AIM: To investigate the performance of Gadofluorine P-enhanced magnetic resonance imaging(MRI) on the diagnosis of diabetes in a streptozotocin(STZ)-induced diabetic rat model.METHODS: Fischer 344 rats were treated wi...AIM: To investigate the performance of Gadofluorine P-enhanced magnetic resonance imaging(MRI) on the diagnosis of diabetes in a streptozotocin(STZ)-induced diabetic rat model.METHODS: Fischer 344 rats were treated with STZ.Rats not treated with STZ served as controls. T1-weighted MRI was performed using a 3T scanner before and after the injection of Gd-DOTA or Gadofluorine P(6 diabetic rats, 5 controls). The normalized signal intensity(SI) and the enhancement ratio(ER) of the pancreas were measured at each time point, and the values were compared between the normal and diabetic rats using the Mann-Whitney test. In addition,the values were correlated with the mean islet number.Optimal cut-off values were calculated using a positive test based on receiver operating characteristics.Intrapancreatic Gd concentration after the injection of each contrast media was measured using laser ablation-inductively coupled plasma-mass spectrometry in a separate set of rats(4 diabetic rats, 4 controls for Gadofluorine P; 2, 2 for Gd-DOTA).RESULTS: The normalized SI and ER of the pancreas using Gd-DOTA were not significantly different between diabetic rats and controls. With Gadofluorine P, the values were significantly higher in the diabetic rats than in the control rats 30 min after injection(P < 0.05). The area under the receiver operating characteristic curve that differentiated diabetic rats from the control group was greater for Gadofluorine P than for Gd-DOTA(0.967 vs 0.667, P = 0.085). An increase in normalized SI 30 min after Gadofluorine P was correlated with a decrease in the mean number of islets(r 2 = 0.510, P = 0.014). Intra-pancreatic Gd was higher in rats with Gadofluorine P injection than Gd-DOTA injection(Gadofluorine P vs Gd-DOTA, 7.37 vs 0.00, P < 0.01). A significant difference in the concentration of intrapancreatic Gd was observed between the control and diabetic animals that were sacrificed 30 min after Gadofluorine P injection(control vs diabetic, 3.25 ng/g vs 10.55 ng/g, P < 0.05)CONCLUSION: In this STZ-induced diabetes rat model,Gadofluorine P-enhanced MRI of the pancreas showed high accuracy in the diagnosis of diabetes.展开更多
The characterization of the shells of snails Achatina achatina and Lanistes varicus indicates that they contain calcium carbonate (98%) essentially aragonite, and organic matter (2%). The heating at 500°C during ...The characterization of the shells of snails Achatina achatina and Lanistes varicus indicates that they contain calcium carbonate (98%) essentially aragonite, and organic matter (2%). The heating at 500°C during three hours (3 h) has destroyed their constitutive organic matter, converted the aragonite form completely into the calcite and reduced their specific surfaces. The effects of these modifications have been revealed in the adsorption in aqueous environment of methylene blue (MB) and methyl orange (MO) which are respectively cationic and anionic dyes. The results showed that the sorption of these dyes on the raw shells is more important than the heated shells. The methylene blue has more affinity for shells than methyl orange. Between these two types of snails, the shells of Lanistes varicus have a higher capacity of adsorption. This sorption of the methylene blue is more in relationship with the Freundlich model ( for EG and for EA) comparatively to Langmuir model If the shells of these snails were calcined before using for the cicatrizing of the human cutaneous wounds in Benin. In the case of the sorption of organic molecule, it will be necessary to avoid submitting them to a preliminary heat treatment.展开更多
The purpose of this work is to review the literature on the analytical aspects of pentazocine-induced drug seizures and intoxication,focusing on the pharmacological,forensic,and toxicological perspectives.A literature...The purpose of this work is to review the literature on the analytical aspects of pentazocine-induced drug seizures and intoxication,focusing on the pharmacological,forensic,and toxicological perspectives.A literature search was conducted using PubMed,ScienceDirect,Web of Science,and Scopus databases,for articles published between January 1,2000,and December 31,2023,using the key terms“Pentazocine,”“Detection,”“Identification,”“Toxicology,”“Analysis,”“Matrix,”and“Forensic.”A total of 56 articles were gathered,with 20 duplicates removed.The authors examined the remaining relevant publications.This systematic review comprised 36 publications,with 4 articles being excluded and summarized.The following information was gathered from the articles by the authors:the number of cases and toxicological findings(samples,analytical procedures,and outcomes).This review concluded that with the help of liquid-liquid extraction and solid-phase extraction,better,faster,and more accurate methods,among which are potentiometry,gas chromatography(GC),liquid chromatography(LC),GC-mass spectrometric(MS),LC-MS,and MS,have been reported in different matrices.These methods can be used for pharmaceutical,forensic,clinical,and toxicological analyses.展开更多
Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol,...Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol, formaldehyde and (+)-bis-[(R)-1-phenylethyl]amine. These new organic compounds were fully characterized via nuclear magnetic resonance spectroscopy (1H and 13C) and elemental analysis. The newly synthesized ligands are suitable candidates for metal-catalyzed ring-opening of lactones and asymmetric catalysis.展开更多
The syntheses of a library of new chiral aminophenolate bidentate O,N-type ligands HOC<sub>6</sub>H<sub>4</sub>(2-R- 4-R′)CH<sub>2</sub>N(Me)CH(Me)C<sub>6</sub>H<sub...The syntheses of a library of new chiral aminophenolate bidentate O,N-type ligands HOC<sub>6</sub>H<sub>4</sub>(2-R- 4-R′)CH<sub>2</sub>N(Me)CH(Me)C<sub>6</sub>H<sub>5</sub> [R = R′ = Bu<sup>t</sup>, 1;R = R′ = Pent, 2;R = Bu<sup>t</sup>, R′ = Me, 3;R = Me, R′ = Bu<sup>t</sup>, 4;R = R′ = Me, 5] and tridentate O,N,O-type ligands HOC<sub>6</sub>H<sub>4</sub>(2,4-Bu<sup>t</sup>)CH = NCH(R′′)C<sub>6</sub>H<sub>5</sub> [R′′ = Me, 6;R′′ = CH<sub>2</sub>OMe, 7] are reported. These ligands were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (<sup>1</sup>H &<sup> 13</sup>C), and single crystal X-ray diffraction. These ligands serve as chiral auxiliaries for inorganic chemists to design chiral metal-based complexes for asymmetric catalysis and stereoselective polymerization reactions. Three new heteroleptic zinc complexes based on these ligands have been synthesized in moderate yields via a ligand-exchange transamination reaction between homoleptic [Zn(N(SiMe<sub>3</sub>)<sub>2</sub>)<sub>2</sub>] and one equivalent of corresponding ligands to afford [L<sup>3</sup>ZnN- (SiMe<sub>3</sub>)<sub>2</sub>] (3a), [L<sup>4</sup>ZnN(SiMe<sub>3</sub>)<sub>2</sub>] (4a), and [L<sup>7</sup>ZnN(SiMe<sub>3</sub>)<sub>2</sub>] (7a). Solvent-free polymerization of raclactide at 130°C using these zinc compounds yielded atactic polylactides with Mw 10,000 g/mol and narrow polydispersity of 1.3.展开更多
Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidel...Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear.Herein,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and N.The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles.Remarkably,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/C.Density functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms.Consequently,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT counterparts.This work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.展开更多
New heteroleptic lanthanide complex [L1ILaN{Si(CH3)2}] (1) containing tridentate [ONO] ancillary ligand was synthesized from an acid-base ligand exchange reaction with ligands H2L1 and corresponding homoleptic lanthan...New heteroleptic lanthanide complex [L1ILaN{Si(CH3)2}] (1) containing tridentate [ONO] ancillary ligand was synthesized from an acid-base ligand exchange reaction with ligands H2L1 and corresponding homoleptic lanthanide compound La[N{Si(CH3)3}2]3. Meanwhile, dimeric complexes [L1LaCl] (2) and [L1ILaCl] (3) were prepared from salt metathesis reaction between one equivalent of ligands H2LI,II, three equivalent of NaN{Si(CH3)3}2, and one equivalent of LaCl3. These compounds were characterized by nuclear magnetic resonance (300 MHz) and elemental analysis. These complexes were used as catalysts in the ring-opening homopolymerization of α-methylene-γ-butyrolactone. While compound 1 did not show any significant reactivity, compounds 2 and 3 gave significant amount of highly branched poly(α-methylene-γ-butyrolactone) as confirmed by 1H NMR spectroscopy and Malvern’s triple detector GPCMax analysis in DMSO with molecular weights of over 500,000 Dalton. The glass-transition temperatures of the branched polymer samples were determined using a Dynamic Mechanical Analyzer, DMA Q800.展开更多
Extractive oxidation, wherein aromatic sulfur- containing compounds are extracted and subsequently oxidized to their corresponding sulfones, has proven to be one of the most effective desulfurization methods for produ...Extractive oxidation, wherein aromatic sulfur- containing compounds are extracted and subsequently oxidized to their corresponding sulfones, has proven to be one of the most effective desulfurization methods for producing ultra-low sulfur content fuels. As non-volatile and highly designable solvents, ionic liquids （ILs） have attracted considerable attention for the oxidative desulfur- ization of fuels. In this review, we systematically discuss the utility of ILs in catalytic and extractive oxidation, including their role as extractant, catalyst, or both. We also discuss the challenges facing the use of ILs in this regard, including their relatively high cost and excessive viscosity, as well as their efficiency and stability as catalyst.展开更多
Sodium ion(Na+)batteries have attracted increased attention for energy storage owing to the natural abundance and low cost of sodium.Herein,we report the synthesis of mesoporous carbon with large pores as anode for Na...Sodium ion(Na+)batteries have attracted increased attention for energy storage owing to the natural abundance and low cost of sodium.Herein,we report the synthesis of mesoporous carbon with large pores as anode for Na-ion batteries.The mesoporous carbon was obtained by carbonization and dense packing of 50 nm resorcinol and formaldehyde spheres synthesized through an extension Sto¨ber method.Our work demonstrates that replacement of lithium by sodium using large pore carbon as anode might offer an alternative route for rechargeable batteries.展开更多
基金Supported by Innovative Research Institute for Cell Therapy,Ministry for Health,Welfare and Family Affairs(A062260)in South Korea
文摘AIM: To investigate the performance of Gadofluorine P-enhanced magnetic resonance imaging(MRI) on the diagnosis of diabetes in a streptozotocin(STZ)-induced diabetic rat model.METHODS: Fischer 344 rats were treated with STZ.Rats not treated with STZ served as controls. T1-weighted MRI was performed using a 3T scanner before and after the injection of Gd-DOTA or Gadofluorine P(6 diabetic rats, 5 controls). The normalized signal intensity(SI) and the enhancement ratio(ER) of the pancreas were measured at each time point, and the values were compared between the normal and diabetic rats using the Mann-Whitney test. In addition,the values were correlated with the mean islet number.Optimal cut-off values were calculated using a positive test based on receiver operating characteristics.Intrapancreatic Gd concentration after the injection of each contrast media was measured using laser ablation-inductively coupled plasma-mass spectrometry in a separate set of rats(4 diabetic rats, 4 controls for Gadofluorine P; 2, 2 for Gd-DOTA).RESULTS: The normalized SI and ER of the pancreas using Gd-DOTA were not significantly different between diabetic rats and controls. With Gadofluorine P, the values were significantly higher in the diabetic rats than in the control rats 30 min after injection(P < 0.05). The area under the receiver operating characteristic curve that differentiated diabetic rats from the control group was greater for Gadofluorine P than for Gd-DOTA(0.967 vs 0.667, P = 0.085). An increase in normalized SI 30 min after Gadofluorine P was correlated with a decrease in the mean number of islets(r 2 = 0.510, P = 0.014). Intra-pancreatic Gd was higher in rats with Gadofluorine P injection than Gd-DOTA injection(Gadofluorine P vs Gd-DOTA, 7.37 vs 0.00, P < 0.01). A significant difference in the concentration of intrapancreatic Gd was observed between the control and diabetic animals that were sacrificed 30 min after Gadofluorine P injection(control vs diabetic, 3.25 ng/g vs 10.55 ng/g, P < 0.05)CONCLUSION: In this STZ-induced diabetes rat model,Gadofluorine P-enhanced MRI of the pancreas showed high accuracy in the diagnosis of diabetes.
文摘The characterization of the shells of snails Achatina achatina and Lanistes varicus indicates that they contain calcium carbonate (98%) essentially aragonite, and organic matter (2%). The heating at 500°C during three hours (3 h) has destroyed their constitutive organic matter, converted the aragonite form completely into the calcite and reduced their specific surfaces. The effects of these modifications have been revealed in the adsorption in aqueous environment of methylene blue (MB) and methyl orange (MO) which are respectively cationic and anionic dyes. The results showed that the sorption of these dyes on the raw shells is more important than the heated shells. The methylene blue has more affinity for shells than methyl orange. Between these two types of snails, the shells of Lanistes varicus have a higher capacity of adsorption. This sorption of the methylene blue is more in relationship with the Freundlich model ( for EG and for EA) comparatively to Langmuir model If the shells of these snails were calcined before using for the cicatrizing of the human cutaneous wounds in Benin. In the case of the sorption of organic molecule, it will be necessary to avoid submitting them to a preliminary heat treatment.
文摘The purpose of this work is to review the literature on the analytical aspects of pentazocine-induced drug seizures and intoxication,focusing on the pharmacological,forensic,and toxicological perspectives.A literature search was conducted using PubMed,ScienceDirect,Web of Science,and Scopus databases,for articles published between January 1,2000,and December 31,2023,using the key terms“Pentazocine,”“Detection,”“Identification,”“Toxicology,”“Analysis,”“Matrix,”and“Forensic.”A total of 56 articles were gathered,with 20 duplicates removed.The authors examined the remaining relevant publications.This systematic review comprised 36 publications,with 4 articles being excluded and summarized.The following information was gathered from the articles by the authors:the number of cases and toxicological findings(samples,analytical procedures,and outcomes).This review concluded that with the help of liquid-liquid extraction and solid-phase extraction,better,faster,and more accurate methods,among which are potentiometry,gas chromatography(GC),liquid chromatography(LC),GC-mass spectrometric(MS),LC-MS,and MS,have been reported in different matrices.These methods can be used for pharmaceutical,forensic,clinical,and toxicological analyses.
文摘Three new chiral monoanionic [ON] ancillary phenolate ligands with varying pendant arms have been synthesized in moderate to high yields (50% - 85%) via Mannich-type condensation reaction of chiral substituted phenol, formaldehyde and (+)-bis-[(R)-1-phenylethyl]amine. These new organic compounds were fully characterized via nuclear magnetic resonance spectroscopy (1H and 13C) and elemental analysis. The newly synthesized ligands are suitable candidates for metal-catalyzed ring-opening of lactones and asymmetric catalysis.
文摘The syntheses of a library of new chiral aminophenolate bidentate O,N-type ligands HOC<sub>6</sub>H<sub>4</sub>(2-R- 4-R′)CH<sub>2</sub>N(Me)CH(Me)C<sub>6</sub>H<sub>5</sub> [R = R′ = Bu<sup>t</sup>, 1;R = R′ = Pent, 2;R = Bu<sup>t</sup>, R′ = Me, 3;R = Me, R′ = Bu<sup>t</sup>, 4;R = R′ = Me, 5] and tridentate O,N,O-type ligands HOC<sub>6</sub>H<sub>4</sub>(2,4-Bu<sup>t</sup>)CH = NCH(R′′)C<sub>6</sub>H<sub>5</sub> [R′′ = Me, 6;R′′ = CH<sub>2</sub>OMe, 7] are reported. These ligands were characterized by elemental analysis, nuclear magnetic resonance spectroscopy (<sup>1</sup>H &<sup> 13</sup>C), and single crystal X-ray diffraction. These ligands serve as chiral auxiliaries for inorganic chemists to design chiral metal-based complexes for asymmetric catalysis and stereoselective polymerization reactions. Three new heteroleptic zinc complexes based on these ligands have been synthesized in moderate yields via a ligand-exchange transamination reaction between homoleptic [Zn(N(SiMe<sub>3</sub>)<sub>2</sub>)<sub>2</sub>] and one equivalent of corresponding ligands to afford [L<sup>3</sup>ZnN- (SiMe<sub>3</sub>)<sub>2</sub>] (3a), [L<sup>4</sup>ZnN(SiMe<sub>3</sub>)<sub>2</sub>] (4a), and [L<sup>7</sup>ZnN(SiMe<sub>3</sub>)<sub>2</sub>] (7a). Solvent-free polymerization of raclactide at 130°C using these zinc compounds yielded atactic polylactides with Mw 10,000 g/mol and narrow polydispersity of 1.3.
文摘Efficacious regulation of the geometric and electronic structures of carbon nanomaterials via the introduction of defects and their synergy is essential to achieving good electrochemical performance.However,the guidelines for designing hybrid materials with advantageous structures and the fundamental understanding of their electrocatalytic mechanisms remain unclear.Herein,superfine Pt and PtCu nanoparticles supported by novel S,N‐co‐doped multi‐walled CNT(MWCNTs)were prepared through the innovative pyrolysis of a poly(3,4‐ethylenedioxythiophene)/polyaniline copolymer as a source of S and N.The uniform wrapping of the copolymer around the MWCNTs provides a high density of evenly distributed defects on the surface after the pyrolysis treatment,facilitating the uniform distribution of ultrafine Pt and PtCu nanoparticles.Remarkably,the Pt_(1)Cu_(2)/SN‐MWCNTs show an obviously larger electroactive surface area and higher mass activity,stability,and CO poisoning resistance in methanol oxidation compared to Pt/SN‐MWCNTs,Pt/S‐MWCNTs,Pt/N‐MWCNTs,and commercial Pt/C.Density functional theory studies confirm that the co‐doping of S and N considerably deforms the CNTs and polarizes the adjacent C atoms.Consequently,both the adsorption of Pt1Cu2 onto the SN‐MWCNTs and the subsequent adsorption of methanol are enhanced;in addition,the catalytic activity of Pt_(1)Cu_(2)/SN‐MWCNTs for methanol oxidation is thermodynamically and kinetically more favorable than that of its CNT and N‐CNT counterparts.This work provides a novel method to fabricate high‐performance fuel cell electrocatalysts with highly dispersed and stable Pt‐based nanoparticles on a carbon substrate.
文摘New heteroleptic lanthanide complex [L1ILaN{Si(CH3)2}] (1) containing tridentate [ONO] ancillary ligand was synthesized from an acid-base ligand exchange reaction with ligands H2L1 and corresponding homoleptic lanthanide compound La[N{Si(CH3)3}2]3. Meanwhile, dimeric complexes [L1LaCl] (2) and [L1ILaCl] (3) were prepared from salt metathesis reaction between one equivalent of ligands H2LI,II, three equivalent of NaN{Si(CH3)3}2, and one equivalent of LaCl3. These compounds were characterized by nuclear magnetic resonance (300 MHz) and elemental analysis. These complexes were used as catalysts in the ring-opening homopolymerization of α-methylene-γ-butyrolactone. While compound 1 did not show any significant reactivity, compounds 2 and 3 gave significant amount of highly branched poly(α-methylene-γ-butyrolactone) as confirmed by 1H NMR spectroscopy and Malvern’s triple detector GPCMax analysis in DMSO with molecular weights of over 500,000 Dalton. The glass-transition temperatures of the branched polymer samples were determined using a Dynamic Mechanical Analyzer, DMA Q800.
文摘Extractive oxidation, wherein aromatic sulfur- containing compounds are extracted and subsequently oxidized to their corresponding sulfones, has proven to be one of the most effective desulfurization methods for producing ultra-low sulfur content fuels. As non-volatile and highly designable solvents, ionic liquids （ILs） have attracted considerable attention for the oxidative desulfur- ization of fuels. In this review, we systematically discuss the utility of ILs in catalytic and extractive oxidation, including their role as extractant, catalyst, or both. We also discuss the challenges facing the use of ILs in this regard, including their relatively high cost and excessive viscosity, as well as their efficiency and stability as catalyst.
基金supported by the Australian Research Council (ARC) Discovery Project Programthe award of UQ Foundation Research Excellence Awards+1 种基金a UQ Early-Career-Research Grantthe support from UTS Chancellor’s Post Doctoral Fellowship (CPDF)
文摘Sodium ion(Na+)batteries have attracted increased attention for energy storage owing to the natural abundance and low cost of sodium.Herein,we report the synthesis of mesoporous carbon with large pores as anode for Na-ion batteries.The mesoporous carbon was obtained by carbonization and dense packing of 50 nm resorcinol and formaldehyde spheres synthesized through an extension Sto¨ber method.Our work demonstrates that replacement of lithium by sodium using large pore carbon as anode might offer an alternative route for rechargeable batteries.
