Polyvinylacetal of 4-[2-(4-formylphenyl)ethenyl]pyridium(PVA-FEP) was synthesized and the layer by layer self-assembly from PVA-FEP as polycation with a series of polyanions was investigated. The multilayer utrathin f...Polyvinylacetal of 4-[2-(4-formylphenyl)ethenyl]pyridium(PVA-FEP) was synthesized and the layer by layer self-assembly from PVA-FEP as polycation with a series of polyanions was investigated. The multilayer utrathin films formed are photoreactive. Under UV irradiation the [2+2] cycloaddition of the styrylpiridium moieties of PVA-FEP takes place to produce crosslinking net works in the layers of the film. And the stability of the irradiated film toward polar solvents enhances greatly. The patterning of the film has been realized by selective UV exposure of the film through a photomask then developing in saturated sodium dodecyl sulfate aqueous solution.展开更多
To compare the tolerability and quality of bowel cleansing between 2 L polyethylene glycol (PEG) and reduced-dose sodium phosphate (NaP) tablets as a preparation for colonoscopy. METHODSTwo hundred patients were rando...To compare the tolerability and quality of bowel cleansing between 2 L polyethylene glycol (PEG) and reduced-dose sodium phosphate (NaP) tablets as a preparation for colonoscopy. METHODSTwo hundred patients were randomly assigned to the PEG or NaP groups at the same ratio. The NaP group patients took 30 tablets with 2 L of clear liquid, while the PEG group patients took 2L of PEG. Tolerability was assessed by a questionnaire about taste, volume, and the overall impression. The bowel cleansing quality was evaluated by colonoscopists. RESULTSAlthough NaP showed better tolerability in terms of taste, volume and overall impression (P < 0.01, P < 0.01 and P = 0.02, respectively), the overall cleansing quality was better in the PEG group (P < 0.01). A subgroup analysis, stratified by sex and age, indicated that NaP was associated with better tolerability and equivalent bowel cleansing quality in females of < 50 years of age. CONCLUSIONDespite the better tolerability, the use of 30 NaP tablets with 2 L of clear liquid should be limited due to its lower cleansing quality; however, in certain cases the regimen may deserve consideration, particularly in cases involving young women.展开更多
The heteroleptic dmit complex Et 4N 2 Ni 2(C 2S 4)(C 3S 5) 2 has been prepared by the reaction of NiCl 2·H 2O with Na 2dmit, NaSC 2H 4OH in the MeOH solution. The compound has been characteriz...The heteroleptic dmit complex Et 4N 2 Ni 2(C 2S 4)(C 3S 5) 2 has been prepared by the reaction of NiCl 2·H 2O with Na 2dmit, NaSC 2H 4OH in the MeOH solution. The compound has been characterized by X ray diffraction study, IR and UV Vis spectroscopy. Crystallographic data : space group: P2 1/n, a=11.843(2), b=11 079(1), c = 15.404(1) , β=110.33(1)°, V = 1895.1 3, Z=2, D c =1.62 g/cm 3 , μ =17.6 cm -1 , F (000)=956, R=0.052, R w =0.061. In the structure of the title complex, the tto (tto=tetrathioxalato) ligand in bridging form is chelated to two nickel atoms and dmit (dmit=1,3 dithiole 2 thione 4,5 dithiolate) ligands coordinated to nickel atoms.展开更多
New liquid-liquid equilibrium data for polyethylene glycol （PEG） 3000 ＋ CHO2K ＋ H20 systems were measured at 298.15 K and pH values of 7.95, 8.40 and 9.98. It was found that an increase in pH caused the binodal cu...New liquid-liquid equilibrium data for polyethylene glycol （PEG） 3000 ＋ CHO2K ＋ H20 systems were measured at 298.15 K and pH values of 7.95, 8.40 and 9.98. It was found that an increase in pH caused the binodal curve to be displaced downward and the two-phase region to expand. Accordingly, the binodal curve was adjusted to the Pirdashti equation and the tie-line compositions were correlated using the Othmer-Tobias, Bancroft and Hand equations. The study measured the refractive index and densities of several homogeneous binary and ternary solutions. The solutions were used for calibration within a range of 0% to 30% of the mass of the PEG and potassium formate. The density and refractive index data show a linear variation with the mass fraction of the polymer and the salt. The effect of pH on the binodal, tie-line lengths （TLL） and slope of the tie-line （STL） in the systems was exam- ined. It was found that an increase in pH increased the TLL and decreased the STL It was observed that the density of the aqueous two-phase system was influenced by the TLL The difference in density between phases （△p） increased as the TLL and pH increased. It was found that the TLL and Ap showed a linear relationship. The effective excluded volume （EEV） of the PEG was obtained and it was found that EEV also increased as the pH increased.展开更多
文摘Polyvinylacetal of 4-[2-(4-formylphenyl)ethenyl]pyridium(PVA-FEP) was synthesized and the layer by layer self-assembly from PVA-FEP as polycation with a series of polyanions was investigated. The multilayer utrathin films formed are photoreactive. Under UV irradiation the [2+2] cycloaddition of the styrylpiridium moieties of PVA-FEP takes place to produce crosslinking net works in the layers of the film. And the stability of the irradiated film toward polar solvents enhances greatly. The patterning of the film has been realized by selective UV exposure of the film through a photomask then developing in saturated sodium dodecyl sulfate aqueous solution.
文摘To compare the tolerability and quality of bowel cleansing between 2 L polyethylene glycol (PEG) and reduced-dose sodium phosphate (NaP) tablets as a preparation for colonoscopy. METHODSTwo hundred patients were randomly assigned to the PEG or NaP groups at the same ratio. The NaP group patients took 30 tablets with 2 L of clear liquid, while the PEG group patients took 2L of PEG. Tolerability was assessed by a questionnaire about taste, volume, and the overall impression. The bowel cleansing quality was evaluated by colonoscopists. RESULTSAlthough NaP showed better tolerability in terms of taste, volume and overall impression (P < 0.01, P < 0.01 and P = 0.02, respectively), the overall cleansing quality was better in the PEG group (P < 0.01). A subgroup analysis, stratified by sex and age, indicated that NaP was associated with better tolerability and equivalent bowel cleansing quality in females of < 50 years of age. CONCLUSIONDespite the better tolerability, the use of 30 NaP tablets with 2 L of clear liquid should be limited due to its lower cleansing quality; however, in certain cases the regimen may deserve consideration, particularly in cases involving young women.
文摘The heteroleptic dmit complex Et 4N 2 Ni 2(C 2S 4)(C 3S 5) 2 has been prepared by the reaction of NiCl 2·H 2O with Na 2dmit, NaSC 2H 4OH in the MeOH solution. The compound has been characterized by X ray diffraction study, IR and UV Vis spectroscopy. Crystallographic data : space group: P2 1/n, a=11.843(2), b=11 079(1), c = 15.404(1) , β=110.33(1)°, V = 1895.1 3, Z=2, D c =1.62 g/cm 3 , μ =17.6 cm -1 , F (000)=956, R=0.052, R w =0.061. In the structure of the title complex, the tto (tto=tetrathioxalato) ligand in bridging form is chelated to two nickel atoms and dmit (dmit=1,3 dithiole 2 thione 4,5 dithiolate) ligands coordinated to nickel atoms.
文摘New liquid-liquid equilibrium data for polyethylene glycol （PEG） 3000 ＋ CHO2K ＋ H20 systems were measured at 298.15 K and pH values of 7.95, 8.40 and 9.98. It was found that an increase in pH caused the binodal curve to be displaced downward and the two-phase region to expand. Accordingly, the binodal curve was adjusted to the Pirdashti equation and the tie-line compositions were correlated using the Othmer-Tobias, Bancroft and Hand equations. The study measured the refractive index and densities of several homogeneous binary and ternary solutions. The solutions were used for calibration within a range of 0% to 30% of the mass of the PEG and potassium formate. The density and refractive index data show a linear variation with the mass fraction of the polymer and the salt. The effect of pH on the binodal, tie-line lengths （TLL） and slope of the tie-line （STL） in the systems was exam- ined. It was found that an increase in pH increased the TLL and decreased the STL It was observed that the density of the aqueous two-phase system was influenced by the TLL The difference in density between phases （△p） increased as the TLL and pH increased. It was found that the TLL and Ap showed a linear relationship. The effective excluded volume （EEV） of the PEG was obtained and it was found that EEV also increased as the pH increased.
