Three new salicylate complexes and derivatives have been synthesized and studied by infrared, 119Sn NMR and UV-visible spectroscopies. The suggested structures for the two compounds are discrete with NH-O and NH-Cl hy...Three new salicylate complexes and derivatives have been synthesized and studied by infrared, 119Sn NMR and UV-visible spectroscopies. The suggested structures for the two compounds are discrete with NH-O and NH-Cl hydrogen bonds. The salicylate oxyanion is monochelating for the first salicylate compound with an octahedral tin (IV) centre and monodentate for the second salicylate compound, the environments around the tin centre being tetrahedral. For the cooper complex, the salicylate ligand is monochelating and the environments around the copper atom centre are tetrahedral.展开更多
This paper presents a reconstruction algorithm to build a surface mesh approximating an object from an unorganized point sampling of the boundary object. It combines 3D Delaunay tetrahedralization and mesh-growing met...This paper presents a reconstruction algorithm to build a surface mesh approximating an object from an unorganized point sampling of the boundary object. It combines 3D Delaunay tetrahedralization and mesh-growing method and uses only once Delau- nay triangulation. It begins with 3D Delaunay triangulation of the sampling. Then initialize the surface mesh with seed facets se- lected from Delaunay triangulation. Selection is based on the angle formed by the circumscribing ball of incident tetrahedral. Finally, grow until complete the surface mesh based on some heuristic rules. This paper shows several experimental results that demonstrate this method can handle open and close surfaces and work efficiently on various object topologies except non-manifold surface with self-intersections. It can reproduce even the smallest details of well-sampled surfaces but not work properly in every under-sampled situation that point density is too low.展开更多
Local mesh refinement is one of the key steps in the implementations of adaptive finite element methods. This paper presents a parallel algorithm for distributed memory parallel computers for adaptive local refinement...Local mesh refinement is one of the key steps in the implementations of adaptive finite element methods. This paper presents a parallel algorithm for distributed memory parallel computers for adaptive local refinement of tetrahedral meshes using bisection. This algorithm is used in PHG, Parallel Hierarchical Grid Chttp://lsec. cc. ac. cn/phg/), a toolbox under active development for parallel adaptive finite element solutions of partial differential equations. The algorithm proposed is characterized by allowing simukaneous refinement of submeshes to arbitrary levels before synchronization between submeshes and without the need of a central coordinator process for managing new vertices. Using the concept of canonical refinement, a simple proof of the independence of the resulting mesh on the mesh partitioning is given, which is useful in better understanding the behaviour of the biseetioning refinement procedure.展开更多
The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN appli...The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN application is automatic creating data structure. Although a raster algorithm has been introduced by some authors, the problems in accuracy, memory requirement, speed and integrity are still existent. In this paper, the raster algorithm is completed and a vector algorithm is presented after a 3-D data model and structure of TEN have been introducted. Finally, experiment, conclusion and future work are discussed.展开更多
Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, ...Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, inflammation should be inhibited, and chondrocyte proliferation should be promoted. Tetrahedral framework nucleic acids can be internalized by chondrocytes(even inflammatory chondrocytes) and can enhance their proliferation and migration. Wogonin, a naturally occurring flavonoid,suppresses oxidative stress and inhibits inflammation. In this study, tetrahedral framework nucleic acids were successfully selfassembled and used to load wogonin. We confirmed the effective formation of tetrahedral framework nucleic acid/wogonin complexes by dynamic light scattering, zeta potential analysis, transmission electron microscopy, and fluorescence spectrophotometry. Tetrahedral framework nucleic acids, wogonin, and especially tetrahedral framework nucleic acid/wogonin complexes effectively alleviated inflammation in vitro and in vivo and prevented cartilage destruction. In addition, these materials remarkably downregulated the expression of inflammatory mediators and matrix metalloproteinases, upregulated chondrogenic markers, and promoted tissue inhibitor of metalloproteinase 1 and B-cell lymphoma 2 expression. In vivo, after treatment with tetrahedral framework nucleic acid/wogonin complexes, the bone mineral density in regenerated tissues was much higher than that found in the untreated groups. Histologically, the complexes enhanced new tissue regeneration, significantly suppressed chondrocyte apoptosis, and promoted chondrogenic marker expression. They also inhibited cell apoptosis, increased chondrogenic marker expression, and suppressed the expression of inflammatory mediators in osteoarthritis. Therefore, we believe that tetrahedral framework nucleic acid/wogonin complexes can be used as an injectable form of therapy for osteoarthritis.展开更多
Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current...Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current therapeutic approaches lack efficacy and immunomodulatory capacity.Thus,a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance.Here,we synthesized a tetrahedral framework nucleic acid(tFNA)nanoparticle that carried resveratrol(RSV)to inhibit tissue inflammation and improve insulin sensitivity in obese mice.The prepared nanoparticles,namely tFNAs-RSV,possessed the characteristics of simple synthesis,stable properties,good water solubility,and superior biocompatibility.The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy.In high-fat diet(HFD)-fed mice,the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status.tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages.As for adaptive immunity,the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg,leading to the alleviation of insulin resistance.Furthermore,this study is the first to demonstrate that tFNAs,a nucleic acid material,possess immunomodulatory capacity.Collectively,our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice,suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.展开更多
Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentant...Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera (G. Don) Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi (Sweet) Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding & Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.展开更多
In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has ...In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has an impact on the convergence and solution in STRs, and they are used in mixing, multiphase modeling or as starting solution of transient models as DES and LES. Although there are several studies with the pitched blade turbine(PBT) impeller, most of them used the Standard model as representative of all k–ε models, using structured hexahedral grids composed of low number of cells, and in some cases under axial symmetry assumptions.Accordingly, in this work the assessment of the Standard, RNG and Realizable models to describe the turbulent flow field of this impeller, using the Multiple Reference Frame(MRF) and Sliding Mesh(SM) approaches with tetrahedral domains in dense grids, is presented. This kind of cell elements is especially suitable to reproduce complex geometries. Flow velocities and turbulent parameters were verified experimentally by PIV and torque measurements. The three models were capable of predicting fairly the pumping number, the power number based on torque, and velocities. Although the RNG improved the predictions of the turbulent kinetic energy and dissipation rate, the Realizable model presented better performance for both approaches. All models failed in the prediction of the total dissipation rate, and a dependence of its value on the number of cells for the MRF was found.展开更多
With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versati...With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids(t FNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, t FNAs have been widely applied in the biomedical field as threedimensional DNA nanomaterials. Surprisingly, t FNAs exhibit positive effects on cellular biological behaviors and tissue regeneration,which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity,t FNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization,intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic t FNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic t FNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone,cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases.展开更多
The microstructure and properties of tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum arc technology has been investigated by visible Raman spectroscopy, AFM and Nano-indentor. The R...The microstructure and properties of tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum arc technology has been investigated by visible Raman spectroscopy, AFM and Nano-indentor. The Raman spectra have been fitted with a single skewed Lorentzian lineshape described by BWF function defining coupling coefficient, which characterizes the degree of asymmetry and is correlated with the sp3 content. When the substrate bias is -80 V, the sp3 content is the most and simultaneously the coupling coefficient is the least, following with the minimum root mean square surface roughness (Rq=0.23 nm) and the highest hardness (51.49 GPa), Young′s modulus (512.39 GPa), and critical scratching load (11.72 mN). As the substrate bias is increased or decreased, the sp3 content and other properties lower correspondingly.展开更多
The chiral sulfido cluster (η5-C5H5)WFeCo(CO)8(μ3--S) was synthesized by refluxing a solution of HFe2Co(CO)9 (μ3,--S) and (η5-C5H5)Fe(CO)3Cl in tetrahydrofuran. It was characterized by elemental analysis, IR and 1...The chiral sulfido cluster (η5-C5H5)WFeCo(CO)8(μ3--S) was synthesized by refluxing a solution of HFe2Co(CO)9 (μ3,--S) and (η5-C5H5)Fe(CO)3Cl in tetrahydrofuran. It was characterized by elemental analysis, IR and 1H/13C--NMR. Theproposal concerning mechanism was discussed herewith and the structure was reportedas well. Crystallographic data: Mr= 563. 85, monoclinicl P21/n(# 14); a= 8. 009(2), b= 17. 600(5), c=12. 003(4) A; β=95. 91(2)°; V= 1683. 0 (9) A3; Z=4;Dc=2. 22 g. cm-3; F(000) = 1048, μ=89. 27 cm-1 ; final R=0. 039 and Rw=0. 049for 2121 observable reflections with (I≥3. cσ(I) ). The crystal structure determinationshows that S atom coordinates to all three metal (W,Fe,Co) atoms in a μ3,-fashion,thetitle cluster core has the tetrahedral skeleton.展开更多
In this study, tetrahedral amorphous carbon (ta-C) films with thicknesses between several 100 nm and several micrometers have been deposited onto polished tungsten carbide and steel substrates by pulsed laser depositi...In this study, tetrahedral amorphous carbon (ta-C) films with thicknesses between several 100 nm and several micrometers have been deposited onto polished tungsten carbide and steel substrates by pulsed laser deposition (PLD) using an excimer laser (248 nm wavelength). We investigate the optical properties (e.g. the refractive index (n) and extinction coefficient (k) in the visible and near-infrared wavelength range) of these layers in dependence of the used laser ablation fluence on the target. It is shown that n of ~2000 nm thick ta-C films can be tuned, depending on the sp3-content, between n = 2.5 and 2.8 at a wavelength of 632 nm. Besides of this k reduces with the sp3-content and is as low as 0.03 at sp3-contents of more than 75%. We proof that this gives the opportunity to prepare coating with tailored optical properties. Furthermore, it is shown that the ta-C films have low background fluorescence in the wavelengths range of 380 - 750 nm, which make this thin films attractive for certain optical, medical and biotechnological applications. We present for the first time that one possible application is the use in Lab-on-a-Chip-systems (LOC). Within these systems, the ultrasensitive detection of fluorescence markers and dyes is a challenge. In order to increase the signal-to-noise-ratio, a setup was developed, that used the specific optical properties of ta-C films produced by PLD. We used the ta-C film as an integrated reflector that combined low background fluorescence, a low reflectivity at the excitation wavelength and the high reflectivity at the emission wavelength. We prove that this setup improves the detection of fluorescence photons.展开更多
An integrated tetrahedrization algorithm in 3D domain which combines the Delaunay tetrahedral method with un-Delaunay tetrahedral method is described. The algorithm was developed by constructing Delaunay Tetrahedrons ...An integrated tetrahedrization algorithm in 3D domain which combines the Delaunay tetrahedral method with un-Delaunay tetrahedral method is described. The algorithm was developed by constructing Delaunay Tetrahedrons from a scattered point set, recovering boundaries using Delaunay and un-Delaunay method, inserting additional nodes in unsuitable tetrahedrons, optimizing tetrahedrons and smoothing the tetrahedral mesh with the 2D-3D Laplacian method. The algorithm has been applied to the injection molding CAE preprocessing.展开更多
The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2...The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2Mo(μ_3-CC_6H_5) Br(CO)_9(Py)_2 (3) and Mn_2Mo(μ_3-CC_6H_5)Br(CO)_(10) (Py)_2 (4) respectively. Tri-metal cluster compound Co_2Mo(μ_3-CC_6H_5)Br(CO)_8-(bipy) (bipy=α,α'dipyridyl) (5) is prepared in a similar reaction sequence from [Br(CO)_2(bipy)Mo(≡CC_6H_5)] (1b) and Co_2(CO)_8. IR, ~1H and ^(13)C NMR spectral data of these compounds are reported and discussed. The crystal structure of compound (5) has been determined by X-ray diffraction.展开更多
Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alka...Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and AI atoms to dissolve from a feedstock such as aluminosilicate. A study of 27A1 MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy (SEM) and X-ray diflYactometry (XRD) were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different A1/Si mole ratios from the starting materials. The higher the AI content, the more sufficient the AI atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si--O--A1--O polymer structure, and then the higher the A1 content, the fewer the octahedral A1 with a uniform Si--O--A1--O structure in four directions, because four AI atoms are combined with SiO4, resulting in a uniform Si--O--AI--O structure in four directions. The results show that they have an amorphous microstructure.展开更多
Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method...Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method, scratch method, heating and shaking method as well as boiling salt solution method is used to test the adhesion of the TAC films on various material substrates. Results The test results show that the adhesion is increased as the ion bombardment energy increases. However, if the bombardment energy were over the corresponding optimum value, the adhesion would be enhanced very slowly for the harder material substrates and drops quickly, for the softer ones. Conclusion The optimum values of the ion bombardment energy are larger for the harder materials than that for the softer ones.展开更多
A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mo...A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mobile phase with various alcohols as modifiers.展开更多
For the numerical simulation of compressible flows,normally different mesh sizes are expected in different regions.For example,smaller mesh sizes are required to improve the local numerical resolution in the regions w...For the numerical simulation of compressible flows,normally different mesh sizes are expected in different regions.For example,smaller mesh sizes are required to improve the local numerical resolution in the regions where the physical variables vary violently(for example,near the shock waves or in the boundary layers)and larger elements are expected for the regions where the solution is smooth.h-adaptive mesh has been widely used for complex flows.However,there are two difficulties when employing h-adaptivity for high-order discontinuous Galerkin(DG)methods.First,locally curved elements are required to precisely match the solid boundary,which significantly increases the difficulty to conduct the"refining"and"coarsening"operations since the curved information has to be maintained.Second,h-adaptivity could break the partition balancing,which would significantly affect the efficiency of parallel computing.In this paper,a robust and automatic h-adaptive method is developed for high-order DG methods on locally curved tetrahedral mesh,for which the curved geometries are maintained during the h-adaptivity.Furthermore,the reallocating and rebalancing of the computational loads on parallel clusters are conducted to maintain the parallel efficiency.Numerical results indicate that the introduced h-adaptive method is able to generate more reasonable mesh according to the structure of flow-fields.展开更多
The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space g...The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.685(2), b = 6.656(1), c = 6.377(1) , V = 326.2(1) 3, Z = 2, Dc = 5.472 g/cm3, Mr = 537.43, F(000) = 476, m = 32.12 mm-1, R = 0.0642, wR = 0.1481 and S = 1.037. The 3-D structure can be regarded as constructed from the alternately stacking of [Cu(2)Se4] tetrahedral layers and Cu(1)PSe tetrahedral layers along the b direction, in which the Cu(2)Se layer is comprised of corner-sharing [Cu(2)Se4] tetrahedra along the a and c directions, and the Cu(1)PSe layer is consisted of alternately corner-sharing [Cu(1)Se4] tetrahedra and [PSe4] tetrahedra along the a and c directions.展开更多
文摘Three new salicylate complexes and derivatives have been synthesized and studied by infrared, 119Sn NMR and UV-visible spectroscopies. The suggested structures for the two compounds are discrete with NH-O and NH-Cl hydrogen bonds. The salicylate oxyanion is monochelating for the first salicylate compound with an octahedral tin (IV) centre and monodentate for the second salicylate compound, the environments around the tin centre being tetrahedral. For the cooper complex, the salicylate ligand is monochelating and the environments around the copper atom centre are tetrahedral.
基金Supported by National Natural Science Foundation of China(No.60875046)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1109)+5 种基金the Key Project of Chinese Ministry of Education(No.209029)the Program for Liaoning Excellent Talents in University(No.LR201003)the Program for Liaoning Science and Technology Research in University(No.LS2010008,2009S008,2009S009, LS2010179)the Program for Liaoning Innovative Research Team in University(Nos.2009T005, LT2010005, LT2011018)Natural Science Foundation of Liaoning Province(201102008)"Liaoning Bai Qian Wan Talents Program(2010921010, 2011921009)"
文摘This paper presents a reconstruction algorithm to build a surface mesh approximating an object from an unorganized point sampling of the boundary object. It combines 3D Delaunay tetrahedralization and mesh-growing method and uses only once Delau- nay triangulation. It begins with 3D Delaunay triangulation of the sampling. Then initialize the surface mesh with seed facets se- lected from Delaunay triangulation. Selection is based on the angle formed by the circumscribing ball of incident tetrahedral. Finally, grow until complete the surface mesh based on some heuristic rules. This paper shows several experimental results that demonstrate this method can handle open and close surfaces and work efficiently on various object topologies except non-manifold surface with self-intersections. It can reproduce even the smallest details of well-sampled surfaces but not work properly in every under-sampled situation that point density is too low.
基金supported by the 973 Program of China 2005CB321702China NSF 10531080.
文摘Local mesh refinement is one of the key steps in the implementations of adaptive finite element methods. This paper presents a parallel algorithm for distributed memory parallel computers for adaptive local refinement of tetrahedral meshes using bisection. This algorithm is used in PHG, Parallel Hierarchical Grid Chttp://lsec. cc. ac. cn/phg/), a toolbox under active development for parallel adaptive finite element solutions of partial differential equations. The algorithm proposed is characterized by allowing simukaneous refinement of submeshes to arbitrary levels before synchronization between submeshes and without the need of a central coordinator process for managing new vertices. Using the concept of canonical refinement, a simple proof of the independence of the resulting mesh on the mesh partitioning is given, which is useful in better understanding the behaviour of the biseetioning refinement procedure.
基金Project supported by the National Natural Science Foundation of China (No.69833010)
文摘The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN application is automatic creating data structure. Although a raster algorithm has been introduced by some authors, the problems in accuracy, memory requirement, speed and integrity are still existent. In this paper, the raster algorithm is completed and a vector algorithm is presented after a 3-D data model and structure of TEN have been introducted. Finally, experiment, conclusion and future work are discussed.
基金supported by National Key R&D Program of China (2019YFA0110600)National Natural Science Foundation of China (81970986, 81771125)
文摘Osteoarthritis, a disorder characterized by articular cartilage deterioration, varying degrees of inflammation, and chondrocyte apoptosis, is the most common chronic joint disease. To slow or reverse its progression, inflammation should be inhibited, and chondrocyte proliferation should be promoted. Tetrahedral framework nucleic acids can be internalized by chondrocytes(even inflammatory chondrocytes) and can enhance their proliferation and migration. Wogonin, a naturally occurring flavonoid,suppresses oxidative stress and inhibits inflammation. In this study, tetrahedral framework nucleic acids were successfully selfassembled and used to load wogonin. We confirmed the effective formation of tetrahedral framework nucleic acid/wogonin complexes by dynamic light scattering, zeta potential analysis, transmission electron microscopy, and fluorescence spectrophotometry. Tetrahedral framework nucleic acids, wogonin, and especially tetrahedral framework nucleic acid/wogonin complexes effectively alleviated inflammation in vitro and in vivo and prevented cartilage destruction. In addition, these materials remarkably downregulated the expression of inflammatory mediators and matrix metalloproteinases, upregulated chondrogenic markers, and promoted tissue inhibitor of metalloproteinase 1 and B-cell lymphoma 2 expression. In vivo, after treatment with tetrahedral framework nucleic acid/wogonin complexes, the bone mineral density in regenerated tissues was much higher than that found in the untreated groups. Histologically, the complexes enhanced new tissue regeneration, significantly suppressed chondrocyte apoptosis, and promoted chondrogenic marker expression. They also inhibited cell apoptosis, increased chondrogenic marker expression, and suppressed the expression of inflammatory mediators in osteoarthritis. Therefore, we believe that tetrahedral framework nucleic acid/wogonin complexes can be used as an injectable form of therapy for osteoarthritis.
基金National Key R&D Program of China(2019YFA0110600)National Natural Science Foundation of China(81970916,81671031)the LU JIAXI International team program supported by the K.C.Wong Education Foundation and CAS and the Youth Innovation Promotion Association of CAS(Grant No.2016236).
文摘Obesity-induced insulin resistance is the hallmark of metabolic syndrome,and chronic,low-grade tissue inflammation links obesity to insulin resistance through the activation of tissue-infiltrating immune cells.Current therapeutic approaches lack efficacy and immunomodulatory capacity.Thus,a new therapeutic approach is needed to prevent chronic inflammation and alleviate insulin resistance.Here,we synthesized a tetrahedral framework nucleic acid(tFNA)nanoparticle that carried resveratrol(RSV)to inhibit tissue inflammation and improve insulin sensitivity in obese mice.The prepared nanoparticles,namely tFNAs-RSV,possessed the characteristics of simple synthesis,stable properties,good water solubility,and superior biocompatibility.The tFNA-based delivery ameliorated the lability of RSV and enhanced its therapeutic efficacy.In high-fat diet(HFD)-fed mice,the administration of tFNAs-RSV ameliorated insulin resistance by alleviating inflammation status.tFNAs-RSV could reverse M1 phenotype macrophages in tissues to M2 phenotype macrophages.As for adaptive immunity,the prepared nanoparticles could repress the activation of Th1 and Th17 and promote Th2 and Treg,leading to the alleviation of insulin resistance.Furthermore,this study is the first to demonstrate that tFNAs,a nucleic acid material,possess immunomodulatory capacity.Collectively,our findings demonstrate that tFNAs-RSV alleviate insulin resistance and ameliorate inflammation in HFD mice,suggesting that nucleic acid materials or nucleic acid-based delivery systems may be a potential agent for the treatment of insulin resistance and obesity-related metabolic diseases.
基金supported by the National Natural Science Foundation of China (Grant No.30370106)
文摘Eighty-four pollen samples were obtained for 80 taxa, of which, 13 species and one variety are from sect. Brachycalyx Sweet, 58 species and two varieties from sect. Tsutsusi Sweet, and six species from subgen. Pentanthera (G. Don) Pojarkova, respectively. Pollen morphology of all samples was observed using LM and SEM. Pollen grains are revealed to be spheroidal and tetrahedral with tricolporate apertures. Pollen sizes of subgen. Tsutsusi (Sweet) Pojarkova range from 37.67 μm to 61.06μm, and the exine sculptures are more or less compactly granulated. Pollen sizes are significantly different between sect. Brachycalyx and sect. Tsutsusi of subgen. Tsutsusi. Rhododendron tashiroi Maxim. of sect. Tsusiopsis Sleumer shows a close affinity to sect. Brachycalyx. Pollen size and exine are consistent with general morphology in differentiating species in sect. Tsutsusi. Rhododendron huadingense B. Y. Ding & Y. Y. Fang, once placed as a member of sect. Brachycalyx, should be considered as a species in subgen. Pentanthera.
基金the National Council of Science and Technology, Mexico CONACyT for the support provided for this research, through the Basic Science project CB-2011/ 169786
文摘In turbulence modeling, the RNG and Realizable models have important improvements in the turbulent production and dissipation terms in comparison to the Standard. The selection of the appropriate turbulence model has an impact on the convergence and solution in STRs, and they are used in mixing, multiphase modeling or as starting solution of transient models as DES and LES. Although there are several studies with the pitched blade turbine(PBT) impeller, most of them used the Standard model as representative of all k–ε models, using structured hexahedral grids composed of low number of cells, and in some cases under axial symmetry assumptions.Accordingly, in this work the assessment of the Standard, RNG and Realizable models to describe the turbulent flow field of this impeller, using the Multiple Reference Frame(MRF) and Sliding Mesh(SM) approaches with tetrahedral domains in dense grids, is presented. This kind of cell elements is especially suitable to reproduce complex geometries. Flow velocities and turbulent parameters were verified experimentally by PIV and torque measurements. The three models were capable of predicting fairly the pumping number, the power number based on torque, and velocities. Although the RNG improved the predictions of the turbulent kinetic energy and dissipation rate, the Realizable model presented better performance for both approaches. All models failed in the prediction of the total dissipation rate, and a dependence of its value on the number of cells for the MRF was found.
基金supported by National Key R&D Program of China(2019YFA0110600)National Natural Science Foundation of China(82101077,81970916)+3 种基金Sichuan Province Youth Science and Technology Innovation Team(2022JDTD0021)Sichuan University Postdoctoral Interdisciplinary Innovation Fundthe Fundamental Research Funds for the Central Universities,Postdoctoral Science Foundation of China(Grant 2021M692271)West China School/Hospital of Stomatology Sichuan University(No.RCDWJS2022-14 and RCDWJS2021-20)。
文摘With the emergence of DNA nanotechnology in the 1980s, self-assembled DNA nanostructures have attracted considerable attention worldwide due to their inherent biocompatibility, unsurpassed programmability, and versatile functions. Especially promising nanostructures are tetrahedral framework nucleic acids(t FNAs), first proposed by Turberfield with the use of a one-step annealing approach. Benefiting from their various merits, such as simple synthesis, high reproducibility, structural stability, cellular internalization, tissue permeability, and editable functionality, t FNAs have been widely applied in the biomedical field as threedimensional DNA nanomaterials. Surprisingly, t FNAs exhibit positive effects on cellular biological behaviors and tissue regeneration,which may be used to treat inflammatory and degenerative diseases. According to their intended application and carrying capacity,t FNAs could carry functional nucleic acids or therapeutic molecules through extended sequences, sticky-end hybridization,intercalation, and encapsulation based on the Watson and Crick principle. Additionally, dynamic t FNAs also have potential applications in controlled and targeted therapies. This review summarized the latest progress in pure/modified/dynamic t FNAs and demonstrated their regenerative medicine applications. These applications include promoting the regeneration of the bone,cartilage, nerve, skin, vasculature, or muscle and treating diseases such as bone defects, neurological disorders, joint-related inflammatory diseases, periodontitis, and immune diseases.
文摘The microstructure and properties of tetrahedral amorphous carbon (ta-C) films deposited by the filtered cathodic vacuum arc technology has been investigated by visible Raman spectroscopy, AFM and Nano-indentor. The Raman spectra have been fitted with a single skewed Lorentzian lineshape described by BWF function defining coupling coefficient, which characterizes the degree of asymmetry and is correlated with the sp3 content. When the substrate bias is -80 V, the sp3 content is the most and simultaneously the coupling coefficient is the least, following with the minimum root mean square surface roughness (Rq=0.23 nm) and the highest hardness (51.49 GPa), Young′s modulus (512.39 GPa), and critical scratching load (11.72 mN). As the substrate bias is increased or decreased, the sp3 content and other properties lower correspondingly.
文摘The chiral sulfido cluster (η5-C5H5)WFeCo(CO)8(μ3--S) was synthesized by refluxing a solution of HFe2Co(CO)9 (μ3,--S) and (η5-C5H5)Fe(CO)3Cl in tetrahydrofuran. It was characterized by elemental analysis, IR and 1H/13C--NMR. Theproposal concerning mechanism was discussed herewith and the structure was reportedas well. Crystallographic data: Mr= 563. 85, monoclinicl P21/n(# 14); a= 8. 009(2), b= 17. 600(5), c=12. 003(4) A; β=95. 91(2)°; V= 1683. 0 (9) A3; Z=4;Dc=2. 22 g. cm-3; F(000) = 1048, μ=89. 27 cm-1 ; final R=0. 039 and Rw=0. 049for 2121 observable reflections with (I≥3. cσ(I) ). The crystal structure determinationshows that S atom coordinates to all three metal (W,Fe,Co) atoms in a μ3,-fashion,thetitle cluster core has the tetrahedral skeleton.
文摘In this study, tetrahedral amorphous carbon (ta-C) films with thicknesses between several 100 nm and several micrometers have been deposited onto polished tungsten carbide and steel substrates by pulsed laser deposition (PLD) using an excimer laser (248 nm wavelength). We investigate the optical properties (e.g. the refractive index (n) and extinction coefficient (k) in the visible and near-infrared wavelength range) of these layers in dependence of the used laser ablation fluence on the target. It is shown that n of ~2000 nm thick ta-C films can be tuned, depending on the sp3-content, between n = 2.5 and 2.8 at a wavelength of 632 nm. Besides of this k reduces with the sp3-content and is as low as 0.03 at sp3-contents of more than 75%. We proof that this gives the opportunity to prepare coating with tailored optical properties. Furthermore, it is shown that the ta-C films have low background fluorescence in the wavelengths range of 380 - 750 nm, which make this thin films attractive for certain optical, medical and biotechnological applications. We present for the first time that one possible application is the use in Lab-on-a-Chip-systems (LOC). Within these systems, the ultrasensitive detection of fluorescence markers and dyes is a challenge. In order to increase the signal-to-noise-ratio, a setup was developed, that used the specific optical properties of ta-C films produced by PLD. We used the ta-C film as an integrated reflector that combined low background fluorescence, a low reflectivity at the excitation wavelength and the high reflectivity at the emission wavelength. We prove that this setup improves the detection of fluorescence photons.
文摘An integrated tetrahedrization algorithm in 3D domain which combines the Delaunay tetrahedral method with un-Delaunay tetrahedral method is described. The algorithm was developed by constructing Delaunay Tetrahedrons from a scattered point set, recovering boundaries using Delaunay and un-Delaunay method, inserting additional nodes in unsuitable tetrahedrons, optimizing tetrahedrons and smoothing the tetrahedral mesh with the 2D-3D Laplacian method. The algorithm has been applied to the injection molding CAE preprocessing.
文摘The carbyne compound [Br(CO)_2(Py)_2Mo(≡CC_6H_5)] (Py=pyridine) (1a) reacts with Co_2 (CO)_8, Fe_2(CO)_9 and Mn_2 (CO)_(10) to give tetrahedral tri-metal cluster compounds Co_2Mo(μ_3-CC_6H_5)Br(CO)_8(Py)_2 (2), Fe_2Mo(μ_3-CC_6H_5) Br(CO)_9(Py)_2 (3) and Mn_2Mo(μ_3-CC_6H_5)Br(CO)_(10) (Py)_2 (4) respectively. Tri-metal cluster compound Co_2Mo(μ_3-CC_6H_5)Br(CO)_8-(bipy) (bipy=α,α'dipyridyl) (5) is prepared in a similar reaction sequence from [Br(CO)_2(bipy)Mo(≡CC_6H_5)] (1b) and Co_2(CO)_8. IR, ~1H and ^(13)C NMR spectral data of these compounds are reported and discussed. The crystal structure of compound (5) has been determined by X-ray diffraction.
基金supported by Energy Resource Technology Development Project [The Development and commercialization of Inorganic Polymer Ceramic Panel] of Korea Energy Management Corporationsupported by NCRC(National Core Research Center) Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology
文摘Inorganic polymers are a novel class of materials formed by the polymerization of silicon, aluminium and oxygen species to form an amorphous three-dimensional framework structure. The basis of this process is the alkaline solutions to induce a certain amount of Si and AI atoms to dissolve from a feedstock such as aluminosilicate. A study of 27A1 MAS-NMR was carried out in an attempt to understand the reaction mechanism of the inorganic polymerization at ambient temperature. Scanning electron microscopy (SEM) and X-ray diflYactometry (XRD) were also employed to establish the composition and microstructure of the inorganic polymerization. Specimens were prepared with different A1/Si mole ratios from the starting materials. The higher the AI content, the more sufficient the AI atoms that can combine with SiO4, and the longer the reaction time, the more the bonded Si--O--A1--O polymer structure, and then the higher the A1 content, the fewer the octahedral A1 with a uniform Si--O--A1--O structure in four directions, because four AI atoms are combined with SiO4, resulting in a uniform Si--O--AI--O structure in four directions. The results show that they have an amorphous microstructure.
文摘Objective The high energy ion bombardment technique is applied to enhancing the adhesion of the tetrahedral amorphous carbon (TAC) films deposited by the filtered cathode vacuum arc (FCVA). Methods The abrasion method, scratch method, heating and shaking method as well as boiling salt solution method is used to test the adhesion of the TAC films on various material substrates. Results The test results show that the adhesion is increased as the ion bombardment energy increases. However, if the bombardment energy were over the corresponding optimum value, the adhesion would be enhanced very slowly for the harder material substrates and drops quickly, for the softer ones. Conclusion The optimum values of the ion bombardment energy are larger for the harder materials than that for the softer ones.
基金supported by the Chinese Academy of Sciences under a‘Hundreds of Talents program’to Yonmnin Li.
文摘A series of novel chiral tetrahedral heterometal clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high performance liquid chrom-atography, using hexane as the mobile phase with various alcohols as modifiers.
基金supported by the funding of the Key Laboratory of Aerodynamic Noise Control(No.ANCL20190103)the State Key Laboratory of Aerodynamics(No.SKLA20180102)+1 种基金the Aeronautical Science Foundation of China(Nos.2018ZA52002,2019ZA052011)the National Natural Science Foundation of China(Nos.61672281,61732006)。
文摘For the numerical simulation of compressible flows,normally different mesh sizes are expected in different regions.For example,smaller mesh sizes are required to improve the local numerical resolution in the regions where the physical variables vary violently(for example,near the shock waves or in the boundary layers)and larger elements are expected for the regions where the solution is smooth.h-adaptive mesh has been widely used for complex flows.However,there are two difficulties when employing h-adaptivity for high-order discontinuous Galerkin(DG)methods.First,locally curved elements are required to precisely match the solid boundary,which significantly increases the difficulty to conduct the"refining"and"coarsening"operations since the curved information has to be maintained.Second,h-adaptivity could break the partition balancing,which would significantly affect the efficiency of parallel computing.In this paper,a robust and automatic h-adaptive method is developed for high-order DG methods on locally curved tetrahedral mesh,for which the curved geometries are maintained during the h-adaptivity.Furthermore,the reallocating and rebalancing of the computational loads on parallel clusters are conducted to maintain the parallel efficiency.Numerical results indicate that the introduced h-adaptive method is able to generate more reasonable mesh according to the structure of flow-fields.
基金This work was supported by the National Natural Science Foundation of China (20001007 20131020) Natural Science Foundation of the Chinese Academy of Sciences (KJCX2-H3) and Fujian Province (2000F006)
文摘The title compound Cu3PSe4 was synthesized by the reaction of CuCl, P2Se5 and Se in a molar ratio of 1:1:1 at 500 C and structurally characterized by X-ray crystallography. The crystal belongs to orthorhombic, space group Pmn21 with cell parameters: a = 7.685(2), b = 6.656(1), c = 6.377(1) , V = 326.2(1) 3, Z = 2, Dc = 5.472 g/cm3, Mr = 537.43, F(000) = 476, m = 32.12 mm-1, R = 0.0642, wR = 0.1481 and S = 1.037. The 3-D structure can be regarded as constructed from the alternately stacking of [Cu(2)Se4] tetrahedral layers and Cu(1)PSe tetrahedral layers along the b direction, in which the Cu(2)Se layer is comprised of corner-sharing [Cu(2)Se4] tetrahedra along the a and c directions, and the Cu(1)PSe layer is consisted of alternately corner-sharing [Cu(1)Se4] tetrahedra and [PSe4] tetrahedra along the a and c directions.