In liquid-liquid solvent extraction processes, diluents have a strong influence on the extraction mechanism and efficiency. In this study, benzene, cyclohexane, trichloromethane, carbon tetrachloride, methyl isobutyl ...In liquid-liquid solvent extraction processes, diluents have a strong influence on the extraction mechanism and efficiency. In this study, benzene, cyclohexane, trichloromethane, carbon tetrachloride, methyl isobutyl ketone (MIBK), butyl acetate, and 1-octanol were used as diluents in the extraction of oxalic acid by trialkylphos-phine oxide (TRPO). The effects of extractant concentration, initial concentration of oxalic acid and diluent type on the extraction equilibrium partition coefficient are analyzed. The sequence of the extraction ability by different diluents is MIBK > butyl acetate > cyclohexane=benzene > carbon tetrachloride > 1-octanol > trichloromethane. Extraction mechanism was analyzed and extraction model parameters were evaluated.展开更多
Objective: To examine expressions of chemokine receptor CXCR4 and its ligand CXCL12 in primary focus and lymphogenous metastasis of salivary adenoid cystic carcinoma (ACC) with lung metastasis. Methods: Using immunohi...Objective: To examine expressions of chemokine receptor CXCR4 and its ligand CXCL12 in primary focus and lymphogenous metastasis of salivary adenoid cystic carcinoma (ACC) with lung metastasis. Methods: Using immunohistochemical hypersensitivity catalyzed signal amplification (CSA), expressions of chemokine receptor CXCR4 and ligand CXCL12 were detected in tissue specimens from 20 cases of primary cancer focus and lymphogenous metastasis of salivary adenoid cystic carcinoma, of which 7 cases were associated with lung metastasis and 3 with lympogenous metastasis. Twenty cases of tongue carcinoma (including 10 cases with lymphogenous metastasis) and 15 cases of mucoepidermoid carcinoma (including 5 cases with lymphogenous metastasis) were used as the malignant control group;and salivary mixed tumor (n=10), tongue leukoceratosis (n=10) and cervical lymph node reactive hyperplasia (n=10) were used as the benign control group. Results: Expression of CXCR4 in the tissues and lymph metastases of oral and maxillofacial salivary ACC, mucoepidermoid carcinoma and tongue carcinoma was significantly higher than that of the benign control group (P<0.05); expression of CXCR4 in the primary focus of ACC was significantly higher than that of the malignant control group; and expression of CXCR4 in the ACC with lung metastasis was 87.1% (6/7), significantly higher than that without lung metastasis(P<0.01). There was evident positive expression of CXCL12 in endotheliocytes of microvessels within cancer and paracancer tissues and significantly high expression of CXCL12 in lymphogenous metastasis(P<0.05). Conclusion: Chemokine receptor CXCR4 and its ligand CXCL12 may be associated with local invasion and lymphogenous metastasis of oral and maxillofacial cancer, especially with lung metastasis of salivary ACC.展开更多
A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), ...A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), c = 15.11280(10) ?, β = 108.724(2)°, V = 2190.09(7) ?3, Mr = 518.83, Z = 4, T = 293(2) K, Dc = 1.574 g/cm3, μ = 1.280 mm-1, F(000) = 1060 and S = 1.085. The final R = 0.0543 and wR = 0.1433 for 2693 observed reflections with I >2σ(I). The penta- coordinated copper (II) complex assumes an approximate square pyramidal geometry. Cyclic volta- mmetry measurement of the complex showed a quasi-reversible CuII/CuI redox couple with E1/2 = –0.467 v and ?E = 68 mv.展开更多
DNA mismatch repair guards the integrity of the genome of almost all organisms by correcting DNA biosynthetic errors and by ensuring the fidelity of homologous genetic recombination. MutL is one of the important prote...DNA mismatch repair guards the integrity of the genome of almost all organisms by correcting DNA biosynthetic errors and by ensuring the fidelity of homologous genetic recombination. MutL is one of the important proteins involved in mismatch repair system. It has been suggested to function as a master coordinator or molecular matchmaker because it interacts physically with MutS, the endonuclease MutH, and DNA helicase UvrD. It also binds to DNA and has an ATPase activity. MutL defective bacteria strains have elevated mutation rates and it has been reported recently that MutL defect may have an important impact on bacterial evolution.展开更多
Four metallodithiolene complexes[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?di[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)](3),[4,8-bis(octyloxy)-1,3,5,7-tetrathia]di[1,3-bis(diphenylphosphino)propane?nickel(II)](4)...Four metallodithiolene complexes[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?di[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)](3),[4,8-bis(octyloxy)-1,3,5,7-tetrathia]di[1,3-bis(diphenylphosphino)propane?nickel(II)](4),[4,8-bis(octyloxy)-1,3,5,7-tetra-thia]?[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)]?[1,3-bis(diphenylphosphino)propane·nickel(II)](5)and di[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)]?nickel(II)(6)were synthesized and the near-infrared(NIR)electrochromic properties were studied.The spectroelectrochemical spectra and the electrochromic parameters such as optical contrast,switching time,optical density change,electrochromic efficiency and optical attenuation of complexes 3–6 were investigated in detail.The symmetric binuclear complex 4 showed relatively high electrochromic efficiency of63.0 and 75.4 cm^2/C both in the two oxidation states.The complexes exhibited excellent electroactive/electrochromic stability characterized by chronoamperometry(>4000 cyclic switches).展开更多
Canonical Watson-Crick base pairs and four representative mismatched base pairs have been studied by quantum chemical computations. Detailed anharmonic vibrational analysis was carried out to reveal some vibrational s...Canonical Watson-Crick base pairs and four representative mismatched base pairs have been studied by quantum chemical computations. Detailed anharmonic vibrational analysis was carried out to reveal some vibrational signatures characteristic of structural aspects of the base monomers and dimers, which were well manifested in simulated 1D IR and 2D IR spectra. The degree of delocalization of the selected normal modes, represented by the potential energy distribution, was found to vary sig-nificantly from isolated bases to H-bonded dimers, and was accompanied by changes in anharmonicities of these modes. Examples are given for the generally accepted carbonyl stretching mode of base pairs appearing in the 6-m wavelength region of IR spectra.展开更多
基金Supported by the National Natural Science Foundation of China (No. 29836130).
文摘In liquid-liquid solvent extraction processes, diluents have a strong influence on the extraction mechanism and efficiency. In this study, benzene, cyclohexane, trichloromethane, carbon tetrachloride, methyl isobutyl ketone (MIBK), butyl acetate, and 1-octanol were used as diluents in the extraction of oxalic acid by trialkylphos-phine oxide (TRPO). The effects of extractant concentration, initial concentration of oxalic acid and diluent type on the extraction equilibrium partition coefficient are analyzed. The sequence of the extraction ability by different diluents is MIBK > butyl acetate > cyclohexane=benzene > carbon tetrachloride > 1-octanol > trichloromethane. Extraction mechanism was analyzed and extraction model parameters were evaluated.
文摘Objective: To examine expressions of chemokine receptor CXCR4 and its ligand CXCL12 in primary focus and lymphogenous metastasis of salivary adenoid cystic carcinoma (ACC) with lung metastasis. Methods: Using immunohistochemical hypersensitivity catalyzed signal amplification (CSA), expressions of chemokine receptor CXCR4 and ligand CXCL12 were detected in tissue specimens from 20 cases of primary cancer focus and lymphogenous metastasis of salivary adenoid cystic carcinoma, of which 7 cases were associated with lung metastasis and 3 with lympogenous metastasis. Twenty cases of tongue carcinoma (including 10 cases with lymphogenous metastasis) and 15 cases of mucoepidermoid carcinoma (including 5 cases with lymphogenous metastasis) were used as the malignant control group;and salivary mixed tumor (n=10), tongue leukoceratosis (n=10) and cervical lymph node reactive hyperplasia (n=10) were used as the benign control group. Results: Expression of CXCR4 in the tissues and lymph metastases of oral and maxillofacial salivary ACC, mucoepidermoid carcinoma and tongue carcinoma was significantly higher than that of the benign control group (P<0.05); expression of CXCR4 in the primary focus of ACC was significantly higher than that of the malignant control group; and expression of CXCR4 in the ACC with lung metastasis was 87.1% (6/7), significantly higher than that without lung metastasis(P<0.01). There was evident positive expression of CXCL12 in endotheliocytes of microvessels within cancer and paracancer tissues and significantly high expression of CXCL12 in lymphogenous metastasis(P<0.05). Conclusion: Chemokine receptor CXCR4 and its ligand CXCL12 may be associated with local invasion and lymphogenous metastasis of oral and maxillofacial cancer, especially with lung metastasis of salivary ACC.
基金This project was supported by "973" program of the Ministry of Science and Technology ofChina and National Natural Science Foundation of China (20376010 20128005)
文摘A Cu(II) complex [CuCl(C19H20N4O)]ClO4 1 containing hydroxymethyl substituted TPA (TPA = tris(2-pyridylmethyl)amine) was prepared. It crystallizes in monoclinic, space group P21/c with a = 11.7628(2), b = 13.0083(3), c = 15.11280(10) ?, β = 108.724(2)°, V = 2190.09(7) ?3, Mr = 518.83, Z = 4, T = 293(2) K, Dc = 1.574 g/cm3, μ = 1.280 mm-1, F(000) = 1060 and S = 1.085. The final R = 0.0543 and wR = 0.1433 for 2693 observed reflections with I >2σ(I). The penta- coordinated copper (II) complex assumes an approximate square pyramidal geometry. Cyclic volta- mmetry measurement of the complex showed a quasi-reversible CuII/CuI redox couple with E1/2 = –0.467 v and ?E = 68 mv.
文摘DNA mismatch repair guards the integrity of the genome of almost all organisms by correcting DNA biosynthetic errors and by ensuring the fidelity of homologous genetic recombination. MutL is one of the important proteins involved in mismatch repair system. It has been suggested to function as a master coordinator or molecular matchmaker because it interacts physically with MutS, the endonuclease MutH, and DNA helicase UvrD. It also binds to DNA and has an ATPase activity. MutL defective bacteria strains have elevated mutation rates and it has been reported recently that MutL defect may have an important impact on bacterial evolution.
基金the National Natural Science Foundation of China (21134005, 21474102, 21474105)the Natural Science and Engineering Research Council of Canada
文摘Four metallodithiolene complexes[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?di[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)](3),[4,8-bis(octyloxy)-1,3,5,7-tetrathia]di[1,3-bis(diphenylphosphino)propane?nickel(II)](4),[4,8-bis(octyloxy)-1,3,5,7-tetra-thia]?[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)]?[1,3-bis(diphenylphosphino)propane·nickel(II)](5)and di[4,8-bis(octyloxy)-1,3,5,7-tetrathia]?[1,1′-bis(diphenylphosphino)ferrocene?palladium(II)]?nickel(II)(6)were synthesized and the near-infrared(NIR)electrochromic properties were studied.The spectroelectrochemical spectra and the electrochromic parameters such as optical contrast,switching time,optical density change,electrochromic efficiency and optical attenuation of complexes 3–6 were investigated in detail.The symmetric binuclear complex 4 showed relatively high electrochromic efficiency of63.0 and 75.4 cm^2/C both in the two oxidation states.The complexes exhibited excellent electroactive/electrochromic stability characterized by chronoamperometry(>4000 cyclic switches).
基金supported by the National Natural Science Foundation of China (20727001 and 30870591)the National Basic Research Program of China (973, 2007CB815205)the Chinese Academy of Sciences through the Hundred Talent Fund
文摘Canonical Watson-Crick base pairs and four representative mismatched base pairs have been studied by quantum chemical computations. Detailed anharmonic vibrational analysis was carried out to reveal some vibrational signatures characteristic of structural aspects of the base monomers and dimers, which were well manifested in simulated 1D IR and 2D IR spectra. The degree of delocalization of the selected normal modes, represented by the potential energy distribution, was found to vary sig-nificantly from isolated bases to H-bonded dimers, and was accompanied by changes in anharmonicities of these modes. Examples are given for the generally accepted carbonyl stretching mode of base pairs appearing in the 6-m wavelength region of IR spectra.
