The dioxygen affinities and biomimetic catalytic performance of transition-metal complexes with (15-crown-5) salophen and its substituted derivatives Mere examined. The oxygenation constants of Co(II) complexes with c...The dioxygen affinities and biomimetic catalytic performance of transition-metal complexes with (15-crown-5) salophen and its substituted derivatives Mere examined. The oxygenation constants of Co(II) complexes with crowned bis-Schiff bases were measured and their Mn(III) complexes were employed as models to mimic monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 57.2% and 100% respectively at ambient temperature and pressure. The effects of crown ether ring and substituents R on the dioxygen affinities and catalytic activities were also investigated through comparing with the uncrowned analogues.展开更多
An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved....An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.展开更多
N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alk...N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alkali metal salts and amines has been studied by UV-Vis spectra.展开更多
目的:探讨使用乳牙金属预成冠(Preformed metal crown,PMC)修复治疗高危患龋患儿对其咬合功能和修复效果的影响。方法:选取2019年8月-2022年5月笔者医院收治的高危患龋儿童120例,根据1∶1随机分组法将患儿分为观察组(n=60)和对照组(n=6...目的:探讨使用乳牙金属预成冠(Preformed metal crown,PMC)修复治疗高危患龋患儿对其咬合功能和修复效果的影响。方法:选取2019年8月-2022年5月笔者医院收治的高危患龋儿童120例,根据1∶1随机分组法将患儿分为观察组(n=60)和对照组(n=60),对照组采用树脂充填修复治疗,观察组采用乳牙PMC修复治疗。比较两组患儿临床疗效。于治疗前及治疗后1个月、3个月评估患儿的咬合功能(最大咬合接触面积和最大咬合力);于治疗后3个月观察两组患儿修复效果(牙体完整性、修复体情况、边缘密合情况、继发龋、磨损和邻接关系),记录患儿并发症发生情况。结果:观察组与对照组患儿临床总有效率比较差异无统计学意义(P>0.05);治疗后1个月、3个月观察组患儿的最大咬合接触面积和最大咬合力均明显高于对照组(P<0.05);观察组修复体情况、边缘密合情况、继发龋、磨损与邻接关系为A级的患儿明显多于对照组(P<0.05),但两组患儿牙体完整性为A级的比较差异无统计学意义(P>0.05);两组并发症发生率比较差异无统计学意义(P>0.05)。结论:两种修复方式治疗小儿高危患龋的疗效相当,但乳牙PMC修复治疗在提高修复效果和咬合功能等方面优势更为显著。展开更多
The patient was a 41-year-old woman experiencing severe lumbago for several years. The physician-in-charge referred her for dental treatment because examination did not reveal any specific abnormality in her lower bac...The patient was a 41-year-old woman experiencing severe lumbago for several years. The physician-in-charge referred her for dental treatment because examination did not reveal any specific abnormality in her lower back. Prior to the treatment, the patient could barely bend forward and backward because of serious back pain. Her body flexibility and lower back pain improved when a gold alloy cast crown was placed near her feet. However, when the crown was covered with aluminum foil, it was again very difficult for her to bend her body forward and backward. These results suggested that her body reacted positively because good electromagnetic waves emitted by the crown were absorbed by the body. The alloy used to make the crown was chosen using the Bi-Digital O-Ring Test. Moreover, the shape, contact strength, and occlusion (biting condition) of the crown were also determined by the Bi-Digital O-Ring Test. After the crown was placed on her upper right first molar, her lumbago completely disappeared and did not recur for >5 years of follow-up. The effectiveness of electromagnetic waves on the condition of the body, as in this case, has not often been acknowledged in modern medicine, and the underlying mechanism remains unclear;therefore, further research is required.展开更多
A new type of ferrocenyl thia crown ethers used as selective ligands to some poisonous metals was synthesized, and the features of their mass spectra in electron ionization mode were summarized as: (1) the strong mol...A new type of ferrocenyl thia crown ethers used as selective ligands to some poisonous metals was synthesized, and the features of their mass spectra in electron ionization mode were summarized as: (1) the strong molecular ion peaks; (2) a characteristic homologous ion series with sequential loss of C 2H 4S or C 2H 4O from M C 5H 5; (3) a new rearrangement reaction of Fe migration; (4) the uncommon loss of alcohol or thiol from the fragments of Fe rearrangement. Some typical fragmentation patterns were discussed in detail with the aid of exact mass measurement and MS/MS technique.展开更多
The oxygenation constants and thermodynamic parameter (ΔHo, ΔSo) of Co (II) complexes with unsymmetrical bis-Schiff baeses were measured and their Mn(III) complexes as models of mimicking monooxygenase were employed...The oxygenation constants and thermodynamic parameter (ΔHo, ΔSo) of Co (II) complexes with unsymmetrical bis-Schiff baeses were measured and their Mn(III) complexes as models of mimicking monooxygenase were employed to catalyze epoxidation of styrene. The effect of substituent R in a salicylidene of ML1~ML4 [ M = Co (II), Mn (III)Cl ] on the dioxygen affinities and biomimetic catalytic oxidation performance were also investigated. Among them, the MnL4Cl containing a pendant benzoaza crown ether ring showed highest conversion and selectiviy up to 54.9% and 96.9% respectively.展开更多
基金the National Natural Science Foundation of China.
文摘The dioxygen affinities and biomimetic catalytic performance of transition-metal complexes with (15-crown-5) salophen and its substituted derivatives Mere examined. The oxygenation constants of Co(II) complexes with crowned bis-Schiff bases were measured and their Mn(III) complexes were employed as models to mimic monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 57.2% and 100% respectively at ambient temperature and pressure. The effects of crown ether ring and substituents R on the dioxygen affinities and catalytic activities were also investigated through comparing with the uncrowned analogues.
文摘An idea on interfacial equilibrium-potential differences () which are generated for the extraction of univalent metal picrate (MPic) and divalent ones (MPic2) by crown ethers (L) into high-polar diluents was improved. These potentials were clarified with some experimental extraction-data reported before on the M = Ag(I), Ca(II), Sr(II) and Ba(II) extraction with 18-crown-6 ether (18C6) and benzo-18C6 into 1,2-dichloroethane (DCE) and nitrobenzene (NB). Consequently, it was demonstrated that the? values from the extraction-experimentally obtained logKD,Pic ones are in agreement with or close to those calculated from charge balance equations in many cases, where the symbol, KD,Pic, denotes an individual distribution constant of Pic﹣ into the DCE or NB phase. Also, it was experimentally shown that extraction constants based on the overall extraction equilibria do not virtually contain the? terms in their functional expressions.
文摘N-pivot lariat ethers with picrylamino group as a chromophore (1, 2 and 3) have been prepared by reaction of N-(4-aminoaryl)monoaza crown ethers with picryl chrolide, and the selective coloration of 1, 2 and 3 for alkali metal salts and amines has been studied by UV-Vis spectra.
文摘目的:探讨使用乳牙金属预成冠(Preformed metal crown,PMC)修复治疗高危患龋患儿对其咬合功能和修复效果的影响。方法:选取2019年8月-2022年5月笔者医院收治的高危患龋儿童120例,根据1∶1随机分组法将患儿分为观察组(n=60)和对照组(n=60),对照组采用树脂充填修复治疗,观察组采用乳牙PMC修复治疗。比较两组患儿临床疗效。于治疗前及治疗后1个月、3个月评估患儿的咬合功能(最大咬合接触面积和最大咬合力);于治疗后3个月观察两组患儿修复效果(牙体完整性、修复体情况、边缘密合情况、继发龋、磨损和邻接关系),记录患儿并发症发生情况。结果:观察组与对照组患儿临床总有效率比较差异无统计学意义(P>0.05);治疗后1个月、3个月观察组患儿的最大咬合接触面积和最大咬合力均明显高于对照组(P<0.05);观察组修复体情况、边缘密合情况、继发龋、磨损与邻接关系为A级的患儿明显多于对照组(P<0.05),但两组患儿牙体完整性为A级的比较差异无统计学意义(P>0.05);两组并发症发生率比较差异无统计学意义(P>0.05)。结论:两种修复方式治疗小儿高危患龋的疗效相当,但乳牙PMC修复治疗在提高修复效果和咬合功能等方面优势更为显著。
文摘The patient was a 41-year-old woman experiencing severe lumbago for several years. The physician-in-charge referred her for dental treatment because examination did not reveal any specific abnormality in her lower back. Prior to the treatment, the patient could barely bend forward and backward because of serious back pain. Her body flexibility and lower back pain improved when a gold alloy cast crown was placed near her feet. However, when the crown was covered with aluminum foil, it was again very difficult for her to bend her body forward and backward. These results suggested that her body reacted positively because good electromagnetic waves emitted by the crown were absorbed by the body. The alloy used to make the crown was chosen using the Bi-Digital O-Ring Test. Moreover, the shape, contact strength, and occlusion (biting condition) of the crown were also determined by the Bi-Digital O-Ring Test. After the crown was placed on her upper right first molar, her lumbago completely disappeared and did not recur for >5 years of follow-up. The effectiveness of electromagnetic waves on the condition of the body, as in this case, has not often been acknowledged in modern medicine, and the underlying mechanism remains unclear;therefore, further research is required.
文摘A new type of ferrocenyl thia crown ethers used as selective ligands to some poisonous metals was synthesized, and the features of their mass spectra in electron ionization mode were summarized as: (1) the strong molecular ion peaks; (2) a characteristic homologous ion series with sequential loss of C 2H 4S or C 2H 4O from M C 5H 5; (3) a new rearrangement reaction of Fe migration; (4) the uncommon loss of alcohol or thiol from the fragments of Fe rearrangement. Some typical fragmentation patterns were discussed in detail with the aid of exact mass measurement and MS/MS technique.
文摘The oxygenation constants and thermodynamic parameter (ΔHo, ΔSo) of Co (II) complexes with unsymmetrical bis-Schiff baeses were measured and their Mn(III) complexes as models of mimicking monooxygenase were employed to catalyze epoxidation of styrene. The effect of substituent R in a salicylidene of ML1~ML4 [ M = Co (II), Mn (III)Cl ] on the dioxygen affinities and biomimetic catalytic oxidation performance were also investigated. Among them, the MnL4Cl containing a pendant benzoaza crown ether ring showed highest conversion and selectiviy up to 54.9% and 96.9% respectively.
