BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote...BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote PFD recovery.AIM To analyze the use of hydrogen peroxide and silver ion disinfection for vaginal electrodes in conjunction with comprehensive rehabilitation therapy for postpartum women with PFD.METHODS A total of 59 women with PFD who were admitted to the hospital from May 2019 to July 2022 were divided into two groups:Control group(n=27)received comprehensive rehabilitation therapy and observation group(n=32)received intervention with pelvic floor biostimulation feedback instrument in addition to comprehensive rehabilitation therapy.The vaginal electrodes were disinfected with hydrogen peroxide and silver ion before treatment.Intervention for both groups was started 6 weeks postpartum,and rehabilitation lasted for 3 months.Pelvic floor muscle voltage,pelvic floor muscle strength,vaginal muscle voltage,vaginal muscle tone,pelvic floor function,quality of life,and incidence of postpartum PFD were compared between the two groups.RESULTS Before comprehensive rehabilitation treatment,basic data and pelvic floor function were not significantly different between the two groups.After treatment,the observation group showed significant improvements in the maximum voltage and average voltage of pelvic floor muscles,contraction time of type I and type II fibers,pelvic floor muscle strength,vaginal muscle tone,vaginal muscle voltage,and quality of life(GQOLI-74 reports),compared with the control group.The observation group had lower scores on the pelvic floor distress inventory(PFDI-20)and a lower incidence of postpartum PFD,indicating the effectiveness of the pelvic floor biostimulation feedback instrument in promoting the recovery of maternal pelvic floor function.CONCLUSION The combination of the pelvic floor biostimulation feedback instrument and comprehensive rehabilitation nursing can improve pelvic floor muscle strength,promote the recovery of vaginal muscle tone,and improve pelvic floor function and quality of life.The use of hydrogen peroxide and silver ion disinfectant demonstrated favorable antibacterial efficacy and is worthy of clinical application.展开更多
The introduction of bifunctional groups into low-cost adsorbents for selective adsorption of Ag(I) through synergistic effect will have a profound impact on the recovery of precious metals. Organo silica nanosheets(or...The introduction of bifunctional groups into low-cost adsorbents for selective adsorption of Ag(I) through synergistic effect will have a profound impact on the recovery of precious metals. Organo silica nanosheets(organo-Si NSs) functionalized by series of azole derivatives(2-mercaptoimidazole(MI), 2-mercaptobenzimidazole(MBT) and 1H-1,2,4-triazole-3-thiol(MTT)), are fabricated and employed for selective removal of Ag(I). The structures of the organo-Si NSs are investigated using several characterization methods. The results of batch adsorption experiments display that the maximum adsorption amounts are 70.3, 103.2 and 139.5 mg·g^(-1) on MI-Si NSs, MBI-Si NSs and MTT-Si NSs for Ag(I) ions, and reach rapid equilibrium within 10–30 min. The adsorption processes are chemisorption and fit pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Notably, MTT-Si NSs is greatly selective for Ag(I) in multicomponent system, and the distribution coefficient value of Ag(I) ions reaches 2331.26 ml·g^(-1). The reusability of organo-Si NSs is verified by four cycles of regeneration tests with 0.1 mol·L^(-1) HNO_(3) as the eluent. A combination of experimental, structural along with theoretical analysis is conducted to proclaim the structure-adsorptivity relationship:(i) The adsorption mechanisms are attributed to complexation.(ii) The amino group and sulfhydryl group of MTT-Si NSs as well as MBISi NSs may have synergistic impacts on Ag(I) capture.(iii) The differences in adsorption behavior and selectivity of the three organo-Si NSs are mainly related to the form of function groups, charge density and steric hindrance of adsorbent. This work not only sheds light on the promise of functionalized organo-Si NSs for the rapid and selective removal/enrichment of Ag(I) ions in complex water systems,but also provides new insights for designing cost-effective Si NSs-based adsorbents.展开更多
A series of acyls (Ac, Bz and Ts) were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver(I) oxide in the presence of a catalytic amount of potass...A series of acyls (Ac, Bz and Ts) were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver(I) oxide in the presence of a catalytic amount of potassium iodide in 56-78% yields.展开更多
The title complex,[Ag 2 (L1) 2 (Pyr)·2.5H 2 O] 1 (L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in...The title complex,[Ag 2 (L1) 2 (Pyr)·2.5H 2 O] 1 (L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in triclinic,space group P1,with a=7.339(5),b=13.105(5),c=14.097(5),α=84.377(5),β=76.921(5),γ=79.628(5)°,V=1296.7(11) 3,C 48 H 50 Ag 4 N 8 O 17 S 4,M r=1570.68,Z=1,D c=2.011 g/cm 3,μ=1.732 mm-1,F(000)=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections (I 2σ(Ⅰ)).Compound 1 shows a rare one-dimensional (1D) double chain,and the chains are further connected through secondary bonding,hydrogen bonds,and π-π interactions to generate a three-dimensional (3D) supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture.展开更多
The cyclic voltammetry(CV) and the square wave technique were used for the investigations of thallium(Ⅰ) underpotential deposition(UPD) on the silver electrode. A solution of 10 \{mmol/L\} HClO 4+10 mmol/L NaCl was s...The cyclic voltammetry(CV) and the square wave technique were used for the investigations of thallium(Ⅰ) underpotential deposition(UPD) on the silver electrode. A solution of 10 \{mmol/L\} HClO 4+10 mmol/L NaCl was selected as the supporting electrolyte. The calibration plots for Tl(Ⅰ) concentration in the range of 2×10 -9 -1×10 -7 mol/L were obtained. The detection limit was 5×10 -10 mol/L. For the solutions of 4 0×10 -9 mol/L thallium added before the urine sample pretreatment procedure, the average recovery was 105 6% with a relative standard deviation(RSD) of 15 5%.展开更多
A new hexanuclear silver (I) compound 2 containing thiosemicarbazone with the group of benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence ...A new hexanuclear silver (I) compound 2 containing thiosemicarbazone with the group of benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound crystallizes in triclinic, space group P with a = 11.611(3), b = 15.610(5), c = 15.624(7) , α = 113.942(6), β = 104.520(6), γ = 104.230(4)°, V = 2304.1(14) 3, C60H77Ag6N22O4.5S6, Mr = 2018.02, Dc = 1.454 g/cm3, μ(MoKα) = 1.435 mm-1, F(000) = 1005, Z = 1, the final R = 0.0468 and wR = 0.1474 for 6608 observed reflections (I 2σ(I)). In the structure, the S atom of the ligand L2 (L2 = benzaldehyde thiosemicarbazone) served as a triply bridged chelator to connect the six silver atoms into a Ag6L26 cluster. The luminescence property of compound 2 was investigated at room temperature.展开更多
Water-soluble CdSe quantum dots (QDs) capped by bovine serum albumin (BSA) is described as selective silver (I) ion probe based on their fluorescence (FL) quenched by silver ion at pH 5.7. The detection limit is 3...Water-soluble CdSe quantum dots (QDs) capped by bovine serum albumin (BSA) is described as selective silver (I) ion probe based on their fluorescence (FL) quenched by silver ion at pH 5.7. The detection limit is 3×10-7 mol L-1 for silver ion. The interference was also investigated.展开更多
In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite ad...In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite adsorbents loaded with silver nitrate was studied.The test results indicated that the bentonite adsorbents loaded with Ag + ions were effective for adsorbing the alkyl dibenzothiophenes.The crystal structure of bentonite adsorbents was characterized by X-ray diffraction (XRD) and their acidity was measured by Fourier transform infrared (FT-IR) spectroscopy.Several factors influencing the desulfurization capability,including the Ag + loading,the baking temperature,as well as the reaction temperature,were investigated.The desulfurization efficiency was enhanced by increasing the Ag + loading and the best result was obtained at a silver loading of 7 m%.It was found that the adsorption capacity of the alkyl dibenzothiophenes on bentonite loaded with Ag + ions increased with a decreasing temperature.Baking of the adsorbent could also improve the desulfurization capacity,and the optimum baking temperature was 423 K.展开更多
The presence of silver ions(Ag(I))in wastewater has a detrimental effect on living organisms.Removal of soluble silver,especially at low concentrations,is challenging.This paper presents the use ofβ-MnO2 particles as...The presence of silver ions(Ag(I))in wastewater has a detrimental effect on living organisms.Removal of soluble silver,especially at low concentrations,is challenging.This paper presents the use ofβ-MnO2 particles as a photocatalyst to remove Ag(I)ions selectively from aqueous solution at various pH levels.Inductively coupled plasma mass spectrometry(ICP-MS),X-ray diffraction(XRD),field emission electron microscope(FESEM),transmission electron microscopy(TEM),and X-ray photoelectron microscopy(XPS)were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface ofβ-MnO2 particles.The optimum pH for the removal of Ag(I)ions was at pH 4 with 99%removal efficiency under 1 h of visible light irradiation.This phenomenon can be attributed to the electrostatic attraction betweenβ-MnO2 particles and Ag(I)ions as well as the suppression of electron–hole recombination in the presence of H+ions.展开更多
Four 20-membered N_2S_4-monoazathiacrown ethers have been synthesized and explored as neutral ionophores for Ag^+-selective electrodes.Potentiometric responses reveal that the flexibility of the ligands has great effe...Four 20-membered N_2S_4-monoazathiacrown ethers have been synthesized and explored as neutral ionophores for Ag^+-selective electrodes.Potentiometric responses reveal that the flexibility of the ligands has great effect on the selectivity and sensitivity to Ag^+ ions.The electrode based on ionophore 9,10,20,25-tetrahydro-5H,12H-tribenzo[b,n,r][1,7,10,16,4,13]tetrathiadiaza cycloicosine 6,13-(7H,14H)-dione(C) with 2-nitrophenyl octyl ether(o-NPOE) as solvent in a poly(vinyl chloride)(PVC) membrane matrix sho...展开更多
As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature stud bolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and th...As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature stud bolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and then Ag-Pd alloy coating was performed on it using ion plating method. The friction coefficient of Ag-Pd alloy film coated bolt was lower than that of N-5000 oil coated bolt by the result of axial force measurement. The cyclic test of heat treatment was conducted to evaluate the durability of Ag-Pd alloy film coated bolt. In a cycle, sample was assembled into the block using torque wrench, followed by heating and disassembling. It was not successful to disassemble the N-5000 oil coated bolt from the block after only one cycle. However, the Ag-Pd alloy film coated bolt was able to be disassembled softly till 12 cycles.展开更多
Silver foils and ion-implanted silver foils exposed to atomic oxygen (AO) generated in a ground simulation facility were investigated by the quartz crystal microbalance (QCM), the scanning electron microscopy (SE...Silver foils and ion-implanted silver foils exposed to atomic oxygen (AO) generated in a ground simulation facility were investigated by the quartz crystal microbalance (QCM), the scanning electron microscopy (SEM) and the X-ray photoelectron spectroscopy (XPS). The experimental results show the presence of Ag2O and AgO in an oxidation process of the silver foil having exposure to AO. As soon as silver comes under the bombardment of atomic oxygen, the oxidation process starts with a thick film forming on the silver surface. Because of the development of stresses, the oxide layer gets cracked and spalled, which leads to appearance of a new silver surface intensifying further oxidation. At last, AgO begins to form on the outer surface of the oxide film. The analytical results of the XPS and the AES attest to formation of a continuous high-quality protective oxide-based layer on the surface of ion-implanted silver films after exposure to AO. This layer can well protect materials in question from erosion.展开更多
In this paper, the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide (PEI)/Pebax2533 (Polynylon12/tetramethylene oxide block copolymer, PA12-P...In this paper, the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide (PEI)/Pebax2533 (Polynylon12/tetramethylene oxide block copolymer, PA12-PTMO)/AgBF4 composite membranes is investigated. For PEI/Pebax2533/AgBF4 composite membranes prepared with different AgBF4 concentration, the permeances of propylene and ethylene increase with the increase of AgBF4 concentration due to the carrier-facilitated transport, resulting in a high selectivity. But for propyl-ene/propane mixture, the mixed-gas selectivity is lower than its ideal selectivity. The hydrogen reduction strongly influences the membrane performance, which causes the decrease of propylene permeance and the increase of pro-pane permeance. With the increase of hydrogen reduction time, the membranes show a clearly color change from white to brown, yielding a great selectivity loss. The data of X-ray diffraction and FT-IR prove that silver ions are reduced to Ag0 after hydrogen reduction, and aggregated on the surface of PEI/Pebax2533/AgBF4 composite mem-branes.展开更多
Capacity of the silver-doped TiO2 under UV-C light to restrain cyanobacterial growth was explored with Anabaena sp. PCC 7120 and Microcystis aeruginosa as test species. The survival, chlorophyll bleaching, photosynthe...Capacity of the silver-doped TiO2 under UV-C light to restrain cyanobacterial growth was explored with Anabaena sp. PCC 7120 and Microcystis aeruginosa as test species. The survival, chlorophyll bleaching, photosynthetic activity, DNA breakages, antioxidant enzyme activities, lipid peroxidation, and cellular morphologic structure of test cyanobacteria were analyzed. The results indicate that the test cyanobacteria with UV-C photocatalysis by silver-doped TiO2 sufferd from effects of reactive oxygen species, which promote the damage of the cell wall and the peroxidation of cell membranes, and subsequently, aggravate the losses of cell organelle and viability. The results suggest that UV-C photocatalysis by the silver ions doped TiO2 could be a promising method to prevent fast and excessive growth of cyanobacteria in eutrophic water sources.展开更多
The goal of the present investigation is to study the interaction of AgNPs with thymus DNA by traditional and original spectra-photometric and thermo-dynamic methods and approaches in darkness and under photo-irradiat...The goal of the present investigation is to study the interaction of AgNPs with thymus DNA by traditional and original spectra-photometric and thermo-dynamic methods and approaches in darkness and under photo-irradiation. 1) At the interaction of DNA with nano-particles hypsochromic shift of 6 nm and hypochromic effect of 20% of AgNPs absorption band are observed. 2) At photo-irradiation (λ = 436 nm or full spectrum of visible band) of AgNPs-DNA complexes absorption spectra band width is changed from 140 nm to 360 nm at half-height. Besides, isosbestic point is observed. 3) Kinetic study of photo-diffusion has made it possible to determine desorption rate constant and desorption reaction activation energy that are equal respectively to kd @ 9 ′ 10-5 s-1, Ed @ 80 kJ/M Ag0 for AgNPs bound with DNA. It is shown that AgNPs represent liquid drops which moisture the DNA surface at interaction. At photo-irradiation of AgNPs-DNA complex DNA dependant conformational transition takes place due to fast and intensive heating.展开更多
In this paper is reported a new method of determining serum albumin with potentiometry. The silver ion selective electrode was used as working electrode and S. C. E as reference electrode. By controlling the ionic s...In this paper is reported a new method of determining serum albumin with potentiometry. The silver ion selective electrode was used as working electrode and S. C. E as reference electrode. By controlling the ionic strength, PH and temperature constant, a good linear relationship was obtained between the cell potential and albumin concentration. This method .possessed characters-of operating simplicity, rapidity and directness. The samples could be detected directly and the results were in accordance with the values detected by classic K method.展开更多
Two novel coordination compounds, [Zn(CBPP)2(H2O)2]·3H2O(1) and[Ag(CBPP)·2H2O](2)(HCBPP = 1-(4?-carboxylatobenzyl)-3-(pyrazin-2-yl)pyrazole), were hydrothermally synthesized and characterize...Two novel coordination compounds, [Zn(CBPP)2(H2O)2]·3H2O(1) and[Ag(CBPP)·2H2O](2)(HCBPP = 1-(4?-carboxylatobenzyl)-3-(pyrazin-2-yl)pyrazole), were hydrothermally synthesized and characterized. Compound 1 crystallizes in monoclinic, space group C2 with a = 26.221(4), b = 8.4211(7), c = 14.295(3)A, β = 114.561(8)°, V = 2705.9(2) A3, Dc = 1.587 g/cm3, C28H28Cl2N8O9 Zn, Mr = 685.97 F(000) = 1416, μ(Mo Kα) = 0.926 mm-1, Z = 4, R = 0.0287, w R = 0.1076 for 2818 observed reflections(I 〉 2σ(I)), and R = 0.0300, w R = 0.1110 for all data. In 1, each deprotonated CBPP-ligand with a bidentate coordination mode connects two Zn(II) atoms to generate a 1D helical chain along the b axis. The adjacent chains intersect with each other through hinged Zn(II) ions to build up an interesting two-dimensional network. Compound 2 crystallizes in monoclinic, space group P21/n with a = 6.3544(1), b = 11.7195(3), c = 19.3188(4)A, β = 94.297(2)°, V = 1434.64(5) A3, Dc = 1.894 g/cm3, C14H13 Ag N4O4, Mr = 409.15 F(000) = 816, μ(Mo Kα) = 11.536 mm-1, Z = 4, R = 0.0456 and w R = 0.1184 for 2402 observed reflections(I 〉 2σ(I)), and R = 0.0517, w R = 0.1275 for all data. In 2, each ligand binds two Ag(I) atoms in a tridentate coordination mode to form an infinite zigzag chain. Their thermal and photoluminescent properties were also investigated.展开更多
Adsorption of silver ions from aqueous solution onto H2TiO3 was studied. Equilibrium experimental studies were performed to determine the adsorption capacity of H2TiO3 for silver ion at various pH values. Batch experi...Adsorption of silver ions from aqueous solution onto H2TiO3 was studied. Equilibrium experimental studies were performed to determine the adsorption capacity of H2TiO3 for silver ion at various pH values. Batch experiments were conducted in the range of pH value 3?7 and silver ions concentration 10?200 mg/L. The results show that the adsorption is strongly dependent on pH value. The equilibrium absorption capacity of H2TiO3 increases significantly with the increase of pH value from 3 to 7. The adsorption of silver ion obeys the Langmuir isothermal equation well in the concentration range studied, the adsorption constant is 0.054 7, 0.052 4, 0.088 1 at pH 5, 6 and 7, respectively, and the maximum adsorption capacities are 23.64, 29.76 and 40.82 mg/g.展开更多
文摘BACKGROUND Pelvic floor dysfunction(PFD)is related to muscle fiber tearing during childbirth,negatively impacting postpartum quality of life of parturient.Appropriate and effective intervention is necessary to promote PFD recovery.AIM To analyze the use of hydrogen peroxide and silver ion disinfection for vaginal electrodes in conjunction with comprehensive rehabilitation therapy for postpartum women with PFD.METHODS A total of 59 women with PFD who were admitted to the hospital from May 2019 to July 2022 were divided into two groups:Control group(n=27)received comprehensive rehabilitation therapy and observation group(n=32)received intervention with pelvic floor biostimulation feedback instrument in addition to comprehensive rehabilitation therapy.The vaginal electrodes were disinfected with hydrogen peroxide and silver ion before treatment.Intervention for both groups was started 6 weeks postpartum,and rehabilitation lasted for 3 months.Pelvic floor muscle voltage,pelvic floor muscle strength,vaginal muscle voltage,vaginal muscle tone,pelvic floor function,quality of life,and incidence of postpartum PFD were compared between the two groups.RESULTS Before comprehensive rehabilitation treatment,basic data and pelvic floor function were not significantly different between the two groups.After treatment,the observation group showed significant improvements in the maximum voltage and average voltage of pelvic floor muscles,contraction time of type I and type II fibers,pelvic floor muscle strength,vaginal muscle tone,vaginal muscle voltage,and quality of life(GQOLI-74 reports),compared with the control group.The observation group had lower scores on the pelvic floor distress inventory(PFDI-20)and a lower incidence of postpartum PFD,indicating the effectiveness of the pelvic floor biostimulation feedback instrument in promoting the recovery of maternal pelvic floor function.CONCLUSION The combination of the pelvic floor biostimulation feedback instrument and comprehensive rehabilitation nursing can improve pelvic floor muscle strength,promote the recovery of vaginal muscle tone,and improve pelvic floor function and quality of life.The use of hydrogen peroxide and silver ion disinfectant demonstrated favorable antibacterial efficacy and is worthy of clinical application.
基金the National Natural Science Foundation of China (21776306)。
文摘The introduction of bifunctional groups into low-cost adsorbents for selective adsorption of Ag(I) through synergistic effect will have a profound impact on the recovery of precious metals. Organo silica nanosheets(organo-Si NSs) functionalized by series of azole derivatives(2-mercaptoimidazole(MI), 2-mercaptobenzimidazole(MBT) and 1H-1,2,4-triazole-3-thiol(MTT)), are fabricated and employed for selective removal of Ag(I). The structures of the organo-Si NSs are investigated using several characterization methods. The results of batch adsorption experiments display that the maximum adsorption amounts are 70.3, 103.2 and 139.5 mg·g^(-1) on MI-Si NSs, MBI-Si NSs and MTT-Si NSs for Ag(I) ions, and reach rapid equilibrium within 10–30 min. The adsorption processes are chemisorption and fit pseudo-second-order kinetic model and Langmuir adsorption isotherm model. Notably, MTT-Si NSs is greatly selective for Ag(I) in multicomponent system, and the distribution coefficient value of Ag(I) ions reaches 2331.26 ml·g^(-1). The reusability of organo-Si NSs is verified by four cycles of regeneration tests with 0.1 mol·L^(-1) HNO_(3) as the eluent. A combination of experimental, structural along with theoretical analysis is conducted to proclaim the structure-adsorptivity relationship:(i) The adsorption mechanisms are attributed to complexation.(ii) The amino group and sulfhydryl group of MTT-Si NSs as well as MBISi NSs may have synergistic impacts on Ag(I) capture.(iii) The differences in adsorption behavior and selectivity of the three organo-Si NSs are mainly related to the form of function groups, charge density and steric hindrance of adsorbent. This work not only sheds light on the promise of functionalized organo-Si NSs for the rapid and selective removal/enrichment of Ag(I) ions in complex water systems,but also provides new insights for designing cost-effective Si NSs-based adsorbents.
基金financially supported by the National Natural Science Foundation of China(No.30300434)the 0utstanding Youth Foundation of Sichuan Province(No.04ZQ026-039).
文摘A series of acyls (Ac, Bz and Ts) were introduced regioselectively to the 2-hydroxyl in methyl and ally 3-O-benzyl-α-L-rhamnopyranosides mediated by silver(I) oxide in the presence of a catalytic amount of potassium iodide in 56-78% yields.
基金supported by the Science Foundation of Suihua University (K1001005)
文摘The title complex,[Ag 2 (L1) 2 (Pyr)·2.5H 2 O] 1 (L1=6-amino-1-naphthalenesulfonate anion,Pyr=pyrazine),has been synthesized and characterized by single-crystal X-ray diffraction analysis.It crystallizes in triclinic,space group P1,with a=7.339(5),b=13.105(5),c=14.097(5),α=84.377(5),β=76.921(5),γ=79.628(5)°,V=1296.7(11) 3,C 48 H 50 Ag 4 N 8 O 17 S 4,M r=1570.68,Z=1,D c=2.011 g/cm 3,μ=1.732 mm-1,F(000)=782,S=1.148,the final R=0.0436 and wR=0.1181 for 4130 observer reflections (I 2σ(Ⅰ)).Compound 1 shows a rare one-dimensional (1D) double chain,and the chains are further connected through secondary bonding,hydrogen bonds,and π-π interactions to generate a three-dimensional (3D) supramolecular structure.The luminescent property of 1 was also studied in the solid state at room temperture.
文摘The cyclic voltammetry(CV) and the square wave technique were used for the investigations of thallium(Ⅰ) underpotential deposition(UPD) on the silver electrode. A solution of 10 \{mmol/L\} HClO 4+10 mmol/L NaCl was selected as the supporting electrolyte. The calibration plots for Tl(Ⅰ) concentration in the range of 2×10 -9 -1×10 -7 mol/L were obtained. The detection limit was 5×10 -10 mol/L. For the solutions of 4 0×10 -9 mol/L thallium added before the urine sample pretreatment procedure, the average recovery was 105 6% with a relative standard deviation(RSD) of 15 5%.
基金supported by the Postdoctoral Science Foundation of Central South University
文摘A new hexanuclear silver (I) compound 2 containing thiosemicarbazone with the group of benzene was synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analysis and fluorescence spectrum. The title compound crystallizes in triclinic, space group P with a = 11.611(3), b = 15.610(5), c = 15.624(7) , α = 113.942(6), β = 104.520(6), γ = 104.230(4)°, V = 2304.1(14) 3, C60H77Ag6N22O4.5S6, Mr = 2018.02, Dc = 1.454 g/cm3, μ(MoKα) = 1.435 mm-1, F(000) = 1005, Z = 1, the final R = 0.0468 and wR = 0.1474 for 6608 observed reflections (I 2σ(I)). In the structure, the S atom of the ligand L2 (L2 = benzaldehyde thiosemicarbazone) served as a triply bridged chelator to connect the six silver atoms into a Ag6L26 cluster. The luminescence property of compound 2 was investigated at room temperature.
文摘Water-soluble CdSe quantum dots (QDs) capped by bovine serum albumin (BSA) is described as selective silver (I) ion probe based on their fluorescence (FL) quenched by silver ion at pH 5.7. The detection limit is 3×10-7 mol L-1 for silver ion. The interference was also investigated.
文摘In order to further reduce the sulfur content in liquid hydrocarbon fuels,a desulfurization process by adsorption for removing alkyl dibenzothiophenes was investigated.Desulfurization of model gasoline by bentonite adsorbents loaded with silver nitrate was studied.The test results indicated that the bentonite adsorbents loaded with Ag + ions were effective for adsorbing the alkyl dibenzothiophenes.The crystal structure of bentonite adsorbents was characterized by X-ray diffraction (XRD) and their acidity was measured by Fourier transform infrared (FT-IR) spectroscopy.Several factors influencing the desulfurization capability,including the Ag + loading,the baking temperature,as well as the reaction temperature,were investigated.The desulfurization efficiency was enhanced by increasing the Ag + loading and the best result was obtained at a silver loading of 7 m%.It was found that the adsorption capacity of the alkyl dibenzothiophenes on bentonite loaded with Ag + ions increased with a decreasing temperature.Baking of the adsorbent could also improve the desulfurization capacity,and the optimum baking temperature was 423 K.
基金This study was funded by Universiti Sains Malaysia, ResearchUniversity Grant (1001.PBAHAN.8014095). The authorsalso acknowledge the support from USM Fellowship.
文摘The presence of silver ions(Ag(I))in wastewater has a detrimental effect on living organisms.Removal of soluble silver,especially at low concentrations,is challenging.This paper presents the use ofβ-MnO2 particles as a photocatalyst to remove Ag(I)ions selectively from aqueous solution at various pH levels.Inductively coupled plasma mass spectrometry(ICP-MS),X-ray diffraction(XRD),field emission electron microscope(FESEM),transmission electron microscopy(TEM),and X-ray photoelectron microscopy(XPS)were employed to determine the removal efficiency and to characterize the deposition of silver onto the surface ofβ-MnO2 particles.The optimum pH for the removal of Ag(I)ions was at pH 4 with 99%removal efficiency under 1 h of visible light irradiation.This phenomenon can be attributed to the electrostatic attraction betweenβ-MnO2 particles and Ag(I)ions as well as the suppression of electron–hole recombination in the presence of H+ions.
基金supported by the Chinese Academy of Sciences(No.KZCX2-YW-410)the National Natural Science Foundation of China(No.40776058)+1 种基金the National 863 High Technology Project of the Ministry of Science and Technology of China(No.2007AA09Z103)the Outstanding Youth Natural Science Foundation of Shandong Province(No.JQ200814)
文摘Four 20-membered N_2S_4-monoazathiacrown ethers have been synthesized and explored as neutral ionophores for Ag^+-selective electrodes.Potentiometric responses reveal that the flexibility of the ligands has great effect on the selectivity and sensitivity to Ag^+ ions.The electrode based on ionophore 9,10,20,25-tetrahydro-5H,12H-tribenzo[b,n,r][1,7,10,16,4,13]tetrathiadiaza cycloicosine 6,13-(7H,14H)-dione(C) with 2-nitrophenyl octyl ether(o-NPOE) as solvent in a poly(vinyl chloride)(PVC) membrane matrix sho...
基金the research fund of the Korea Institute of Materials Science, a subsidiary branch of the Korea Institute of Machinery and Materialssupported by a grant from the Fundamental R&D Program for Core Technology of Materials funded by the Ministry of Knowledge Economy, Republic of Korea
文摘As a solid lubricant, silver-palladium (Ag-Pd) alloy coating was investigated for the application to high temperature stud bolt. A glue layer nickel (Ni) film was deposited on the surface of the hex bolt sample and then Ag-Pd alloy coating was performed on it using ion plating method. The friction coefficient of Ag-Pd alloy film coated bolt was lower than that of N-5000 oil coated bolt by the result of axial force measurement. The cyclic test of heat treatment was conducted to evaluate the durability of Ag-Pd alloy film coated bolt. In a cycle, sample was assembled into the block using torque wrench, followed by heating and disassembling. It was not successful to disassemble the N-5000 oil coated bolt from the block after only one cycle. However, the Ag-Pd alloy film coated bolt was able to be disassembled softly till 12 cycles.
基金Natural Science Foundation of JX Province (0650035)
文摘Silver foils and ion-implanted silver foils exposed to atomic oxygen (AO) generated in a ground simulation facility were investigated by the quartz crystal microbalance (QCM), the scanning electron microscopy (SEM) and the X-ray photoelectron spectroscopy (XPS). The experimental results show the presence of Ag2O and AgO in an oxidation process of the silver foil having exposure to AO. As soon as silver comes under the bombardment of atomic oxygen, the oxidation process starts with a thick film forming on the silver surface. Because of the development of stresses, the oxide layer gets cracked and spalled, which leads to appearance of a new silver surface intensifying further oxidation. At last, AgO begins to form on the outer surface of the oxide film. The analytical results of the XPS and the AES attest to formation of a continuous high-quality protective oxide-based layer on the surface of ion-implanted silver films after exposure to AO. This layer can well protect materials in question from erosion.
基金Supported by the National Natural Science Foundation of China (20776137) and the National High Technology Research and Develooment Prozram of China (2008AA06Z325).
文摘In this paper, the effect of hydrogen reduction of silver ions on the performance and structure of new solid polymer electrolyte polyetherimide (PEI)/Pebax2533 (Polynylon12/tetramethylene oxide block copolymer, PA12-PTMO)/AgBF4 composite membranes is investigated. For PEI/Pebax2533/AgBF4 composite membranes prepared with different AgBF4 concentration, the permeances of propylene and ethylene increase with the increase of AgBF4 concentration due to the carrier-facilitated transport, resulting in a high selectivity. But for propyl-ene/propane mixture, the mixed-gas selectivity is lower than its ideal selectivity. The hydrogen reduction strongly influences the membrane performance, which causes the decrease of propylene permeance and the increase of pro-pane permeance. With the increase of hydrogen reduction time, the membranes show a clearly color change from white to brown, yielding a great selectivity loss. The data of X-ray diffraction and FT-IR prove that silver ions are reduced to Ag0 after hydrogen reduction, and aggregated on the surface of PEI/Pebax2533/AgBF4 composite mem-branes.
基金Funded by the National Natural Science Foundation of China(No.30540070)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20060487018)
文摘Capacity of the silver-doped TiO2 under UV-C light to restrain cyanobacterial growth was explored with Anabaena sp. PCC 7120 and Microcystis aeruginosa as test species. The survival, chlorophyll bleaching, photosynthetic activity, DNA breakages, antioxidant enzyme activities, lipid peroxidation, and cellular morphologic structure of test cyanobacteria were analyzed. The results indicate that the test cyanobacteria with UV-C photocatalysis by silver-doped TiO2 sufferd from effects of reactive oxygen species, which promote the damage of the cell wall and the peroxidation of cell membranes, and subsequently, aggravate the losses of cell organelle and viability. The results suggest that UV-C photocatalysis by the silver ions doped TiO2 could be a promising method to prevent fast and excessive growth of cyanobacteria in eutrophic water sources.
文摘The goal of the present investigation is to study the interaction of AgNPs with thymus DNA by traditional and original spectra-photometric and thermo-dynamic methods and approaches in darkness and under photo-irradiation. 1) At the interaction of DNA with nano-particles hypsochromic shift of 6 nm and hypochromic effect of 20% of AgNPs absorption band are observed. 2) At photo-irradiation (λ = 436 nm or full spectrum of visible band) of AgNPs-DNA complexes absorption spectra band width is changed from 140 nm to 360 nm at half-height. Besides, isosbestic point is observed. 3) Kinetic study of photo-diffusion has made it possible to determine desorption rate constant and desorption reaction activation energy that are equal respectively to kd @ 9 ′ 10-5 s-1, Ed @ 80 kJ/M Ag0 for AgNPs bound with DNA. It is shown that AgNPs represent liquid drops which moisture the DNA surface at interaction. At photo-irradiation of AgNPs-DNA complex DNA dependant conformational transition takes place due to fast and intensive heating.
文摘In this paper is reported a new method of determining serum albumin with potentiometry. The silver ion selective electrode was used as working electrode and S. C. E as reference electrode. By controlling the ionic strength, PH and temperature constant, a good linear relationship was obtained between the cell potential and albumin concentration. This method .possessed characters-of operating simplicity, rapidity and directness. The samples could be detected directly and the results were in accordance with the values detected by classic K method.
基金financially supported by the National Natural Science Foundation of China(21571034)the Natural Science Foundation of Fujian Province(2014J01033)
文摘Two novel coordination compounds, [Zn(CBPP)2(H2O)2]·3H2O(1) and[Ag(CBPP)·2H2O](2)(HCBPP = 1-(4?-carboxylatobenzyl)-3-(pyrazin-2-yl)pyrazole), were hydrothermally synthesized and characterized. Compound 1 crystallizes in monoclinic, space group C2 with a = 26.221(4), b = 8.4211(7), c = 14.295(3)A, β = 114.561(8)°, V = 2705.9(2) A3, Dc = 1.587 g/cm3, C28H28Cl2N8O9 Zn, Mr = 685.97 F(000) = 1416, μ(Mo Kα) = 0.926 mm-1, Z = 4, R = 0.0287, w R = 0.1076 for 2818 observed reflections(I 〉 2σ(I)), and R = 0.0300, w R = 0.1110 for all data. In 1, each deprotonated CBPP-ligand with a bidentate coordination mode connects two Zn(II) atoms to generate a 1D helical chain along the b axis. The adjacent chains intersect with each other through hinged Zn(II) ions to build up an interesting two-dimensional network. Compound 2 crystallizes in monoclinic, space group P21/n with a = 6.3544(1), b = 11.7195(3), c = 19.3188(4)A, β = 94.297(2)°, V = 1434.64(5) A3, Dc = 1.894 g/cm3, C14H13 Ag N4O4, Mr = 409.15 F(000) = 816, μ(Mo Kα) = 11.536 mm-1, Z = 4, R = 0.0456 and w R = 0.1184 for 2402 observed reflections(I 〉 2σ(I)), and R = 0.0517, w R = 0.1275 for all data. In 2, each ligand binds two Ag(I) atoms in a tridentate coordination mode to form an infinite zigzag chain. Their thermal and photoluminescent properties were also investigated.
基金Project(04GK2007) supported by the Key Project of Scientific and Technological Department of Hunan Province, China
文摘Adsorption of silver ions from aqueous solution onto H2TiO3 was studied. Equilibrium experimental studies were performed to determine the adsorption capacity of H2TiO3 for silver ion at various pH values. Batch experiments were conducted in the range of pH value 3?7 and silver ions concentration 10?200 mg/L. The results show that the adsorption is strongly dependent on pH value. The equilibrium absorption capacity of H2TiO3 increases significantly with the increase of pH value from 3 to 7. The adsorption of silver ion obeys the Langmuir isothermal equation well in the concentration range studied, the adsorption constant is 0.054 7, 0.052 4, 0.088 1 at pH 5, 6 and 7, respectively, and the maximum adsorption capacities are 23.64, 29.76 and 40.82 mg/g.