bluuebunny/crossref_metadata_2025 huggingface dataset:
The potential role of occupational therapy in acute care with clients with HIV/AIDS
Authors: Fish Gillian , Rudman Deborah Laliberte
Published: April 2006

As medical interventions aimed at prolonging the lives of people with Human Immunodeficiency Virus (HIV) and Acquired Immunodeficiency Syndrome (AIDS) are implemented, HIV/AIDS is evolving into a chronic disease with associated disability. People with HIV/AIDS can experience numerous occupational performance problems and occupational therapists need to examine and develop their role in helping to meet the needs of this population. Acute‐care occupational therapists work with clients with HIV/AIDS who experience multiple admissions and who present with varying levels of occupational function. This paper outlines the potential role of occupational therapy in acute care with clients with HIV/AIDS using the Model of Occupational Performance (Canadian Association of Occupational Therapists, 1991) as a conceptual framework. The results of a retrospective chart review that investigated the role of two occupational therapists working with clients with HIV/AIDS in an acute‐care setting are presented and compared with the potential role. Practice and research recommendations to address the discrepancies between the potential and present role are presented. Copyright © 1998 Whurr Publishers Ltd.
Understanding assessment concepts within the occupational therapy context
Authors: Clemson Lindy , Fitzgerald Maureen H.
Published: April 2006

This paper explores therapists' perceptions about issues of validity, reliability and usefulness of assessment tools. It draws on the findings of a qualitative inquiry that was designed to evaluate the usefulness of the Westmead Home Safety Assessment. The study also explored therapists attitudes and beliefs about reliability, validity and related concepts, and how they understand and use these concepts in practice. In‐depth, semi‐structured interviews and participant‐observations were conducted. The findings suggest that issues of reliability and validity were not clearly understood, terms were confused and therapists had difficulty in applying the concepts in their practice. Reliability was viewed as important but much less attention was given to validity. By not understanding validity, therapists may not give themselves credit where it is due, lack confidence in their assessments and their ability, and, therefore, may not always use tools to their best advantage. Copyright © 1998 Whurr Publishers Ltd.
Supervising students: exploring the experience through reflective journals
Authors: Jung Bonny , Tryssenaar Joyce
Published: April 2006

Fieldwork is a vital component of undergraduate occupational therapy education and is dependent on effective clinical educators. This study explored the lived experience of clinical preceptors, through an interpretive approach. Thirteen clinical preceptors kept reflective journals during a six‐week fieldwork experience. Data were analysed using an inductive retrospective content analysis of the journals. Results included the anticipation related to preparing for the students, self‐doubt about personal abilities; preparation and organization for the student; the time consuming nature of the task; balancing workload demands; personal enjoyment and rewards from the experience; desire for a positive experience to validate personal skill level; and closure reaction. The themes were consistent across the majority of the journals. Isolated therapists reported a collegial benefit from student supervision. The results may be helpful in connecting continuing education opportunities with preceptors' needs and in the orientation of new preceptors. Copyright © 1998 Whurr Publishers Ltd.
Creative arts in occupational therapy: ancient history or contemporary practise?
Authors: Thompson Melanie , Blair Sheena E.E.
Published: April 2006

This paper is primarily concerned with the use of creative arts by occupational therapists in adult mental health rehabilitation. A review of relevant literature within and beyond occupational therapy suggests that creative arts have therapeutic value. The first section considers the more traditional, psychodynamic framework for creative arts in mental health. This underpinned much therapeutic creative art work between the 1960s and 1980s. The second section draws on a broader, more eclectic framework of theorising and research. This offers a rationale for the use of creative arts in their own therapeutic right. It is hoped that this will stimulate thinking among occupational therapists about retaining and promoting creative arts within their practice. Copyright © 1998 Whurr Publishers Ltd.
Pilot study of the inpatient rehabilitation – scales of therapeutic occupation
Authors: Sass Pamela L. , Nelson David L.
Published: April 2006

The IR – SOTO is a self‐help instrument that assists the occupational therapist in evaluating the adherence of an inpatient rehabilitation facility to an occupational approach to therapy. The IR – SOTO focuses on individualization of therapy, holism, naturalistic occupations, documentation of occupation and communication of occupational therapy principles. A series of practitioner panels provided feedback on the content validity of early versions of the instrument. Pilot testing of the revised instrument (a 62‐item survey using seven‐point Likert scales) was carried out using a mailed survey (n = 138) to nine inpatient rehabilitation facilities in different areas of the United States. The pilot version of the IR–SOTO was internally consistent, with alpha = 0.91. The overall mean score across items and across subjects of 5.48 on a seven‐point scale (sd = 0.52) indicates some adherence to an occupational approach to therapy. The scores of one facility were significantly lower than five of the other facilities. Continued revision of the instrument to enhance reliability and validity is recommended, with testing of test–retest reliability as a priority. The IR–SOTO holds promise for measuring a facility's approach to the use of occupation as therapy in inpatient rehabilitation. Copyright © 1998 Whurr Publishers Ltd.
Heat and fire resistance of polyurethane‐polydimethylsiloxane hybrid material
Authors: Belva Frederic , Bourbigot Serge , Duquesne Sophie , Jama Charaf , Le Bras Michel , Pelegris Christine , Rivenet Murielle
Published: April 2006

This work examines the synthesis of polyurethane (PU)—polydimethylsiloxane (PDMS) hybrid in order to provide low flammability to PU. Chemical characterization of PU/PDMS hybrid by solid state NMR of carbon and FT‐IR shows that some PDMS segments are incorporated in the macromolecular chains of PU. Heat stability of PU (thermo‐oxidative decomposition) is not enhanced by the incorporation of PDMS except that the amount of the high temperature residue is improved and depends on the amount of PDMS incorporated in the PU chains. It is explained by the formation and the accumulation of silica. On the contrary, thermal stabilization (charring) occurs in the pyrolytic conditions when incorporating PDMS. The accumulation of silica as well as charring enhancement enables the flammability properties of the PU/PDMS hybrid to form a protective layer limiting heat transfer between the flame and the substrate. The heat release rate measured by cone calorimetry of PU/PDMS hybrid is significantly decreased compared to virgin PU and temperature of the back of the sample is comparatively low compared to virgin PU. Copyright © 2006 John Wiley & Sons, Ltd.
Complex activity of clay and CNT particles in flame retarded EVA copolymer
Authors: Marosfői B. B. , Marosi Gy. J. , Szép A. , Anna P. , Keszei S. , Nagy B. J. , Martvonova H. , Sajó I. E.
Published: April 2006

Interface modifications optimized for fire retardancy require detailed research. Confocal Raman microscopy was used to analyze the degradation locally in the area of the nanotube and clay additives. The double‐walled carbon nanotube (DWCNT), containing Co catalyst residue, accelerates the deacetylation process of poly(ethylene‐co‐vinylacetate) (EVA) considerably, while the montmorillonite (MMT) has no significant influence under static circumstances. The compounding process influences the effect of MMT, which causes partial crosslinking in EVA during the compounding. This mechanochemical reaction is catalyzed by uncovered MMT particles, while organophillized MMT promotes the charring process. Inorganic surface modification with various metal ions has also some stabilizing effect. Spray drying of MMT results in microparticles of increased surface area and improved thermal stability of the EVA system. The lowest rate of flame spreading was achieved using uncoated MMT, while coating with cationic surfactant was most efficient for hindering dripping. The rate of heat release (RHR) of the organically modified and the spray dried MMT was approximately the same. The combined organic‐inorganic modified clay moderates both the dripping and the flame spreading in the EVA. Copyright © 2006 John Wiley & Sons, Ltd.
Use of prescription medications with a potential for fetal harm among pregnant women
Authors: Andrade Susan E. , Raebel Marsha A. , Morse Abraham N. , Davis Robert L. , Chan K. Arnold , Finkelstein Jonathan A. , Fortman Kris K. , McPhillips Heather , Roblin Douglas , Smith David H. , Yood Marianne Ulcickas , Platt Richard , Gurwitz Jerry H.
Published: April 2006

Purpose

To estimate the prevalence of use of prescription drugs with a potential for fetal harm among pregnant women in the United States.

Methods

A retrospective study was conducted using the automated databases of eight health maintenance organizations involved in the HMO Research Network Center for Education and Research on Therapeutics (CERT). Women who delivered an infant from January 1996 to December 2000 were identified. The frequency of use of prescription drugs with a potential for fetal harm was based upon the expert review of a clinical teratologist and the U.S. Food and Drug Administration (FDA) risk classification system, assuming a gestational duration of 270 days.

Results

Among the 114 165 women with no documentation of a diagnosis suggesting potential pre‐term birth or dispensing of ovulation stimulants in the 270 days before delivery, 1305 (1.1%) received a teratogenic drug during the 270 days before delivery, based upon the expert review of a clinical teratologist. A larger proportion of women received U.S. FDA category D or X drugs (5.8%; N = 6600). However, the general patterns of use were similar, with higher use in early pregnancy compared to later trimesters. The proportion of women dispensed a teratogen during pregnancy was substantially higher among women who received a teratogen in the 90 days before pregnancy compared to women who did not (adjusted RR = 38.9, 95%CI, 33.5, 45.3).

Conclusions

Our results suggest that further efforts directed at physicians to counsel women or at the women themselves about the potential risks of particular medications appear warranted. Copyright © 2006 John Wiley & Sons, Ltd.
Initial non‐compliance with antihypertensive monotherapy is followed by complete discontinuation of antihypertensive therapy
Authors: Van Wijk Boris L.G. , Klungel Olaf H. , Heerdink Eibert R. , de Boer Anthonius
Published: April 2006

Purpose

Discontinuation with treatment is a major problem in the treatment of hypertension. The objective of our study was to assess the association between non‐compliance and discontinuation in patients who started using antihypertensive monotherapy.

Methods

A nested case‐control study within a cohort of new users of antihypertensive drugs between 1st January 1999 and 31st December 2002 was performed. We used data from the PHARMO database, a record linkage system containing drug‐dispensing records from community pharmacies and linked hospital discharge records of approximately 950,000 subjects. Cases discontinued their use of antihypertensive monotherapy and were not switched to other antihypertensive treatment, controls stayed on their initially prescribed monotherapy. Conditional logistic regression was used to calculate odds ratios (OR) and their 95% confidence intervals (CI).

Results

In a cohort of 39,714 new users of antihypertensive drugs, we identified 9111 cases and 9111 matched controls. The percentage of non‐compliant patients (compliance <80%) among cases and controls was 14.0% and 5.8%, respectively [OR 2.86 (95%CI: 2.52–3.24)]. Patients who used less than 90 days had a higher risk on discontinuation [OR 3.10 (95%CI: 2.67–3.59)] than patients who used more than 90 days [OR 2.28 (95%CI: 1.79–2.92)]. The association was generally similar among males and females, among the different types of antihypertensives and among the different age groups.

Conclusion

In patients who start antihypertensive monotherapy, non‐compliance is often followed by discontinuation of this antihypertensive treatment. The pharmacy medication history is a valuable tool for physicians to identify patients who have a high risk on discontinuation with antihypertensive treatment. Copyright © 2006 John Wiley & Sons, Ltd.
Factors associated with the pharmacist counselling without dispensing
Authors: Caamaño Francisco , Tomé‐Otero Manuel , Takkouche Bahi
Published: April 2006

Purpose

To describe the pharmacist counselling without dispensing and to analysed the characteristics of pharmacies and pharmacists that provide this type of counselling, and the characteristics of customers that receive it to a greater extent.

Methods

We carried out a cohort study on a sample of 166 pharmacists in North West Spain. Different characteristics of pharmacists and clients and other variables related to counselling were measured (who initiates the consultation; type of consultation; whether or not the patient consulted with a doctor previously and who is the receptor of the counselling) were included in the models as independent variables. Pharmacist Counselling without dispensing (PhCwD) were included as dependent variable. We constructed logistic regression models.

Results

The response rate to the first questionnaire was 98.8% and the participation rate in the follow‐up was 60%. Out of 7010 registered pharmacist counselling, 6034 were included in the final analysis (86.1%). The proportion of PhCwD is 26.3% (95%IC: 25.2–27.4).

Conclusions

Our results show the number of working hours of the pharmacist and the amount of customers are associated with PhCwD. So working hours and amount customers should be reduced. Other factor that should be taken into account is the fact that pharmacists with less experience should give less counsels. Thus during the university period pharmacist counselling should be studied. Finally, our results show that an important proportion of counselling is given regardless the dispensation process, and this should be taken into account when defining the pharmacists remuneration system. Copyright © 2006 John Wiley & Sons, Ltd.
Optimization of opto‐electronic property and device efficiency of polyfluorenes by tuning structure and morphology
Authors: Chen Peng , Yang Guizhong , Liu Tianxi , Li Tingcheng , Wang Min , Huang Wei
Published: April 2006

Polyfluorene‐based oligomers and polymers (PFs) have been studied intensively as active materials for organic optoelectronic devices. In this review, the optimization of the opto‐electronic property and device efficiency of polyfluorenes in the field of light‐emitting diodes (LEDs) and photovoltaic cells (PVs) by tuning structure and morphology are summarized in terms of two typical modification techniques: copolymerization and blending. The relationships between molecular structures, thin film morphologies, opto‐electronic properties and device efficiencies are discussed, and some recent progress in LEDs and PVs is simultaneously reviewed. After the introduction, the basic knowledge of molecular structures and properties of polyfluorene homopolymers is presented as a background for a better understanding of their great potential for opto‐electronic applications. Immediately after this, three different opinions on the origin of low‐energy emission band at 520–540 nm in polyfluorene‐based LEDs are addressed. Rod–coil block copolymers and alternative copolymers are focused on in the next section, which are a vivid embodiment of controlling supramolecular structures and tailoring molecular structures, respectively. In particular, various supramolecular architectures induced by altering coil blocks are carefully discussed. Recent work that shows great improvement in opto‐electronic properties or device performance by blending or doping is also addressed. Additionally, the progress of understanding concerning the mechanisms of exciton dynamics is briefly referred to. Copyright © 2006 Society of Chemical Industry
Behavior of quaternary ammonium salt photobase generators on initiating free radical photo‐polymerization
Authors: Zhong Rong , Yang Jianwen , Zeng Zhaohua , Chen Yonglie
Published: April 2006

Series of quaternary ammonium tetraphenyl borates salt photobase generators (PBGs) were synthesized using p‐methoxyphenacylmethylene and 2‐naphthoymethylene as chromophores, and triethylene diamine, pyridine or 3‐methyl pyridine as tertiary amine. The kinetics for polymerization of trimethylolpropane triacrylate (TMPTA) monomer using PBGs as free radical photo‐initiator was monitored by differential photo‐calorimeter (DPC). It was found that all the quaternary ammonium tetraphenyl borate salt photobase generators synthesized could initiate free radical polymerization of the acrylate monomer TMPTA by exposure to UV irradiation, but the activity was relatively low. Addition of a small amount of polar solvent to the system could largely increase the polymerization rate and final conversion. Photo‐polymerization was also improved by increasing light intensity or raising reaction temperature. PBGs with p‐methoxyphenacylmethylene as chromophore had higher absorbance at around 280 nm and showed higher activity in initiating photo‐polymerization than those with N‐(2‐naphthoylmethyl) as chromophore. Copyright © 2006 Society of Chemical Industry
Synthesis and characterization of pH‐ and temperature‐sensitive silk sericin/poly(N‐isopropylacrylamide) interpenetrating polymer networks
Authors: Wu Wen , Li Wenjing , Wang Li Qun , Tu Kehua , Sun Weilin
Published: April 2006

Interpenetrating polymer networks (IPNs) composed of silk sericin (SS) and poly(N‐isopropylacrylamide) (PNIPAAm) were prepared simultaneously. The properties of the resultant IPN hydrogels were characterized by differential scanning calorimetry and SEM as well as their swelling behavior at various temperatures and pH values. The single glass transition temperature (Tg) presented in the IPN thermograms indicated that SS and PNIPAAm form a miscible pair. The swollen morphology of the IPNs observed by SEM demonstrated that water channels (pores present in SEM micrographs) were distributed homogeneously through out the network membranes. The swelling ratio of the IPNs depended significantly on the composition, temperature and pH of the buffer solutions. The dynamic transport of water into the IPN membrane was analyzed based on the Fickian equation. Copyright © 2006 Society of Chemical Industry
Interfacial‐initiated seeded emulsion polymerization: preparation of polystyrene/poly(methacrylic acid) core/shell particles in the absence of surfactant
Authors: Liu Wei‐Jun , He Wei‐Dong , Wang Yan‐Mei , Wang De , Zhang Zhi‐Cheng
Published: April 2006

Composite polymer particles with hydrophobic polystyrene (PSt) as the core and hydrophilic poly(methacrylic acid) (PMAA) as the shell were prepared through two‐stage emulsion polymerization without any surfactant. In the first step, narrowly distributed PSt seed particles were prepared by surfactant‐free emulsion polymerization with 2,2′‐azobis(2‐methylpropionamide) dihydrochloride (AMPA) as the initiator. In the second step, hydrophilic PMAA shells were fabricated onto PSt seed particles through redox interfacial‐initiated seeded emulsion polymerization with cumyl hydroperoxide (CHPO)/ferrous sulfate/ethylenediaminetetraacetic acid (EDTA)/sodium formaldehydesulfoxylate (SFS), where the initiation took place mainly at the interface between PSt seed particles and the aqueous medium. The composite particles were characterized with transmission electron microscopy, fourier transform infrared spectroscopy and dynamic light scattering, and the results show that a core/shell structure was successfully built. Hydrodynamic radius (Rh) of the composite particles increased with the amount of polymerized monomers in the seeded emulsion polymerization. Copyright © 2006 Society of Chemical Industry
The use of polyelectrolyte stabilisers for suspension polymerisation: the effect of pH on particle size distribution
Authors: Georgiadou Styliani , Brooks Brian W
Published: April 2006

Ammonium polymethacrylate (APMA) and sodium polymethacrylate (PMA‐Na) were used as suspending agents for the suspension polymerisation of methyl methacrylate (MMA). The effect of pH on particle sizes and the stabilisation mechanism were examined. Increasing the pH caused a decrease in the particle sizes, and the formation of fine particles with diameters smaller than 10 µm. The amount of suspending agent required to stabilise a monomer dispersion and to prevent coalescence during suspension polymerisation decreases with increasing pH. The prevailing stabilisation mechanism that governs the dispersion stability is probably the electrosteric mechanism. Copyright © 2006 Society of Chemical Industry
Preparation and mechanical properties of clay/polystyrene‐block‐polybutadiene‐block‐polystyrene triblock copolymer (SBS) intercalated nanocomposites using organoclay containing stearic acid
Authors: Yamaguchi Tomohiro , Yamada Eisuke
Published: April 2006

Organoclays containing various amounts of stearic acid (SA) were synthesized, and clay/polystyrene‐block‐polybutadiene‐block‐polystyrene triblock copolymer (SBS) intercalated nanocomposites were prepared using organoclays containing SA by melt‐blending. Montmorillonite was the clay used, and both stearylamine and SA were used as surface modifiers. The amount of SA added was 0, 20, 50 and 100% of the cation‐exchange capacity (CEC). In this study, the effects of SA on the microstructure and mechanical properties of the clay/SBS nanocomposites were investigated. In clay/SBS with 100% CEC of SA, although no exfoliation of the clay occurred, the stacked clay layers were uniformly dispersed at the nanometer level (100–800 nm) without agglomeration. Clay/SBSs containing SA exhibited superior mechanical properties compared to clay/SBS without SA. It was found that SA effectively improved the clay dispersion in the SBS matrix and the mechanical properties of the clay/SBSs. Copyright © 2006 Society of Chemical Industry
Copolymers of acrylic acid with N‐vinylpyrrolidinone and 2‐hydroxyethyl methacrylate as pH‐responsive hydrogels synthesized through a photoinitiator‐free photopolymerization technique
Authors: Ng Loo‐Teck , Swami Salesh
Published: April 2006

pH‐sensitive hydrogels for biomedical applications were synthesized using a photoinitiator‐free technique involving the initiation of photopolymerization by donor/acceptor pairs. The differential photocalorimetric technique indicated a high polymerization rate for the N‐vinylpyrrolidinone (NVP, donor)/acrylic acid (AA, acceptor) pair at a 1:1 molar ratio. However, photopolymerization of larger quantities of these monomers (1:1 molar ratio) produced a water‐soluble polymer. Nevertheless, an anionic hydrogel was successfully formed when a small quantity of 2‐hydroxyethyl methacrylate (HEMA) was included in the NVP/AA formulation. A mixture of HEMA and AA, although both are classified as acceptors, photopolymerized to produce a copolymer which functioned as an anionic hydrogel. The swelling and drug release of these hydrogels were investigated in acidic, neutral and basic pH environments. Their biocompatibility with HaCaT human epidermal keratinocyte cells was tested and a positive cell growth as evidenced by the 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyl tetrazolium bromide (MTT) cell proliferation assay indicated that these hydrogels have no toxic effect on HaCaT. Copyright © 2006 Society of Chemical Industry
Synthesis, characterization and properties of poly(butylene succinate) modified with rosin maleopimaric acid anhydride
Authors: Liu Xiaoqing , Li Chuncheng , Zhang Dong , Xiao Yaonan , Guan Guohu
Published: April 2006

Huge hydrogenated phenanthrene ring segments were introduced into the main chain of poly(butylene succinate) by polymerization of succinic acid (SA), 1,4‐butanediol (BD) and rosin maleopimaric acid anhydride (RMA), which was obtained from maleic rosin. The chemical structure and composition of the copolyesters were determined with the aid of 1H‐NMR, FTIR and elemental analysis. The thermal properties, crystallization behaviour and mechanical properties of the copolyester were then investigated using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), polarized light microscopy (PLM) and mechanical testing. With increasing content of hydrogenated phenanthrene ring segments, the melting temperature, the crystallization temperature and the relative degree of crystallinity decreased gradually, but the elongation at break and the notched impact strength of poly(butylene succinate) were enhanced without a significant deterioration of tensile strength. Copyright © 2006 Society of Chemical Industry
Synthesis and characterization of four‐arm star‐shaped polymers and copolymers
Authors: Wang Tzong‐Liu , Tseng Ching‐Guey
Published: April 2006

Four‐arm star‐shaped polymers and copolymers were obtained by transition metal‐catalyzed atom‐transfer radical polymerization (ATRP). The polymers were characterized by FTIR and 1H‐NMR spectroscopy. Gel permeation chromatography results indicated the formation of polystyrene and polystyrene‐block‐poly(methyl methacrylate) (PS‐b‐PMMA) arms with controlled molecular weights. In dilute solution, the linear polymers had higher inherent viscosities than star‐shaped ones. Thermogravimetric analysis showed a similar degradation mechanism for linear and star‐shaped polymers. Differential scanning calorimetry indicated the successful formation of diblock star‐shaped copolymers. Copyright © 2006 Society of Chemical Industry
Electron‐beam processing of nylon 6 and HNBR blends. Part II: development of high strength, heat‐ and oil‐resistant thermoplastic elastomers
Authors: Das PK , Ambatkar SU , Sarma KSS , Sabharwal S , Banerji MS
Published: April 2006

The effects of electron‐beam irradiation on morphology, mechanical properties and on the heat and hot oil resistance of the thermoplastic elastomeric blend of 30:70 and 70:30, nylon 6 and hydrogenated nitrile rubber (HNBR) were investigated over the dose range 0–8 Mrad. The insoluble content of blends increased with increase in the radiation dose. The morphology of the blend was studied in scanning electron microscopy, with special reference to the effect of radiation prior to processing via injection molding. Irradiated pellets showed better mechanical properties after injection molding compared with irradiated sheets at low radiation dose. The observed differences in mechanical properties are explained on the basis of morphology of the blend. The blend properties were also found to have a strong dependence on nylon content. It was found that the blends rich in nylon had superior mechanical properties, hot oil and solvent resistance, whereas blends with higher HNBR content had better set and heat resistance. The effect of radiation on interaction in these blends was also evaluated and was found to induce possible inter‐chain crosslinking in the blends. Copyright © 2006 Society of Chemical Industry
Synthesis and aggregation behavior of four types of different shaped PCL‐PEG block copolymers
Authors: Lu Chengfei , Guo Sheng‐rong , Zhang Yaqiong , Yin Ming
Published: April 2006

Biodegradable, amphiphilic, linear (diblock and triblock) and star‐shaped (three‐armed and four‐armed) poly[(ethylene glycol)‐block‐(ε‐caprolactone)] copolymers (PEG–PCL copolymers) were synthesized by ring‐opening polymerization of ε‐caprolactone (CL) with stannous octoate as a catalyst, in the presence of monomethoxypoly(ethylene glycol) (MPEG), poly(ethylene glycol) (PEG), three‐armed poly(ethylene glycol) (3‐arm PEG) or four‐armed poly(ethylene glycol) (4‐arm PEG) as an initiator, respectively. The monomer‐to‐initiator ratio was varied to obtain copolymers with various PEG weight fractions in a range 66–86%. The molecular structure and crystallinity of the copolymers, and their aggregation behavior in the aqueous phase, were investigated by employing 1H‐NMR spectroscopy, gel permeation chromatography and differential scanning calorimetry, as well as utilizing the observational data of gel–sol transitions and aggregates in aqueous solutions. The aggregates of the PEG–PCL block copolymers were prepared by directly dissolving them in water or by employing precipitation/solvent evaporation technique. The enthalpy of fusion (ΔHm), enthalpy of crystallization (ΔHcrys) and degrees of crystallinity (χc) of PEG blocks in copolymers and the copolymer aggregates in aqueous solutions were influenced by their PEG weight fractions and molecular architecture. The gel–sol transition properties of the PEG–PCL block copolymers were related to their concentrations, composition and molecular architecture. Copyright © 2006 Society of Chemical Industry
From N‐(dinitrophenyl) amino acids to benzimidazole N‐oxides. Synthesis, kinetics and mechanism
Authors: Buján Elba I. , Salum María Laura
Published: April 2006

Several benzimidazole N‐oxide derivatives were synthesized in very good yields by heating under reflux the corresponding N‐(2,4‐ or 2,6‐dinitrophenyl) amino acid derivative with NaOH in 60% 1,4‐dioxane–H2O. The N‐oxides obtained from glycine and α‐ and β‐alanine derivatives lost the carboxylic group. The observed rate constant for the reaction of N‐(2,4‐dinitrophenyl) glycine (2a) in 10% 1,4‐dioxane–H2O to give 5‐nitro‐1H‐benzimidazole‐3‐oxide (4a) is first order on [NaOH]; the second‐order rate constant is kN=1.7×10−3 M−1 s−1. The mechanism proposed includes the formation of an N‐alkylidene 2‐nitrosoaniline‐type intermediate as the rate‐determining step. Copyright © 2006 John Wiley & Sons, Ltd.
Matrix dependence of blue light emission from a novel NH2‐functionalized dicyanoquinodimethane derivative
Authors: Szablewski Marek , Bloor David , Kagawa Yasuyuki , Mosurkal Ravi , Cole Jacqueline M. , Clark Stewart J. , Cross Graham H. , Pålsson Lars‐Olof
Published: April 2006

The reactions of primary and secondary amines with (cyclohexa‐2,5‐diene‐1,4‐diylidene)‐dimalononitrile (TCNQ) lead to mono‐ and disubstituted dicyanoquinodimethane derivatives and fluorescence emission has been observed for several of these compounds. We report the luminescence properties, synthesis and crystal structure of the novel dicyanoquinodimethane derivative 2‐{4‐[amino‐(2,6‐dimethyl‐morpholin‐4‐yl)‐methylene]‐cyclohexa‐2,5‐ dienylidene}‐malononitrile (Ammor), a unique example of an asymmetric dicyanoquinodimethane derivative in which one of the nitrile groups has been replaced with an NH2 moiety, which provides a reactive centre for potential further substitution or tethering to larger molecules or polymers. The luminescence properties of the title compound were investigated in a variety of environments, including alcohol solutions at room temperature and a glass‐forming solvent at low temperature. The fluorescence quantum yields and Stokes' shifts of the blue emission were found to be very sensitive to the matrix. The crystal structure of the subject compound was determined, revealing that the molecules are non‐planar in the ground state. The environmentally sensitive emission is discussed in terms of the conformational change during photoexcitation and the constraint imposed on this by the matrix. This behaviour is also compared with that of other related amino‐functionalized dicyanoquinodimethane derivatives. Copyright © 2006 John Wiley & Sons, Ltd.
Conformational properties of C2v‐symmetrical resorcin[4]arene tetraethers
Authors: Morikawa Osamu , Iyama Eiichi , Oikawa Tomoyoshi , Kobayashi Kazuhiro , Konishi Hisatoshi
Published: April 2006

Resorcin[4]arene tetraether derivatives, in which a resorcinol unit and a 1,3‐dialkoxybenzene unit are incorporated in an alternating order, were synthesized by the Sc(OTf)3 catalyzed ‘2 + 2’ fragment condensation. The conformational properties were studied using variable temperature 1H‐NMR spectroscopy, indicating that the resorcinarenes are flexible at room temperature but frozen in the cone formation at −90 °C in CD2Cl2, and they interconvert between two equivalent cone conformations with an energy barrier of ΔGc‡ = 10.2–10.5 kcal mol−1. These values are slightly lower than that for the resorcin[4]arene containing four 2‐hexylresorcinol units. The cone conformation is stabilized by intramolecular hydrogen bonds between the OH hydrogen and ether oxygen, which is evidenced by the low frequencies (3423–3434 cm−1) of the OH‐stretching vibrations in CDCl3 solution. Copyright © 2006 John Wiley & Sons, Ltd.
Partition of polyhydroxy compounds of biological and pharmacological significance between AOT reverse microemulsions and aqueous salt solutions
Authors: Reta Mario , Waymas Omar , Silber Juana J.
Published: April 2006

The partition behavior of shikimic acid, gallic acid, gallotannic acid, rutin and quercetin between reverse microemulsions of the surfactant bis(2‐ethylhexyl) sulfosuccinate (AOT) and aqueous salt solutions of LiCl, NaCl and KCl at different salt concentrations and pH was studied. Quantification of the extracted analytes was performed by HPLC on an octadecyl silica column using a methanol–buffer mobile phase at pH 3.0. Clean‐up before injection was not needed because the micellar organic phase was compatible with the HPLC mobile phase. A solvent gradient was used to elute all compounds and the surfactant in a reasonable time. The extraction from the aqueous media is fast and reproducible. Different solubilization behavior was observed by changing the salt concentration and the type of cation in the aqueous phase. By proper selection of the experimental conditions, it is observed that shikimic acid and gallic acid remain mostly in the aqueous phase, whereas significant amounts of gallotannic acid and rutin are transferred to the micellar phase in only one contact and quercetin is completely solubilized in this phase. Thus, the different solubilization behavior that these compounds exhibit in the AOT micellar media can be very useful for extraction and preconcentration purposes. Copyright © 2006 John Wiley & Sons, Ltd.
Plasma‐Based De‐Pyrogenization
Authors: Kylián Ondřej , Hasiwa Marina , Rossi François
Published: April 2006

Summary: Applicability of low‐pressure microwave discharges for the de‐pyrogenization of the heat sensitive materials has been tested. It has been found that discharges in selected gas mixtures are capable to reduce the amount of deposited pyrogens significantly within 1 min of plasma treatment. Moreover, it has been demonstrated that de‐pyrogenization is due to the plasma interactions with the pyrogens, and it cannot be ascribed to other possible side effects.

Time evolution of de‐pyrogenization in a O2:H2 (50:50) microwave discharge.

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Time evolution of de‐pyrogenization in a O2:H2 (50:50) microwave discharge.
Surface Analysis of Plasma Deposited Polymer Films, 7
Authors: Oran Umut , Swaraj Sufal , Lippitz Andreas , Unger Wolfgang E. S.
Published: April 2006

Summary: Plasma deposited allylamine films were studied by “in situ” ToF‐SSIMS, XPS and NEXAFS Spectroscopy before exposure to ambient air. The influence of external plasma parameters such as duty cycle, plasma power, and monomer flow rate on (i) unsaturation, (ii) branching and cross‐linking, (iii) nitrogen surface concentration and (iv) retention of amino groups was investigated. Harder plasma conditions, which can be obtained when high duty cycles, high plasma power, and low monomer flow rates are employed, increase the unsaturated, branched and cross‐linked character of the plasma deposited films, while the surface concentration of N as well as the retention of the monomer's amino group decrease. As proven by NEXAFS findings and cross‐checked by ToF‐SSIMS results, the allylamine monomer's primary amino groups are partially transformed into other nitrogen functionalities during its plasma polymerization. Amongst them imines and nitriles are the conversion products with the highest probabilities of formation. Another conversion channel is the formation of nitrogen species not participating in the film growth. This is the reason for an increased N loss in plasma deposited allylamine films as observed independently by XPS and ToF‐SSIMS when the plasma parameters are changed from mild to hard.

Summations of π*(CN) and π*(CN) resonance intensities for NEXAFS N K‐edge spectra measured with plasma deposited allylamine films vs. variation of duty cycle, or power.

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Summations of π*(CN) and π*(CN) resonance intensities for NEXAFS N K‐edge spectra measured with plasma deposited allylamine films vs. variation of duty cycle, or power.
Stop‐flow kinetics studies of the interaction of surfactant, sodium dodecyl sulfate, with acid‐denatured cytochrome c
Authors: Xu Qi , Keiderling Timothy A.
Published: April 2006

Interactions of sodium dodecyl sulfate (SDS) at submicellar and micellar concentration, with the globular protein, horse heart cytochrome c, at low pH have been shown to stabilize two molten globule‐like intermediates. These dynamic studies were performed using far‐UV, near‐UV, and Soret‐band circular dichroism (CD) as well as fluorescence methods. Stopped‐flow CD and fluorescence studies of acid‐denatured cytochrome c refolding with SDS were performed at both submicellar and micellar concentrations. Distinctive refolding mechanisms (from analysis of both CD and fluorescence) were found under these two conditions, and an obvious refolding intermediate was evident in the fluorescence traces. In addition, stopped‐flow CD in the Soret region showed multistep kinetics, suggesting that the spectral changes in this region are not only solvent effect related but also connected with the change of secondary structure. A possible folding mechanism is proposed to rationalize the kinetics results. Proteins 2006. © 2006 Wiley‐Liss, Inc.
FMR investigations of half‐metallic ferromagnets
Authors: Rameev B. , Yildiz F. , Kazan S. , Aktas B. , Gupta A. , Tagirov L. R. , Rata D. , Buergler D. , Gruenberg P. , Schneider C. M. , Kämmerer S. , Reiss G. , Hütten A.
Published: April 2006

Thin films of various half‐metallic ferromagnets, such as chromium dioxide (CrO2) and Heusler alloys (Co2Cr0.6Fe0.4Al, Co2MnSi) have been investigated by ferromagnetic resonance (FMR) technique. It is demonstrated that FMR is a very efficient method to study the nanoscale magnetic properties, in particular to probe the magnetic anisotropy and magnetic inhomogeneities of ferromagnetic thin films. Epitaxial CrO2 thin films of various thicknesses (25–535 nm) have been deposited on TiO2(100) substrates by chemical vapor deposition process. It is shown that the magnetic behavior of the CrO2 films results from a competition between the magnetocrystalline and strain anisotropies. For the ultrathin CrO2 film (25 nm) the magnetic easy axis switches from the c‐direction to the b‐direction of the rutile structure. Thin‐film Co2Cr0.6Fe0.4Al samples (25 nm or 100 nm) have been grown by DC magnetron sputtering either on unbuffered SiO2(100) substrates or on the substrates capped by a 50 nm thick V buffer layer. The effects of the vanadium buffer layer and of the film thickness are revealed by FMR studies of the Co2Cr0.6Fe0.4Al samples. Well‐resolved multiple spin‐wave modes are observed in the unbuffered Co2Cr0.6Fe0.4Al sample with a thickness of 100 nm and the exchange stiffness constant has been estimated. Thin films of Co2MnSi (4–100 nm) have been grown by DC sputtering on silicon substrates on top of a 42 nm thick V seed layer and capped either by Al2O3 or by Co and V layers. A set of the 80 nm thick films has been annealed at different temperatures in the range of 425–550 °C. FMR studies of the Co2MnSi samples shows that at the fixed annealing temperature (450 °C) the highest magnetization is observed in the sample with a thickness of 61 nm, while the thicker samples (100 nm) reveal not only a lower magnetization but greater magnetic inhomogeneity as well. An annealing treatment at T ≥ 450 °C is essential to obtain higher magnetization as well as uniform magnetic properties in the Co2MnSi films. Weak SWR modes have also been observed in the thick Heusler films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Differentiation of estriol glucuronide isomers by chemical derivatization and electrospray tandem mass spectrometry
Authors: Lampinen‐Salomonsson Matilda , Bondesson Ulf , Petersson Carl , Hedeland Mikael
Published: April 2006

This paper describes a way of differentiating between the three isomers of estriol glucuronide by the use of chemical derivatization and liquid chromatography/electrospray tandem mass spectrometry (MS/MS). In their native form, these isomers gave rise to almost identical product ion spectra, involving the neutral loss of 176 Da (i.e. monodehydrated glucuronic acid), which made it impossible to determine the position of conjugation by MS/MS alone. In order to change the fragmentation pathways, positive charges were introduced into the analytes by chemical derivatization. The following reagents were tested: 2‐chloro‐1‐methylpyridinium iodide, 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide and 2‐picolylamine. Interestingly, derivatization using a combination of all three reagents gave a selective fragmentation pattern that could differentiate between the isomers estriol‐16‐glucuronide and estriol‐17‐glucuronide. Estriol‐3‐glucuronide, which lacks a free phenolic group, could be differentiated through a different type of reaction product when exposed to 2‐chloro‐1‐methylpyridinium iodide. Furthermore, in order to assist structural assignment of the fragments, their accurate masses were determined using a hybrid quadrupole time‐of‐flight mass spectrometer and fragmentation pathways were elucidated by the use of MS3 on an ion trap mass spectrometer. Copyright © 2006 John Wiley & Sons, Ltd.
Characterization of a mini membrane inlet mass spectrometer for on‐site detection of contaminants in both aqueous and liquid organic samples
Authors: Janfelt Christian , Frandsen Helle , Lauritsen Frants R.
Published: April 2006

A mini membrane inlet mass spectrometer (mini‐MIMS) of a total weight of 12 kg was constructed using a miniature Multipole mass spectrometer, a small vacuum system and a flexible flat sheet membrane inlet, where the exposed membrane area can be changed by a factor of 80. The variable membrane area together with the possibility of operating the Multipole at pressures up to 1 × 10−3 Torr made it possible to test the system with three microporous membranes (cellulose, polyether sulfone and polypropylene) normally not compatible with standard electron ionization MIMS systems and a standard non‐porous polydimethylsiloxane membrane. We found that the hydrophilic cellulose and polyether sulfone membranes had selectivity characteristics opposite to those of the standard silicone membrane. They demonstrated preferential detection of hydrophilic compounds in hydrophobic organic solvents, whereas the silicone membrane preferentially detects hydrophobic organic compounds in aqueous solution. Using the cellulose membrane, organic contaminants and water could be detected in organic solvents at 10–100 ppm levels by weight, the relative high detection limits primarily caused by interference from a high chemical background from the solvent. When being used with the standard silicone membrane the mini‐MIMS behaved just like most standard MIMS systems with detection limits of volatile organic compounds in water at concentrations just below 1 ppm. The hydrophobic microporous polypropylene membrane was not found to be useful with the mini‐MIMS. Copyright © 2006 John Wiley & Sons, Ltd.
A high‐performance liquid chromatography/tandem mass spectrometry method for the determination of artemisinin in rat plasma
Authors: Xing Jie , Yan Hongxia , Zhang Shuqiu , Ren Guolian , Gao Yanhui
Published: April 2006

Artemisinin is a widely used antimalarial drug. To evaluate the pharmacokinetics of artemisinin in rats, a sensitive and specific liquid chromatography/tandem mass spectrometric (LC/MS/MS) method was developed and validated for the determination of artemisinin in rat plasma. For detection, a Sciex API 4000 LC/MS/MS instrument with an electrospray ionization (ESI) TurboIonSpray inlet in the positive ion multiple reaction monitoring (MRM) mode was used to monitor precursor ([M+NH4]+) → product ions of m/z 300.4 → 209.4 for artemisinin and m/z 316.4 → 163.4 for artemether, the internal standard (IS). The plasma samples were pretreated by a simple liquid‐liquid extraction with ether. The standard curve was linear (r > 0.99) over the artemisinin concentration range of 1.0–200.0 ng/mL in plasma. The method had a lower limit of quantification of 1.0 ng/mL for artemisinin in 100 µL of plasma, which offered a satisfactory sensitivity for the determination of artemisinin. The intra‐ and inter‐day precisions were measured to be within ±5.3% and accuracy between −2.6% and 1.2% for all quality control samples, lower limit of quantification and upper limit of quantification samples. The extraction recoveries of artemisinin and the IS were 95.4 ± 4.5% and 92.8 ± 3.9%, respectively. This present method was successfully applied to the characterization of the pharmacokinetic profile of artemisinin in rats after oral administration. Copyright © 2006 John Wiley & Sons, Ltd.
Metabolism of a new P‐glycoprotein inhibitor HM‐30181 in rats using liquid chromatography/electrospray mass spectrometry
Authors: Paek In Bok , Ji Hye Young , Kim Maeng Sup , Lee Gwansun , Lee Hye Suk
Published: April 2006

HM‐30181, 4‐oxo‐4H‐chromene‐2‐carboxylic acid, [2‐(2‐{4‐[2‐(6,7‐dimethoxy‐3,4‐dihydro‐1H‐isoquinolin‐2‐yl)‐ethyl]‐phenyl}‐2H‐tetrazol‐5‐yl)‐4,5‐dimethoxyphenyl]amide, is a new P‐glycoprotein inhibitor. This study was performed to identify the in vitro and in vivo metabolic pathway of HM‐30181 in rats. Rat liver microsomal incubation of HM‐30181 in the presence of NADPH resulted in the formation of four metabolites, M1–M4. M1 and M2 were identified as 2‐(2‐{4‐[2‐(6,7‐dimethoxy‐3,4‐dihydro‐1H‐isoquinolin‐2‐yl)‐ethyl]‐phenyl}‐2H‐tetrazol‐5‐yl)‐4,5‐dimethoxyaniline and 4‐ or 5‐O‐desmethyl‐HM‐30181, respectively, on the basis of liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis with the synthesized authentic standards. M3 and M4 were suggested to be 6‐ or 7‐O‐desmethyl‐HM‐30181 and hydroxy‐HM‐30181, respectively. These in vitro metabolites were also detected in feces and urine samples after an intravenous administration of HM‐30181 to male rats. The metabolic routes for HM‐30181 were O‐demethylation of the methoxy group to M2 and M3, hydrolysis of the amide group to M1, and hydroxylation to M4. Copyright © 2006 John Wiley & Sons, Ltd.
The use of recently described ionisation techniques for the rapid analysis of some common drugs and samples of biological origin
Authors: Williams Jonathan P. , Patel Vibhuti J. , Holland Richard , Scrivens James H.
Published: April 2006

Three ionisation techniques that require no sample preparation or extraction prior to mass analysis have been used for the rapid analysis of pharmaceutical tablets and ointments. These methods were (i) the novel direct analysis in real time (DART), (ii) desorption electrospray ionisation (DESI), and (iii) desorption atmospheric pressure chemical ionisation (DAPCI). The performance of the three techniques was investigated for a number of common drugs. Significant differences between these approaches were observed. For compounds of moderate to low polarity DAPCI produced more effective ionisation. Accurate DESI and DAPCI tandem mass spectra were obtained and these greatly enhance the selectivity and information content of the experiment. The detection from human skin of the active ingredients from ointments is reported together with the detection of ibuprofen metabolites in human urine. Copyright © 2006 John Wiley & Sons, Ltd.