bluuebunny/crossref_metadata_2025_split huggingface dataset:
Monitoring statin safety in primary care
Authors: Tragni Elena , Filippi Alessandro , Mazzaglia Giampiero , Sessa Emiliano , Cricelli Claudio , Catapano Alberico L. 
Published: February 2007

AbstractPurposeTo verify General Practitioners (GPs) compliance to the recommended laboratory monitoring for statin users.MethodsA retrospective study was conducted collecting data from the database of Italian College of General Practitioners, named Health Search; all the participant physicians used an automatic pop‐up which reminds them to periodically check liver enzyme levels in statin‐users. We examined the patients who received their first statin prescription from 29 November 1999 to 28 November, 2002. CPK, ASL, AST, and creatinine values recorded before and after the first prescription were evaluated. The minimum and maximum observation time before and after prescription were 6 and 42 months, respectively. The prevalence of laboratory monitoring prescribed by GPs was calculated at baseline and during follow‐up for all patients and for the subgroup of high‐risk patients.ResultsWe identified 14 120 first‐ever statin users (male 47.4%). CPK, AST, ALT and creatinine tests were prescribed at least once at baseline in 8.5%, 53.9%, 50.9%, and 64.0% of patients, respectively; during the follow‐up 37.8%, 64.4%, 60.3%, and 61.5% of patient received the same tests prescriptions, respectively. No difference between high‐risk and non‐high‐risk patients was observed. During the follow‐up enzyme levels greater than three times the upper normal limit were recorded in 0.4%, 0.1%, 0.1%, and 0.3% of subjects for CPK, AST, ALT and creatinine, respectively.ConclusionAdherence to the recommended laboratory monitoring for statin users is very low among Italian GPs, even for high‐risk patients. Automatic reminders which pop‐up whenever statins are prescribed are ineffective. Copyright © 2007 John Wiley & Sons, Ltd.
Supramolecular inclusion complexation of polyhedral oligomeric silsesquioxane capped poly(ε‐caprolactone) with α‐cyclodextrin
Authors: Ni Yong , Zheng Sixun 
Published: February 2007

AbstractSupramolecular inclusion complexes (ICs) involving polyhedral oligomeric silsesquioxane (POSS) capped poly(ϵ‐caprolactone) (PCL) and α‐cyclodextrin (α‐CD) were investigated. POSS‐terminated PCLs with various molecular weights were prepared via the ring‐opening polymerization of ϵ‐caprolactone (CL) with 3‐hydroxypropylheptaphenyl POSS as an initiator. Because of the presence of the bulky silsesquioxane terminal group, the inclusion complexation between α‐CD and the POSS‐capped PCL was carried out only with a single end of a PCL chain threading inside the cavity of α‐CD, which allowed the evaluation of the effect of the POSS terminal groups on the efficiency of the inclusion complexation. The X‐ray diffraction results indicated that the organic–inorganic ICs had a channel‐type crystalline structure. The stoichiometry of the organic–inorganic ICs was quite dependent on the molecular weights of the POSS‐capped PCLs. With moderate molecular weights of the POSS‐capped PCLs (e.g., Mn =3860 or 9880), the stoichiometry was 1:1 mol/mol (CL unit/α‐CD), which was close to the literature value based on the inclusion complexation of α‐CD with normal linear PCL chains with comparable molecular weights. When the PCL chains were shorter (e.g., for the POSS‐capped PCL of Mn = 1720 or 2490), the efficiency of the inclusion complexation decreased. The decreased efficiency of the inclusion complexation could be attributed to the lower mobility of the bulky POSS group, which restricted the motion of the PCL chain attached to the silsesquioxane cage. This effect was pronounced with the decreasing length of the PCL chains. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1247–1259, 2007
Novel route to styrene/p‐aminostyrene copolymers
Authors: Lukey Christopher A. , Tymichova Michaela , Brown Hugh R. 
Published: February 2007

AbstractA novel route to styrene/p‐aminostyrene copolymers is described that involves the introduction of amino functionality into the structure of pure monodisperse polystyrene. The simple two‐step synthesis involves the introduction of a bromo group into the aromatic ring by electrophilic substitution and then a palladium‐catalyzed reaction with LiN(SiMe3)2 followed by an acid and base treatment to release the free amine. All reactions are carried out at room temperature. This approach avoids the difficulties often associated with the preparation of copolymers from incompatible monomers. The technique also gives a product with a precisely known molecular weight and polydispersity, important parameters governing many physical properties. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1282–1286, 2007
Potassium enolates of N,N‐dialkylamides as initiators of anionic polymerization
Authors: Ishizone Takashi , Yashiki Daizaburo , Kobayashi Motoyasu , Suzuki Takashi , Ito Mana , Nakahama Seiichi 
Published: February 2007

AbstractStable potassium enolates of N,N‐diethylacetamide [α‐potassio‐N,N‐diethylacetamide (1)], N,N‐diethylpropionamide [α‐potassio‐N,N‐diethylpropionamide (2)], and N,N‐diethylisobutyramide [α‐potassio‐N,N‐diethylisobutyramide (3)] were prepared by the proton abstraction of the corresponding N,N‐diethylamides with diphenylmethylpotassium (Ph2CHK) or potassium naphthalenide in THF. The relative nucleophilicity of 1–3 was estimated to be in the order of 1 < 3 < 2 from the results of the alkylation reaction with methyl iodide. N,N‐diethylacetamide transferred its α‐proton to 2 quantitatively in THF at 0 °C, whereas no reaction occurred between N,N‐diethylisobutyramide and 2; this indicated the relative basicity to be 1 < 2 ∼ 3. Anionic polymerizations of N,N‐diethylacrylamide (DEA) and methyl methacrylate were quantitatively initiated with 2 in THF at −78 °C, whereas the initiation efficiencies of 2 for styrene and 2‐vinylpyridine were about 2 and 67%, respectively. The initiation of DEA with 1–3 at −78 or 0 °C in THF gave poly (DEA)s having broad molecular weight distributions (MWDs; Mw/Mn = 2) and ill‐controlled molecular weights. In contrast, poly(DEA)s of narrow MWDs (Mw/Mn < 1.2) and predicted Mn's were obtained with 2 in the presence of diethylzinc (Et2Zn) at −78 °C, whereas the initiations with 1/Et2Zn and 3/Et2Zn at −78 °C resulted in poor control of the molecular weights. At the higher temperature of 0 °C, all the binary initiator systems (1–3/Et2Zn) induced controlled polymerizations of DEA in terms of the conversion, molecular weight, and MWD. The poly(DEA)s produced with 1–3/Et2Zn at 0 °C showed mr‐rich configurations (mr = 76–89%), as observed for the poly(DEA) generated with Ph2CHK/Et2Zn. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1260–1271, 2007
Thymine‐based, water‐soluble phototerpolymers: Their preparation and synthesis
Authors: Bianchini Jason R. , Saito Kei , Balin Taylor B. , Dua Vineet , Warner John C. 
Published: February 2007

AbstractTerpolymers of vinylbenzylthymine, vinylbenzyltriethylammonium chloride, and N‐butyl‐N,N‐dimethyl‐(4‐vinylbenzyl)ammonium chloride with different monomer ratios have been prepared, and the effect of the monomer ratios on the properties of the terpolymers has been investigated. These polymers are water‐soluble and, when irradiated with low levels of UV light, undergo a 2π+2π photodimerization reaction of thymine. This photodimerization significantly reduces the water solubility, immobilizing the polymer to the substrate, and shows potential for water‐soluble photoresists. Thermogravimetric analysis has revealed that the terpolymers have two degradation stages corresponding to the quaternary ammonium pendant groups and to the thymine. An evaluation of the contact‐angle measurements has shown that the surface properties and hydrophobicity can be controlled by the variation of the monomer ratios. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1296–1303, 2007
Asymmetric radical polymerization and copolymerization of N‐(1‐phenyldibenzosuberyl)methacrylamide and its derivative leading to optically active helical polymers
Authors: Azam A. K. M. Fakhrul , Kamigaito Masami , Okamoto Yoshio 
Published: February 2007

AbstractN‐(1‐Phenyldibenzosuberyl)methacrylamide (PDBSMAM) and its derivative N‐[(4‐butylphenyl)dibenzosuberyl]methacrylamide (BuPDBSMAM) were synthesized and polymerized in the presence of (+)‐ and (−)‐menthols at different temperatures. The tacticity of the polymers was estimated to be nearly 100% isotactic from the 1H NMR spectra of polymethacrylamides derived in D2SO4. Poly(PDBSMAM) was not soluble in the common organic solvents, and its circular dichroism spectrum in the solid state was similar to that of the optically active poly(1‐phenyldibenzosuberyl methacrylate) (poly(PDBSMA)) with a prevailing one‐handed helicity, indicating that the poly(PDBSMAM) also has a similar helicity. Poly(BuPDBSMAM) was optically active and soluble in THF and chloroform. Its optical activity was much higher than that of the poly[N‐(triphenylmethayl)methacrylamide], suggesting that one‐handed helicity may be more efficiently induced on the poly(BuPDBSMAM). The copolymerization of BuPDBSMAM with a small amount of optically active N‐[(R)‐(+)‐1‐(1‐naphthyl)ethyl]methacrylamide, particularly in the presence of (−)‐menthol, produced a polymer with a high optical activity. The prevailing helicity may also be efficiently induced. The chiroptical properties of the obtained polymers were studied in detail. The chiral recognition by the polymers was also evaluated. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1304–1315, 2007
UV curing of a novel resin derived from poly(ethylene terephthalate)
Authors: R. Auvergne , R. Saint‐Loup , C. Joly‐Duhamel , J. J. Robin , B. Boutevin 
Published: February 2007

AbstractThe synthesis and characterization of photopolymerizable unsaturated polyester resins based on PET waste are described. The resins came from a depolymerization process based on the glycolysis of PET by diethylene glycol (DEG). Different molecular weights of glycolysates were synthesized. Then, the latter was functionalized by a methyl hemiester of maleic acid to obtain unsatured α,ω‐bismaleate PET oligomers. In the presence of an electron donor monomer, such as triethylene glycol divinyl ether, these electron acceptor oligomers were copolymerized by way of charge‐transfer complexes under UV irradiation. The reaction was monitored in situ by real‐time IR spectroscopy to study the kinetics of photopolymerization. This one was studied in relation with the physical and chemical characteristics of oligoesters and the composition of mixtures containing divinyl ethers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1324–1335, 2007
Immobilization of aminothiols on poly(oxyethylene H‐phosphonate)s and poly(oxyethylene phosphate)s—An approach to polymeric protective agents for radiotherapy of cancer
Authors: Troev Kolio , Tsatcheva Ivelina , Koseva Neli , Georgieva Radostina , Gitsov Ivan 
Published: February 2007

AbstractThis study describes the synthesis and characterization of polymer complexes constructed from the radioprotective agent S‐2(3‐aminopropylamino) ethylphosphorothioic acid dihydrate (amifostine or WR‐2721), applied in the radiation cancer treatment, and biodegradable poly(oxyethylene H‐phosphonate), poly(hydroxyoxyethylene phosphate), or poly(methyloxyethylene phosphate). The immobilization of another radioprotector, used in cancer radiotherapy, 1‐(3‐aminopropyl)aminoethanethiol (WR‐1065) on the same polymers is also achieved through a covalent bond (Atherton‐Todd reaction coupling), ionic bond, and physical complexation, respectively. The structure of the complexes formed is elucidated by 1H‐ 13C‐, 31P NMR and FTIR spectroscopy. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1349–1363, 2007
Propylene polymerizations with a binary metallocene system—Chain shuttling caused by trimethylaluminium between active catalyst centers
Authors: Tynys Antti , Eilertsen Jan L. , Seppälä Jukka V. , Rytter Erling 
Published: February 2007

AbstractPropylene was polymerized at varying trimethylaluminium (TMA) concentration with a homogeneous binary metallocene catalyst system activated by methylaluminoxane (MAO) in an attempt to better understand interactions between active catalyst sites and to clarify the role of the TMA as a chain shuttling agent. TMA‐free polymerization conditions were obtained by chemical treatment of MAO solution with 2,6‐di‐tert‐butyl‐4‐methylphenol (BHT). A binary catalyst system consisting of catalyst precursors diphenylmethyl(cyclopentadienyl)(9‐fluorenyl)zirconium dichloride (1) producing high Mw syndiotactic polypropylene and rac‐dimethylsilylbis(4‐tert‐butyl‐2‐methyl‐cyclopentadienyl)zirconium dichloride (2) producing low Mw isotactic polypropylene was investigated. At the studied polymerization conditions, chain shuttling between the active catalysts caused by TMA was confirmed. The chain shuttling reactions caused changes in catalyst activity, molecular weights, melting behavior, and polymer microstructure. We propose that TMA is capable to transfer a growing polymer chain from catalyst 2 to catalyst 1, and a stereoblock copolymer is formed. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1364–1376, 2007
Elastic properties of two‐dimensional soft polydisperse trimers at zero temperature
Authors: Narojczyk J. W. , Wojciechowski K. W. 
Published: February 2007

AbstractThe elastic properties of two‐dimensional (2D) cyclic trimers, each constituted of three soft polydisperse disks interacting by n ‐inverse‐power‐potential, were numerically determined for the static case (i.e. at temperature T = 0). The influence of a structural disorder (polydispersity of the disk sizes) on the bulk modulus, the shear modulus, and the Poisson's ratio of the system was studied. Negative Poisson's ratio has been found for a range of densities at some values of the softness parameter n–1 and polydispersity. Simple mathematical formulae describing the dependence of elastic properties of the model on the softness parameter and polydispersity are proposed. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stability of elastic material with negative stiffness and negative Poisson's ratio
Authors: Xinchun Shang , Lakes Roderic S. 
Published: February 2007

AbstractMost elastic systems exhibit a positive stiffness: a deformed object experiences a force in the same direction as the deformation. An object with negative stiffness is possible, but it is unstable. Such an object can be stabilized by a hard constraint on the entire surface. In the Editor's Choice by Shang Xinchun and Roderic S. Lakes, it is shown that a partial constraint suffices to stabilize a body with negative stiffness [1].The diagram on the cover of this issue shows regions of stability in a map of bulk modulus (resistance to volume change) and shear modulus (resistance to shape change). A region corresponding to negative Poisson's ratio is also shown. Negative Poisson's ratio materials were developed by one of the authors (Lakes). Stability of solids with negative moduli is of interest in the context of composites. In the authors' laboratory, composites have been made with inclusions of negative modulus. These composites exhibit extreme values of viscoelastic damping and of stiffness.Corresponding author Roderic S. Lakes is Professor of Engineering Physics at the University of Wisconsin. His research focus is the creation and characterization of materials with extreme and unusual physical properties. His group is developing materials with reversed properties, including negative Poisson's ratio, negative stiffness, and negative thermal expansion.
A sensitive method for the detection and quantification of ginkgo flavonols from plasma
Authors: Zhao Yang , Wang Li , Bao Yuanwu , Li Chuan 
Published: February 2007

AbstractExtracts from Ginkgo biloba leaves (family Ginkgoaceae) have antioxidant and free radical scavenging effects, largely attributed to the flavonols, which are a major class of functional components in ginkgo extracts. In order to facilitate analysis of systemic exposure to ginkgo‐derived products in animals and/or humans, we developed a liquid chromatography/tandem mass spectrometry (LC/MS/MS)‐based method that is capable of routinely monitoring plasma levels of ginkgo flavonols. We used an initial acidic hydrolysis step to convert the plasma ginkgo flavonol conjugates into their aglycone forms [quercetin (QCT), kaempferol (KMF) and isorhamnetin (ISR)] prior to EtOAc‐based extraction and subsequent LC/MS/MS‐based analysis. Comparative studies showed that the use of a mobile phase containing an extremely low concentration of HCOOH (0.01‰) dramatically improved the electrospray ionization efficiency of the analytes in the negative ion mode; the efficiencies were ∼4‐, ∼8‐ and ∼20‐fold higher for QCT, KMF and ISR, respectively, versus the results obtained using an electrolyte‐free mobile phase, or ∼2‐, ∼3‐ and ∼4‐fold higher, respectively, versus the results obtained using a mobile phase containing the more commonly utilized concentration of HCOOH (1‰). In addition, use of the low concentration of HCOOH also decreased undesired matrix effects. These favorable effects have been referred to as ‘LC‐electrolyte effects’. Due to structural differences in the B‐ring substituent, different types of precursor‐to‐product ion pairs (m/z 301 → 151 for QCT, 285 → 187 for KMF, and 315 → 300 for ISR) were used for the selected reaction monitoring of the analytes. In addition, the chromatographic conditions were optimized on the basis of an initial scouting of matrix effects on analyte ionization. Despite the absence of an internal standard, the validation results consistently demonstrated that our bioassay is valid, reproducible, and reliable. The newly developed assay provided lower limits of quantification of 1.3, 1.3 and 0.4 pg on‐column for QCT, KMF and ISR, respectively, which is more sensitive than any previously reported method for determining ginkgo flavonols. Finally, the assay suitability was demonstrated in a pilot pharmacokinetic measurement of a pharmaceutical ginkgo product in a beagle dog. This newly developed method should prove useful for wide‐scale monitoring of ginkgo flavonol plasma concentrations for both pharmaceutical investigations and clinical applications. Copyright © 2007 John Wiley & Sons, Ltd.
Pharmacokinetic study of intraperitoneally administered troglitazone in mice using ultra‐performance liquid chromatography/tandem mass spectrometry
Authors: New Lee‐Sun , Saha Sudipta , Ong Michie M. K. , Boelsterli Urs Alex , Chan Eric C. Y. 
Published: February 2007

AbstractA rapid and sensitive ultra‐performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) method was developed and validated for the determination of troglitazone in mouse plasma. Troglitazone and its internal standard (IS), rosiglitazone, were separated on an ACQUITY UPLC BEH C18 column (1.7 µm particle size, 50 × 2.1 mm i.d.) by gradient elution with water and methanol at a flow rate of 0.5 mL/min. The cycle time of each analysis was 2.5 min. Rosiglitazone and troglitazone eluted at 1.13 and 1.57 min, respectively, and were chromatographically resolved from the ion suppression and enhancement zones due to the biological matrix effect. Quantitation of the analytes was performed in electrospray negative ionization mode (ESI −ve) using multiple reaction monitoring (MRM) experiments. The weighted (1/x) calibration curve was quadratic over the plasma concentration range 1–2500 ng/mL with a correlation coefficient (r2) of 0.9966. The limit of quantitation (LOQ) of troglitazone in mouse plasma was lower than 1 ng/mL. The inter‐ and intra‐day variations of the assay were lower than 12.1%; the overall accuracy ranged from 86.4–110.2% and recovery from spiked plasma was more than 60%. The developed method was successfully applied to determine troglitazone in mouse plasma after intraperitoneal administration. Copyright © 2007 John Wiley & Sons, Ltd.
Changes in carbon and nitrogen stable isotopes of chironomid larvae during growth, starvation and metamorphosis
Authors: Doi Hideyuki , Kikuchi Eisuke , Takagi Shigeto , Shikano Shuichi 
Published: February 2007

AbstractWe conducted experiments to determine isotope changes in the deposit‐feeding chironomid larvae Chironomus acerbiphilus during feeding, starvation and metamorphosis. Isotope changes in chironomid larvae occurred mainly during growth and rarely afterward. This finding indicates that chironomid isotope turnover mainly occurs in conjunction with growth and suggests that chironomid larvae only break down newly assimilated food for energy during periods of no growth. Chironomid δ13C values significantly increased throughout the starvation experiment, indicating that chironomids preferentially break down components with lower δ13C content during starvation. We found significant changes in chironomid isotope ratios (15N enrichment) during pupation. This evidence suggests that the physiological condition of animals (such as during an active growth phase or pre‐ or post‐molting) is important to their stable isotope ratios. Copyright © 2007 John Wiley & Sons, Ltd.
Do b‐ions occur from vibrational excitation upon H‐desorption in electron capture dissociation?
Authors: Haselmann Kim F. , Schmidt Marcel 
Published: February 2007

AbstractElectron capture dissociation (ECD) has recently been shown in some cases to produce abundant N‐terminal b‐ion peptide fragments. These product ions are usually only observed when activation occurs via vibrational excitation as in collision‐induced dissociation (CID). Here, we show that occurrence of b‐ions in the ECD spectra of synthetic peptides are correlated with low gas‐phase basicity and that the observed b‐ion fragments are N‐terminal products. Furthermore, all ECD spectra containing b‐ions also had abundant losses of hydrogen and ammonia from the charge‐reduced species. Copyright © 2007 John Wiley & Sons, Ltd.
Exploration of oligosaccharide‐protein interactions in glycoprotein quality control by synthetic approaches
Authors: Hagihara Shinya , Totani Kiichiro , Ito Yukishige 
Published: February 2007

AbstractHigh‐mannose‐type oligosaccharides, which are cotranslationally introduced to nascent polypeptides, play important roles in glycoprotein quality control. This process is highly complex, involving a number of lectins, chaperones, and glycan‐processing enzymes. For example, calnexin and calreticulin (CRT) are molecular chaperones that recognize monoglucosylated forms of high‐mannose‐type glycans. UDP‐glucose : glycoprotein glucosyltransferase (UGGT) only glucosylates high‐mannose‐type glycans attached to partially folded proteins. Fbs1 is a component of ubiquitin ligase that recognizes sugar chains. Although recent studies have clarified the properties of these proteins, most of them used oligosaccharides derived from natural sources, which contain structural heterogeneity. In order to gain a more precise understanding, we started our program to comprehensively synthesize high‐mannose‐type glycans associated with a protein quality control system. Additionally, investigation of artificial glycoproteins led us to the discovery of the first nonpeptidic substrate of UGGT. These synthetic oligosaccharide probes have allowed us to conduct quantitative evaluations of the activity and specificity of CRT, Fbs1, and UGGT. © 2007 The Japan Chemical Journal Forum and Wiley Periodicals, Inc. Chem Rec 6: 290–302; 2006: Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/tcr.20088