AIM To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory b...AIM To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory bowel disease.METHODS Systematic searches were performed( January 1980-September 2016) using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge for randomized trials assessing preparations with or without adjuvants, given in split and non-split dosing, and in high(> 3 L) or low-volume(2 L or less) regimens. Bowel cleansing quality was the primary outcome. Secondary outcomes included patient willingness-torepeat the procedure and side effects/complications.RESULTS Out of 439 citations, 4 trials fulfilled our inclusion criteria(n = 449 patients). One trial assessed the impact of adding simethicone to polyethylene glycol(PEG) 4 L with no effect on bowel cleansing quality, but a better tolerance. Another trial compared senna to castor oil, again without any differences in term of bowel cleansing. Two trials compared the efficacy of PEG high-volume vs PEG low-volume associated to an adjuvant in split-dose regimens: PEG low-dose efficacy was not different to PEG high-dose; OR = 0.84(0.37-1.92). A higher proportion of patients were willing to repeat low-volume preparations vs high-volume; OR = 5.11(1.31-20.0). CONCLUSION In inflammatory bowel disease population, PEG lowvolume regimen seems not inferior to PEG high-volume to clean the colon, and yields improved willingness-torepeat. Further additional research is urgently required to compare contemporary products in this population.展开更多
An accurate reliable analysis method for dehydration of ethanol to ethylene was established using chromatographic separation technique and the principle of carbon balance, and the activivity of HZSM-5 molecular seive ...An accurate reliable analysis method for dehydration of ethanol to ethylene was established using chromatographic separation technique and the principle of carbon balance, and the activivity of HZSM-5 molecular seive was evaluated. The results showed that at an ethanol mass concentration of 50%, a mass space velocity of 2.0/h and a temperature of 280 ℃, the activity of catalyst was ideal, and the conversion rate of ethanol and the selectivity of ethylene were up to 99.60% and98.10%, respectively. The selectively of ethylene decreased notably with further increase of reaction temperature.展开更多
Reactive distillation processes for synthesis of ethylene glycol (EG) and ethyl tert-butyl ether (ETBE) were modeled with the simulation package ASPEN PLUS. The input multiplicity and output multiplicity were disc...Reactive distillation processes for synthesis of ethylene glycol (EG) and ethyl tert-butyl ether (ETBE) were modeled with the simulation package ASPEN PLUS. The input multiplicity and output multiplicity were discussed with the method of sensitivity analysis for both cases. In EG production process, steady state multiplicities were studied in terms of effective liquid holdup volume and boil-up ratio. In ETBE synthesis process, the user kinetic subroutine was supplied into ASPEN PLUS firstly, and then the composition, temperature and reaction-rate profiles within the reactive distillation column were presented in detail. A set of stable solution branches based on distinct initial guesses for a range of boil-up ratio were found in EG synthesis. Input multiplicities were observed for a range of reboiler duty at several values of reflux ratio for ETBE synthesis process. These results can be used to avoid excessive energy consumption and achieve optimum design of reactive distillation column.展开更多
[Objective] This study aims to conduct cloning and sequence analysis of ADH gene in D. Antiqua. [Method] Full-length cDNA of ADH gene in D. antiqua was cloned by using RACE technology (GenBank access number: JQ66600...[Objective] This study aims to conduct cloning and sequence analysis of ADH gene in D. Antiqua. [Method] Full-length cDNA of ADH gene in D. antiqua was cloned by using RACE technology (GenBank access number: JQ666006). Analysis of the homology, characteristics and functional domains of ADH sequence and the phy- Iogenetic relationship to other dipteran ADH were conducted. [Result] The full length of ADH cDNA is 1 088 bp containing a 771 bp of ORF, encoding 256 amino acids, with a calculated relative molecular weight of 30.80 kDa and a theoretical isoelectric point of 8.22. The deduced amino acid sequence shares the highest homology with Glossina morsitans morsitans based on homological analysis and phylogenetic analysis. [Conclusion] This study provides basis for further research of ADH gene.展开更多
AIM: To analyze the long-term prognosis in a cohort of western cirrhotic patients with single hepatocellular carcinoma treated with ethanol injection.METHODS: One-hundred forty-eight patients with solitan/hepatocell...AIM: To analyze the long-term prognosis in a cohort of western cirrhotic patients with single hepatocellular carcinoma treated with ethanol injection.METHODS: One-hundred forty-eight patients with solitan/hepatocellular carcinoma were enrolled. The tumor diameter was lower than 2 cm in 47 patients but larger in the remaining 101 patients. The impact of some pre- treatment clinical and laboratory parameters and of tu- mor recurrence on patients' survival was assessed.RESULTS: Among the pre-treatment parameters, only a tumor diameter of less than 2 cm was an independent prognostic factor of survival. The occurrence of new nodules in other liver segments and the neoplastic portal invasion were linked to a poorer prognosis at univariate analysis. Patients with a single hepatocellular carcinoma smaller than 2 cm showed a better 5-year cumulative survival (73.0% vs 47.9%) (P = 0.009), 3-year local re- currence rate (29.1% vs 51.5%) (P = 0.011), and 5-year distant intrahepatic recurrence rate (52.g% vs 62.8%) (P = 0.054) compared to patients with a larger tumor. CONCLUSION: The 5-year survival rate of patients with single hepatocellular carcinoma 〈 2 cm undergoing ethanol injection is excellent and comparable to that achieved using radiofrequency ablation.展开更多
The microenapsulated polyethylene glycol (PEG) with different molecular weight by a fluidized coating method has been prepared and the crystallization behaviors of PEG particles in three-dimensional confined vohume ...The microenapsulated polyethylene glycol (PEG) with different molecular weight by a fluidized coating method has been prepared and the crystallization behaviors of PEG particles in three-dimensional confined vohume were investigated by using differential scanning calorimetry (DSC) measurement. The results showed that the width of the crystallization peak of PEG increases and its height gradually diminishes in case that the PEG particles are microencapsulated. Compared with the non-microencapsulated PEG particles, the proportion of the first crystallization peak of microencapsulated PEG particle increases, and that of the second one decreases. The reason for the difference maybe is that the crystallization process of microencapsulated PEG particles is uniform and the crystallization ends when the spherulites touch the wall, thus the opportunity of producing the second crystallization peak was relatively reduced.展开更多
Low-grade invasive ductal carcinoma is almost diploid, and has frequent losses of chromosome 16q, which is shared by other precancerous lesions of the mammary gland such as flat epithelial atypia (FEA), atypical duc...Low-grade invasive ductal carcinoma is almost diploid, and has frequent losses of chromosome 16q, which is shared by other precancerous lesions of the mammary gland such as flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), and lownuclear grade ductal carcinoma in situ (DCIS). The genetic alterations accumulate in a stepwise fashion as the precancerous lesions progress to invasve ductal carcinoma. This supports the linear progression model of breast cancer from FEA, through ADH, to low- nuclear grade DCIS as non-obligate early events in low-grade IDC evolution. In contrast, high-grade carcinoma tends to aneuploidy with complex genetic alterations--most importantly, frequent gains at chromosome 16q. Frequent losses at chromosome 16q in low-grade IDC and gains in the same arm of the same chromosome in high-grade IDC imply that these lesions are two end outcomes of different disease processes and that they do not lie in the same continuum of a process. Therefore, low-grade and high-grade IDC are two distinct diseases with a divergent route of progression.展开更多
157 nm photodissociation of jet-cooled CH3OH and C2HsOH was studied using the high-n Rydberg atom time-of-flight (TOF) technique. TOF spectra of nascent H atom products were measured. Simulation of these spectra rev...157 nm photodissociation of jet-cooled CH3OH and C2HsOH was studied using the high-n Rydberg atom time-of-flight (TOF) technique. TOF spectra of nascent H atom products were measured. Simulation of these spectra reveals three different atomic H loss processes: one from hydroxyl H elimination, one from methyl (ethyl) H elimination, and one from secondary dissociation of the methoxy (ethoxy) radical. The relative branching ratio indicates secondary dissociation of ethoxy is less important than that of methoxy. The average angular anisotropy parameter of methanol is negative (with β≈-0.3), indicating the transition dipole moment is perpendicular to the C-O-H plane. The slightly more negative β value of ethanol (with β≈-0.4) implies that ethanol has a longer rotational period. These experimental results indicate that both systems undergo fast internal conversion to the 3s surface after it is excited to the 3px surface, and then dissociate on the 3s surface. The translational energy distribution of the CH3O+H products reveals extensive CH3 rocking or CH3 umbrella excitation in the CH30 radical. However the vibrational structures are not resolved in the C2H5O radical.展开更多
The binding energy spectra and electron momentum distributions for the complete valence orbitals of ethanethiol were measured for the first time by binary (e, 2e) electron momentum spectroscopy employing non-coplana...The binding energy spectra and electron momentum distributions for the complete valence orbitals of ethanethiol were measured for the first time by binary (e, 2e) electron momentum spectroscopy employing non-coplanar symmetric kinematics at an impact energy of 1200 eV plus binding energy. The experimental results are generally consistent with the theoretical calculations using density functional theory and Hartree-Fock methods with various basis sets. A possible satellite line at 17.8 eV in binding energy spectrum was observed and studied by electron momentum spectroscopy.展开更多
A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/p-...A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/p-toluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.展开更多
This paper reports the results of monopropoxylation and monoethoxylation of ethylhexyl alcohol performed in the presence of KOH and a DMC type catalyst, respectively. The existing differences are discussed in terms of...This paper reports the results of monopropoxylation and monoethoxylation of ethylhexyl alcohol performed in the presence of KOH and a DMC type catalyst, respectively. The existing differences are discussed in terms of kinetic performance of the syntheses, as well as the obtained products' compositions. The investigated DMC type catalyst showed 60 to 70 times as high conversion rates, narrower homolog distributions and higher selectivity, in comparison with KOH. Interpretation of the experimental results was performed using kinetic parameters of the WeibulI-Nycander-Gold model and the Natta Mantica relationships. In spite of any differences between the reactivity of the investigated catalysts and alkylene oxides, a significant contribution ofpolymerisation parallel to the target polyaddition was determined, absorbing a major part of the converted adducts, both in the presence of DMC and KOH.展开更多
AIM:To evaluate the possibility of an association between polyethylene glycol(PEG) and acute renal failure(ARF) in elderly patients using a health insurance claims database.METHODS:We conducted a population-based case...AIM:To evaluate the possibility of an association between polyethylene glycol(PEG) and acute renal failure(ARF) in elderly patients using a health insurance claims database.METHODS:We conducted a population-based casecrossover study using information obtained from Korean Health Insurance Review and Assessment Service(HIRA) claims from January 1,2005 to December 31,2005(Seoul,Korea).The study population consisted of elderly patients who received PEG prior to experiencing their first ARF-related hospitalization from April 1,2005 to December 31,2005.For each patient,one case and two control periods were matched.PEG use in a 2-or 4-wk window period prior to hospitalization for ARF was compared with PEG use in two earlier 2-or 4-wk control window periods.Conditional logistic regression analysis was used to estimate odds ratios(ORs) and 95% CI,adjusting for concomitant uses of diuretics,angiotensin converting enzyme inhibitors,non-steroidal anti-inflammatory drugs,antibiotics,anti-cancer drugs,and contrast media.RESULTS:Within the HIRA database which contained 1 093 262 elderly patients,1156 hospitalized ARF cases were identified.Among these cases,PEG was prescribed to 17(1.5%) patients before hospitalization.The adjusted ORs when applying the 2-and 4-wk window periods were 0.4(95% CI:0.03-5.24) and 2.1(95% CI:0.16-27.78),respectively.CONCLUSION:No increased risk of ARF was found in elderly PEG users.However,based on the limited number of study subjects,further analysis should be performed to confirm these results.展开更多
Considering energy security and greenhouse gas emission, many governments are developing bio-liquid fuel industries. The Chinese Government advocates the development of a fuel ethanol industry with non-food crops such...Considering energy security and greenhouse gas emission, many governments are developing bio-liquid fuel industries. The Chinese Government advocates the development of a fuel ethanol industry with non-food crops such as cassava. However, scientists debate the carbon emission of these bio-liquid fuels. The focuses are the influence of soil carbon pool destruction and by-product utilization. This study built a carbon balance analysis model, and assessed carbon emission of cassava fuel ethanol across its life cycle. The results show that the carbon emission of cassava fuel ethanol per kilogram in its life cycle was 0.457 kg under new technical conditions and 0.647 kg under old technical conditions. Carbon emission mainly came from the use of nitrogen fertilizer (9% of total emissions), the destruction of the soil carbon pool (29%) and fossil energy inputs (50%). Taking gasoline as a reference, the carbon emission of cassava fuel ethanol was 90% of that of gasoline. This percentage would drop to 64% if soil carbon pool destruction was avoided. Therefore, in order to promote the development of cassava fuel ethanol in China, farms should apply fertilizer properly, grow cassava on marginal land, and not alter land use patterns of woodland, grassland and other environments. In addition, we should exploit efficient fuel ethanol conversion technologies and strengthen the use of by-products.展开更多
The structure of [Bmim]2CuCl4 ionic liquids (Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2O and C2H5OH was investigated using X-ray absorption fine structure (XAFS) technique. In this study, XAFS...The structure of [Bmim]2CuCl4 ionic liquids (Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2O and C2H5OH was investigated using X-ray absorption fine structure (XAFS) technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2CuCl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2CuCl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]zCuCIa/C2H5OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2CuC14. The structure of [Bmim]2CuCl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids.展开更多
文摘AIM To performed a systematic review and meta-analysis to determine any possible differences in terms of effectiveness, safety and tolerability between existing colon-cleansing products in patients with inflammatory bowel disease.METHODS Systematic searches were performed( January 1980-September 2016) using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge for randomized trials assessing preparations with or without adjuvants, given in split and non-split dosing, and in high(> 3 L) or low-volume(2 L or less) regimens. Bowel cleansing quality was the primary outcome. Secondary outcomes included patient willingness-torepeat the procedure and side effects/complications.RESULTS Out of 439 citations, 4 trials fulfilled our inclusion criteria(n = 449 patients). One trial assessed the impact of adding simethicone to polyethylene glycol(PEG) 4 L with no effect on bowel cleansing quality, but a better tolerance. Another trial compared senna to castor oil, again without any differences in term of bowel cleansing. Two trials compared the efficacy of PEG high-volume vs PEG low-volume associated to an adjuvant in split-dose regimens: PEG low-dose efficacy was not different to PEG high-dose; OR = 0.84(0.37-1.92). A higher proportion of patients were willing to repeat low-volume preparations vs high-volume; OR = 5.11(1.31-20.0). CONCLUSION In inflammatory bowel disease population, PEG lowvolume regimen seems not inferior to PEG high-volume to clean the colon, and yields improved willingness-torepeat. Further additional research is urgently required to compare contemporary products in this population.
基金Supported by National Science Foundation for Distinguished Young Scholars(21225626)Natural Science Foundation of China(21406112)National High Technology Research and Development Program of China(863 Torch Program)(2012AA022300,2014AA021206)~~
文摘An accurate reliable analysis method for dehydration of ethanol to ethylene was established using chromatographic separation technique and the principle of carbon balance, and the activivity of HZSM-5 molecular seive was evaluated. The results showed that at an ethanol mass concentration of 50%, a mass space velocity of 2.0/h and a temperature of 280 ℃, the activity of catalyst was ideal, and the conversion rate of ethanol and the selectivity of ethylene were up to 99.60% and98.10%, respectively. The selectively of ethylene decreased notably with further increase of reaction temperature.
基金Supported by the Key Project of National Natural Science Foundation of China (No.20436040) and the National Natural Scicnce Foundation of China (No.20176044, No.20476084).
文摘Reactive distillation processes for synthesis of ethylene glycol (EG) and ethyl tert-butyl ether (ETBE) were modeled with the simulation package ASPEN PLUS. The input multiplicity and output multiplicity were discussed with the method of sensitivity analysis for both cases. In EG production process, steady state multiplicities were studied in terms of effective liquid holdup volume and boil-up ratio. In ETBE synthesis process, the user kinetic subroutine was supplied into ASPEN PLUS firstly, and then the composition, temperature and reaction-rate profiles within the reactive distillation column were presented in detail. A set of stable solution branches based on distinct initial guesses for a range of boil-up ratio were found in EG synthesis. Input multiplicities were observed for a range of reboiler duty at several values of reflux ratio for ETBE synthesis process. These results can be used to avoid excessive energy consumption and achieve optimum design of reactive distillation column.
基金Supported by National Natural Science Foundation of China (30870340,31071968)Scientific and Technological Research Project of Chongqing Municipal Education Commission (KJ100620)Key Project of Chongqing Normal University (2011XLZ12)~~
文摘[Objective] This study aims to conduct cloning and sequence analysis of ADH gene in D. Antiqua. [Method] Full-length cDNA of ADH gene in D. antiqua was cloned by using RACE technology (GenBank access number: JQ666006). Analysis of the homology, characteristics and functional domains of ADH sequence and the phy- Iogenetic relationship to other dipteran ADH were conducted. [Result] The full length of ADH cDNA is 1 088 bp containing a 771 bp of ORF, encoding 256 amino acids, with a calculated relative molecular weight of 30.80 kDa and a theoretical isoelectric point of 8.22. The deduced amino acid sequence shares the highest homology with Glossina morsitans morsitans based on homological analysis and phylogenetic analysis. [Conclusion] This study provides basis for further research of ADH gene.
文摘AIM: To analyze the long-term prognosis in a cohort of western cirrhotic patients with single hepatocellular carcinoma treated with ethanol injection.METHODS: One-hundred forty-eight patients with solitan/hepatocellular carcinoma were enrolled. The tumor diameter was lower than 2 cm in 47 patients but larger in the remaining 101 patients. The impact of some pre- treatment clinical and laboratory parameters and of tu- mor recurrence on patients' survival was assessed.RESULTS: Among the pre-treatment parameters, only a tumor diameter of less than 2 cm was an independent prognostic factor of survival. The occurrence of new nodules in other liver segments and the neoplastic portal invasion were linked to a poorer prognosis at univariate analysis. Patients with a single hepatocellular carcinoma smaller than 2 cm showed a better 5-year cumulative survival (73.0% vs 47.9%) (P = 0.009), 3-year local re- currence rate (29.1% vs 51.5%) (P = 0.011), and 5-year distant intrahepatic recurrence rate (52.g% vs 62.8%) (P = 0.054) compared to patients with a larger tumor. CONCLUSION: The 5-year survival rate of patients with single hepatocellular carcinoma 〈 2 cm undergoing ethanol injection is excellent and comparable to that achieved using radiofrequency ablation.
基金Science and Technical Development Foundation of Colleges and Universities,Tianjin,China(No.20050511)Development Program of Science & Technology of Tianjin,China(No.06TXTJJC14400)Key Item of TianjinPolytechnic University(No.20060526)
文摘The microenapsulated polyethylene glycol (PEG) with different molecular weight by a fluidized coating method has been prepared and the crystallization behaviors of PEG particles in three-dimensional confined vohume were investigated by using differential scanning calorimetry (DSC) measurement. The results showed that the width of the crystallization peak of PEG increases and its height gradually diminishes in case that the PEG particles are microencapsulated. Compared with the non-microencapsulated PEG particles, the proportion of the first crystallization peak of microencapsulated PEG particle increases, and that of the second one decreases. The reason for the difference maybe is that the crystallization process of microencapsulated PEG particles is uniform and the crystallization ends when the spherulites touch the wall, thus the opportunity of producing the second crystallization peak was relatively reduced.
文摘Low-grade invasive ductal carcinoma is almost diploid, and has frequent losses of chromosome 16q, which is shared by other precancerous lesions of the mammary gland such as flat epithelial atypia (FEA), atypical ductal hyperplasia (ADH), and lownuclear grade ductal carcinoma in situ (DCIS). The genetic alterations accumulate in a stepwise fashion as the precancerous lesions progress to invasve ductal carcinoma. This supports the linear progression model of breast cancer from FEA, through ADH, to low- nuclear grade DCIS as non-obligate early events in low-grade IDC evolution. In contrast, high-grade carcinoma tends to aneuploidy with complex genetic alterations--most importantly, frequent gains at chromosome 16q. Frequent losses at chromosome 16q in low-grade IDC and gains in the same arm of the same chromosome in high-grade IDC imply that these lesions are two end outcomes of different disease processes and that they do not lie in the same continuum of a process. Therefore, low-grade and high-grade IDC are two distinct diseases with a divergent route of progression.
文摘157 nm photodissociation of jet-cooled CH3OH and C2HsOH was studied using the high-n Rydberg atom time-of-flight (TOF) technique. TOF spectra of nascent H atom products were measured. Simulation of these spectra reveals three different atomic H loss processes: one from hydroxyl H elimination, one from methyl (ethyl) H elimination, and one from secondary dissociation of the methoxy (ethoxy) radical. The relative branching ratio indicates secondary dissociation of ethoxy is less important than that of methoxy. The average angular anisotropy parameter of methanol is negative (with β≈-0.3), indicating the transition dipole moment is perpendicular to the C-O-H plane. The slightly more negative β value of ethanol (with β≈-0.4) implies that ethanol has a longer rotational period. These experimental results indicate that both systems undergo fast internal conversion to the 3s surface after it is excited to the 3px surface, and then dissociate on the 3s surface. The translational energy distribution of the CH3O+H products reveals extensive CH3 rocking or CH3 umbrella excitation in the CH30 radical. However the vibrational structures are not resolved in the C2H5O radical.
基金ACKNOWLEDGMENTS This work was supported by the National Natural Science Foundation of China (No.10734040) and the Foundation for Major Research Program of Education Department of Anhui Province (No.ZD2007002-1).
文摘The binding energy spectra and electron momentum distributions for the complete valence orbitals of ethanethiol were measured for the first time by binary (e, 2e) electron momentum spectroscopy employing non-coplanar symmetric kinematics at an impact energy of 1200 eV plus binding energy. The experimental results are generally consistent with the theoretical calculations using density functional theory and Hartree-Fock methods with various basis sets. A possible satellite line at 17.8 eV in binding energy spectrum was observed and studied by electron momentum spectroscopy.
文摘A two steps direct copolymerisation process was developed. The first step is to produce oligomer and then the oligomer of lactic acid/glycolic acid (90/10) is polymerized with binary catalyst tin chloride dihydrate/p-toluenesulfonic acid. In this way, the direct synthesis of copoly (lactic acid/glycolic acid) without any organic solvent was investigated. The properties and structures of products were characterized by nuclear magnetic resonance (NMR), differential scanning calorimetry (DSC), X-ray diffraction and so on. The results show that comparatively high molecular weight copolymer of lactic acid and glycolic acid can be prepared by direct processing under appropriate technological conditions.
文摘This paper reports the results of monopropoxylation and monoethoxylation of ethylhexyl alcohol performed in the presence of KOH and a DMC type catalyst, respectively. The existing differences are discussed in terms of kinetic performance of the syntheses, as well as the obtained products' compositions. The investigated DMC type catalyst showed 60 to 70 times as high conversion rates, narrower homolog distributions and higher selectivity, in comparison with KOH. Interpretation of the experimental results was performed using kinetic parameters of the WeibulI-Nycander-Gold model and the Natta Mantica relationships. In spite of any differences between the reactivity of the investigated catalysts and alkylene oxides, a significant contribution ofpolymerisation parallel to the target polyaddition was determined, absorbing a major part of the converted adducts, both in the presence of DMC and KOH.
文摘AIM:To evaluate the possibility of an association between polyethylene glycol(PEG) and acute renal failure(ARF) in elderly patients using a health insurance claims database.METHODS:We conducted a population-based casecrossover study using information obtained from Korean Health Insurance Review and Assessment Service(HIRA) claims from January 1,2005 to December 31,2005(Seoul,Korea).The study population consisted of elderly patients who received PEG prior to experiencing their first ARF-related hospitalization from April 1,2005 to December 31,2005.For each patient,one case and two control periods were matched.PEG use in a 2-or 4-wk window period prior to hospitalization for ARF was compared with PEG use in two earlier 2-or 4-wk control window periods.Conditional logistic regression analysis was used to estimate odds ratios(ORs) and 95% CI,adjusting for concomitant uses of diuretics,angiotensin converting enzyme inhibitors,non-steroidal anti-inflammatory drugs,antibiotics,anti-cancer drugs,and contrast media.RESULTS:Within the HIRA database which contained 1 093 262 elderly patients,1156 hospitalized ARF cases were identified.Among these cases,PEG was prescribed to 17(1.5%) patients before hospitalization.The adjusted ORs when applying the 2-and 4-wk window periods were 0.4(95% CI:0.03-5.24) and 2.1(95% CI:0.16-27.78),respectively.CONCLUSION:No increased risk of ARF was found in elderly PEG users.However,based on the limited number of study subjects,further analysis should be performed to confirm these results.
基金the National Natural Science Foundation of China (40971270)
文摘Considering energy security and greenhouse gas emission, many governments are developing bio-liquid fuel industries. The Chinese Government advocates the development of a fuel ethanol industry with non-food crops such as cassava. However, scientists debate the carbon emission of these bio-liquid fuels. The focuses are the influence of soil carbon pool destruction and by-product utilization. This study built a carbon balance analysis model, and assessed carbon emission of cassava fuel ethanol across its life cycle. The results show that the carbon emission of cassava fuel ethanol per kilogram in its life cycle was 0.457 kg under new technical conditions and 0.647 kg under old technical conditions. Carbon emission mainly came from the use of nitrogen fertilizer (9% of total emissions), the destruction of the soil carbon pool (29%) and fossil energy inputs (50%). Taking gasoline as a reference, the carbon emission of cassava fuel ethanol was 90% of that of gasoline. This percentage would drop to 64% if soil carbon pool destruction was avoided. Therefore, in order to promote the development of cassava fuel ethanol in China, farms should apply fertilizer properly, grow cassava on marginal land, and not alter land use patterns of woodland, grassland and other environments. In addition, we should exploit efficient fuel ethanol conversion technologies and strengthen the use of by-products.
基金supported by the National Natural Science Foundation of China(11079007,21306220)
文摘The structure of [Bmim]2CuCl4 ionic liquids (Bmim: 1-butyl-3-methylimidazolium) with different ratios of H2O and C2H5OH was investigated using X-ray absorption fine structure (XAFS) technique. In this study, XAFS was employed to directly probe the conformational variations of copper ions in [Bmim]2CuCl4 with the addition of either water or ethanol. XAFS analysis confirmed that the structure of ionic liquids gradually transformed from tetrahedral to octahedral configuration with the increase in ratio of H2O. Our results also showed that water molecules coordinated with the copper ions of [Bmim]2CuCl4, leading to the conformational change in ionic liquids. However, the XAFS spectra of [Bmim]zCuCIa/C2H5OH indicated no coordination of anhydrous ethanol with the copper ions of [Bmim]2CuC14. The structure of [Bmim]2CuCl4 ionic liquids is maintained as the tetrahedral configuration in presence of ethanol. Therefore, anhydrous ethanol causes little variation in the structure of ionic liquids and it is a good solvent for the dilution of ionic liquids.