bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation of YBa2Cu3O7−δ Superconductor through Organornetallic Route
Authors: Hirano Shin-ichi , Hayashi Takashi , Baney Ronald H , Miura Masashi , Tomonaga Hiroyuki 
Published: July 2006

Abstract
The preparation of high Tc superconducting YBa2Cu3O7−δ compound was investigated through organometallic route, using Ba metal, Y(O–iPr)3 and Cu-alkoxides or Cu-acetylacetonate as starting materials. Chemically homogeneous submicron powder of orthorhombic YBa2Cu3O7−δ was prepared as a single phase by controlled partial hydrolysis of metal alkoxides. It was confirmed by dc resistivity and magnetic susceptibility measurements that single phase YBa2Cu3O7−δ ceramics exhibited superconductivity at about 90 K (Tc onset).
Application of Free Radical Substitution Reaction into Interconversion of 1-Alkenylsulfides, 1-Alkenylgermanes, and 1-Alkenylstannanes
Authors: Ichinose Yoshifumi , Oshima Koichiro , Utimoto Kiitiro 
Published: July 2006

Abstract
Treatment of 1-alkenylsulfides or 1-alkenylstannanes with Ph3GeH in the presence of Et3B provides 1-alkenyltriphenylgermanes in good yields. 1-Alkenylstannanes are converted into 1-alkenylsulfides easily with PhSH–Et3B, whereas 1-alkenyltriphenylgermanes are recovered unchanged upon treatment with Ph3SnH–Et3B or PhSH–Et3B.
Non-Catalyzed Cleavage Reactions of Ethers with Acyl Halides under High-Pressure Conditions
Authors: Kotsuki Hiyoshizo , Ichikawa Yoshikatsu , Nishizawa Hitoshi 
Published: July 2006

Abstract
Various cyclic and acyclic ethers are efficiently cleaved with acyl chlorides or bromides to give ω-chloro- or ω-bromoesters under high-pressure conditions.
C=C Double Bond Insertion in Catalytic C–H Activation. Dehydrogenative Cross Coupling of Arenes with Olefins
Authors: Sasaki Koushi , Sakakura Toshiyasu , Tokunaga Yuko , Wada Keisuke , Tanaka Masato 
Published: July 2006

Abstract
The reaction of benzene with methyl acrylate and ethylene catalyzed by RhCl(CO)(PMe3)2 under irradiation gave methyl cinnamate and styrene, respectively. The reaction of toluene afforded meta-substituted isomers as major products.
Stereospecific Cleavage of Adenosine 2′,3′-Cyclic Monophosphate Catalyzed by Cyclodextrins
Authors: Komiyama Makoto 
Published: July 2006

Abstract
Stereospecific cleavage of adenosine 2′3′-cyclic monophosphate to the 2′-monophosphate is achieved at pH 11.08, 20 °C by use of β-and γ-cyclodextrins as catalysts. The 2′/3′ ratio for the product is 7.7 at the concentration 1.5×10−2 mol dm−3 of β-cyclodextrin. In contrast, α-cyclodextrin promotes the formation of the 3′-monophosphate, giving the product 2′/3′ ratio 0.49 at the concentration 1.0×10−2 mol dm−3.
Electrochemical Formation of a Phthalocyanine Thin Film by Disruption of Micellar Aggregates
Authors: Saji Tetsuo 
Published: July 2006

Abstract
Phthalocyanine (1) was dissolved to the micellar solution formed by non-ionic surfactants with ferrocenyl moiety. A 1 thin film was prepared on an indium tin oxide (ITO) electrode by the controlled-potential electrolysis of this solution. This film consisted of rod-like crystals of 500 nm in length.
Photorearrangement of 4,4,5,5-Tetramethoxycyclohepta-2,6-dienones to 6,6,7,7-Tetramethoxybicyclo[3.2.0]hept-3-en-2-ones
Authors: Mori Akira , Kubota Tadahiko , Takeshita Hitoshi 
Published: July 2006

Abstract
The photorearrangement of 2,6-cycloheptadienones to bicyclo[3.2.0]hept-3-en-2-ones was observed. The bicycloketones further photoisomerized to bicyclo[2.2.1]heptenones via a [1,3] sigmatropy.
Ammonia-Hydrochloric Acid Equilibrium Product over Solid and Aqueous Ammonium Chloride at 25 °C
Authors: Hara Hiroshi 
Published: July 2006

Abstract
Relative humidity dependence of the equilibrium product of NH3 and HCl was thermodynamically calculated for ammonium chloride at 25 °C. This compound was found to be deliquescent at relative humidity greater than 77%, where the product began to decrease steeply. When the solution was treated as ideal, the product was mispredicted several factors higher than that for non-ideal solution.
Reactivity of α-Metal(group 4) Esters. Lewis Acid Mediated Reactions of α-Triphenyltin Esters with Aldehydes and Acetals
Authors: Kiyooka Syun-ichi , Nakata Masumi 
Published: July 2006

Abstract
Ethyl triphenylstannylacetate and ethyl α-triphenylstannylpropionate reacted with aldehydes and acetals to give β-hydroxy and β-alkoxy esters at room temperature in the presence of TiCl4, in moderate yields. Under these conditions ethyl triphenylgermylacetate and ethyl trimethylsilylacetate did not work.
A Novel [2+4] Photocyclization Reaction between Quinone and Allene
Authors: Maruyama Kazuhiro , Imahori Hiroshi 
Published: July 2006

Abstract
1,1-Diphenylallene underwent a [2+4] photocycloaddition reaction with the carbonyl group of 2,3-dichloro-1,4-naphthoquinone to produce a novel spiro compound.
Formation of [η5,η1–C5H4C (OCOR)=C(OCOR)CO]Fe(CO)2 Complexes via Triple CO Insertion into Cyclopentadienyl Anions by Fe(CO)5
Authors: Nakanishi Saburo , Hirano Takehiro , Otsuji Yoshio 
Published: July 2006

Abstract
The reaction of cyclopentadienyl anions with Fe(CO)5 in the presence of acyl chlorides gave [η5,η1–C5H4C (OCOR)=C(OCOR) CO] Fe(CO)2 complexes, accompaning a triple CO insertion into the anions and a double acylation.
The Crystal and Molecular Structures of 1:2 Complexes of N,N′-Dimethylpiperazine with 1-(o-Chlorophenyl)-1-phenyl-2-propyn-1-ol
Authors: Yabuki Tetsuro , Yasui Masanori , Tezuka Hiroshi , Harada Shigeharu , Kasai Nobutami , Tanaka Koichi , Toda Fumio 
Published: July 2006

Abstract
The N,N′-dimethylpiperazine molecule in the title crystals is bound by two chiral acetylenic alcohol molecules through the strong O–H···N hydrogen bonds. The symmetric 1:2 complex of N,N′-dimethylpiperazine with (+)- and (−)-1-(o-chlorophenyl)-1-phenyl-2-propyn-1-ol(CPPOH), which is useful for the optical purification of partially resolved CPPOH, has the denser packing of molecules in the crystal than the asymmetric 1:2 complex of N,N′-dimethylpiperazine with two (−)-CPPOH.
Formation and Spin Density Distribution of the Radical Anion and Radical Trianion of Bis[diphenylpyradino]tetracyanoquinodimethane Studied by ESR
Authors: Hirayama Masatoshi , Seki Akihiko , Yamashita Yoshiro , Suzuki Takanori , Miyashi Tsutomu 
Published: July 2006

Abstract
The radical trianion of title compound as well as its radical anion was formed by electrolytic reduction of its neutral precursor in acetonitrile at room temperature and characterized by their ESR and calculated spin density distributions.
Preparation and Structure of a Mixed Benzenethiolatosulfido Trinuclear Nickel Complex
Authors: Matsumoto Keiji , Nakano Hideyuki , OOI Shun’ichiro 
Published: July 2006

Abstract
X-Ray structure analysis of [Ni3S(SPh)6]2− has revealed that a central μ3-S and three Ni atoms form a trigonal pyramid, a μ-SPh ligand bridges each pair of the three Ni atoms situated at the apexes of a triangle, and each Ni is terminally coordinated by SPh, completing a trinuclear complex. The stereochemistry around Ni is tetrahedrally distorted square planar.
Reaction of Stabilized Bismuthonium Ylides with Aldehydes. A Novel Reaction Mode of the Heaviest Group V Element Ylide
Authors: Ogawa Takuji , Murafuji Toshihiro , Suzuki Hitomi 
Published: July 2006

Abstract
Stabilized bismuthonium ylides, triphenylbismuthonio-4,4-dimethyl-2,6-dioxocyclohexane-1-ide and triphenylbismuthonio-4,4-dimethyl-2,6-dioxo-3,5-dioxan-1-ide, react with aldehydes to afford three types of products; tetraacylcyclopropanes, dihydrofurans, and α,β-unsaturated carbonyl compounds, the relative importance of these depending greatly on the ylides, aldehydes, and reaction conditions employed.
Trapping of Trifluoromethyl Radical with Enolacetate and in situ Generated Enol
Authors: Uneyama Kenji , Ueda Kunimasa 
Published: July 2006

Abstract
Electrochemically generated trifluoromethyl radical can be trapped with enolacetates and enol generated in situ from β-ketoesters and 1,3-diketones, affording trifluoromethylated active methylene compounds.
Crystal and Electronic Structures of a New Two-dimensional Molecular Metal, α-Et2Me2N[Ni(dmit)2]2
Authors: Kato Reizo , Kobayashi Hayao , Kim Hyerjoo , Kobayashi Akiko , Sasaki Yukiyoshi , Mori Takehiko , Inokuchi Hiroo 
Published: July 2006

Abstract
The anion radical salt α-Et2Me2N[Ni(dmit)2]2 retains metallic behavior down to 1.5 K. Planar Ni(dmit)2 units lying side-by-side along the b axis stack along the c axis in such a way that one molecule overlaps with two molecules. Such a “spanning overlap” mode has provided two-dimensional electronic structure.
Significance of Silicate Source for Controlling Pentasil Zeolite Phase Synthesized from Organic-Free System
Authors: Dai Feng-Yuen , Deguchi Kenzo , Suzuki Minoru , Takahashi (late)Hiroshi , Saito Yasukazu 
Published: July 2006

Abstract
High resolution 29Si NMR spectra of silica sols and water glass in addition to a wide survey of hydrothermal zeolite syntheses from them with no aid of organic templates brought forth such a view that pentasil zeolite phases to be formed are contrlled at the aging stage of room temperature in the liquid phase. Pure ZSM-5 crystals were synthesized at high yields, only when a small-sized silica sol(10–20 nm) was used, indicating that appropriate amounts of silicate species(Q2 and Q3) are required to react with aluminate at room temperature in the alkaline solution.
Palladium-Catalyzed Regio- and Stereoselective Aryldesilylation of α-Silylstyrenes with Arenediazonium Salts
Authors: Ikenaga Kazutoshi , Matsumoto Satoshi , Kikukawa Kiyoshi , Matsuda Tsutomu 
Published: July 2006

Abstract
α-Trialkylsilylstyrenes[Ph(R3Si)C=CH2: R=Me(1), Et(2), and Ph (3)] easily reacted with arenediazonium tetrafluoroborates[ArN2+BF4− (4)] to give (E)-PhCH=CHAr under palladium(0) catalysis. The bulky substituents on silicon gave better stereoselectivity.
Ullmann Ether Synthesis in DMI. Preparation of m-Phenoxybenzyl Alcohol
Authors: OI Ryu , Shimakawa Chitoshi , Takenaka Shinji 
Published: July 2006

Abstract
The condensation of m-hydroxybenzyl alcohol with chlorobenzene was examined in several different solvents, and an effective route to m-phenoxybenzyl alcohol has been developed by using 1,3-dimethyl-2-imidazolidinone (DMI) as a solvent.
Improvement of Adsorption Capacity for Copper (II) Ion by N-Nonanoylation of Chitosan
Authors: Kurita Keisuke , Chikaoka Satoyuki , Koyama Yoshiyuki 
Published: July 2006

Abstract
Chitosan was selectively N-nonanoylated, and the influence of the long acyl groups on the adsorption of copper (II) ion was studied. The acylation with nonanoyl chloride was achieved efficiently on a highly swelled chitosan precipitate. The adsorption capacity could be improved markedly by a small extent of acylation.
The Stereoselective Michael Reaction of α,β-Unsaturated Thioesters with Silyl Enol Ethers Promoted by Combined Use of Antimony(V) Chloride and Tin(II) Triflate
Authors: Kobayashi Shu , Tamura Masanori , Mukaiyama Teruaki 
Published: July 2006

Abstract
α, β-Unsaturated thioesters react with silyl enol ethers to afford the corresponding Michael adducts stereoselectively in high yields by the use of a new catalyst, combined use of antimony(V) chloride and tin(II) triflate.
Crystal Structure of Potassium Salt of Synthetic Carboxylic Ionophore
Authors: Kuboniwa Hitoshi , Yamaguchi Kazuo , Nakahama Seiichi , Hori Kayako , Ohashi Yuji 
Published: July 2006

Abstract
Crystal structure of potassium [[2-[2-[2-[2-[2-[2-[2-(2-hydroxyethoxy)phenoxy]ethoxy]phenoxy]ethoxy]phenoxy]ethoxy]phenoxy]methyl]benzoate (2) has been determined. The backbone forms pseudocycle by head-to-tail hydrogen bonding. Conformations about C–C and C–O bonds are gauche and trans respectively, except for two of the C–O bonds which are gauche to make the pseudocyclic backbone bend like seam of a tennis ball. Ten oxygens except for one of the benzoate group coordinate with the potassium ion.
Thermoinitiated Cationic Polymerization of Styrene with a Pyridinium Salt
Authors: Uno Hitomi , Takata Toshikazu , Endo Takeshi 
Published: July 2006

Abstract
N-Benzyl-p-cyanopyridinium hexafluoroantimonate behaved as a thermally latent catalyst to initiate the cationic polymerization of styrene at 120 °C leading to polystyrene possessing a bimodal molecular weight distribution.
Preparation of YBa2Cu3O7−x Films by Chemical Vapor Deposition
Authors: Yamane Hisanori , Kurosawa Hideyuki , Hirai Toshio 
Published: July 2006

Abstract
YBa2Cu3O7−x films were prepared on yttria stabilized zirconia substrates at a deposition temperature of 1073 K under reduced pressures using β-diketonate chelates of Y, Ba, and Cu as source materials for CVD.
Molecular Orbital Considerations for Kinetically-Controlled Cycloaddition Reactions of Cyclohepta[b]furan-2-ones to 2,3-Bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]heptadiene, Enamines, and Alkoxyethenes
Authors: Tian Guan Rong , Sugiyama Shigeru , Mori Akira , Takeshita Hitoshi , Higashi Miwako , Yamaguchi Hiroyuki 
Published: July 2006

Abstract
2,3-Bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]heptadiene gave the [4+2] cycloadducts with 8,8-dicyanoheptafulvene and cycloheptaf[b]-furan-2-ones. This mode is different from the [8+2] cycloadduct formations with the previously studied enamines and alkoxyethenes. The results from MNDO calculations were in accord to the observed modes of the cycloadditions. Thermolysis of the cycloadducts gave the methylidene derivatives of “homobarrelenes”.
Spectroscopic Evidence for the Inter-Chain Charge–Transfer Interaction in Copper-bis(2,5-dimethyl-N,N′-dicyanoquinonediimine), Cu(2,5-DM-DCNQI)2
Authors: Yakushi Kyuya , Ojima Gen , Ugawa Akito , Kuroda Haruo 
Published: July 2006

Abstract
Polarized reflectance spectra of the single crystals of Cu(2,5-DM-DCNQI)2 and Na(2,5-DM-DCNQI)2 were measured at room temperature. The spectrum of Cu(2,5-DM-DCNQI)2 clearly indicated the inter-chain interaction through the coordinate bonds, whereas the spectrum of Na(2,5-DM-DCNQI)2 showed a typical one-dimensional feature along the stacking direction.
Palladium-Catalyzed, Atmospheric Pressure Carbonylation of Allylic Chlorides in Two-Phase Aqueous Sodium Hydroxide–Organic Solvent Media
Authors: Kiji Jitsuo , Okano Tamon , Nishiumi Wataru , Konishi Hisatoshi 
Published: July 2006

Abstract
The palladium-catalyzed, atmospheric pressure carbonylation of allylic chlorides is realized in aqueous NaOH/benzene. Phosphine complexes PdCl2L2 (I) (a, L=Ph2P(m-C6H4SO3Na); b, L=Ph3P), or Na2PdCl4 can be used as the catalyst.
Molecular Structure of Novel 1,2,3-Butatriene Episulfides
Authors: Tokitoh Norihiro , Hayakawa Hiroshi , Goto Midori , Ando Wataru 
Published: July 2006

Abstract
Molecular structures of novel 1,2,3-butatriene 1-episulfide and 2-episulfide derivatives have been determined by X-ray crystallographical analysis, and the structure of the 1-episulfide is in good agreement with the optimized geometries of the parent allene episulfide skeleton obtained from the RHF Closed-Shell SCF calculation.
Selective Detection of Nitrogen Monoxide by the Mixed Oxide of Cr2O3–Nb2O5
Authors: Ishihara Tatsumi , Shiokawa Kazuhiko , Eguchi Koichi , Arai Hiromichi 
Published: July 2006

Abstract
Several single and mixed oxides were used as sensors for detection of CO, CO2, NO, and NO2. The conductivity of (Cr2O3)1-x (Nb2O5)x was greatly changed by a contact with 1-1000 ppm of NO, but was unchanged by that with CO or CO2. The sensitivity to NO was maximum by operating at 573 K using oxide with x=0.1. The influence of CO during detection of NO was negligible at x=0.5.
Short-term administration of an angiotensin-receptor antagonist in patients with impaired fasting glucose improves insulin sensitivity and increases free IGF-I
Authors: Zandbergen Adrienne A M , Lamberts Steven W J , Janssen Joop A M J L , Bootsma Aart H 
Published: July 2006

Objective: Blocking the renin–angiotensin system (RAS) may reduce the risk of developing type-2 diabetes, but data are inconclusive and the mechanisms involved are unclear. RAS and RAS inhibition also influence the IGF-I system, which is important in glucose homeostasis. We investigated the effects of the angiotensin-receptor antagonist, losartan, on insulin resistance and IGF-I levels
Design and methods: In this hypothesis-generating study, five individuals with impaired fasting glucose received 100 mg losartan during 8 weeks. Before and after the treatment period, insulin sensitivity was assessed using the homeostasis model assessment of insulin resistance (HOMA), as well as the 2-h continuous infusion of glucose with model assessment (CIGMA). Furthermore, serum levels of free and total IGF-I, IGF-binding protein-3 (IGFBP-3), lipids and HbAlc were measured.
Results: After the treatment period, the HOMA score for insulin resistance had decreased from 5.3 ± 1.1 to 3.7 ± 0.9 (P = 0.004) and the 2-h CIGMA score from 23.4 ± 3.1 to 15.9 ± 2.1 (P = 0.07). The serum levels of free IGF-I had increased from 57 ± 18.8 to 134 ± 31.3 pmol/l (P = 0.04). In terms of percentage, the decrease of HOMA correlated with the increase in free IGF-I levels (Pearson’s correlation coefficient r = −0.8; P = 0.07). A trend in the same direction was observed with 2-h CIGMA. No differences were observed in lipids, total IGF-I, IGFBP-3 or HbAlc.
Conclusions: Losartan raised serum levels of free IGF-I, which might contribute to the improvement of insulin resistance associated with losartan treatment. These observations, if confirmed in broader studies, will help our understanding of the pathogenesis of type-2 diabetes mellitus, as well as the role of angiotensin-receptor antagonists in its prevention.
Noncell- and Cell-Autonomous G-Protein-Signaling Converges With Ca2+/Mitogen-Activated Protein Kinase Signaling to Regulate str-2 Receptor Gene Expression in Caenorhabditis elegans
Authors: Lans Hannes , Jansen Gert 
Published: July 2006

Abstract
In the sensory system of C. elegans, the candidate odorant receptor gene str-2 is strongly expressed in one of the two AWC neurons and weakly in both ASI neurons. Asymmetric AWC expression results from suppression of str-2 expression by a Ca2+/MAPK signaling pathway in one of the AWC neurons early in development. Here we show that the same Ca2+/MAPK pathway promotes str-2 expression in the AWC and ASI neurons together with multiple cell-autonomous and noncell-autonomous G-protein-signaling pathways. In first-stage larvae and adult animals, signals mediated by the Gα subunits ODR-3, GPA-2, GPA-5, and GPA-6 and a Ca2+/MAPK pathway involving the Ca2+ channel subunit UNC-36, the CaMKII UNC-43, and the MAPKK kinase NSY-1 induce strong str-2 expression. Cell-specific rescue experiments suggest that ODR-3 and the Ca2+/MAPK genes function in the AWC neurons, but that GPA-5 and GPA-6 function in the AWA and ADL neurons, respectively. In Dauer larvae, the same network of genes promotes strong str-2 expression in the ASI neurons, but ODR-3 functions in AWB and ASH and GPA-6 in AWB. Our results reveal a complex signaling network, encompassing signals from multiple cells, that controls the level of receptor gene expression at different developmental stages.
Lack of In Vivo Correlation Between Indinavir and Saquinavir Exposure and Cytochrome P450 3A Phenotype as Assessed with Oral Midazolam as a Phenotype Probe
Authors: Robertson Sarah M. , Formentini Elizabeth , Alfaro Raul M. , Falloon M.S. Judith , Penzak Scott R. 
Published: July 2006

Study Objective. To investigate a potential correlation between exposure to oral midazolam, a commonly used cytochrome P450 (CYP) 3A probe, and saquinavir and indinavir exposure.Design. Open‐label, prospective, pharmacokinetic study.Setting. Outpatient research center.Subjects. Thirty‐six healthy volunteers aged 22–50 years.Intervention. Subjects received a single oral dose of midazolam 8 mg; 4 hours later, blood was drawn to determine their serum midazolam concentrations. Midazolam phenotyping was followed by successive administration of the protease inhibitors indinavir and saquinavir, with blood sampling and pharmacokinetic analyses performed at steady state.Measurements and Main Results. Pharmacokinetic parameters of each protease inhibitor were evaluated to assess for a potential relationship with 4‐hour concentrations of midazolam. No correlations between phenotype results for midazolam and any pharmacokinetic parameter for indinavir or saquinavir were identified (r2=0.00002–0.073). When the results were analyzed based on race, significant correlations were identified in five African‐American subjects, including correlations between 4‐hour midazolam levels and apparent oral clearance of saquinavir (r2=0.734, p=0.064), area under the plasma concentration–time curve from 0–8 hours (r2=0.914, p=0.011), minimum concentration (r2=0.857, p=0.024), and maximum concentration (r2=0.969, p=0.002). These findings for African‐American subjects were not seen with indinavir. No correlation was found between indinavir and saquinavir pharmacokinetic parameters (r2=0.017–0.261).Conclusion. Oral midazolam was not a useful probe for predicting saquinavir or indinavir exposure at steady state. Reasons for the lack of correlation likely included differences between midazolam and protease inhibitor P‐glycoprotein specificity, differences in the relative contribution of CYP3A5‐mediated metabolism, and/or variation in intestinal and hepatic CYP3A specificity. The strong correlation between midazolam phenotype and pharmacokinetic parameters for saquinavir in African‐American subjects indicated a racial difference in one or more of these confounding variables.
Drug Copayment and Adherence in Chronic Heart Failure: Effect on Cost and Outcomes
Authors: Cole J. Alexander , Norman Heather , Weatherby Lisa B. , Walker Alexander M. 
Published: July 2006

Study Objective. To measure the association among prescription copayment, drug adherence, and subsequent health outcomes among patients with chronic heart failure (CHF).Design. Retrospective cohort study.Data Source. Database of a large, national health insurance plan.Patients. Patients with CHF receiving commercial and Medicare supplemental benefits.Measurements and Main Results. We estimated adherence to therapy with β‐blockers or angiotensin‐converting enzyme (ACE) inhibitors in 2002 by using the medication possession ratio, an estimate of the proportion of days a patient was exposed to a drug while taking a drug regimen. For 2003, we measured the annualized total cost of health care and identified hospitalizations with a diagnostic code for CHF. We used a two‐stage regression approach to model the association among copayment, adherence, and patient outcomes. For patients taking ACE inhibitors, a $10 increase in copayment was associated with a 2.6% decrease in the medication possession ratio (95% confidence interval [CI] 2.0–3.1%). This change in adherence was associated with a predicted 0.8% decrease in medical costs (95% CI‐4.2–2.5%) but a predicted 6.1% increase in the risk of hospitalization for CHF (95% CI 0.5–12.0%). Among patients taking β‐blockers, a $10 increase in copayment was associated with a 1.8% decrease in the medication possession ratio (95% CI 1.4–2.2%). This change in adherence was associated with a predicted 2.8% decrease in medical costs (95% CI −5.9–0.1%) and a predicted 8.7% increase in the risk of hospitalization for CHF (95% CI 3.8–13.8%).Conclusion. Among patients with CHF, higher drug copayments were associated with poorer adherence. The change was relatively small and did not affect predicted total health care costs, but it was sufficient to increase the predicted risk of hospitalization for CHF.