Health in U.S.A.for the R01 grants(AR 045172,AR 052353)to Yang Xia.
文摘Fourier transform infrared imaging(FTIRI)was used to examine the depth-dependent content variations of macromolcular components,ollagen and protooglycan(PG),in osteoarthritic and healthy cartilages.Dried 6 pmm thick sections of canine knee cartilages were imaged at 6.25 pμrm pixel-size in FTIRI.By analyzing the infrared(IR)images and spectra,the depth dependence of characteristic band(sugar)intensity of PG show obvious difference bet ween the cartilage sections of(OA)and bealth.The result confimns that PG content decreases in the ostcoarthritic cartilage.However,no clear change occurs to collagen,suggesting that the OA influences little on the collagen content at early stage of OA.This observation will be helpful to further understand PG loss associated with pathological conditions in OA,and demonstrates that FIIRI has the po-tential to become an important analytical tool to identify early clinical signs of tissue degna-dation,such as PG loss even collagen disruption.
基金This work was finacially supported by the National Key Research and Development Program of China(No.2017YFA0403103)the Key Programs of the Chinese Academy of Sciences(No.ZDRW-CN-2018-2)the Youth Innovation Promotion Association CAS(No.2018040).
文摘Cellulose diacetate(CDA)can be melt processed to produce numerous and widely-used plastic products.However,due to the high glass transition temperature(Tg)of CDA,the addition of up to 30 wt%of micromolecular plasticizers is indispensable,which significantly reduces the dimensional stability and raises safety concerns from the migration of plasticizers.In this work,a series of CDA-graft poly(lactic acid)(CDA-g-PLA)copolymers were synthesized by ring-opening polymerization of lactide onto the hydroxyI groups of CDA.The resultant CDA-g-PLA copolymers possess adjustable degrees of substitution(DSpua)and side chain length(DPpLa)by controlling the reaction time and feed ratio.The Tgs and thermal flow temperatures(Ts)of CDA-g-PLA strongly depend on DPpA such as the Tgs decrease linearly with the increase of DPA.The CDA-g-PLA copolymers with the DPLA of 3-9 can be directly processed to transparent plastics by melt processing without any external plasticizers,because of their low Tfs of 170-215℃.More impressively.the CDA-g PLA can act as the macromolecular plasticizer.The obtained CDA/CDA-g-PLA has higher storage modulus,flexural modulus and Young's modulus than the commercial CDA plasticized with triethyl citrate.In addition,the CDA/CDA-g PLA exhibits high dimensional stabilty and anti-migration property.During a long term treatment at 80℃ and 60%humidity,the CDA/CDA-g-PLA can retain the initial shape.Therefore,this work not only proposes a facile method for achieving a direct thermoplastic processing of CDA,but also provides a macromolecular plasticizer for CDA to make lightweight,stable and safer biobased thermoplastics.
基金supported by the National Key Research and Development Program of China(No.2021YFC2301405)the National Natural Science Foundation of China(No.31971121)Shanghai Science and Technology Plan Project(No.21ZR14718)。
文摘Macromolecular crystallography beamline BL17U1 at the Shanghai Synchrotron Radiation Facility has been relocated,upgraded,and given a new ID(BL02U1).It now delivers X-rays in the energy range of 6–16 keV,with a focused beam of 11.6μm×4.8μm and photon flux greater than 1012 phs/s.The high credibility and stability of the beam and good timing synchronization of the equipment significantly improve the experimental efficiency.Since June 2021,when it officially opened to users,over 4200 h of beamtime have been provided to over 200 research groups to collect data at the beamline.Its good performance and stable operation have led to the resolution of several structures based on data collected at the beamline.
文摘Objective:To investigate the anti-tumor effect of macromolecular fractions of fresh gecko (M-AG) in vivo and their differentiation-inducing activity in Bel-7402 cells in vitro.Methods:An H22 hepatocarcinoma-bearing mouse model was used to evaluate the anti-tumor activity of M-AG samples.The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was applied to analyze cell viability.Cell morphology was observed by phase contrast microscopy.The quantity of the alpha-fetoprotein was detected by a radioimmunoassay.Chromatometry was used to assay the albumin quantity.Activities of alkaline phosphatase and γ-glutamyl trans-peptidase were measured by biochemical methods.Finally,western blotting was applied to assess proteins in the mitogen-activated protein kinase (MAPK) signaling pathway.Results:Macromolecular fractions of fresh gecko exerted a significant anti-tumor effect in mice.The inhibition rate of tumor growth was 63% in the moderate M-AG dose group.Cells treated with M-AG displayed a differentiated state.The treatment lowered alphafetoprotein secretion and significantly decreased the activities of γ-glutamyl trans-peptidase and alkaline phosphatase in Bel-7402 cells.In contrast,M-AG increased the amount of albumin in the cell culture medium.All biochemical indices demonstrated that M-AG induced Bel7402 cell differentiation.Western blotting showed no changes in the quantities of extracellular signal-regulated kinase (ERK) 1/2,p38MAPK,or c-Jun N-terminal protein kinase 1/2.However,M-AG significantly activated the phosphorylation of ERK1/2 in a dose-dependent manner.In addition,M-AG had no significant influence on the expression of nuclear factor-kappa B.Conclusion:Macromolecular fractions of fresh gecko has an anti-tumor activity in H22 hepatocarcinoma-bearing mice in vivo and inhibits Bel-7402 cell proliferation in vitro by inducing cell differentiation related to activation of ERK1/2.
基金Project supported by the National Natural Science Foundation of China (Nos. 10372007, 30571900 and 10572006)the Natural Science Foundation of Beijing (No.7062015)
文摘A numerical analysis of the steady/pulsatile flow and macromolecular （such as LDL and Albumin） transport in curved blood vessels was carried out. The computational results predict that the vortex of the secondary flow is time-dependent in the aortic arch. The concentration of macromolecule concentrates at the region of sharp curve, and the wall concentration at the outer part is higher than that at the inner part. Atherosclerosis and thrombosis are prone to develop in such regions with sharp flow.
