Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
Add more filters










Publication year range
1.
Korean Circ J ; 54(6): 339-350, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38767441

ABSTRACT

BACKGROUND AND OBJECTIVES: Ultimaster™, a third-generation sirolimus-eluting stent using biodegradable polymer, has been introduced to overcome long term adverse vascular events, such as restenosis or stent thrombosis. In the present study, we aimed to evaluate the 12-month clinical outcomes of Ultimaster™ stents in Korean patients with coronary artery disease. METHODS: This study is a multicenter, prospective, observational registry across 12 hospitals. To reflect real-world clinical evidence, non-selective subtypes of patients and lesions were included in this study. The study end point was target lesion failure (TLF) (the composite of cardiac death, target vessel myocardial infarction [MI], and target lesion revascularization [TLR]) at 12-month clinical follow up. RESULTS: A total of 576 patients were enrolled between November 2016 and May 2021. Most of the patients were male (76.5%), with a mean age of 66.0±11.2 years. Among the included patients, 40.1% had diabetes mellitus (DM) and 67.9% had acute coronary syndrome (ACS). At 12 months, the incidence of TLF was 4.1%. The incidence of cardiac death was 1.5%, MI was 1.0%, TLR was 2.7%, and stent thrombosis was 0.6%. In subgroup analysis based on the presence of ACS, DM, hypertension, dyslipidemia, or bifurcation, there were no major differences in the incidence of the primary endpoint. CONCLUSIONS: The present registry shows that Ultimaster™ stent is safe and effective for routine real-world clinical practice in non-selective Korean patients, having a low rate of adverse events at least up to 12 months.

2.
Sensors (Basel) ; 20(21)2020 Nov 09.
Article in English | MEDLINE | ID: mdl-33182260

ABSTRACT

A beryllium(II)-ion-selective poly(ethylenedioxythiophene) (PEDOT) solid contact electrode comprising 9,10-dinitrobenzo-9-crown-3-ether was successfully developed. The all-solid-state contact electrode, with an oxygen-containing cation-sensing membrane combined with an electropolymerized PEDOT layer, exhibited the best response characteristics. The performance of the constructed electrode was evaluated and optimized using potentiometry, conductance measurements, constant-current chronopotentiometry, and electrochemical impedance spectroscopy (EIS). Under optimized conditions, which were found for an ion-selective membrane (ISM) composition of 3% ionophore, 30% polyvinylchloride (PVC), 64% o-nitro phenyl octyl ether (o-NPOE), and 3% sodium tetraphenylborate (NaTPB), the fabricated electrode exhibited a good performance over a wide concentration range (10-2.5-10-7.0 M) and a wide pH range of 2.0-9.0, with a Nernstian slope of 29.5 mV/D for the beryllium (II) ion and a detection limit as low as 10-7.0 M. The developed electrode shows good selectivity for the beryllium(II) ion over alkali, alkaline earth, transition, and heavy metal ions.

3.
Heart ; 97(17): 1425-32, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21700754

ABSTRACT

OBJECTIVE: Telmisartan is a peroxisome proliferator-activated receptor-γ activator with potent anti-inflammatory and antiatherogenic effects. The authors compared the effects of telmisartan and valsartan on neointima volume, atherosclerosis progression and brachial-ankle pulse wave velocity (baPWV) after stenting in hypertensive type 2 diabetes. DESIGN: This was a prospective, randomised, 8-month follow-up study that included patients with significant coronary stenosis who received telmisartan (n=36) or valsartan (n=37). SETTING: University hospital. MAIN OUTCOME MEASURES: Neointima volume and atherosclerosis progression 10 mm proximal and distal to the stented segment were analysed using repeat intravascular ultrasonography. baPWV and inflammatory markers such as interleukin 6, tumour necrosis factor α, C-reactive protein and adiponectin were compared. RESULTS: Neointima volume at 8 months was significantly lower in the telmisartan group than the valsartan group (1.9±1.0 vs 2.6±1.4 mm(3)/1 mm, p=0.007, respectively). Total plaque volumes 10 mm proximal (7.1±1.5 vs 7.8±1.6 mm(3)/1 mm, p=0.032, respectively) and distal (3.5±1.4 vs 4.1±1.3 mm(3)/1 mm, p=0.028, respectively) to the stent were significantly lower in the telmisartan group than the valsartan group at 8 months. The decrease from baseline in baPWV was significantly greater in the telmisartan group than the valsartan group (-52±104 vs 30±113 cm/s, p=0.002, respectively). The increase from baseline in adiponectin levels and the decreases from baseline in interleukin 6 and tumour necrosis factor α levels were significantly greater in the telmisartan group at 8 months. Retinol-binding protein-4, homeostasis model of assessment index, hemoglobin A(1c) and low-density lipoprotein cholesterol levels decreased significantly in both groups without differences in changes from baseline between the two groups. CONCLUSIONS: Telmisartan reduced neointima volume; atherosclerosis progression 10 mm proximal and distal to the stented segment and baPWV independent of blood pressure, glucose and lipid control in hypertensive type 2 diabetes. Clinical trial no NCT00599885 (clinicaltrials.gov.).


Subject(s)
Anti-Inflammatory Agents/pharmacology , Benzimidazoles/pharmacology , Benzoates/pharmacology , Coronary Stenosis/drug therapy , Diabetes Mellitus, Type 2/complications , Neointima/drug therapy , Tetrazoles/pharmacology , Valine/analogs & derivatives , Adiponectin/blood , Aged , Ankle Brachial Index , Anti-Inflammatory Agents/therapeutic use , Benzimidazoles/therapeutic use , Benzoates/therapeutic use , C-Reactive Protein , Coronary Stenosis/etiology , Disease Progression , Drug-Eluting Stents , Female , Follow-Up Studies , Humans , Hypertension/complications , Hypertension/drug therapy , Interleukin-6 , Male , Middle Aged , Prospective Studies , Single-Blind Method , Sirolimus/administration & dosage , Sirolimus/analogs & derivatives , Telmisartan , Tetrazoles/therapeutic use , Time Factors , Treatment Outcome , Tumor Necrosis Factor-alpha , Ultrasonography, Interventional , Valine/pharmacology , Valine/therapeutic use , Valsartan
4.
Heart Vessels ; 26(5): 502-10, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21153029

ABSTRACT

Cilostazol, a phosphodiesterase III inhibitor, is known to have anti-proliferative activity. We investigated the effects of cilostazol 200 mg, in addition to aspirin 100 mg and clopidogrel 75 mg, on carotid intima-media thickness (IMT) progression during a 2-year follow-up period in patients with acute coronary syndrome (ACS) requiring stent implantation. Patients with ACS (n = 130) were randomly assigned to the cilostazol group (n = 64) or the control group (n = 66). Longitudinal images of left and right carotid IMT were measured at baseline, at 6, 12, and 24 months using a 10-MHz linear vascular probe. The primary endpoint was to compare the changes in maximum carotid IMT at 2 years. Other parameters such as inflammatory markers [interleukin (IL)-6, tumor necrosis factor (TNF)-α, C-reactive protein (CRP), and adiponectin] and bleeding risk were also compared. The carotid IMT showed no significant progression from baseline in the cilostazol group compared to significant progression in the control group at 12 months (0.78 ± 0.38 and 0.85 ± 0.41 mm, p = 0.034, respectively) and 24 months (0.82 ± 0.41 and 0.96 ± 0.39 mm, p = 0.022, respectively). Major bleeding (p = 1.00), minor bleeding (p = 0.68), and total bleeding rates (p = 0.74) were similar between the two groups during the 2-year follow-up. Decreases from baseline in IL-6 (-2.79 ± 2.83 and -2.14 ± 3.36 pg/ml, p = 0.010, respectively) and TNF-α (-2.81 ± 1.97 and -2.21 ± 2.68 pg/ml, p = 0.029, respectively) were significantly greater in the cilostazol group than the control group during the follow-up. Cilostazol treatment, with greater anti-inflammatory effect, inhibited the progression of carotid IMT without increasing the risk of bleeding in patients with ACS during the 2-year follow-up.


Subject(s)
Acute Coronary Syndrome/therapy , Angioplasty, Balloon, Coronary , Anti-Inflammatory Agents/therapeutic use , Carotid Arteries/drug effects , Carotid Stenosis/drug therapy , Phosphodiesterase 3 Inhibitors/therapeutic use , Platelet Aggregation Inhibitors/therapeutic use , Tetrazoles/therapeutic use , Tunica Intima/drug effects , Tunica Media/drug effects , Acute Coronary Syndrome/complications , Acute Coronary Syndrome/diagnostic imaging , Aged , Aged, 80 and over , Analysis of Variance , Angioplasty, Balloon, Coronary/adverse effects , Angioplasty, Balloon, Coronary/instrumentation , Anti-Inflammatory Agents/adverse effects , Aspirin/therapeutic use , Carotid Arteries/diagnostic imaging , Carotid Stenosis/complications , Carotid Stenosis/diagnostic imaging , Chi-Square Distribution , Cilostazol , Clopidogrel , Coronary Angiography , Disease Progression , Drug Therapy, Combination , Hemorrhage/chemically induced , Humans , Inflammation Mediators/blood , Middle Aged , Phosphodiesterase 3 Inhibitors/adverse effects , Platelet Aggregation Inhibitors/adverse effects , Prospective Studies , Republic of Korea , Risk Assessment , Risk Factors , Single-Blind Method , Stents , Tetrazoles/adverse effects , Ticlopidine/analogs & derivatives , Ticlopidine/therapeutic use , Time Factors , Treatment Outcome , Tunica Intima/diagnostic imaging , Tunica Media/diagnostic imaging , Ultrasonography
5.
Phytother Res ; 25(2): 239-49, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20641058

ABSTRACT

The effects of red ginseng extract on circulating angiogenic cell mobilization and improvement of microvascular integrity were evaluated in ST-elevation acute myocardial infarction (AMI) patients during 8-month follow-up. AMI patients (n = 50) were randomly assigned to the red ginseng group (3 g/day, n = 25) or the placebo group (n = 25) after coronary stenting. Coronary flow reserve (CFR) was measured at baseline and at 8 months with an intracoronary Doppler wire. Serial changes in the absolute numbers of circulating angiogenic cells such as CD34(+) , CXCR4(+) , CD117(+) , CD133(+) and C-met(+) were measured at baseline, 1 day, 5 days and at 8 months. CFR were similar between the two groups at baseline, and CFR was significantly higher in the red ginseng group than in the placebo group (2.80 ± 0.91 and 2.56 ± 0.77, p < 0.05, respectively) after 8 months of red ginseng administration. The absolute numbers of circulating CD34(+) , CXCR4(+) and CD117(+) cells were significantly higher in the red ginseng group at 1 and 5 days after stenting. Significant positive correlations were found between the numbers of circulating angiogenic cells at day 1 and the changes from baseline in CFR for CD34(+) , CXCR4(+) , CD117(+) and C-met(+) cells. Red ginseng extract increased CD34(+) , CXCR4(+) and CD117(+) circulating angiogenic cell mobilization and decreased inflammation in AMI patients, thereby improving CFR during the 8-month follow-up.


Subject(s)
Heart/drug effects , Myocardial Infarction/drug therapy , Panax/chemistry , Phytotherapy , Plant Extracts/therapeutic use , Aged , Blood Flow Velocity , Echocardiography, Doppler , Female , Humans , Male , Middle Aged , Neovascularization, Physiologic/drug effects , Plant Extracts/pharmacology , Prospective Studies , Single-Blind Method
6.
Heart ; 96(10): 756-64, 2010 May.
Article in English | MEDLINE | ID: mdl-20448126

ABSTRACT

OBJECTIVE: To compare the effects of atorvastatin 10 mg versus 40 mg in circulating angiogenic cell mobilisations and in restoring coronary flow reserve (CFR) during the 8-month follow-up in patients with a first acute myocardial infarction (AMI). DESIGN: CFR was measured using an intracoronary Doppler wire in 102 patients with AMI at baseline and at 8 months. Changes in the absolute number of circulating angiogenic cells were measured at baseline, 1 day, 5 days and at 8 months. Stented patients were randomly assigned to either low-dose atorvastatin 10 mg (ATOR10, n=52) or moderate-dose atorvastatin 40 mg (ATOR40, n=50). Setting University Hospital. RESULTS: CFR increased significantly in both groups during the 8-month follow-up. The 8-month increases from baseline in CFR were significantly greater in the ATOR40 group than in the ATOR10 group (0.99+/-0.69 vs 0.55+/-0.47, p=0.017, respectively). The serial increases in the absolute number of CD34+ and CXCR4+ cells were significantly greater in the ATOR40 group, especially at 24 h after the procedure (two-way repeated-measures analysis of variance: p=0.046 and p=0.022, respectively). Decreases from baseline for interleukin 6 (-2.94+/-3.31 vs -1.52+/-2.82 pg/ml), tumour necrosis factor alpha (-1.31+/-2.96 vs -0.01+/-1.29 pg/ml), soluble intercellular adhesion molecule-1 (-71+/-95 vs 37+/-83 ng/ml) and soluble vascular cell adhesion molecule-1 (-51+/-364 vs 190+/-204 ng/ml) were significantly greater in the ATOR40 group. CONCLUSIONS: The recovery of microvascular integrity after acute ischaemic injury in the ATOR40 group was expedited by greater circulating angiogenic cell mobilisations such as CD34+ and CXCR4+ cells, together with greater decreases in inflammatory cytokines and low-density lipoprotein-cholesterol concentrations. Registration number http://ClinicalTrials.gov number, NCT00536887.


Subject(s)
Coronary Circulation/drug effects , Heptanoic Acids/administration & dosage , Hydroxymethylglutaryl-CoA Reductase Inhibitors/administration & dosage , Myocardial Infarction/drug therapy , Neovascularization, Physiologic/drug effects , Pyrroles/administration & dosage , Adolescent , Adult , Aged , Aged, 80 and over , Antigens, CD34/blood , Atorvastatin , Biomarkers/blood , Cholesterol, LDL/blood , Cytokines/blood , Dose-Response Relationship, Drug , Follow-Up Studies , Heptanoic Acids/therapeutic use , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Inflammation Mediators/blood , Middle Aged , Myocardial Infarction/physiopathology , Pyrroles/therapeutic use , Receptors, CXCR4/blood , Stents , Young Adult
7.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 10): o2471, 2010 Sep 04.
Article in English | MEDLINE | ID: mdl-21587472

ABSTRACT

The title compound, C(17)H(16)F(3)NO(2), crystallizes with two independent mol-ecules in the asymmetric unit. The dihedral angles between the isopropoxyphenyl and trifluoro-methyl-phenyl rings are 85.78 (5) and 63.15 (6)° in the two mol-ecules. In the crystal structure, inter-molecular N-H⋯O and C-H⋯π inter-actions are observed.

8.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 12): o3211, 2010 Nov 17.
Article in English | MEDLINE | ID: mdl-21589504

ABSTRACT

In the title compound, C(18)H(18)N(4), the dihedral angles between the pyrrole rings and the phenyl ring are 85.07 (8)° and 77.13 (9)°. Inter-molecular N-H⋯N hydrogen bonds contribute to the stabilization of the crystal packing.

9.
Anal Chim Acta ; 614(1): 85-92, 2008 Apr 28.
Article in English | MEDLINE | ID: mdl-18405685

ABSTRACT

We have synthesized a bis(terthiophene)-appended uranyl-salophen complex, comprising N,N'-bis[4-(5,2':5',2''-terthiophen-3'-yl)salicylidene]-1,2-ethanediamine-uranyl complexes (TUS), and used it as a monomer for the electrochemical polymerizations (poly-TUS) on glassy carbon surfaces to prepare functionalized conducting polymer (CP) films. The poly-TUS films prepared from propylene carbonate/0.1 M tetrabutyl ammonium perchlorate (TBAP) on a glassy carbon electrode have both the functionality of ion-to-electron transducers (solid contact) and Lewis-acidic binding sites for a monohydrogen phosphate (MHP) ion-selective electrode (ISE). The CP/poly-TUS sensor showed a linear range between 1.0 x 10(-1) and 1.0 x 10(-4.5) M with a near-Nernstian behavior (-30.4 mV decade(-1)) at a pH of 8.2. The detection limit of the electrode was 10(-5.0) M and the response time was improved (< 10s) compared to that of conventional ISEs (< 20s). For comparison, a conventional ISE (with an internal aqueous solution) based on a TUS monomer/o-nitrophenyl octylether (o-NPOE)/polyvinyl chloride (PVC) liquid membrane with or without tridodecylmethylammonium chloride (TDMACl) as an additive was also constructed and its performance as an MHP-ISE were studied. The superior selectivity and sensitivity of the CP/poly-TUS sensor enabled the direct measurement of MHP in a wide variety of applications.

11.
Mol Cell Biol ; 27(12): 4293-305, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17438128

ABSTRACT

In the developing mouse brain, the highest Bcl-X(L) expression is seen at the peak of neurogenesis, whereas the peak of Bax expression coincides with the astrogenic period. While such observations suggest an active role of the Bcl-2 family proteins in the generation of neurons and astrocytes, no definitive demonstration has been provided to date. Using combinations of gain- and loss-of-function assays in vivo and in vitro, we provide evidence for instructive roles of these proteins in neuronal and astrocytic fate specification. Specifically, in Bax knockout mice, astrocyte formation was decreased in the developing cortices. Overexpression of Bcl-X(L) and Bax in embryonic cortical precursors induced neural and astrocytic differentiation, respectively, while inhibitory RNAs led to the opposite results. Importantly, inhibition of caspase activity, dimerization, or mitochondrial localization of Bcl-X(L)/Bax proteins indicated that the differentiation effects of Bcl-X(L)/Bax are separable from their roles in cell survival and apoptosis. Lastly, we describe activation of intracellular signaling pathways and expression of basic helix-loop-helix transcriptional factors specific for the Bcl-2 protein-mediated differentiation.


Subject(s)
Cerebral Cortex/cytology , Cerebral Cortex/embryology , Gene Expression Regulation, Developmental , bcl-2-Associated X Protein/metabolism , bcl-X Protein/metabolism , Animals , Astrocytes/cytology , Astrocytes/physiology , Basic Helix-Loop-Helix Transcription Factors/metabolism , Caspase Inhibitors , Cell Differentiation , Cells, Cultured , Coated Materials, Biocompatible/metabolism , Crosses, Genetic , Dimerization , Enzyme Activation , Fibronectins/metabolism , Homozygote , Mice , Mice, Knockout , Mitochondria/metabolism , Mutagenesis, Site-Directed , Neurons/cytology , Neurons/physiology , RNA, Small Interfering/genetics , Retroviridae/genetics , Signal Transduction/physiology , Transduction, Genetic , bcl-2-Associated X Protein/chemistry , bcl-2-Associated X Protein/genetics , bcl-X Protein/chemistry , bcl-X Protein/genetics
12.
Talanta ; 74(2): 223-8, 2007 Nov 30.
Article in English | MEDLINE | ID: mdl-18371633

ABSTRACT

The new ion-selective electrodes (ISEs) based on salphenH2 derivatives such as N,N'-(propylenedioxy)benzenebis(salicylideneimine) L1 and N,N'-4,5-(propylenedioxy)benzenebis(3,5-di-tert-butylsalicylideneimine) L2 as cation carriers are developed for a uranyl ion. The combination of these new ionophores with tris(2-ethylhexyl)phosphate (TEHP) as a plasticizer particularly shows near Nernstian slope in the wide concentration range (1.0 x 10(-6) to 1.0 x 10(-2) M) of UO2(2+) and is observed well in the pH range from 1.0 to 5.0 with a response time less than 20s. Since the employed ionophores were confirmed to form well-defined stable 1:1 complexes with UO2(2+), the observed high selectivity for a uranyl ion over the other cations was attributed to the selective complexation as well as the lipophilic behavior of these ligands especially for L2. The proposed electrodes offered practically low detection limit of 6.5 x 10(-7) M and reasonably good end-points within experimental error were obtained when the sensor was used as an indicator electrode for the potentiometric titration.


Subject(s)
Ionophores , Polymers , Salicylates , Uranium/analysis , Ion-Selective Electrodes , Ionophores/chemical synthesis , Ionophores/chemistry , Ions , Molecular Structure , Plasticizers/chemistry , Polymers/chemical synthesis , Polymers/chemistry , Potentiometry/instrumentation , Potentiometry/methods , Salicylates/chemical synthesis , Salicylates/chemistry , Sensitivity and Specificity
13.
J Cell Sci ; 119(Pt 11): 2310-20, 2006 Jun 01.
Article in English | MEDLINE | ID: mdl-16723737

ABSTRACT

The steroid receptor-type transcription factor Nurr1 has a crucial role in the development of the mesencephalic dopamine (DA) neurons. Although ectopic expression of Nurr1 in cultured neural precursor cells is sufficient in establishing the DA phenotype, Nurr1-induced DA cells are morphologically and functionally immature, suggesting the necessity of additional factor(s) for full neuronal differentiation. In this study, we demonstrate that neurogenic basic helix-loop-helix (bHLH) factors Mash1, neurogenins (Ngns) and NeuroD play contrasting roles in Nurr1-induced DA neuronal differentiation. Mash1, but not Ngn2, spatially and temporally colocalized with aldehyde dehydrogenase 2 (AHD2), a specific midbrain DA neuronal progenitor marker, in the early embryonic ventral mesencephalon. Forced expression of Mash1 caused immature Nurr1-induced DA cells to differentiate into mature and functional DA neurons as judged by electrophysiological characteristics, release of DA, and expression of presynaptic DA neuronal markers. By contrast, atonal-related bHLHs, represented by Ngn1, Ngn2 and NeuroD, repressed Nurr1-induced expression of DA neuronal markers. Domain-swapping experiments with Mash1 and NeuroD indicated that the helix-loop-helix domain, responsible for mediating dimerization of bHLH transcription factors, imparts the distinct effect. Finally, transient co-transfection of the atonal-related bHLHs with Nurr1 resulted in an E-box-independent repression of Nurr1-induced transcriptional activation of a reporter containing Nurr1-binding element (NL3) as well as a reporter driven by the native tyrosine hydroxylase gene promoter. Taken together, these findings suggest that Mash1 contributes to the generation of DA neurons in cooperation with Nurr1 in the developing midbrain whereas atonal-related bHLH genes inhibit the process.


Subject(s)
Aldehyde Dehydrogenase/genetics , Basic Helix-Loop-Helix Transcription Factors/physiology , DNA-Binding Proteins/physiology , Dopamine/physiology , Mitochondrial Proteins/genetics , Neurons/cytology , Neurons/drug effects , Transcription Factors/physiology , Aldehyde Dehydrogenase/physiology , Aldehyde Dehydrogenase, Mitochondrial , Amino Acid Sequence , Animals , Basic Helix-Loop-Helix Transcription Factors/biosynthesis , Basic Helix-Loop-Helix Transcription Factors/pharmacology , Cell Differentiation/drug effects , DNA-Binding Proteins/pharmacology , Female , Gene Expression Regulation/drug effects , Gene Expression Regulation/physiology , Mesencephalon/embryology , Mesencephalon/growth & development , Mesencephalon/physiology , Mitochondrial Proteins/physiology , Molecular Sequence Data , Nerve Tissue Proteins/pharmacology , Nerve Tissue Proteins/physiology , Neurons/physiology , Nuclear Receptor Subfamily 4, Group A, Member 2 , Pregnancy , Rats , Rats, Sprague-Dawley , Transcription Factors/pharmacology , Tyrosine 3-Monooxygenase/antagonists & inhibitors , Tyrosine 3-Monooxygenase/biosynthesis
14.
Inorg Chem ; 45(9): 3487-9, 2006 May 01.
Article in English | MEDLINE | ID: mdl-16634576

ABSTRACT

The S3O2 macrocycle L1 was synthesized by a dithiol-dihalide coupling reaction under high-dilution conditions. The reaction of L1 with K2PdCl4 afforded an exocoordinated complex 1, [cis-Cl2Pd(L1)], which can then be manipulated to provide a heterobinuclear complex 3, {[Pd(L1)Ag(NO3)(2.5)](NO3)(0.5)}n, utilizing endocyclic Pd(II) and exocyclic Ag(I) in a single macrocycle through a successive reaction with AgNO3. The network of 3 contains a unique honeycomb-like 2-D sheet made up of the repeating unit [Ag6(NO3)6].

16.
Analyst ; 127(7): 947-50, 2002 Jul.
Article in English | MEDLINE | ID: mdl-12173655

ABSTRACT

Three diaza-18-crown-6 derivatives having methyl (L1), methoxy (L2) and phenyl (L3) end-groups in para-substituted phenolic side-arms have been investigated as potentiometric sensing materials for silver(I)-selective poly(vinyl chloride) membrane electrodes. The aim of the present work is to establish whether a combination of macrocyclic coordination to Ag+ ion and Ag-pi interaction might produce synergic effect in Ag+ ion sensing. The electrode based on the aromatic end-groups, L3 was found to give remarkably better electrochemical performance than their aliphatic counterparts (L1 and L2). The sensing ability for Ag+ ion with the proposed electrode was enhanced noticeably due to the pi-coordination of Ag+ ion, which was elucidated by NMR. The present findings may serve as an alternative approach for designing advanced sensing materials.

SELECTION OF CITATIONS
SEARCH DETAIL
...