bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of polylimonene: Polymer of an optically active terpene
Authors: Singh Anamika , Kamal Meet 
Published: January 2012

AbstractRadical polymerization of limonene (limonene) using benzoyl peroxide (BPO) as an initiator at 85°C ± 1°C under an inert atmosphere of nitrogen in xylene as solvent was carried out. The system follows nonideal kinetics: Rp α [I]0.3 [M]1.4, due to both primary radical termination and degradative chain transfer reaction. The activation energy of the polymerization was estimated to be 22.97 kJ mol−1. 1H‐NMR spectrum of polymer shows the presence of a triplet between 2 and 2.5 δ, which reveals that β‐carbon of limonene is the active site in the polymerization of limonene. The FTIR spectrum of the polymer shows band at 1645 cm−1 due to gem disubstituted CC stretching vibrations. The glass transition temperature (Tg) of the polylimonene of the polylimonene is 116°C. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Crosslinked microparticle preparation in supercritical carbon dioxide with photopolymerization
Authors: Meng Zhun , He Yong , Liang Pengzong , Nie Jun 
Published: January 2012

AbstractAn antisolvent processing technique by simultaneous compressed antisolvent precipitation and photopolymerization for cross‐linked polymer microparticles formation was presented in this paper. In this process, photopolymerization of the homogeneous solution composed of methylene chloride, poly(ethylene glycol)600 diacrylate (PEG600DA) as monomer and diphenyl‐(2,4,6‐trimethylbenzoyl)‐phosphine oxide (TPO) or 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA) as photoinitiator resulted to microparticle when it was sprayed into supercritical carbon dioxide (scCO2) and simultaneously exposed to initiating light. High miscibility of the solvent in scCO2 made methylene chloride quickly extracted from the dispersion phase, leaving very high concentrations of monomer (PEG600DA) dispersed in scCO2. The high monomer concentration combined with photo initiating polymerization facilitates rapid reaction rates and ultimately lead to polymer precipitation. Particle size and morphology were adjustable by changing the processing conditions, such as temperature and pressure. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Microwave‐assisted preparation of poly(2‐EHA‐co‐ST) copolymer and poly(2‐EHA‐co‐ST)/MMT nanocomposite
Authors: Biswal Trinath , Samal Ramakanta , Sahoo Prafulla K. 
Published: January 2012

AbstractCopolymerization of 2‐ethylhexylacrylate and styrene was performed in presence of benzoyl peroxide as initiator at varying concentrations of the comonomers in a microwave oven. Montmorillonite (MMT) clay was added with a view to prepare nanocomposites, which actually enhanced the water absorption capacity and pressure sensitive adhesive properties. The copolymer and its nanocomposite were characterized by Fourier Transform Infrared, 1H‐ and 13C‐NMR, thermogravimetric‐differential thermal analysis (TG‐DTA), differential scanning calorimeter, scanning electron microscopy, X‐ray diffraction (XRD), and transmission electron microscopy (TEM). The MMT layers were partially exfoliated/intercalated during the polymerization process as evident from the XRD and TEM observations. Their adhesive properties, water absorbancy, and biodegradability in different conditions were studied for their future applications. The monomer reactivity ratios were determined using Finemann–Ross and Kelen–Tüdos method. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis, characterization, and drug release properties of poly(N‐isopropylacrylamide) gels prepared in methanol–water cononsolvent medium
Authors: Biswas Chandra Sekhar , Patel Vijay Kumar , Vishwakarma Niraj Kumar , Mishra Avnish Kumar , Bhimireddi Rajasekhar , Rai RamaNand , Ray Biswajit 
Published: January 2012

AbstractPoly(N‐isopropylacrylamide) (PNIPAM) hydrogels were simply prepared by free radical polymerization in different methanol–water mixture. A scanning electron microscopy study revealed that the freeze‐dried hydrogels were macroporous. The swelling ratios in water at 20°C of the resulting hydrogels followed the order: X0.43>X0.21>X0.76 ≈ X0.57>X0.31>X0.13>X0.06>X0, where Xm denotes a gel prepared in a methanol–water mixture with m mole fraction of methanol (xm). Below the lower critical solution temperature, the swelling ratio values of all of the hydrogels gradually decreased with the increase in the temperature. The complete collapse of the PNIPAM chain of all the gels occurred at about 38°C, whereas the same was observed at about 35°C for the conventional gel prepared in water. The swelling ratio values of all the PNIPAM gels in the methanol–water mixtures with different xm values at 20°C passed through a minimum in the cononsolvency zone. The deswelling rates of the hydrogels decreased in the following order: X0.43> X0.31> X0.21> X0.57> X0.76 ≈ X0.13> X0.06> X0. The reswelling rates of these hydrogels decreased in the following order: X0> X0.31> X0.06 ≈ X0.13 > X0.76> X0.57> X0.21> X0.43. The release rates of the Tramadol Hydrochloride drug at 37°C from the drug‐loaded hydrogels were almost same for all of the hydrogels. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
EMI shielding effectiveness and dielectrical properties of SBS/PAni.DBSA blends: Effect of blend preparation
Authors: Magioli M. , Soares B. G. , Sirqueira A. S. , Rahaman M. , Khastgir D. 
Published: January 2012

AbstractThis work investigates the effect of different preparation routes including mechanical mixing and in situ polymerization of aniline on the electromagnetic interference shielding effectiveness (EMI SE) over the X‐band (8–12 GHz) frequency range for polyaniline doped with dodecylbenzene sulfonic acid (PAni.DBSA) filled in styrene–butadiene–styrene triblock copolymer matrix. The dc conductivity and dielectrical properties were also investigated. For all systems, the electrical conductivity, dielectric constant, and EMI SE increased with the increase in the concentration of PAni.DBSA. Blends prepared by the in situ polymerization exhibited higher conductivity and dielectric constant and better EMI SE characteristics than the physical blends with similar amount of PAni.DBSA. EMI SE value as high as −35 dB has been achieved with about 30% of PAni.DBSA prepared by the in situ polymerization. Regarding physical blends, those involving PAni.DBSA prepared by a redoping process displayed better EMI SE. For all systems under consideration, the conductivity and EMI SE bear an exponential relationship that can be represented by a master curve. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Highly Efficient Hydrophosphonylation of Aldehydes and Unactivated Ketones Catalyzed by Methylene‐Linked Pyrrolyl Rare Earth Metal Amido Complexes
Authors: Zhou Shuangliu , Wu Zhangshuan , Rong Jiewei , Wang Shaowu , Yang Gaosheng , Zhu Xiancui , Zhang Lijun 
Published: January 2012

AbstractA series of rare earth metal amido complexes bearing methylene‐linked pyrrolyl‐amido ligands were prepared through silylamine elimination reactions and displayed high catalytic activities in hydrophosphonylations of aldehydes and unactivated ketones under solvent‐free conditions for liquid substrates. Treatment of [(Me3Si)2N]3Ln(μ‐Cl)Li(THF)3 with 2‐(2,6‐Me2C6H3NHCH2)C4H3NH (1, 1 equiv) in toluene afforded the corresponding trivalent rare earth metal amides of formula {(μ‐η5:η1):η1‐2‐[(2,6‐Me2C6H3)NCH2](C4H3N)LnN(SiMe3)2}2 [Ln=Y (2), Nd (3), Sm (4), Dy (5), Yb (6)] in moderate to good yields. All compounds were fully characterized by spectroscopic methods and elemental analyses. The yttrium complex was also characterized by 1H NMR spectroscopic analyses. The structures of complexes 2, 3, 4, and 6 were determined by single‐crystal X‐ray analyses. Study of the catalytic activities of the complexes showed that these rare earth metal amido complexes were excellent catalysts for hydrophosphonylations of aldehydes and unactivated ketones. The catalyzed reactions between diethyl phosphite and aldehydes in the presence of the rare earth metal amido complexes (0.1 mol %) afforded the products in high yields (up to 99 %) at room temperature in short times of 5 to 10 min. Furthermore, the catalytic addition of diethyl phosphite to unactivated ketones also afforded the products in high yields of up to 99 % with employment of low loadings (0.1 to 0.5 mol %) of the rare earth metal amido complexes at room temperature in short times of 20 min. The system works well for a wide range of unactivated aliphatic, aromatic or heteroaromatic ketones, especially for substituted benzophenones, giving the corresponding α‐hydroxy diaryl phosphonates in moderate to high yields.
Decay of material properties of degraded MEA caused by repeated cold starts under subzero conditions in polymer electrolyte fuel cells
Authors: Takagi Yasuo , Onoda Mitsuru , Toriyama Tamotsu , Kawasaki Katsunori , Hattori Toshiyuki 
Published: January 2012

AbstractThis study investigated the characteristics of cell performance degradation, decline of component performance, and changes in the properties of membrane electrode assembly materials caused by repeated cold starts under a subzero condition of −30 °C. It was made clear that functional decay appeared mainly at the cathode due to increased proton conductive impedance and reduction of reactivity of the electrode catalyst. Among the cathode components, an increase in proton conductive impedance in the cathode electrolyte was dominant. Furthermore, the application of ion chromatography and a newly developed proton‐induced gamma‐ray emission method to measure fluorine in the off‐gas drain revealed that decomposition of the electrolyte was dominant in the cathode catalyst layer. A decrease in fluorine in the cathode electrolyte measured by fluorine‐19 nuclear magnetic resonance confirmed this decomposition. A hypothesis is also presented concerning the cause of the performance degradation. © 2012 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20394
The association between pain intensity and the prescription of analgesics and non‐steroidal anti‐inflammatory drugs
Authors: Muller S. , Bedson J. , Mallen C.D. 
Published: January 2012

AbstractBackgroundIt is not known whether general practitioners (GPs) prescribe analgesic medication according to intensity of pain or a hierarchical prescribing regimen.AimsThe aim of this study was to assess the association of strength of pain‐relief medication prescribed by the GP with the strength of previous prescription and pain level.MethodsThe PROG‐RES study collected data on pain intensity in 428 patients aged ≥50 years with non‐inflammatory musculoskeletal pain during a consultation with their GP. Prescriptions for analgesics and non‐steroidal anti‐inflammatory drugs (NSAIDs) were identified on the day of the consultation and in the previous year and were classified as basic, moderate or strong analgesic or NSAID. Regression models were used to assess the association of strength of analgesia and prescription of a NSAID with the strength of previous prescription and the level of pain.ResultsThe majority of patients were not prescribed medication for their pain at the index consultation, but had such a prescription the previous year. There was an association between strength of analgesic and intensity of pain: more intense pain resulted in a stronger drug. This association was attenuated by adjustment for prescribed analgesia in the previous year. There was no association between intensity of pain and NSAID prescription, but previous NSAID prescription predicted another such prescription.ConclusionGPs do not always issue prescriptions for musculoskeletal pain. In cases where a prescription is issued, this is more strongly influenced by previous prescriptions than the patient's pain level. GPs adopt an individualized approach to the treatment of musculoskeletal pain in older adults.
Inactivation of Bcl‐2 through IκB kinase (IKK)‐dependent phosphorylation mediates apoptosis upon exposure to 4‐hydroxynonenal (HNE)
Authors: Bodur Cagri , Kutuk Ozgur , Tezil Tugsan , Basaga Huveyda 
Published: January 2012

AbstractApoptosis of macrophage foam cells loaded with modified/oxidized lipids is implicated in destabilization of advanced atherosclerotic plaques in humans. Concentration of HNE, main aldehydic product of plasma LDL peroxidation, elevates in atherosclerotic lesions as well as in cultured cells under oxidative stress. Although this reactive aldehyde has been shown to promote apoptosis with the involvement of p38 MAPK and JNK in various mammalian cell lines, roles of B‐cell lymphoma 2 (Bcl‐2) family proteins remain to be deciphered. We demonstrated that HNE‐induced apoptosis was accompanied by concurrent downregulations of antiapoptotic Bcl‐xL and Mcl‐1 as well as upregulation of proapoptotic Bak. Furthermore, phoshorylation of Bcl‐2 at Thr56, Ser70, and probably more phosphorylation sites located on N‐terminal loop domain associated with HNE‐induced apoptosis in both U937 and HeLa cells while ectopic expression of a phospho‐defective Bcl‐2 mutant significantly attenuated apoptosis. In parallel to this, HNE treatment caused release of proapoptotic Bax from Bcl‐2. Pharmacological inhbition of IKK inhibited HNE‐induced Bcl‐2 phosphorylation. Similarly, silencing IKKα and ‐β both ended up with abrogation of Bcl‐2 phosphorylation along with attenuation of apoptosis. Moreover, both IKKα and ‐β coimmunoprecipitated with Bcl‐2 and in vitro kinase assay proved the ability of IKK to phosphorylate Bcl‐2. In view of these findings and considering HNE inhibits DNA‐binding activity of nuclear factor‐κB (NF‐κB) through prevention of IκB phosphorylation/ubiquitination/proteolysis, IKK appears to directly interfere with Bcl‐2 activity through phosphorylation in HNE‐mediated apoptosis independent of NF‐κB signaling. J. Cell. Physiol. 227: 3556–3565, 2012. © 2012 Wiley Periodicals, Inc.
Impact of the etiology of acute kidney injury on outcomes following liver transplantation: acute tubular necrosis versus hepatorenal syndrome
Authors: Nadim Mitra K. , Genyk Yuri S. , Tokin Chris , Fieber Jenny , Ananthapanyasut Wanwarat , Ye Wei , Selby Rick 
Published: January 2012

Abstract
Acute kidney injury (AKI) at the time of liver transplantation (LT) has been associated with increased morbidity and mortality. In patients with potentially reversible renal dysfunction, predicting whether there will be sufficient return of native kidney function is sometimes difficult. Previous studies have focused mainly on the effect of the severity of renal dysfunction or the duration of pretransplant dialysis on posttransplant outcomes. We performed a retrospective analysis of patients who underwent LT at our center after Model for End-Stage Liver Disease–based allocation so that we could determine the impact of the etiology of AKI [acute tubular necrosis (ATN) versus hepatorenal syndrome (HRS)] on post-LT outcomes. The patients were stratified according to the severity of AKI at the time of LT as described by the Risk, Injury, Failure, Loss, and End-Stage Kidney Disease (RIFLE) classification: risk, injury, or failure. The RIFLE failure group was further subdivided according to the etiology of AKI: HRS or ATN. The patient survival and renal outcomes 1 and 5 years after LT were significantly worse for those with ATN. At 5 years, the incidence of chronic kidney disease (stage 4 or 5) was statistically higher in the ATN group versus the HRS group (56% versus 16%, P < 0.001). A multivariate analysis revealed that the presence of ATN at the time of LT was the only variable associated with higher mortality 1 year after LT (P < 0.001). Our study is the first to demonstrate that the etiology of AKI has the greatest impact on patient and renal outcomes after LT. Liver Transpl, 2012. © 2012 AASLD.
Predicting physical activity and fruit and vegetable intake in adolescents: A test of the information, motivation, behavioral skills model
Authors: Kelly Stephanie , Melnyk Bernadette Mazurek , Belyea Michael 
Published: January 2012

AbstractMost adolescents do not meet national recommendations regarding physical activity and/or the intake of fruits and vegetables. The purpose of this study was to explore whether variables in the information, motivation, behavioral skills (IMB) model of health promotion predicted physical activity and fruit and vegetable intake in 404 adolescents from 2 high schools in the Southwest United States using structural equation modeling (SEM). The SEM models included theoretical constructs, contextual variables, and moderators. The theoretical relationships in the IMB model were confirmed and were moderated by gender and race. Interventions that incorporate cognitive‐behavioral skills building may be a key factor for promoting physical activity as well as fruit and vegetable intake in adolescents. © 2012 Wiley Periodicals, Inc. Res Nurs Health 35:146–163, 2012
In hepatocellular carcinoma miR‐519d is up‐regulated by p53 and DNA hypomethylation and targets CDKN1A/p21, PTEN, AKT3 and TIMP2
Authors: Fornari Francesca , Milazzo Maddalena , Chieco Pasquale , Negrini Massimo , Marasco Elena , Capranico Giovanni , Mantovani Vilma , Marinello Jessica , Sabbioni Silvia , Callegari Elisa , Cescon Matteo , Ravaioli Matteo , Croce Carlo M , Bolondi Luigi , Gramantieri Laura 
Published: January 2012

AbstractMiR‐519d belongs to the chromosome 19 miRNA cluster (C19MC), the largest human miRNA cluster. One of its members, miR‐519d, is over‐expressed in hepatocellular carcinoma (HCC) and we characterized its contribution to hepatocarcinogenesis. In HCC cells, the over‐expression of miR‐519d promotes cell proliferation, invasion and impairs apoptosis following anticancer treatments. These functions are, at least in part, exerted through the direct targeting of CDKN1A/p21, PTEN, AKT3 and TIMP2. The mechanisms underlying miR‐519d aberrant expression in HCC were assayed by genomic DNA amplification, methylation analysis and ChIP assay. The aberrant hypomethylation of C19MC and TP53 were respectively identified as an epigenetic change allowing the aberrant expression of miR‐519d and one of the factors able to activate its transcription. In conclusion, we assessed the oncogenic role of miR‐519d in HCC by characterizing its biological functions, including the modulation of response to anticancer treatments and by identifying CDKN1A/p21, PTEN, AKT3 and TIMP2 among its targets. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
A policy framework for public health uses of electronic health data
Authors: McGraw Deven , Rosati Kristen , Evans Barbara 
Published: January 2012

ABSTRACTSuccessful implementation of a program of active safety surveillance of drugs and medical products depends on public trust. This article summarizes how the initial pilot phase of the FDA's Sentinel Initiative, Mini‐Sentinel, is being conducted in compliance with applicable federal and state laws. The article also sets forth the attributes of Mini‐Sentinel that enhance privacy and public trust, including the use of a distributed data system (where identifiable information remains at the data partners) and the adoption by participants of additional mandatory policies and procedures implementing fair information practices. The authors conclude by discussing the implications of this model for other types of secondary health data uses. Copyright © 2012 John Wiley & Sons, Ltd.
Statistical approaches to group sequential monitoring of postmarket safety surveillance data: current state of the art for use in the Mini‐Sentinel pilot
Authors: Cook Andrea J. , Tiwari Ram C. , Wellman Robert D. , Heckbert Susan R. , Li Lingling , Heagerty Patrick , Marsh Tracey , Nelson Jennifer C. 
Published: January 2012

ABSTRACTPurposeThis manuscript describes the current statistical methodology available for active postmarket surveillance of pre‐specified safety outcomes using a prospective incident user concurrent control cohort design with existing electronic healthcare data.MethodsMotivation of the active postmarket surveillance setting is provided using the Food and Drug Administration's Mini‐Sentinel Pilot as an example. Four sequential monitoring statistical methods are presented including the Lan–Demets error spending approach, a matched likelihood ratio test statistic approach with the binomial MaxSPRT as a special case, the conditional sequential sampling procedure with stratification, and a generalized estimating equation regression approach using permutation. Information on the assumptions, limitations, and advantages of each approach is provided, including how each method defines sequential monitoring boundaries, what test statistic is used, and how robust it is to settings of rare events or frequent testing.ResultsA hypothetical example of how the approaches could be applied to data comparing a medical product of interest, drug A, to a concurrent control drug, drug B, is presented including providing the type of information one would have available for monitoring such drugs.SummaryWe have described the current state of methodology for postmarket surveillance of pre‐specified safety outcomes. We describe the limitations and advantages of the approaches while acknowledging areas for future development. Copyright © 2012 John Wiley & Sons, Ltd.
A systematic review of validated methods for identifying venous thromboembolism using administrative and claims data
Authors: Tamariz Leonardo , Harkins Thomas , Nair Vinit 
Published: January 2012

ABSTRACTBackgroundVenous thromboembolism (VTE) is a serious complication. Large claims databases can potentially identify the effects that medications have on VTE. The purpose of this study is to evaluate the evidence supporting the validity of VTE codes.MethodsA search of MEDLINE database is supplemented by manual searches of bibliographies of key relevant articles. We selected all studies in which a claim code was validated against a medical record. We reported the positive predictive value (PPV) for the VTE claim compared to the medical record.ResultsOur search strategy yielded 345 studies, of which only 19 met our eligibility criteria. All of the studies reported on ICD‐9 codes, but only two studies reported on pharmacy codes, and one study reported on procedure codes. The highest PPV (65%–95%) was reported for the combined use of ICD‐9 codes 415 (pulmonary embolism), 451, and 453 (deep vein thrombosis) as a VTE event. If a specific event like DVT (PPV 24%–92%) or PE (PPV 31%–97%) was evaluated, the PPV was lower than when the combined events were examined. Studies that included patients after orthopedic surgery reported the highest PPV (96%–100%).ConclusionsThe use of ICD‐9 415, 451, and 453 are appropriate for the identification of VTE in claims databases. The codes performed best when codes were evaluated in patients at higher risk of VTE. Copyright © 2012 John Wiley & Sons, Ltd.