bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal operation of a multipurpose multireservoir system in the Eastern Nile River Basin
Authors: Goor Q. , Halleux C. , Mohamed Y. , Tilmant A.
Published: July 2010

Abstract. The upper Blue Nile River Basin in Ethiopia is a largely untapped resource despite its huge potential for hydropower generation and irrigated agriculture. Controversies exist as to whether the numerous infrastructural development projects that are on the drawing board in Ethiopia will generate positive or negative externalities downstream in Sudan and Egypt. This study attempts at 1) examining the (re-)operation of infrastructures, in particular the proposed reservoirs in Ethiopia and the High Aswan Dam and 2) assessing the economic benefits and costs associated with the storage infrastructures in Ethiopia and their spatial and temporal distribution. To achieve this, a basin-wide integrated hydro-economic model has been developed. The model integrates essential hydrologic, economic and institutional components of the river basin in order to explore both the hydrologic and economic consequences of various policy options and planned infrastructural projects. Unlike most of the deterministic economic-hydrologic models reported in the literature, a stochastic programming formulation has been adopted in order to: i) understand the effect of the hydrologic uncertainty on management decisions, ii) determine allocation policies that naturally hedge against the hydrological risk, and iii) assess the relevant risk indicators. The study reveals that the development of four mega dams in the upper part of the Blue Nile Basin would change the drawdown refill cycle of the High Aswan Dam. Should the operation of the reservoirs be coordinated, they would enable an average annual saving of at least 2.5 billion m3 through reduced evaporation losses from the Lake Nasser. Moreover, the new reservoirs (Karadobi, Beko-Abo, Mandaya and Border) in Ethiopia would have significant positive impacts on hydropower generation and irrigation in Ethiopia and Sudan: at the basin scale, the annual energy generation is boosted by 38.5 TWh amongst which 14.2 TWh due to storage. Moreover, the regulation capacity of the above mentioned reservoirs would enable an increase of the Sudanese irrigated area by 5.5%.
Role of executive dysfunction in predicting frequency and severity of violence
Authors: Hancock Megan , Tapscott Jennifer L. , Hoaken Peter N.S.
Published: July 2010

The adverse consequences of violence on society are tremendous. The proportion of offenders incarcerated for violent offenses is large, and the cost of keeping these offenders incarcerated is startling. Understanding and treating the causal underpinnings of violent crime is of utmost importance for individuals and society as a whole. Several factors have been identified as potential contributors to violent crime, including cognitive deficits in executive functioning [Hoaken et al., 2007]. To investigate this further, 77 offenders from Fenbrook Institution, a federal facility, were tested on a battery of executive functioning measures. Offenders were found to have broad and pervasive dysfunction in their executive abilities. In addition, specific scores from the battery were found using regression techniques, to predict the frequency and severity of past violent offending but not nonviolent offending. This speaks of the possibility of a new type of correctional rehabilitation program, one that focuses on the rehabilitation of basic executive functions. Aggr. Behav. 36:338–349, 2010. © 2010 Wiley‐Liss, Inc.
Abatacept improves health‐related quality of life, pain, sleep quality, and daily participation in subjects with juvenile idiopathic arthritis
Authors: Ruperto Nicolino , Lovell Daniel J. , Li Tracy , Sztajnbok Flavio , Goldenstein‐Schainberg Claudia , Scheinberg Morton , Penades Inmaculada Calvo , Fischbach Michael , Alcala Javier Orozco , Hashkes Philip J. , Hom Christine , Jung Lawrence , Lepore Loredana , Oliveira Sheila , Wallace Carol , Alessio Maria , Quartier Pierre , Cortis Elisabetta , Eberhard Anne , Simonini Gabriele , Lemelle Irene , Chalom Elizabeth Candell , Sigal Leonard H. , Block Alan , Covucci Allison , Nys Marleen , Martini Alberto , Giannini Edward H.
Published: July 2010

Objective

To assess health‐related quality of life (HRQOL) in abatacept‐treated children/adolescents with juvenile idiopathic arthritis (JIA).

Methods

In this phase III, double‐blind, placebo‐controlled trial, subjects with active polyarticular course JIA and an inadequate response/intolerance to ≥1 disease‐modifying antirheumatic drug (including biologics) received abatacept 10 mg/kg plus methotrexate (MTX) during the 4‐month open‐label period (period A). Subjects achieving the American College of Rheumatology Pediatric 30 criteria for improvement (defined “responders”) were randomized to abatacept or placebo (plus MTX) in the 6‐month double‐blind withdrawal period (period B). HRQOL assessments included 15 Child Health Questionnaire (CHQ) health concepts plus the physical (PhS) and psychosocial summary scores (PsS), pain (100‐mm visual analog scale), the Children's Sleep Habits Questionnaire, and a daily activity participation questionnaire.

Results

A total of 190 subjects from period A and 122 from period B were eligible for analysis. In period A, there were substantial improvements across all of the CHQ domains (greatest improvement was in pain/discomfort) and the PhS (8.3 units) and PsS (4.3 units) with abatacept. At the end of period B, abatacept‐treated subjects had greater improvements versus placebo in all domains (except behavior) and both summary scores. Similar improvement patterns were seen with pain and sleep. For participation in daily activities, an additional 2.6 school days/month and 2.3 parents' usual activity days/month were gained in period A responders with abatacept, and further gains were made in period B (1.9 versus 0.9 [P = 0.033] and 0.2 versus −1.3 [P = 0.109] school days/month and parents' usual activity days/month, respectively, in abatacept‐ versus placebo‐treated subjects).

Conclusion

Improvements in HRQOL were observed with abatacept, providing real‐life tangible benefits to children with JIA and their parents/caregivers.
Graphene‐Based Nanoporous Materials Assembled by Mediation of Polyoxometalate Nanoparticles
Authors: Zhou Ding , Han Bao‐Hang
Published: July 2010

A kind of graphene‐based nanoporous material is prepared through assembling graphene sheets mediated through polyoxometalate nanoparticles. Owing to the strong interaction between graphene and polyoxometalate, 2D graphene sheets with honeycomb‐latticed carbon atoms could assemble into a porous structure, in which 3D polyoxometalate nanoparticles serve as the crosslinkers. Nitrogen and hydrogen sorption analysis reveal that the as‐prepared graphene‐based hybrid material possesses a specific surface area of 680 m2 g−1 and a hydrogen uptake volume of 0.8−1.3 wt%. Infrared spectrometry is used to probe the electron density changes of polyoxometalate particle in the redox‐cycle and to verify the interaction between graphene and polyoxometalate. The as‐prepared graphene‐based materials are further characterized by Raman spectroscopy, X‐ray diffraction, scanning electron microscopy, and transmission electron microscopy.
Triple‐Shape Polymeric Composites (TSPCs)
Authors: Luo Xiaofan , Mather Patrick T.
Published: July 2010

In this paper, the fabrication and characterization of triple‐shape polymeric composites (TSPCs) that, unlike traditional shape memory polymers (SMPs), are capable of fixing two temporary shapes and recovering sequentially from the first temporary shape (shape 1) to the second temporary shape (shape 2), and eventually to the permanent shape (shape 3) upon heating, are reported. This is technically achieved by incorporating non‐woven thermoplastic fibers (average diameter ∼760 nm) of a low‐Tm semicrystalline polymer into a Tg‐based SMP matrix. The resulting composites display two well‐separated transitions, one from the glass transition of the matrix and the other from the melting of the fibers, which are subsequently used for the fixing/recovery of two temporary shapes. Three thermomechanical programming processes with different shape fixing protocols are proposed and explored. The intrinsic versatility of this composite approach enables an unprecedented large degree of design flexibility for functional triple‐shape polymers and systems.
Anomalous Oxidation States in Multilayers for Fuel Cell Applications
Authors: Perkins James M. , Fearn Sarah , Cook Stuart N. , Srinivasan Rajagopalan , Rouleau Chris M. , Christen Hans M. , West Geoff D. , Morris Richard J. H. , Fraser Hamish L. , Skinner Stephen J. , Kilner John A. , McComb David W.
Published: July 2010

Significant recent interest has been directed towards the relationship between interfaces and reports of enhanced ionic conductivity. To gain a greater understanding of the effects of hetero‐interfaces on ionic conductivity, advanced analytical techniques including electron microscopy (TEM/STEM), electron energy loss spectroscopy (EELS), and secondary ion mass spectrometry (SIMS) are used to characterize CeO2/Ce0.85Sm0.15O2 multilayer thin films grown by pulsed laser deposition. High quality growth is observed, but ionic conductivity measured by impedance spectroscopy and 18O tracer experiments is consistent with bulk materials. EELS analysis reveals the unusual situation of layers containing only Ce(IV) adjacent to layers containing both Ce(III) and Ce(IV). Post oxygen annealing induced oxygen diffusion and mixed oxidation states in both layers, but only in the vicinity of low angle grain boundaries perpendicular to the layers. The implications of the anomalous behavior of the Ce oxidation states on the design of novel electrolytes for solid oxide fuel cells is discussed.
Electrical Percolation Behavior in Silver Nanowire–Polystyrene Composites: Simulation and Experiment
Authors: White Sadie I. , Mutiso Rose M. , Vora Patrick M. , Jahnke David , Hsu Sam , Kikkawa James M. , Li Ju , Fischer John E. , Winey Karen I.
Published: July 2010

The design and preparation of isotropic silver nanowire‐polystyrene composites is described, in which the nanowires have finite L/D (< 35) and narrow L/D distribution. These model composites allow the L/D dependence of the electrical percolation threshold, ϕc, to be isolated for finite‐L/D particles. Experimental ϕc values decrease with increasing L/D, as predicted qualitatively by analytical percolation models. However, quantitative agreement between experimental data and both soft‐core and core–shell analytical models is not achieved, because both models are strictly accurate only in the infinite‐L/D limit. To address this analytical limitation, a soft‐core simulation method to calculate ϕc and network conductivity for cylinders with finite L/D are developed. Our simulated ϕc results agree strongly with our experimental data, suggesting i) that the infinite‐aspect‐ratio assumption cannot safely be made for experimental networks of particles with L/D < 35 and ii) in predicting ϕc, the soft‐core model makes a less significant assumption than the infinite‐L/D models do. The demonstrated capability of the simulations to predict ϕc in the finite‐L/D regime will allow researchers to optimize the electrical properties of polymer nanocomposites of finite‐L/D particles.
Chemiluminescence‐Generating Nanoreactor Formulation for Near‐Infrared Imaging of Hydrogen Peroxide and Glucose Level in vivo
Authors: Lim Chang‐Keun , Lee Yong‐Deok , Na Jinhee , Oh Jung Min , Her Song , Kim Kwangmeyung , Choi Kuiwon , Kim Sehoon , Kwon Ick Chan
Published: July 2010

Water‐dispersed all‐in‐one nanoprobes composed of densely integrated peroxyoxalate fuel and a cyanine dye are formulated to optimize the nanoscopic chemiluminescence reaction. It is demonstrated that the chemiluminescent nanoformulation can generate bright near‐infrared signal in response to external hydrogen peroxide that is biologically implicated with cell signaling and diseases. Successful imaging of endogenously overproduces hydrogen peroxide and indirect determination of glucose level in vivo with the chemiluminescent nanoprobes offers an opportunity for early diagnosis of diseases.
Copper(I) Acetate: A Structurally Simple but Highly Efficient Dinuclear Catalyst for Copper‐Catalyzed Azide‐Alkyne Cycloaddition
Authors: Shao Changwei , Cheng Guolin , Su Deyong , Xu Jimin , Wang Xinyan , Hu Yuefei
Published: July 2010

In this article, the structurally well‐defined dinuclear complex copper(I) acetate was studied in detail and was developed as a highly practical and efficient catalyst for the copper(I)‐catalyzed azide‐alkyne cycloaddition. The “bare” phenylethynylcopper(I) (i.e., with no exogeneous ligands) was isolated as an intermediate, which can be converted into an active catalytic species by treatment with acetic acid (in situ produced in the reaction) to efficiently catalyze the azide‐alkyne cycloaddition under mild conditions.
Three‐Component Reactions of 2‐Alkynylbenzaldoximes and α,β‐Unsaturated Carbonyl Compounds with Bromine or Iodine Monochloride
Authors: Ye Shengqing , Gao Ke , Wu Jie
Published: July 2010

The three‐component reaction of 2‐alkynylbenzaldoximes and α,β‐unsaturated carbonyl compounds with bromine or iodine monochloride is described, which generates the unexpected 2‐(4‐haloisoquinolin‐1‐yl)ethanol derivatives in good to excellent yields.
Iron‐Catalysed Regio‐ and Stereoselective Head‐to‐Tail Dimerisation of Styrenes
Authors: Cabrero‐Antonino Jose R. , Leyva‐Pérez Antonio , Corma Avelino
Published: July 2010

Cationic iron salts and complexes catalyse the head‐to‐tail dimerisation of styrene derivatives to form the corresponding dimers with good to excellent yields and stereoselectivities. In particular, the use of a phosphine‐iron(III) complex allows the recovery and reuse of the catalyst. The counteranion plays an important role in both the activity and selectivity. These catalysts constitute an alternative to those based on toxic and expensive late‐transition metals.
Phase‐Transfer‐Catalyzed Olefin Isomerization/α‐Alkylation of α‐Alkynylcrotonates as a Route for 1,4‐Enynes
Authors: Hashimoto Takuya , Sakata Kazuki , Maruoka Keiji
Published: July 2010

The phase‐transfer‐catalyzed alkylation of α‐alkynylcrotonates was developed as a means to provide 1,4‐enynes deconjugated by an all‐carbon quaternary center. Extension to the asymmetric version using the chiral phase‐transfer catalyst (S)‐3 provided the alkylated compounds with up to 87% ee.
Stabilized Copper(I) Oxide Nanoparticles Catalyze Azide‐Alkyne Click Reactions in Water
Authors: Zhang Zhenfang , Dong Changming , Yang Cuihong , Hu Di , Long Jing , Wang Ling , Li He , Chen Yue , Kong Deling
Published: July 2010

A novel form of polyvinylpyrrolidone (PVP) coated copper(I) oxide nanoparticle (Cu2O‐NP) was prepared and used to catalyze azide‐alkyne click reactions in water under aerobic conditions. The nanoparticles were well dispersed in aqueous solutions and have a size of 20±10 nm, as determined by transmission electron microscope (TEM). Inductively coupled plasma (ICP), X‐ray powder diffraction (XRD), and X‐ray photoelectron spectroscopy (XPS) analyses demonstrated that the main content of Cu2O‐NP is copper(I). The cytotoxicity of it was evaluated by an in vitro 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay and its catalytic efficiency for azide‐alkyne click reactions was studied in water and organic solvents at physiological temperatures. Our results indicate that Cu2O‐NP is more efficient in catalytic reactions in water for both aliphatic and aromatic azides and alkynes and less toxic than the commonly used CuSO4/reductant catalyst systems.
Enantioselective Aldol Reaction using Recyclable Montmorillonite‐Entrapped N‐(2‐Thiophenesulfonyl)prolinamide
Authors: Hara Noriyuki , Nakamura Shuichi , Shibata Norio , Toru Takeshi
Published: July 2010

N‐(2‐Thiophenesulfonyl)prolinamide could be easily introduced into Montmorillonite by a simple ion‐exchange reaction. The asymmetric aldol reactions between various isatins with acetone or acetaldehyde using a heterogeneous Montmorillonite‐entrapped organocatalyst afforded products with high enantioselectivity. The catalyst was readily reusable without significant loss of catalytic activity or enantioselectivity.
Iron and Copper Salts in the Synthesis of Benzo[b]furans
Authors: Bonnamour Julien , Piedrafita María , Bolm Carsten
Published: July 2010

Intramolecular CO bond forming reactions of aryl 2‐bromobenzyl ketones lead to benzo[b]furans. The cyclizations can be catalyzed by 10 mol% of iron trichloride (of 98% or of 99.995% purity) or sub‐mol% quantities of copper(II) chloride (of 99.995% purity).
Characterization of ionic liquid‐based biocatalytic two‐phase reaction system for production of biodiesel
Authors: Devi B. L. A. Prabhavathi , Guo Zheng , Xu Xuebing
Published: July 2010

The property of a variety of ionic liquids (ILs) as reaction media was evaluated for the production of biodiesel by enzymatic methanolysis of rapeseed oil. The IL Ammoeng 102, containing tetraaminum cation with C18 acyl and oligoethyleneglycol units, was found to be capable of forming oil/IL biphasic reaction system by mixing with substrates, which is highly effective for the production of biodiesel with more than 98% biodiesel yield and nearly 100% conversion of oil. Conductor‐like screening model for real solvent (COSMO‐RS) in silico prediction of substrate solubility and simulation of partition coefficient change vs. reaction evolution indicated that the amphiphilic property of Ammoeng 102 might be responsible for creating efficient interaction of immiscible substrates; while big difference of partition coefficients of generated biodiesel and glycerol between the two phases suggests a large chemical potential to move reaction equilibrium for maximum oil conversion and yield of target biodiesel. The reaction behavior and specificity of oil/IL biphasic system for enzymatic production of biodiesel were theoretically delineated through COSMO‐RS computation with experimental validation. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Segmental paternal uniparental disomy (patUPD) of 14q32 with abnormal methylation elicits the characteristic features of complete patUPD14
Authors: Irving Melita D. , Buiting Karin , Kanber Deniz , Donaghue Celia , Schulz Reiner , Offiah Amaka , Mohammed Shehla N. , Oakey Rebecca J.
Published: July 2010

Uniparental disomy (UPD) for chromosome 14 is associated with well‐recognized phenotypes, depending on the parent of origin. Studies in mouse models and human patients have implicated the involvement of the distal region of the long arm of chromosome 14 in the distinctive phenotypes. This involvement is supported by the identification of an imprinting cluster at chromosome 14q32, encompassing the differentially methylated regions (DMRs), IG‐DMR and MEG3‐DMR, as well as the maternally expressed genes GTL2, DIO3, and RTL1 and the paternally expressed genes DLK1, RTL1as, and MEG8. Here we report on a preterm female infant with distal segmental paternal UPD14 (upd(14)pat) of 14q32‐14q32.33, which resulted in thoracic deformity secondary to rib abnormalities (“coat‐hanger” rib sign), polyhydramnios, and other congenital abnormalities characteristically described in cases of complete upd(14)pat. Microsatellite investigation demonstrated UPD of markers D14S250 and D14S1010, encompassing a ∼3.5 Mb region of distal 14q and involving the imprinting cluster. This case provided insight into the etiology of the phenotypic effects of upd(14)pat, prompting methylation analysis of the GTL2 promoter and the DMR between GTL2 and DLK1. We compare the physical findings seen in this case with those of patients with other causes of abnormal methylation of 14q32, which consistently result in certain distinct clinical features, regardless of the cytogenetic and molecular etiology. © 2010 Wiley‐Liss, Inc.
NF1 exon 22 analysis of individuals with the clinical diagnosis of neurofibromatosis type 1
Authors: Muram‐Zborovski Talia M. , Vaughn Cecily P. , Viskochil David H. , Hanson Heather , Mao Rong , Stevenson David A.
Published: July 2010

Café‐au‐lait macules are frequently seen in Ras‐MAPK pathway disorders and are a cardinal feature of neurofibromatosis type 1 (NF1). Most NF1 individuals develop age‐related tumorigenic manifestations (e.g., neurofibromas), although individuals with a specific 3‐bp deletion in exon 22 of NF1 (c.2970_2972delAAT) have an attenuated phenotype with primarily pigmentary manifestations. Previous reports identify this deletion c.2970_2972delAAT in exon 17 of NF1 using NF Consortium nomenclature. For this report, we elected to use standard NCBI nomenclature, which places this identical deletion within exon 22. SPRED1 mutations cause Legius syndrome, which clinically overlaps with this attenuated NF1 phenotype. In an unselected cohort of 50 individuals who fulfilled NIH clinical diagnostic criteria from an NF Clinic and did not have SPRED1 mutations, we sequenced NF1 exon 22 in order to identify children and adolescents with multiple café‐au‐lait spots who could be projected to have lower likelihood to develop tumors. Two individuals with NF1 exon 22 mutations were identified: an 11‐year‐old boy with the c.2970_2972delAAT in‐frame deletion and a 4‐year‐old boy with c.2866dupA. The father of the second patient had an attenuated form of NF1 and showed 24% germline mosaicism of the c.2866dupA mutation in whole blood. These individuals emphasize the need for mutation analysis in some individuals with the clinical diagnosis of NF1 who lack the tumorigenic or classic skeletal abnormalities of NF1. Specifically, with the identification of Legius syndrome, the need to recognize the attenuated phenotype of NF1 mosaicism and confirmation by mutation analysis is increasingly important for appropriate medical management and family counseling. © 2010 Wiley‐Liss, Inc.
Current hypotheses for the underlying biology of amyotrophic lateral sclerosis
Authors: Rothstein Jeffrey D.
Published: July 2010

The mechanisms involved in selective motor neuron degeneration in amyotrophic lateral sclerosis remain unknown more than 135 years after the disease was first described. Although most cases have no known cause, mutations in the gene encoding Cu/Zn superoxide dismutase (SOD1) have been implicated in a fraction of familial cases of the disease. Transgenic mouse models with mutations in the SOD1 gene and other ALS genes develop pathology reminiscent of the disorder, including progressive death of motor neurons, and have provided insight into the pathogenesis of the disease but have consistently failed to predict therapeutic efficacy in humans. However, emerging research has demonstrated that mutations and pathology associated with the TDP‐43 gene and protein may be more common than SOD1 mutations in familial and sporadic ALS. Putative mechanisms of toxicity targeting motor neurons include oxidative damage, accumulation of intracellular aggregates, mitochondrial dysfunction, defects in axonal transport, growth factor deficiency, aberrant RNA metabolism, glial cell pathology, and glutamate excitotoxicity. Convergence of these pathways is likely to mediate disease onset and progression. Ann Neurol 2009;65 (suppl):S3–S9
The eastward displacement of a freely falling body on the rotating Earth: Newton and Hooke's debate of 1679
Authors: Dittrich W.
Published: July 2010

In this article I would like to tell the story of the beginning of modern theoretical physics, freed from all kinds of questionable anecdotes which have entered the scientific literature over the centuries. It all began in the seventeenth century when the mathematical theory of astronomy began to take shape. A major step in the history of modern science was taken when a few members of The Royal Society in London realized that the laws ruling the motions of heavenly bodies as manifested in Kepler's three laws are also effective in the dynamics of Earth‐bound particle motion. Everything started, not with I. Newton, but with R. Hooke. Not Newton's falling apple (Voltaire's invention), but a far‐reaching response by R. Hooke to a letter by I. Newton, dated November 28, 1679, ignited Newton's interest in gravity. That letter contained the famous spiral which a falling body would follow when released from a certain height above the surface of the Earth. Hooke's answer, based on Keplerian orbits, expressed the opinion that the body's trajectory would rather follow an elliptical path. In his spiral sketch Newton, however, predicted correctly that the falling body would be found to suffer an eastward deviation from the vertical in consequence of the Earth's rotation. In the course of time, many a researcher, including Hooke himself, was able to verify this conjecture. But it took until 1803 for the first satisfactory calculation of the eastward displacement of a freely falling body to be performed, and was provided by C.F. Gauss.
Optical and thermo electrical properties of ZnO nano particle filled polystyrene
Authors: Gaur Mulayam S. , Singh Pramod Kumar , Chauhan Ramvir S.
Published: July 2010

The study of optical and thermally stimulated electrical properties such as optical band gap, refractive index, X‐ray spectra, SEM spectra, thermally stimulated discharge current (TSDC), differential scanning calorimetry (DSC) have been undertaken in ZnO nanoparicle filled polystyrene nanocomposite thin film of 30 μm thickness. The appearance of single TSDC peak at temperature 408 ± 5 K in nanocomposite samples shows the charge carriers injected from deeper trapping levels. It is due to the modification of surface and bulk properties of polystyrene by filling of ZnO nanoparticles. In other hand, the strong interaction of nanoparticles with polymer matrix is the expected reason of improvement of crystallite size, optical energy band gap, refractive index, TSDC, glass transition temperature, and charge storage. It is confirmed from SEM images that the modifications of these properties are caused by creation of clusters in amorphous–crystalline boundaries of pristine polystyrene. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Influence of phenoxy addition on the curing kinetics for uncatalyzed and catalyzed cyanate ester resin
Authors: Remiro Pedro M. , De La Caba Koro , Mondragon Iñaki , Riccardi Carmen C.
Published: July 2010

The curing behavior of the dicyanate ester of bisphenol‐A (DCBA) modified with poly(hydroxy ether of bisphenol‐A) (phenoxy) is studied by differential scanning calorimetry in dynamic and isothermal tests at temperatures between 120 and 240°C. The addition of phenoxy to DCBA produces an increase in the reaction rate and a decrease in the temperature of maximum reaction rate for the uncatalyzed resin, and also for the system catalyzed with copper (II) acetyl acetonate/nonylphenol. The exothermic heat of curing for the mixtures is also dependent on the phenoxy content. These facts evidence a catalytic effect of phenoxy on the curing of the cyanate ester resin, even though an autocatalytic behavior is observed for all uncatalyzed DCBA/phenoxy mixtures. A simplified mechanistic kinetic model is used to calculate the kinetic parameters. For the uncatalyzed systems, a decrease in the kinetic constant for the initiation reactions, and an increase in the propagation constant are measured when the cyanate content increases. The thermal activation energy for the initiation reaction of the catalyzed systems is lower than that of the uncatalyzed ones, and it depends on the weight fraction of cyanate in the mixture. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Self‐oscillating pH‐responsive cryogels as possible candidates of soft materials for generating mechanical energy
Authors: Bilici Cigdem , Karayel Sehri , Demir Tuba T. , Okay Oguz
Published: July 2010

This research highlights the use of poly(acrylic acid) (PAAc) cryogels as a pH oscillator in oscillatory bromate–sulfite–ferrocyanide reactions. The cryogels were prepared from frozen aqueous solutions of acrylic acid monomer and N,N′‐methylenebis(acrylamide) crosslinker at −18°C. Fast responsive macroporous PAAc cryogels were obtained at or below 4 w/v % initial monomer concentration. SEM images of PAAc cryogel networks exhibited a heterogeneous morphology consisting of pores of sizes 101 μm, typical for macroporous networks formed by the cryogelation technique. PAAc cryogels coupled with the bromate oscillator oscillate between swollen and collapsed states, during which a cyclic three‐fold change in the gel volume was observed. The results show that, due to the fast response rate of cryogels, macroscopic gel samples can be used as a pH oscillator which would provide generation of significant amount of mechanical energy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation and properties of biocomposites composed of glycerol‐based epoxy resins, tannic acid, and wood flour
Authors: Shibata Mitsuhiro , Teramoto Naozumi , Takada Yoshiro , Yoshihara Satoru
Published: July 2010

After polyglycerol polyglycidyl ether (PGPE) and glycerol polyglycidyl ether (GPE) were mixed with tannic acid (TA) in ethanol and without solvent at epoxy/hydroxyl ratio 1/1, the obtained GPE‐TA and PGPE‐TA solutions were mixed with wood flour (WF), prepolymerized at 50°C, and subsequently compressed at 160°C for 3 h to give GPE‐TA/WF and PGPE‐TA/WF biocomposites with WF content 50–70 wt %, respectively. The storage moduli of the biocomposites in the rubbery state at more than 80°C were much higher than that of the control cured resins. The PGPE‐TA/WF composites had higher tensile modulus and rather lower tensile strength than PGPE‐TA. On the other hand, both the tensile modulus and strength of GPE‐TA/WF were much higher than those of GPE‐TA (2.4 GPa and 37 MPa). Those values of GPE‐TA/WF increased with WF content, became maximal values (5.1 GPa and 51 MPa) at WF content 60 wt %, and were lowered at 70 wt %. FE‐SEM analysis of the fractured surface of the biocomposites revealed that WF is tightly incorporated into the crosslinked epoxy resins. As a result of optimization of the epoxy/hydroxyl molar ratio for GPE‐TA/WF composite with WF content 60 wt %, the composite prepared at the ratio of 1.0/0.8 showed the highest tensile modulus and strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Development and characterization of a gelatin‐based coating with unique sealing properties
Authors: Farris Stefano , Cozzolino Carlo A. , Introzzi Laura , Piergiovanni Luciano
Published: July 2010

The experimental results on the development of thin (∼ 1.5 μm) gelatin‐based coatings and the investigation on their sealing attribute when applied onto oriented polypropylene (OPP) are reported. The sealing performance, expressed as the strain energy required to separate the sealed joints, was studied as a function of three different influencing factors. pH of the hydrogel solution was varied between 5 and 11. The highest seal strength values were obtained for pH values beyond the isoelectric point (IEP) of the gelatin molecule. The effect of the plasticizer (glycerol) was studied by changing its concentration from 2.5 wt % to 7.5 wt % to the total weight of the hydrogel solution. Glycerol concentration = 7.5 wt % was found to be the best for achieving adequate strain energy values. The influence of a hydrophobic component on the capability of the coating to act as a sealant has also been assessed. The hydrophobic component had a positive effect only up to a certain level (1 wt %, weight percent), whereas beyond this value, it affected the seal strength attribute. According to the best setting conditions, seal strength values for the OPP biocoated films of ∼ 61 N × mm were attained, with a corresponding maximum force required to break the joints of 2.4 N. These results are discussed by taking into consideration the modality of seals opening. Interestingly, the heat‐seal (temperature: 90°C; dwell time: 1 s; pressure: 4 bar) failed in both peeling and tearing mode failure, as confirmed by microscopy, spectrophotometric, and particle size analyzes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Flammability and mechanical properties of Al(OH)3 and BaSO4 filled polypropylene
Authors: Tan S. , Tinçer T.
Published: July 2010

The flammability and mechanical properties of Al(OH)3/BaSO4/polypropylene (PP) composites were investigated. The flow, morphological, and thermal properties were also analyzed by melt flow index (MFI), Scanning electron microscopy (SEM), and Differential scanning calorimeter (DSC) studies, respectively. Total filler amount was fixed at 30 wt % to optimize physical characteristics of the composites. In addition to the flame retardant filler Al(OH)3, BaSO4 was used to balance the reduction in impact strength at high filler loadings. Substantial improvement in mechanical properties was achieved for 20 wt % Al(OH)3 (i.e., 10 wt % BaSO4) composition while maximum flammability resistance was obtained for 30 wt % Al(OH)3 composite. SEM studies showed that the presence of aggregated Al(OH)3 particles led to low interfacial adhesion between them and PP matrix ending up with decreased mechanical strength. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Glycolytic depolymerization of PET waste in a microwave reactor
Authors: Achilias Dimitris S. , Redhwi Halim Hamid , Siddiqui Mohammad Nahid , Nikolaidis Alexandros K. , Bikiaris Dimitrios N. , Karayannidis George P.
Published: July 2010

Recycling of waste PET bottles was examined using glycolytic depolymerization with diethylene glycol, under microwave irradiation. The objective was to investigate if depolymerization using microwave energy could provide the same product distribution, while carried out in milder experimental conditions and/or shorter reaction times, resulting, thus besides to polymer recycling, in substantial energy saving. The reaction was carried out in a sealed microwave reactor in which the pressure and temperature were controlled. Experiments under constant temperature or microwave power were carried out at several time intervals. The main glycolysis product was analyzed and identified by FTIR measurements. The average molecular weight of the PET residues was found to decrease with the percentage of PET degradation. In the experiments carried out under constant microwave power, complete depolymerization was observed at irradiation powers greater than 150 W for 2 min, or 100 W for 5 min. In the constant temperature experiments, it was clear that at temperatures below 150°C no degradation occurs, whereas complete depolymerization takes place at temperatures greater than or equal to 180°C for 5 min. These results when compared to the conventional heating, where more than 4 h are needed for complete with PET degradation, confirm the importance of the microwave power technique and the substantial energy saving achieved. Finally, from a simple kinetic model the activation energy of the reaction was evaluated. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Three‐layer sheets based on gelatin and poly(lactic acid), part 1: Preparation and properties
Authors: Martucci J. F. , Ruseckaite R. A.
Published: July 2010

Glycerol‐plasticized gelatin (Ge‐30Gly) and poly(lactic acid) (PLA) films were prepared by heat‐compression, molded, and then piled to produce a biodegradable three‐layer sheet with PLA as outer layers and Ge‐30Gly as the inner layer. Lamination with PLA increased the moisture resistance and reduced the total soluble matter with respect to a single gelatin layer, while keeping transparency. The tensile strength of the multilayer sheet (36.24±4.27 MPa) increased 16 folds when compared to that of Ge‐30Gly. Lamination also exerted beneficial effects on the barrier properties. The WVP of the multilayer sheet (1.2 ± 0.1 10−14 kg·m·Pa−1·s−1·m−2) decreased with reference to that of Ge‐30Gly, while oxygen permeability (17.1 ± 2.3 cm3(O2)·mm·m−2·day−1) was reduced with respect to that of neat PLA, and the value obtained was comparable to that of Ge‐30Gly layer. The presence of plasticized gelatin in the multilayer increased the energy at crack initiation (1.4 ± 0.3 J·m−1) with respect to that of PLA. The improvement attained in all these properties was ascribed to the good compatibility and adhesion of the individual layers featured through hydrogen interactions between the carbonyl group from PLA and the hydrogen from the peptide bonds in gelatin. Compatibility was corroborated by scanning electron microscopy observations at PLA/Ge‐30Gly interface and by the absence of additional peaks in the tan δ curve of dynamic‐mechanical analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Oxidized pea starch/chitosan composite films: Structural characterization and properties
Authors: Wu Haixia , Liu Changhua , Chen Jianguang , Chen Yun , Anderson Debbie P. , Chang Peter R.
Published: July 2010

In this article, a series of oxidized pea starch/chitosan (OPS/CS) blend films were prepared by a casting and solvent evaporation method. The structure, thermal behavior, and mechanical properties of the films were investigated by means of Fourier transform infrared spectroscopy, wide‐angle X‐ray diffraction, scanning electron microscopy, thermogravimetric analysis, and tensile testing. The results suggested that, in addition to hydrogen bonding, the interactions between OPS and CS molecules were enhanced by the formation of electrostatic interaction between the negatively charged carboxyl groups on OPS and the positively charged amino groups on CS. Compared with the pea starch/chitosan (PS/CS) blend films, OPS/CS blend films exhibited significantly higher tensile strength with significantly lower elongation at break. Moreover, incorporation of CS into the OPS matrix also led to a decrease in moisture uptake by the composite film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Linear Poly(methyl glycerol) and Linear Polyglycerol as Potent Protein and Cell Resistant Alternatives to Poly(ethylene glycol)
Authors: Weinhart Marie , Grunwald Ingo , Wyszogrodzka Monika , Gaetjen Linda , Hartwig Andreas , Haag Rainer
Published: July 2010

The nonspecific interaction of proteins with surfaces in contact with biofluids leads to adverse problems and is prevented by a biocompatible surface coating. The current benchmark material among such coatings is poly(ethylene glycol) (PEG). Herein, we report on the synthesis of linear polyglycerol derivatives as promising alternatives to PEG. Therefore, gold surfaces as a model system are functionalized with a self‐assembled monolayer (SAM) by a two‐step anhydride coupling and a direct thiol immobilization of linear poly(methyl glycerol) and polyglycerol. Surface plasmon resonance (SPR) spectroscopy reveals both types of functionalized surfaces to be as resistant as PEG towards the adsorption of the test proteins fibrinogen, pepsin, albumin, and lysozyme. Moreover, linear polyglycerols adsorb even less proteins from human plasma than a PEG‐modified surface. Additional cell adhesion experiments on linear poly(methyl glycerol) and polyglycerol‐modified surfaces show comparable cell resistance as for a PEG‐modified surface. Also, in the case of long‐term stability, high cell resistance is observed for all samples in medium. Additional in vitro cell‐toxicity tests add to the argument that linear poly(methyl glycerol) and polyglycerol are strong candidates for promising alternatives to PEG, which can easily be modified for biocompatible functionalization of other surfaces.
Analyzing transit service reliability using detailed data from automatic vehicular locator systems
Authors: El‐Geneidy Ahmed M. , Horning Jessica , Krizek Kevin J.
Published: July 2010

The widespread adoption of automated vehicle location (AVL) systems and automatic passenger counters (APCs) in the transit industry has opened new venues in operations and system monitoring. In 2005, Metro Transit, Minnesota, implemented AVL system and partially implemented APC technologies. To date there has been little effort to employ the collected data in evaluating transit performance. This research uses such data to assess performance issues along a cross‐town route in the Metro Transit system. We generate a series of visual and analytical analyses to predict run time, schedule adherence and reliability of the transit route at two scales: the time point segment and the route level to demonstrate ways of identifying causes of decline in reliability levels. The analytical models show that while headways are maintained, schedule revisions are needed to improve run time and schedule adherence. Finally, the analysis suggests that many scheduled stops along this route are underutilized and recommends stop consolidation as a tool to decrease variability of service through concentrating passenger demand along a fewer number of stops. Copyright © 2010 John Wiley & Sons, Ltd.
Feelings of dread and intertemporal choice
Authors: Harris Christine R.
Published: July 2010

It frequently has been observed that people discount future rewards relative to present rewards. However, the literature on intertemporal choices involving emotional upsets and losses is fraught with inconsistencies, with some studies finding similar discounting of gains and losses, and others reporting that participants elect to undergo negative experiences sooner rather than later. To help resolve these contradictions, time preferences for different types of aversive experiences (social rejection, embarrassment, pain, monetary and property loss) were examined in five studies. Most participants preferred to postpone monetary and property losses, but intertemporal choices for other unpleasant experiences showed highly variable responses, with some participants deferring them as long as possible, and many electing to experience them immediately. Time preferences for these negative experiences were correlated, but were independent of time preference for rewards. It is argued (following Loewenstein, 1987) that anticipation of dread plays a key role in many people's choices about timing of aversive experiences. This interpretation was supported by choices about when to learn of a very unpleasant event whose timing was fixed (Study 3), and by a novel preference reversal (Study 4). Study 5 examined how actual and hypothetical experiences of dread unfolded over time; the results were consistent with a dread‐based interpretation of choices in the preceding studies. Copyright © 2010 John Wiley & Sons, Ltd.
Hypoxia and the Edema Syndrome: elucidation of a mechanism of teratogenesis
Authors: Chernoff Neil , Rogers John M.
Published: July 2010

The elucidation of mechanisms and pathogenesis of birth defects is exceedingly complex. Consequently, there are few examples where the etiology of birth defects caused by a specific agent has been well described. One such example is the “Edema Syndrome” first described by Casimer Grabowski in the 1960s as a mechanism of hypoxia‐induced malformations in the chick embryo. The Edema Syndrome comprised a series of events in the embryo starting with osmotic imbalances followed by edema, distention, blisters, hematomas, and hemorrhage in or near developing structures. Malformation or deformation of structures resulted from mechanical disruption or loss of blood supply. A similar etiology has since been described by others in a variety of laboratory mammals following treatment with drugs including epinephrine, hydroxyurea, cocaine, phenytoin, and potassium channel–blocking drugs. Free radical excess following transient hypoxia may be a common factor in all of these insults. Vascular disruption is also associated with a number of birth defects in humans, including limb and digit reduction defects and urogenital defects. Birth Defects Res (Part B) 89:300–303, 2010. Published 2010 Wiley‐Liss, Inc.
L‐Cysteine capped CdTe–CdS core–shell quantum dots: preparation, characterization and immuno‐labeling of HeLa cells
Authors: Zhang Hongyan , Sun Pan , Liu Chang , Gao Huanyu , Xu Linru , Fang Jin , Wang Meng , Liu Jinling , Xu Shukun
Published: July 2010

Functionalized CdTe–CdS core–shell quantum dots (QDs) were synthesized in aqueous solution via water‐bathing combined hydrothermal method using L‐cysteine (L‐Cys) as a stabilizer. This method possesses both the advantages of water‐bathing and hydrothermal methods for preparing high‐quality QDs with markedly reduced synthesis time, and better stability than a lone hydrothermal method. The QDs were characterized by transmission electronic microscopy and powder X‐ray diffraction and X‐ray photoelectron spectroscopy. The CdTe–CdS QDs with core–shell structure showed both enhanced fluorescence and better photo stability than nude CdTe QDs. After conjugating with antibody rabbit anti‐CEACAM8 (CD67), the as‐prepared l‐Cys capped CdTe–CdS QDs were successfully used as fluorescent probes for the direct immuno‐labeling and imaging of HeLa cells. It was indicated that this kind of QD would have application potential in bio‐labeling and cell imaging. Copyright © 2009 John Wiley & Sons, Ltd.
Combined first-stage hepatectomy and colorectal resection in a two-stage hepatectomy strategy for bilobar synchronous liver metastases
Authors: Karoui M , Vigano L , Goyer P , Ferrero A , Luciani A , Aglietta M , Delbaldo C , Cirillo S , Capussotti L , Cherqui D
Published: July 2010

Background

This study assessed the feasibility and outcomes of combined colorectal and hepatic resection as the first step of two-stage hepatectomy in patients with bilobar synchronous colorectal liver metastases.

Methods

All patients with bilobar synchronous colorectal liver metastases who were considered for two-stage hepatectomy, combining resection of the primary tumour with the first stage of hepatectomy, between 2000 and 2008 were selected from a prospectively collected database at two institutions. Data were analysed retrospectively on an intention-to-treat basis.

Results

Thirty-three patients were studied. Twenty patients received neoadjuvant chemotherapy. Combined colorectal resection and clearance of left-sided liver metastases was the first-stage procedure in all but one patient, in whom right clearance was performed. In 17 patients right portal vein ligation was undertaken at the same time. No patient died. Two patients had anastomotic leakage. Interval chemotherapy was given to 25 patients, five of whom also had percutaneous portal vein embolization. Twenty-five patients had the second-stage hepatectomy, but not eight patients with disease progression. There was one postoperative death after the second stage, and eight patients experienced morbidity. Median follow-up from the first stage was 28·7 months. Overall and disease-free survival rates for patients who completed the procedure were 80 and 44 per cent respectively at 3 years, and 48 and 22 per cent at 5 years.

Conclusion

In patients with bilobar synchronous colorectal liver metastases who are candidates for two-stage hepatectomy, combined resection of the primary tumour and first-stage hepatectomy reduces the number of procedures, optimizes chemotherapy administration and may improve outcome.
Evidence-based management of pain after haemorrhoidectomy surgery
Authors: Joshi G P , Neugebauer E A M
Published: July 2010

Background

Haemorrhoidectomy is associated with intense postoperative pain, but optimal evidence-based pain therapy has not been described. The aim of this systematic review was to evaluate the available literature on the management of pain after haemorrhoidal surgery.

Methods

Randomized studies published in the English language from 1966 to June 2006, assessing analgesic and anaesthetic interventions in adult haemorrhoidal surgery, and reporting pain scores, were retrieved from the Embase and MEDLINE databases.

Results

Of the 207 randomized studies identified, 106 met the inclusion criteria, with mixed methodological quality. Of these, 41 studies evaluating surgical and alternative interventions were excluded. Quantitative analyses were not performed, as there were limited numbers of trials with a sufficiently homogeneous design.

Conclusion

Local anaesthetic infiltration, either as a sole technique or as an adjunct to general or regional anaesthesia, and combinations of analgesics (non-steroidal anti-inflammatory drugs, paracetamol and opiates) are recommended. If appropriate, a stapled operation may be preferable.