bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the National Emergency Department Overcrowding Scale and the Emergency Department Work Index for Quantifying Emergency Department Crowding
Authors: Weiss Steven J. , Ernst Amy A. , Nick Todd G. 
Published: March 2006

Abstract
Background:
Emergency department (ED) crowding is just beginning to be quantified. The only two scales presently available are the National Emergency Department Overcrowding Scale (NEDOCS) and the Emergency Department Work Index (EDWIN).
Objectives:
To assess the value of the NEDOCS and the EDWIN in predicting overcrowding. The hypothesis of this study was that the NEDOCS and the EDWIN would be equally sensitive and specific for overcrowding.
Methods:
The NEDOCS, the EDWIN, and an overcrowding measure (OV) were determined every two hours for a ten‐day period in December 2004. The NEDOCS is a statistically derived calculation, and the EDWIN is a formula‐based calculation. The overcrowding measure is a composite of physician and charge nurse expert opinion on the degree of overcrowding as measured on a 100‐mm visual analogue scale (VAS). The primary outcome, overcrowding, was based on the dichotomized OV VAS score at the midpoint of 50 mm (≥50, overcrowded; <50, not overcrowded). The area under the receiver operator characteristic curve (AUC) and an index of adequacy (relative prognostic content) of each measure, on the basis of the likelihood ratio chi‐square statistic, were computed to evaluate the performance of NEDOCS and EDWIN.
Results:
There were 130 completed sampling times over ten days. The OV indicated that the ED was overcrowded 62% of the time. The AUC for the NEDOCS was 0.83 (95% CI = 0.75 to 0.90), and the AUC for the EDWIN was 0.80 (95% CI = 0.73 to 0.88). The NEDOCS score accounts for 97% of the prognostic information provided by combining all variables used in each model into one combined model. The EDWIN score accounts for only 86% (χ2 test for difference, p = 0.02).
Conclusions:
Both scales had high AUCs, correlated well with each other, and showed good discrimination for predicting ED overcrowding. This establishes construct validity for these scales as measures of overcrowding. Which scale is used in an ED is dependent on which set of data is most readily available, with the favored scale being the NEDOCS.
Computed Tomographic Angiography for the Evaluation of Aneurysmal Subarachnoid Hemorrhage
Authors: Carstairs Shaun D. , Tanen David A. , Duncan Timothy D. , Nordling Olaf B. , Wanebo John E. , Paluska Thomas R. , Theodore Nicholas , Riffenburgh Robert H. 
Published: March 2006

Abstract
Objectives:
Computed tomography (CT) followed by lumbar puncture (LP) is currently the criterion standard for diagnosing subarachnoid hemorrhage (SAH) in the emergency department (ED); however, this is based on studies involving a limited number of patients. The authors sought to assess the ability of CT angiography (CTA), a new diagnostic modality, in conjunction with CT/LP to detect SAH.
Methods:
Consecutive patients presenting to the ED with symptoms concerning for SAH were approached. All patients had an intravenous catheter placed and underwent a noncontrast head CT followed by CTA. Patients whose CT did not reveal evidence of SAH or other pathology underwent LP in the ED. CTAs were read within 24 hours by a neuroradiologist blinded to the patient's history.
Results:
A total of 131 patients were approached, 116 were enrolled, and 106 completed the study. In six of 116 patients (5.1%), aneurysm was found on CTA with normal CT and positive findings on LP; three had a positive CTA with normal CT and LP findings (one of which had a negative cerebral angiogram), and there was one false‐positive CTA. Follow‐up of all 131 patients showed no previously undiagnosed intracranial pathology. In this patient population, 4.3% (5/116) were ultimately found to have an SAH and/or aneurysm.
Conclusions:
In this pilot study, CTA was found to be useful in the detection of cerebral aneurysms and may be useful in the diagnosis of aneurysmal SAH. A larger multicenter study would be useful to confirm these results.
Adiponectin in Umbilical Cord Blood Is Inversely Related to Low-Density Lipoprotein Cholesterol But Not Ethnicity
Authors: Bansal Narinder , Charlton-Menys Valentine , Pemberton Philip , McElduff Patrick , Oldroyd John , Vyas Avni , Koudsi Abir , Clayton Peter E. , Cruickshank J. Kennedy , Durrington Paul N. 
Published: March 2006

Abstract
Context: Adiponectin is a recognized protective risk marker for cardiovascular disease in adults and is associated with an optimal lipid profile. The role of adiponectin at birth is not well understood, and its relationship with the neonatal lipid profile is unknown. Because ethnic disparities in cardiovascular risk have been attributed to low adiponectin and its associated low high-density lipoprotein cholesterol (HDL-C), investigation at birth may help determine the etiology of these risk patterns.
Objective: Our objective was to investigate the relationship between neonatal adiponectin and lipid profile at birth in two ethnic groups in cord blood.
Design, Setting, and Participants: Seventy-four healthy mothers and their newborns of South Asian and White European origin were studied in this cross-sectional study at St. Mary’s Hospital, Manchester, United Kingdom.
Main Outcome Measures: Serum adiponectin, total cholesterol, HDL-C, low-density lipoprotein cholesterol (LDL-C), and triglyceride levels were measured in umbilical venous blood at birth and in maternal blood collected at 28 wk gestation.
Results: Cord adiponectin was significantly inversely associated with cord LDL-C (r = −0.32; P = 0.005) but not HDL-C. In a multiple regression analysis, cord LDL-C remained the most significant association of cord adiponectin (β = −0.13; P &lt; 0.001). We did not find any significant ethnic differences in cord adiponectin or lipids with the exception of triglycerides, which were significantly lower in South Asian newborns (P &lt; 0.05).
Conclusion: This is the first report of an inverse relationship between cord adiponectin and LDL-C at birth. In contrast to adult studies, we found no significant association between adiponectin and HDL-C in cord blood. Our results and the strong independent association between adiponectin and HDL-C observed in adult studies suggest a role for adiponectin in lipid metabolism. Ethnic differences in adiponectin may arise after birth.
Photo-Oxidative Polymerization of Bis(3,5-dimethylphenyl) Disulfide for Synthesis of Poly(thioarylene)
Authors: Yamamoto Kimihisa , Oyaizu Kenichi , Tsuchida Eishun 
Published: March 2006

Abstract
Bis(3,5-dimethylphenyl) disulfide was subject to photo-oxidation in the presence of 2,3-dicyanonaphthalene as a sensitizer. The photo-redox system enabled efficient formation of poly(thio-2,6-dimethyl-1,4-phenylene) non-contaminated with metal salt at room temperature through the electrophilic reaction of the sulfonium cation produced by the photo-oxidation.
Cationic Polyaddition of p-Xylylene Glycol to 1,4-Bis(allenyloxy)xylene. Synthesis of Functional Polyacetal Containing Vinyl Groups in the Side Chain
Authors: Sato Eiichi , Yokozawa Tsutomu , Endo Takeshi 
Published: March 2006

Abstract
Polyaddition of p-xylylene glycol to 1,4-bis(allenyloxy)xylene was examined. Hydroxy groups of the diol added to the internal double bonds of allenyloxy moieties of bis(alkoxyallene) selectively to afford polymers containing both vinyl groups in the side chain and acetal skeleton in the main chain. The obtained polymer was degradable by the reaction of acetal skeleton in the backbone with aqueous acid.
Diastereoselective Conjugate Addition for Construction of Taxane Precursors
Authors: Furukawa Takashi , Seto Masaki , Horiguchi Yoshiaki , Kuwajima Isao 
Published: March 2006

Abstract
Copper catalyzed conjugate addition of Grignard reagents to enones was effected with high 1,4-diastereoinduction and was used for the preparation of taxane precursors.
Production of Hydrogen Peroxide and Organic Hydroperoxides in the Reactions of Ozone with Natural Hydrocarbons in Air
Authors: Hatakeyama Shiro , Lai Haiping , Gao shidong , Murano Kentaro 
Published: March 2006

Abstract
Reaction of ozone with three kinds of olefins in air was studied. H2O2, CH3OOH, and HOCH2OOH were collected and analyzed with HPLC with a fluorometric detector. Direct reaction of CH2OO with H2O was found to be the source of HOCH2OOH. CH3OOH was formed only from the olefins which have a methyl group. Detailed reaction mechanisms are discussed.
Catalytic Reduction of Nitrogen Monoxide by Methane over Palladium-Loaded Zeolites in the Presence of Oxygen
Authors: Nishizaka Yukiko , Misono Makoto 
Published: March 2006

Abstract
Palladium ion-exchanged H-ZSM-5 showed a high catalytic activity for the removal of dilute nitrogen monoxide in the presence of methane and oxygen at 350–550 °C. The presence of palladium and (protonic) acidity is essential for the high activity.
Reversible Electrochromism in the Thin Films of Single-Transition Metal Phthalocyanines
Authors: Toshima Naoki , Kawamura Shin-ichi , Tominaga Tsuyoshi 
Published: March 2006

Abstract
The reversible electrochromism in the thin films of single-transition metal phthalocyanines is reported. Copper and nickel phthalocyanine films can be oxidized and rereduced reversibly, when the film is enough thin, the scan range is well controlled, and the appropriate anion is used as the electrolyte. Especially, the cyclic voltammogram of nickel phthalocyanine films in a sodium nitrate solution is almost Nernstian.
Extraordinary Diastereoselectivity Coupled to Altered Structure of Dipeptide Esters
Authors: Matsumoto Yoko , Matsumoto Yoshito , Inoue Junichi , Ueoka Ryuichi 
Published: March 2006

Abstract
The diastereoselectivity for the hydrolysis of Z-D(L)-Phe-L-Phe p-methoxycarbonylphenyl ester was maximized (ksDL/ksLL = 34) at the optimum temperature (30 °C). This could be attributed to the conformational change in the DL isomer, which was supported by the circular dichroism measurements.
On the Transmetallation of (E)-1-Phenyl-3-(tributylstannyl)propene and 3-Phenyl-3-(tributylstannyl)propene with BuSnCl3
Authors: Miyake Hideyoshi , Yamamura Kimiaki 
Published: March 2006

Abstract
Transmetallation of (E)-1-phenyl-3-(tributylstannyl)propene and 3-phenyl-3-(tributylstannyl)propene with BuSnCl3, and the isomerization of the transmetallated product are described. The application of the reactions to stereoselective (Z)-3-phenyl-2-propenylation and threo-1-phenyl-2-propenylation of aldehydes is also described.
A New Bis(benzo-15-crown-5)-type Ionophore Having 1,10-Phenanthroline Moiety as a Highly-selective Potassium Ion-carrier
Authors: Himeda Yuichiro , Hiratani Kazuhisa , Kasuga Kazuyuki , Hirose Takuji 
Published: March 2006

Abstract
2,9-Disubstituted 1,10-phenanthroline derivative with two benzo-15-crown-5 moieties can transport potassium ion with extremely high selectivity over other alkali and alkaline earth metal ions through chloroform liquid membrane.
Alumina-supported Catalysts for the Selective Reduction of Nitric Oxide by Propene
Authors: Miyadera Tatsuo , Yoshida Kiyohide 
Published: March 2006

Abstract
The effect of water vapor and SO2 on the selective reduction of nitric oxide over alumina-supported Ag, In, Ga, Sn, and Zn catalysts has been investigated. Water vapor and SO2 had large effect on the reactivity of propene and on the reduction of NO over those catalysts.
Novel Dibenzopolyether Resin Possessing Dicarboxylic Acid Side Arm Functionality for Use in Specific Lead(II) Separation
Authors: Hayashita Takashi , Yamasaki Kenji , Huang Xiaowu , Bartsch Richard A 
Published: March 2006

Abstract
A novel dibenzopolyether resin possessing dicarboxylic acid side arm functionality (EDPAR) was synthesized by condensation polymerization of ethylenedi(oxy-o-phenoxyacetic acid) with formaldehyde in formic acid. The excellent sorption for Pb(II) over Cu(II) obtained with EDPAR was not observed with commercially available iminodiacetic acid resin (CR-10). For EDPAR, the percent sorption of Pb(II) exceeded 90% at pH 2.5, while Cu(II) sorption was less than 30% at this pH.
1,7-Acetal Carbon Rearrangement via 1,5-Hydride Transfer in an Oxocanyl Carbenium Ion. Conversion of O-(5-Hexenyl)-Se,O-heteroacetals or O,O-Acetals into 7-Oxohexanols or 7-Oxohexyl Chlorides
Authors: Yoshimatsu Mitsuhiro , Hatae Noriyuki , Shimizu Hiroshi , Kataoka Tadashi 
Published: March 2006

Abstract
Oxacyclooctyl (oxocanyl) carbenium ions generated by treatment of O-(5-hexenyl)-Se,O-heteroacetals or O,O-acetals with SnCl4 underwent intramolecular 1,5-hydride transfer, and the α-oxy carbenium ions newly formed were hydrolyzed to give the 7-oxohexanols or 7-oxohexyl chlorides in good yields. Various O-(5-hexenyl)-Se,O-heteroacetals or O,O-acetals were converted into 7-oxohexanols or 7-oxohexyl chlorides.
Novel Reduction of Carboxylic Acids, Esters, Amides and Nitriles Using Samarium Diiodide in the Presence of Water
Authors: Kamochi Yasuko , Kudo Tadahiro 
Published: March 2006

Abstract
Aromatic carboxylic acids, esters, amides, nitriles, chlorides, ketones and nitro compounds were rapidly reduced by the samarium diiodide–H2O system to the corresponding products at room temperature in good yields.
Synthesis of Quinone-Bearing Peptides. Photoinduced Electron-Transfer of Peptide-Bridged Porphyrin-Quinone Molecules
Authors: Tamiaki Hitoshi , Maruyama Kazuhiro 
Published: March 2006

Abstract
Synthetic peptide-bridged porphyrin-quinone molecules were easily available by use of a precursor for a chiral α-amino acid bearing quinone moiety on the side chain, l-(2,5-dimethoxyphenyl)alanine. Photoinduced electron transfer from porphyrin to quinone in the molecules occurred in 2-methyltetrahydrofuran.
Efficient Synthesis of the Optically Active Cyclopentane Derivative, A Versatile Intermediate Toward the Euphorbia Diterpenes
Authors: Matsuura Tomoo , Nishiyama Shigeru , Yamamura Shosuke 
Published: March 2006

Abstract
A practical synthesis of the cyclopentane derivative shared by the diterpenes isolated from the plant Euphorbia helioscopia L. has successfully been accomplished starting from the optically active cyclopenten-diol derivative.
Novel Photocatalytic Asymmetric Synthesis of Δ (or Λ)-[Co(acac)3] (Hacac = pentane-2,4-dione) from [Co(acac)2(H2O)2] and Hacac with Helical Ruthenium(II) Tris-bidentate Complexes
Authors: Ohkubo Katsutoshi , Hamada Taisuke , Watanabe Megumi , Fukushima Mitsuhiro 
Published: March 2006

Abstract
The photoinduced asymmetric synthesis of Δ (or Λ)-[Co(acac)3] from [Co(acac)2(H2O)2] and Hacac was achieved by using helical Ruthenium(II) complexes of [Ru(Menbpy)3]2+ (Menbpy = 4,4′-di((1R,2S,5R)-(−)-menthoxycarbonyl)-2,2′-bipyridine), and [Ru(R(or S)-PhEtbpy)3]2+ (R(or S)-PhEtbpy = 4,4′-di((R)-(+)(or (S)-(−))-1-phenylethylamino-carbonyl)-2,2′-bipyridine) with the maximum 10.0% e.e. for the Λ-[Co(acac)3] formation by [Ru(Menbpy)3]2+ in 50–70% v/v EtOH/H2O at 25 °C.
Construction of N-Acylated 4-Piperidones via Selective Carbon-Nitrogen and Carbon-Carbon Bond Formation
Authors: Takahashi Mitsumasa , Tanino Keiji , Kuwajima Isao 
Published: March 2006

Abstract
N-Acylated 4-piperidone was prepared in good overall yield through an initial formation of the imine from the reaction of α′-aminomethylated enol silyl ether with an aldehyde followed by cyclization effected with an acid anhydride. The latter cyclization reaction seems to proceed preferentially through a boat-like transition state to give the piperidone having exo substituent.
Preparation of Nonmetallic Silver Clusters in Aqueous Solutions Using UV Lasers
Authors: Kobayashi Makoto , Sato Hiroyasu 
Published: March 2006

Abstract
Nonmetallic silver clusters (λmax = 275 nm) were prepared by UV laser irradiation of aqueous solutions of silver perchlorate in the presence of 2-propanol and sodium polyphosphate. They were transformed into silver colloids (λmax = 380 nm) obeying second-order kinetics. Effects of added electrolytes on the kinetics were studied.
Reactivating Effect of Water on Freon 12 Decomposition Catalysts
Authors: Imamura Seiichiro , Higashihara Takao , Jindai Hitoshi 
Published: March 2006

Abstract
Effect of water was investigated on the durability of titania–silica (TiO2/SiO2), phosphate–supported zirconia (PO4/ZrO2), and boron phosphate (BPO4) catalysts in the vapor phase decomposition of dichloro–difluoromethane (Freon 12). Water helped to maintain their catalytic activity by eliminating inorganic fluorines produced during the reaction. No deactivation nor configuration change was observed for BPO4 catalyst even after 35 h. Thus the way is open to the development of practical process for catalytic detoxification of chlorofluorocarbons (Freon’s).
Different Magnetic Properties of Charge-Transfer Complexes and Cation Radical Salts of Tetrathiafulvalene Derivatives Substituted with Imino Pyrolidine- and Piperidine-1-oxyls
Authors: Sugimoto Toyonari , Yamaga Seiji , Nakai Makoto , Tsujii Masaya , Nakatsuji Hiroshi , Hosoito Nobuyoshi 
Published: March 2006

Abstract
The magnetic properties of charge-transfer (CT) complexes and cation radical salts of tetrathiafulvalene (TTF) derivatives bearing two different radical substituents were investigated. Preferential spin interactions occurred between TTF cation radical (TTF+•) and an acceptor anion radical for the CT complexes, and between two TTF+•’s for the cation radical salts, respectively. In addition, the magnitude was markedly different by the kind of radical substituent, which behaved as an isolated spin.
Unusual Enhancement of Protease Activity in Organic Solvents by Amines
Authors: Yamamoto Yasuhito , Kise Hideo 
Published: March 2006

Abstract
The catalytic activities of subtilisin BPN’ and α-chymotrypsin for transesterification of N-acetyl-L-tyrosine methyl ester in organic solvents were dramatically increased by addition of tertiary amines. The effects may be ascribed to the change in dissociation state of polar groups on the surface of the enzymes.
A Methano-Bridged Dehydro[24]annulenedione. A Highly Diatropic Dicationic 22π-Electron Species in D2SO4
Authors: Yamamoto Gaku , Higuchi Hiroyuki , Asano Kaori , Ojima Juro 
Published: March 2006

Abstract
A methanodehydro[24]annulenedione with a 1,4-dichlorobutatriene moiety was synthesized. The compound formed a highly stable dicationic species in D2SO4, which showed the strongest diatropicity hitherto reported for 22π-electron aromatic systems.
Buckminsterfullerene C60 – o-Quinone Methide Cycloadduct
Authors: Ohno Masatomi , Azuma Toshihiro , Eguchi Shoji 
Published: March 2006

Abstract
Buckminsterfullerene C60 underwent [4+2]cycloaddition reaction across 6,6 ring junction with o-quinone methide generated in situ from o-hydroxybenzylalcohol in 1,2-dichlorobenzene (180 °C).
Selective Synthesis of the Geometrical Isomers of O,O-Diethyl O-1-(N-methoxyimino)ethylphosphorothioate and a New Thiono-Thiolo Rearrangement Reaction
Authors: Sasaki Mitsuru , Itoh Yoshikazu , Yamamoto Noboru , Yamada Yoshimi 
Published: March 2006

Abstract
Condensation of O,O-diethyl phosphorochloridothioate with N-methoxyacetamide in the presence of a base gave selectively the geometrical isomers of O,O-diethyl O-1-(N-methoxyimino)ethylphosphorothioate which on heating rearranged to the corresponding thiolo isomers having P–S–C=N linkage.
A Pronounced Catalytic Activity of PW11CoO395− for Epoxidation of Alkenes by Molecular Oxygen in the Presence of Aldehyde
Authors: Mizuno Noritaka , Hirose To-oru , Tateishi Masaki , Iwamoto Masakazu 
Published: March 2006

Abstract
The epoxidation of cyclohexene, 1-decene, and styrene by molecular oxygen in the presence of aldehydes such as isobutyraldehyde and pivalaldehyde was efficiently catalyzed at 303 K by mono-cobalt-substituted Keggin-type heteropolytungstate.
Synthesis, Conductivity, and Structure of a Novel Organic Conductor (TMET-STF)2ClO4. Coexistence of One- and Two-dimensional Donor Columns
Authors: Okano Yoshinori , Sawa Hiroshi , Aonuma Shuji , Kato Reizo 
Published: March 2006

Abstract
An organic π-donor TMET-STF (trimethylene(ethylenedithio)diselenadithiafulvalene) was synthesized using a method via a titanocene complex. The cation radical salt (TMET-STF)2ClO4 is metallic down to 22 K and shows an upturn of resistivity. Crystal structure analysis and band calculation indicate that this system contains two types of donor columns; the one is one-dimensional and the other is two-dimensional.
Ion-Exchanged Glass Optical Waveguide Systems for Surface Spectroscopy. Composite Structures for Realization of High Sensitivity and Low Loss
Authors: Itoh Kiminori , Chen Xiao-Min , Murabayashi Masayuki 
Published: March 2006

Abstract
A K+-doped glass optical waveguide (OWG) and an Ag+-doped glass OWG were combined on one substrate using tapered velocity couplers to realize OWG systems for surface spectroscopy with high sensitivity and low loss. The high sensitivity part (Ag+-doped region) was more than 1000 times sensitive compared with optical measurements with normal incidence of monitoring light.
Synthesis, Conformational Analysis, and Optical Resolution of 2,2′:6′,2″:6″,2′′′-Tris(ethano)tetraphenyltin Derivatives
Authors: Okada Keiji , Minami Masato , Oda Masaji 
Published: March 2006

Abstract
Two derivatives of 2,2′:6′,2″:6″,2′′′-tris(ethano)tetraphenyltin were synthesized and their conformational analysis was carried out. An X-ray analysis and optical resolution were performed for one of the derivatives.
Preparation of Textured Ag Thin Films by Using Mixed Monomolecular Layer Spread at Air/Solution Interface
Authors: Masuda Hideki , Baba Nobuyoshi 
Published: March 2006

Abstract
A textured Ag skeleton film was fabricated by using a heterogeneous monolayer spread at an air/solution interface as a support. The mechanism of the formation of the textured film was discussed based on the difference of the rate of Ag deposition in the amphipatic molecules.
Chiral Helical Conformation of the Polyphenylacetylene Having Optically-Active Bulky Substituent
Authors: Aoki Toshiki , Kokai Masayuki , Shinohara Ken-ichi , Oikawa Eizo 
Published: March 2006

Abstract
Poly[p-{L-(−)-menthoxycarbonyl}phenylacetylene]s prepared by [Rh(norbornadiene)Cl]2 as a polymerization catalyst exhibited a much higher [α]D20 (= −605) than that(= −68.8) of the monomer and a very high molar ellipticity(more than 104) at the π–π* region in the CD spectrum: A chiral helical conformation of the main chain in solution is suggested. The solid membrane of this polymer showed enantioselective permeability (54%ee) for DL-tryptophan.
Catalytic Disproportionation of Alkylsilanes over Sulfated ZrO2
Authors: Fujisawa Hideo , Yamaguchi Tsutomu 
Published: March 2006

Abstract
Gas phase heterogeneous catalytic conversions of diethylsilane(E2), triethylsilane(E3) and diethyldimethylsilane(E2M2) were examined at 373–573 K in a closed recirculation reactor by using a sulfated ZrCO2(SO3/ZrO2) catalyst. The catalyst exhibited high disproportionation activity even at 373 K.
An Observation of the Electric Birefringence Signal of κ-Carrageenan Gel
Authors: Ueda Kazuyoshi , Ochiai Hiroshi , Imamura Akira , Yamaoka Kiwamu 
Published: March 2006

Abstract
Electric birefringence signal of κ-carrageenan gel was measured for the first time. The signal was found to consist of two processes, which correspond to the orientational motion of the junction zone and the deformation of the whole network structure of the gel.
Silver Selectivity of Novel Monoazapolythioether Derivatives Bearing a Hydrazone Group in the Solvent Extraction
Authors: Sakamoto Hidefumi , Ishkawa Junichi , Mizuno Tamao , Doi Kunio , Otomo Makoto 
Published: March 2006

Abstract
Novel acyclic and cyclic monoazapolythioether derivatives incorporating a substituted hydrazone group were synthesized. The acyclic and the cyclic monoazatetrathioether derivatives exhibited high Ag+ ion selectivity in the extraction with 1,2-dichloroethane. The monoazatetrathioether derivatives gave hypsochromic and bathochromic shifts in the visible absorption spectra when extracted Ag+ ion from the aqueous phase of varying acidities into the organic phase.