We present an efficient approach for the chemoselective synthesis of arylamines from nitroarenes and formate over an oxygen-implanted MoS2 catalyst（O-MoS2）.O-MoS2 was prepared by incomplete sul idation and reduction...We present an efficient approach for the chemoselective synthesis of arylamines from nitroarenes and formate over an oxygen-implanted MoS2 catalyst（O-MoS2）.O-MoS2 was prepared by incomplete sul idation and reduction of an ammonium molybdate precursor.A number of Mo-O bonds were implanted in the as-synthesized ultrathin O-MoS2 nanosheets.As a consequence of the different coordination geometries of O（Mo O2） and S（MoS2）,and lengths of the Mo-O and Mo-S bonds,the implanted Mo-O bonds induced obvious defects and more coordinatively unsaturated（CUS） Mo sites in O-MoS2,as confirmed by X-ray diffraction,Raman spectroscopy,X-ray photoelectron spectroscopy,high resolution transmission electron microscopy,and extended X-ray absorption fine structure characterization of various MoS2-based materials.O-MoS2 with abundant CUS Mo sites was found to efficiently catalyze the chemoselective reduction of nitroarenes to arylamines.展开更多
AIM:To investigate the role of p53 antibodies (p53Abs),metallothioneins (MTs) and oxidative stress markers in the early detection of dysplasia in chronic ulcerative colitis (UC).METHODS:The study included 30 UC patien...AIM:To investigate the role of p53 antibodies (p53Abs),metallothioneins (MTs) and oxidative stress markers in the early detection of dysplasia in chronic ulcerative colitis (UC).METHODS:The study included 30 UC patients,15 without dysplasia (group Ⅱ) and 15 with dysplasia (group Ⅲ),in addition to 15 healthy volunteers (group Ⅰ,control subjects).The enzyme-linked immunosorbent assay technique was used to measure serum p53Abs and MTs,while advanced oxidation protein products (AOPPs),and reduced glutathione (GSH) levels were measured by spectrophotometric method in all subjects.RESULTS:In group Ⅱ and group Ⅲ compared to group Ⅰ,there were significant increases in serum levels of AOPPs (145.94 ± 29.86 μmol/L and 192.21 ± 46.71 μmol/L vs 128.95 ± 3.06 μmol/L,P < 0.002 and P <0.001,respectively),MTs (8.18 ± 0.35 μg/mL and 9.20 ± 0.58 μg/mL vs 6.12 ± 0.25 μg/mL,P < 0.05 and P < 0.05,respectively),and p53Abs (20.19 ± 3.20 U/mL and 34.66 ± 1.34 U/mL vs 9.42 ± 1.64 U/mL,P < 0.001 and P < 0.001,respectively).There were significantly higher levels of AOPPs (P < 0.05) and p53Abs (P < 0.001) in UC patients with dysplasia compared to those without dysplasia,while MTs showed no significant difference between the 2 groups (P > 0.096).In contrast,GSH levels showed a significant decrease in both patients' groups (1.87 ± 0.02 μmol/mL and 1.37 ± 0.09 μmol/mL vs 2.49 ± 0.10 μmol/mL,P < 0.05 and P < 0.05 in groups Ⅱ and Ⅲ,respectively) compared with group Ⅰ,and the levels were significantly lower in group Ⅲ than group Ⅱ (P < 0.05).There was a positive correlation between AOPPs and both MTs (r=0.678,P < 0.001) and p53Abs (r=0.547,P < 0.001),and also between p53Abs and MTs (r=0.739,P < 0.001).There was a negative correlation between AOPPs and GSH (r =-0.385,P < 0.001),and also between GSH and both MTs (r=-0.662,P < 0.001) and p53Abs (r=-0.923,P < 0.001).CONCLUSION:Oxidative stress and oxidative cellular damage play an important role in the pathogenesis of chronic UC and the associated carcinogenetic process.p53Abs levels could help in early detection of dysplasia in these conditions.展开更多
A systematic study of the effect of microstructure on the EL properties of ZnS:Er thin film devices fabricated by thermal evaporatio n was carried out using XRD, XPS and EL techniques. The experimental results i ndica...A systematic study of the effect of microstructure on the EL properties of ZnS:Er thin film devices fabricated by thermal evaporatio n was carried out using XRD, XPS and EL techniques. The experimental results i ndicate that the high brightness of the devices is attributed to the deposition growth of cr ystallites oriented in the (311), (400) directions. This can be explained by ass uming a higher population of erbium being in the trivalent charge state in the ( 311), (400) planes of the films grown under certain deposition condition. It is concluded that only the part of rare earth dopant being in trivalent charge stat e in the film contributes to luminescence. The mechanism of the formation of lum inescence center and the excitation of Er 3+ ion by the electric field are discussed.展开更多
Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with...Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with sodium sulphide at boil to develop affinity for cotton. Application of sulphide has generated global debate because of its eco-unfriendly technology of dyeing. In this work, attempts were made to substitute sodium sulphide with alkaline pectinase. Obtained results suggested the ability of the latter to cause effective reduction and solubilisation of sulphur dyes. Stability of reduction baths as well as colour fastness was also reported to be in line with those obtained using sodium sulphide.展开更多
The first successful attempt to prepare W_3S_4 {S_2P (OEt )_2}_4(H_2O) in organic phase is reported. Its substitution and addition reactions are investigated systematically, and the substitution sequences of the '...The first successful attempt to prepare W_3S_4 {S_2P (OEt )_2}_4(H_2O) in organic phase is reported. Its substitution and addition reactions are investigated systematically, and the substitution sequences of the 'loose' ligands are determined. The crystallographic data of the cluster compounds with [W_3S_4]￣(4+) and [W_3CuS_4]￣(5+) cores are compared and their UV-Vis spectra are firstly reported. Thus, the 'quasi-aromaticity' of the [W_3S_4]￣(4+) core of these cluster compounds is discussed.展开更多
基金supported by the National Natural Science Foundation of China(21422308,21403216,21273231)Dalian Excellent Youth Foundation(2014J11JH126)~~
文摘We present an efficient approach for the chemoselective synthesis of arylamines from nitroarenes and formate over an oxygen-implanted MoS2 catalyst（O-MoS2）.O-MoS2 was prepared by incomplete sul idation and reduction of an ammonium molybdate precursor.A number of Mo-O bonds were implanted in the as-synthesized ultrathin O-MoS2 nanosheets.As a consequence of the different coordination geometries of O（Mo O2） and S（MoS2）,and lengths of the Mo-O and Mo-S bonds,the implanted Mo-O bonds induced obvious defects and more coordinatively unsaturated（CUS） Mo sites in O-MoS2,as confirmed by X-ray diffraction,Raman spectroscopy,X-ray photoelectron spectroscopy,high resolution transmission electron microscopy,and extended X-ray absorption fine structure characterization of various MoS2-based materials.O-MoS2 with abundant CUS Mo sites was found to efficiently catalyze the chemoselective reduction of nitroarenes to arylamines.
文摘AIM:To investigate the role of p53 antibodies (p53Abs),metallothioneins (MTs) and oxidative stress markers in the early detection of dysplasia in chronic ulcerative colitis (UC).METHODS:The study included 30 UC patients,15 without dysplasia (group Ⅱ) and 15 with dysplasia (group Ⅲ),in addition to 15 healthy volunteers (group Ⅰ,control subjects).The enzyme-linked immunosorbent assay technique was used to measure serum p53Abs and MTs,while advanced oxidation protein products (AOPPs),and reduced glutathione (GSH) levels were measured by spectrophotometric method in all subjects.RESULTS:In group Ⅱ and group Ⅲ compared to group Ⅰ,there were significant increases in serum levels of AOPPs (145.94 ± 29.86 μmol/L and 192.21 ± 46.71 μmol/L vs 128.95 ± 3.06 μmol/L,P < 0.002 and P <0.001,respectively),MTs (8.18 ± 0.35 μg/mL and 9.20 ± 0.58 μg/mL vs 6.12 ± 0.25 μg/mL,P < 0.05 and P < 0.05,respectively),and p53Abs (20.19 ± 3.20 U/mL and 34.66 ± 1.34 U/mL vs 9.42 ± 1.64 U/mL,P < 0.001 and P < 0.001,respectively).There were significantly higher levels of AOPPs (P < 0.05) and p53Abs (P < 0.001) in UC patients with dysplasia compared to those without dysplasia,while MTs showed no significant difference between the 2 groups (P > 0.096).In contrast,GSH levels showed a significant decrease in both patients' groups (1.87 ± 0.02 μmol/mL and 1.37 ± 0.09 μmol/mL vs 2.49 ± 0.10 μmol/mL,P < 0.05 and P < 0.05 in groups Ⅱ and Ⅲ,respectively) compared with group Ⅰ,and the levels were significantly lower in group Ⅲ than group Ⅱ (P < 0.05).There was a positive correlation between AOPPs and both MTs (r=0.678,P < 0.001) and p53Abs (r=0.547,P < 0.001),and also between p53Abs and MTs (r=0.739,P < 0.001).There was a negative correlation between AOPPs and GSH (r =-0.385,P < 0.001),and also between GSH and both MTs (r=-0.662,P < 0.001) and p53Abs (r=-0.923,P < 0.001).CONCLUSION:Oxidative stress and oxidative cellular damage play an important role in the pathogenesis of chronic UC and the associated carcinogenetic process.p53Abs levels could help in early detection of dysplasia in these conditions.
文摘A systematic study of the effect of microstructure on the EL properties of ZnS:Er thin film devices fabricated by thermal evaporatio n was carried out using XRD, XPS and EL techniques. The experimental results i ndicate that the high brightness of the devices is attributed to the deposition growth of cr ystallites oriented in the (311), (400) directions. This can be explained by ass uming a higher population of erbium being in the trivalent charge state in the ( 311), (400) planes of the films grown under certain deposition condition. It is concluded that only the part of rare earth dopant being in trivalent charge stat e in the film contributes to luminescence. The mechanism of the formation of lum inescence center and the excitation of Er 3+ ion by the electric field are discussed.
文摘Sulphur dyes are invariably applied on cotton to produce deep shades at cheaper cost possessing all-round fastness properties except against chlorine. Being water insoluble, these dyes are reduced and solubilised with sodium sulphide at boil to develop affinity for cotton. Application of sulphide has generated global debate because of its eco-unfriendly technology of dyeing. In this work, attempts were made to substitute sodium sulphide with alkaline pectinase. Obtained results suggested the ability of the latter to cause effective reduction and solubilisation of sulphur dyes. Stability of reduction baths as well as colour fastness was also reported to be in line with those obtained using sodium sulphide.
文摘The first successful attempt to prepare W_3S_4 {S_2P (OEt )_2}_4(H_2O) in organic phase is reported. Its substitution and addition reactions are investigated systematically, and the substitution sequences of the 'loose' ligands are determined. The crystallographic data of the cluster compounds with [W_3S_4]￣(4+) and [W_3CuS_4]￣(5+) cores are compared and their UV-Vis spectra are firstly reported. Thus, the 'quasi-aromaticity' of the [W_3S_4]￣(4+) core of these cluster compounds is discussed.
