bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of aspect ratio, surface modification and compatibilizer on the mechanical and thermal properties of ldpe-mwcnt nanocomposites
Authors: Abbasi Sarfraz H. , Al-Juhani Abdulhadi A. , Ul-Hamid Anwar , Hussein Ibnelwaleed A.
Published: August 2014

In this work, nanocomposites of low density polyethylene (LDPE) / multiwall carbon nanotubes (MWCNTs) were prepared using melt blending. The effects of CNT aspect ratio, CNT loading, CNT chemical modification and the presence of a compatibilizer (maleated polyethylene) on morphology, mechanical and thermal properties of the CNT/LDPE composites were studied. Different MWCNTs were used: long CNT (LCNT); COOH modified CNT (MCNT) and short CNT (SCNT). FE-SEM images of produced nanocomposites show agglomeration of the MWCNTs. Addition of compatibilizer to both LCNT and MCNT nanocomposites improved their dispersion in the LDPE matrix. Yield strength and modulus increased with loading of various MWCNTs. However, ultimate strength, percent elongation and toughness reduced significantly for CNT loadings of 2% CNT and higher. The addition of maleated PE resulted in improvements of Young’s modulus, yield strength and ultimate strength but no impact on elongation at break or toughness. Addition of compatibilizer did not affect the crystallinity of the produced nanocomposites. In general, the use of CNT with high aspect ratio and the addition of compatibilizer and chemical modification improved the dispersion of MWCNTs and consequently improved most of the mechanical properties except elongation at break and toughness.
SPPO/PEI-based acid-base blend membranes for direct methanol fuel cells
Authors: Tsen Wen-Chin , Chuang Fu-Sheng , Shu Yao-Chi , Chen Chien-Chung , Gong Chunli , Wen Sheng
Published: August 2014

New acid-base polymer blends based on sulfonated poly(phenylene oxide) (SPPO) as the proton-conducting component and poly(ether imide) (PEI) as the basic component were considered for use as proton-exchange membranes (PEM). The obtained blend membranes had a higher thermal stability and a higher glass transition temperature (Tg) than the pure SPPO, as revealed by TGA and DSC. The morphology of blend membranes indicated that PEI was highly compatible with SPPO polymers because of the formation of hydrogen bonds between the sulfonated acid and PEI. Although the blend membranes exhibited a lower water uptake and lower proton conductivity than the pure SPPO membrane, the PEI component improved the dimensional stability, mechanic properties, and especially inhibited methanol permeation. The methanol permeability coefficient of the blend membrane with 30 wt.% PEI content was 9.68×10-8 cm2/s, which is lower than that of the pure SPPO and just one tenth of that of Nafion® 112. This considerable reduction in methanol crossover revealed the feasibility of the blend membranes as promising electrolytes for direct methanol fuel cells.
Ring-opening polymerization of ethylene carbonate using ionic liquids as catalysts
Authors: Zhou Jiancheng , Cheng Ling , Wu Dongfang
Published: August 2014

The ring-opening polymerization of ethylene carbonate was examined using ionic liquids, 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF4) and 1-butyl-3-methylimidazolium chlorozincate ([bmim]Cl-(ZnCl2)x), as polymerization catalysts. It was shown that the polymerization was accompanied with decarboxylation and chain cleavage reaction. As the reaction time increased, the monomer conversion increased and the content of ethylene carbonate units in the resultant polymer decreased, while the polymer molecular weight increased at first, reached a maximum and then decreased. It was also found that not only the polymerizing activity of the [bmim]Cl-(ZnCl2)x but also its performance for suppressing the decarboxylation and chain cleavage increased with the molar fraction of ZnCl2. It was deduced that the catalytic performance of ionic liquids mainly depended on their inorganic anions and that the larger the amount of these anions in the reaction system, the better the catalytic performance. The polymerizing activity of ionic liquids was much higher than conventional catalysts often used for the polymerization of ethylene carbonate.
Synthesis and magnetic properties of poly(amic acid) complexes containing 1,10-phenanthroline
Authors: Zheng Renhua , Jiang Huajiang , Guo Haichang , Sun Weilin
Published: August 2014

A novel poly(amic acid) containing 1,10-phenanthroline (PPHPA) was first synthesized by the polycondensation of 4,4'-oxydiphthalic dianhydride (ODPA) with 5,6-diamine-1,10-phenanthroline (DAPH). Three polymeric complexes were first prepared by the reaction of polymer (PPHPA) with NiSO4, CuSO4, and NdCl3, respectively. The structures of the polymer and the complexes were characterized by IR, 1H-NMR, and elemental analysis. The magnetic behaviors of these complexes were measured as a function of magnetic field strength (0-50 kOe) at 5 K and as a function of temperature (5-300 K) at a magnetic field strength of 30 kOe. The results show that PPHPA-Ni2+ and PPHPA-Nd3+ were soft ferromagnets, whereas PPHPA-Cu2+ exhibited the features of an antiferromagnet.
Toughening of glass fiber reinforced Nylon 66 with EPDMMAH: Dynamic mechanical, rheological, and morphological investigations
Authors: Soltani Iman , Zeynali Mohammad Ebrahim , Yousefi Ali Akbar
Published: August 2014

In this research the variation of mechanical and rheological properties of the composite as a function of different processing parameters and ethylene propylene diene monomer (EPDM) rubber content was studied. The optimum amount of dicumyl peroxide (DCP) to achieve the highest percentage of grafting of maleic anhydride to EPDM was obtained by Fourier transform infrared (FTIR) spectroscopy. In general, immiscibility between nylon 66 and EPDM, and their high interfacial tension makes their blending difficult. Maleic anhydride was grafted to EPDM to reduce interfacial tension between two phases. Also the blends were prepared at highest possible speed of mixing (screw speed in extrusion) and lowest temperature to reach a well mixed sample which can be seen in scanning electron microscopy (SEM) images and impact strength results. Dynamic mechanical thermal analysis (DMTA) tests were conducted to evaluate the miscibility of the components and to measure the glass transition temperature of the blends. Rheological measurement showed that the viscosities of the components of the blend getting closer to each other when EPDM content, time of mixing and shear rate increase.
Synthesis of cross-linked comb-type polysiloxane for polymer electrolyte membranes
Authors: Mukbaniani Omar , Aneli Jimsher , Tatrishvili Tamara , Markarashvili Eliza , Chigvinadze Maia , Abadie Marc Jean Medard
Published: August 2014

Abstract Hydrosilylation reaction of 2.4.6.8-tetrahydro-2.4.6.8-tetramethylcyclotetrasiloxane with allyl acetoacetate and vinyltriethoxysilane at 1:3:1 ratio of initial compounds in the presence of Karstedt’s catalyst (Pt2[(VinSiMe2)2O]3), platinum hydrochloric acid (0.1 M solution in THF) and platinum on the carbon have been studied and D4R,R’ type methylorganocyclotetrasiloxane has been obtained. Ring-opening co-polymerization reactions of methylorganocyclotetrasiloxane and hexamethyldisiloxane, in the presence of catalytic amount of powder-like potassium hydroxide, have been carried out and linear methylsiloxane oligomer with regular arrangement of propyl acetoacetate and triethoxysilane groups in the side chain has been obtained. The synthesized methylorganocyclotetrasiloxane and oligomers were studied by FTIR, 1H, 13C, 29Si NMR spectroscopy. Comb-type oligomers were characterized by gel-permeation chromatography, wide- angle X-ray and differential scanning calorimetric methods. Via sol-gel processes of doped with lithium trifluoromethylsulfonate (triflate) or lithium bis- (trifluoromethylsulfonyl)imide oligomer systems solid polymer electrolyte membranes have been obtained. The dependence of ionic conductivity as a function of temperature and salt concentration has been studied. The electrical conductivity of these materials at room temperature belongs to the range of 7x10-8 to 4x10-6 S cm-1 and depends on the structures of grafted anion receptors and the polymer backbones.
Effect of clay modification on the dynamic mechanical and dielectric properties of PMMA nanocomposites via melt blending
Authors: Wang Yeh , Chen Wei-C.
Published: August 2014

The dynamic mechanical and dielectric properties of poly(methyl methacrylate)/ clay nanocomposites (PCNs) prepared with melt blending was studied in terms of clay modification and nanoscale dispersion. The pristine clay was modified via various routes, including PMMA concentrates from in situ polymerization and POP-diamine intercalation. Partially exfoliated clay layers were uniformly dispersed in the nanocomposites as evidenced from x-ray diffraction study. The subglass β relaxation, the segmental α relaxation, and the α β-merging process above Tg were observed in the nanocomposites from the dielectric analysis. Compared to neat PMMA, with only 5 wt% clay loading, the modified PCN materials exhibit higher glass-transition temperatures and higher dynamic storage moduli, which was attributed to the polymer chain tethering and confinement effect. Significant increase in dielectric permittivity’s and losses due to interfacial polarization and ionic conduction were observed for the PCNs. The intensity of the interfacial polarization process increases with the dispersion degree of clay layers and hence the relaxation process can be assigned to the space charge polarization of the ionic species in the clay intergalleries.
Properties and structural characterization of chitosan/poly(vinyl alcohol)/graphene oxide nano composites
Authors: Ma Jun , Liu Changhua , Li Rui , Wang Jia
Published: August 2014

Chitosan (CS)/poly(vinyl alcohol) (PVA)/graphene oxide (GO) nanocomposites in the form of films are prepared in a casting and solvent evaporation method. Fourier-transform infrared spectroscopy (FTIR), X-ray diffractions (XRD), atomic force microscopy (AFM), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), tensile testing and moisture uptake were used to study the structure and properties of these chitosan/poly(vinyl alcohol) /graphene oxide (PCS/GO-n) nanocomposites. The result from tensile testing indicated that the nanocomposite containing 2 wt% GO exhibits high tensile strength (71.21 MPa) with a large elongation at break (51.8%). The high mechanical properties of the nanocomposite films are mainly due to uniform dispersion of GO sheets in the polymer matrix and strong interfacial interactions among components.
Morphology, thermal properties and mechanical relaxations of metallocene syndiotactic polypropylenes
Authors: Moya Ester López , Gómez-Elvira José M. , Benavente Rosario , Pérez Ernesto
Published: August 2014

The complex polymorphic behaviour of four syndiotactic polypropylene (sPP) samples have been analysed by means of DSC and WAXD techniques. Two samples (sPP1, sPP2) were synthesised via metallocene polymerization by using the ansa-zirconocene Ph2C(Cp)(9-Flu)ZrCl2 as catalyst. Finally, two additional specimens with different molar masses (sPP1-Fr1, sPP1-Fr2) were prepared from the most syndiotactic sPP1 sample by temperature gradient extraction. The WAXD analysis shows that together with the orthorhombic form I, form II can coexist in a variable but small proportion depending on both the chain features and the processing conditions. The relative contribution of the disordered and the ordered types of form I is also dictated by molar mass, configurational microstructure as well as processing conditions. The observed changes in the thermal properties as measured by DSC and in the mechanic-dynamical relaxations of the samples, on slowing the crystallisation rate down, can be rationalised in terms of two concurrent processes, namely the perfection undergone by the crystals and the segregation of the amorphous phase.
Preparation and properties of molecular-weight-controlled polyimide adhesive film
Authors: Huo Haitao , Mo Song , Sun Hongjie , Yang Shiyong , Fan Lin
Published: August 2014

A series of molecular-weight-controlled aromatic polyimides based on 4,4’-oxydiphthalic anhydride (ODPA), 1,4-bis(4-amino-2-trifluoromethylphenoxy) benzene (6FAPB) and 4,4’-diaminodiphenylsulphone (4,4’-DDS) were synthesized in the presence of phthalic anhydride (PA) as end-capping agent. The effect of molecular weight on solubility, melt viscosity, thermal and mechanical properties of polyimides was investigated. Experimental results demonstrated that these polyimides have good solubility not only in most of polar aprotic solvents but also in some of common organic solvents, such as DMSO and THF. Homogeneous and stable polyimide solutions with solid content as high as 40-45 wt.% could be achieved. High-quality polyimide films could be obtained by casting the polyimide solutions onto glass plate followed by baking at a relatively low temperature. The polyimide films exhibited outstanding thermal and mechanical properties. The rheological behavior of these polyimides depends on their molecular weight. Adhesive properties of polyimide films bonded to stainless steel were evaluated by lap shear strength (LSS) test. The bonding conditions were optimized with respect to the melt temperature, bonding pressure and time, as well as thickness of the adhesive layer. It is found that the polyimides with moderate molecular weight exhibited better adhesive properties.
Tissue engineering scaffold electrospun from poly(ε- caprolactone)-b-poly(sulfobetaine methacrylate) block copolymers with improved hydrophilicity and good cytocompatibility
Authors: Li Qian , Wang Zhihong , Zhao Qiang , Wang Lianyong , Wang Shufang , Kong Deling
Published: August 2014

An amphiphilic block copolymer, poly(ε-caprolactone)-b-poly (sulfobetaine methacrylate), (PCL-b-PSBMA), which comprising of hydrophobic polyester segment and hydrophilic zwitterionic segment, was synthesized by ringopening polymerization (ROP) together with atom transfer radical polymerization (ATRP). The chemical structure and composition of the synthesized copolymers were first investigated by 1HNMR and GPC. The copolymers were further processed into non-woven fabrics by electrospinning. The surface chemical composition, fiber morphology, hydrophilic/hydrophobic property, and cell viability of the as-prepared scaffold were evaluated by X-ray photoelectron spectroscopy, SEM, water contact angle and uptake measurement, and MTT assay, respectively. All these results indicate that this kind of copolymers is a suitable candidate for the biomedical application.
ARGET ATRP of copolymerization of styrene and acrylonitrile with environmentally friendly catalyst and ligand
Authors: Wang Guoxiang , Lu Mang
Published: August 2014

The atom transfer radical polymerization of styrene and acrylonitrile using activators regenerated electron transfer (ARGET) has been carried out in N,N-dimethylformamide (DMF) at 90 °C in the presence of air with a catalyst system of FeCl3·6H2O/succinic acid using 2-bromoisobutyrate as the initiator and ascorbic acid as the reducing agent. The ARGET ATRP of styrene and acrylonitrile was proved a ‘living’/controlled polymerization such as a linear increase in molecular weights of polymers with monomer conversion and relatively narrow polydispersities (<1.25) when the conversion was beyond 20%. The chain extension experiment was carried out to confirm the controlled manner of the polymerization system. The resultant SAN was characterized by nuclear magnetic resonance and gel permeation chromatography.
Polymerization of 1,3-butadiene using (salen)Ni(II) and (salphen)Ni(II) complexes in combination with methylaluminoxane
Authors: Wang Baolin , Gong Dirong , Wu Guangfeng , Zhang Xuequan
Published: August 2014

Eight nickel complexes with various imino-backbones and substituents at ortho- and para-positions on the aromatic ring of the salicylaldehyde are prepared and characterized. Activated by MAO, the precursors have been investigated for 1,3-butadiene polymerization. All the complexes display high cis- 1,4 selectivity (cis-1,4 contents: 90.4 to 93.4 %), while the catalytic activity strongly depends on the position of bulky group located. Introduction of t-butyl at 3,3′- position on the aromatic ring of the ligands remarkably increases catalytic activity, while that at the 5,5′-position decreases the activity. Relatively, variation of iminobackbone shows little influence on catalytic performance. Effects of [Al]/[Ni] molar ratio and temperature on catalytic activity and stereo-selectivity are also investigated.
Effects of sterically hindered N-alkoxyamines on photooxidative stability of reinforced polypropylene
Authors: Enescu Daniela , Frache Alberto
Published: August 2014

In the present paper the influence of Flamestab® NORTM 116 (abbrev. FNOR), a sterically hindered N-alkoxyamine stabilizer, on the photo-oxidative stability of calcium carbonate reinforced polypropylene (abbrev. CCPP) used for production of plastic collars has been investigated. The samples, prepared by melt compounding, were exposed to artificial accelerated photo-ageing carried out at λ>300 nm and 45 °C in air. FT-IR and UV-VIS analysis revealed that the deterioration of neat CCPP takes place very rapidly in comparison with the composites containing FNOR. Hydroperoxides and various carbonyl species are formed as the main degradation products during the photo-oxidation process. Moreover, the intensity of the absorption bands grows with increasing of UV exposure time indicating that the material suffers a photo-oxidative degradation process. Indeed, addition of only 0.1 wt.-% FNOR did not significantly modify the length of the induction period of neat CCPP, but a strong efficiency was obtained by increasing the amount of FNOR (0.5 wt.-%) which shows an increase of eight times more as compared with neat CCPP. Therefore, it may be supposed that OIT is linked to the level of concentration of the stabilizer. This remarkable increase in composite stability demonstrated by a lengthening of OIT is typical for sterically hindered N-alkoxyamine stabilizers since they are very efficient at scavenging freeradicals formed as the polymer degrades. In other words, these UV stabilizers are converted to nitroxide radicals (see Scheme 1) which readily trap the polymer degradation species to produce alkoxyamines. Then, the formed alkoxyamines do subsequently react with peroxy radicals to regenerate the active nitroxide radical, thereby this process (called Denisov cycle) proceed in a regenerative cycle, thus retarding oxidative polymer degradation. The increase of absorbance in the carbonyl region as a function of irradiation time was used to determinate the photooxidation rate. It was found out that the photooxidation rate measured from the slope of linear part of the curves is significantly decreased for the CCPP/FNOR 0.5 composite compared to neat CCPP. In the light of the above mentioned findings, FNOR could be taken into consideration as an UV stabilizer for CCPP.
Influence of hydrophobe fraction content on the rheological properties of hydrosoluble associative polymers obtained by micellar polymerization
Authors: Jiménez-Regalado Enrique J. , Hernández-Flores Elva B.
Published: August 2014

The synthesis, characterization and rheological properties in aqueous solutions of water-soluble associative polymers (AP’s) are reported. Polymer chains consisting of water-soluble polyacrylamides, hydrophobically modified with low amounts of N,N-dihexylacrylamide (1, 2, 3 and 4 mol%) were prepared via free radical micellar polymerization. The properties of these polymers, with respect to the concentration of hydrophobic groups, using steady-flow and oscillatory experiments were compared. An increase of relaxation time (TR) and modulus plateau (G0) was observed in all samples studied. Two different regimes can be clearly distinguished: a first unentangled regime where the viscosity increase rate strongly depends on hydrophobic content and a second entangled regime where the viscosity follows a scaling behavior of the polymer concentration with an exponent close to 4.
Synthesis and characterization of salt resistance hydrogel microspheres by inverse suspension polymerization
Authors: Zhou Ming , Zhao Jinzhou , Pu Wanfen , Wang Xu , Yang Yan
Published: August 2014

A series of novel salt-resistance hydrogel microspheres P(AM-co-AMPS) are synthesized by inverse suspension copolymerization using ammonium persulfate (APS) as the initiator and N,N-methylene bisacrylamide (MBA) as the crosslinker and polyvinyl alcohol (PVA) as disperse agent. Optimization syntheses condition of hydrogel microspheres copolymer P(AM-co-AMPS) SAPs is crosslinker content 0.01%, ratio of water to oil 4%, ratio of monomer to surfactant 30%, ratio of acrylamide to 2-acrylamido-2-methylpropane sulphonic acid 80:20 and initiator APS content 1.0%. Their effects on the salt absorbency of the synthesized hydrogel microspheres are investigated. FTIR indicates the two monomeric units of the acrylamide and 2-acrylamido-2-methylpropane sulphonic acid exists in copolymer backbone. SEM indicates that the number of the micropores largely decrease with the water/oil ratio increasing from 4% to 10%. Elemental analysis indicate that the measured values of carbon, sulfur, nitrogen, hydrogen four elements is very close to theoretical value. The experimental results of salt-resistance hydrogel microspheres show the salt absorbency decrease with the increase of salt concentration. The maximum salt absorbency is 132g/g within 75min in 0.9% sodium chloride solution and the effect of calcium ion on salt absorbency is much greater than that of sodium ion.
Erythrina lysistemon-derived flavonoids account only in part for the plant’s specific effects on rat uterus and vagina
Authors: Njamen Dieudonné , Mvondo Marie Alfrede , Gueyo Telesphore Nanbo , Zingue Stéphane , Fomum Stephen Tanee , Wandji Jean
Published: August 2014

Background: The stem bark ethyl acetate extract of Erythrina lysistemon was found to induce vaginal proliferation in ovariectomized rats orally treated. Alpinumisoflavone (AIF) and abyssinone V-4′-methyl-ether (AME), isolated as its major constituents, were reported to separately provoke uterine growth and/or vaginal proliferation. The present study aimed at evaluating the effects of the mixture of AIF and AME (51 mg/kg [AIF]+153 mg/kg [AME]) following their relative abundance in the extract, in order to compare these effects to those of E. lysistemon.

Methods: The study was performed in ovariectomized rats treated intraperitoneally for 3 days. Estradiol valerate (E2 V) and AME were used for positive controls. Morphological and histological changes of animals’ uterus and vagina were used as the hallmark of estrogenicity.

Results:
E. lysistemon extract induced estrogen-like effects only on the uterus and significantly increased uterine wet weight (p<0.01) and uterine epithelial height (p<0.01). These results suggest a tissue-selective action of E. lysistemon extract depending on the route of administration. The mixture of AIF and AME induced E. lysistemon-like effects only at a dose of 1 mg/kg BW/d (0.25 mg/kg+0.75 mg/kg), although these effects were lower in magnitude (p<0.05) compared to those induced by E. lysistemon extract.

Conclusions: Effects induced by the mixture of AIF and AME are analogous to those of E. lysistemon, but the low magnitude of these effects suggests that there are minor metabolites that interact with AIF and AME to provoke the specific effects of E. lysistemon.
Consumptive hypothyroidism associated with parotid infantile hemangioma
Authors: De Corti Federica , Crivellaro Carlo , Zanon Giovanni Franco , Luzzatto Claudia
Published: August 2014

Consumptive hypothyroidism is a rare condition usually described in association with diffuse infantile hemangioma of the liver, over-expressing type 3 iodothyronine-deiodinase. We report a case of acquired hypothyroidism associated with a parotid hemangioma in a male child, who was initially evaluated at 48 days of age due to persistent jaundice. Replacement hormonal therapy was promptly started, but resolution of the clinical and laboratory findings of hypothyroidism was only achieved at 3 months of age, when propranolol treatment was added to the therapeutic regimen. Our review of the literature retrieved only one case of proven consumptive hypothyroidism associated with a parotid infantile hemangioma, making a real incidence an underestimate: we believe one should consider this association a real possibility.
Variability of lipid and lipoprotein concentrations during puberty in Brazilian boys
Authors: Mascarenhas Luis Paulo Gomes , Leite Neiva , Titski Ana Cláudia C. Kapp , Brito Lilian Messias Sampaio , Boguszewski Margaret C.S.
Published: August 2014

Evaluation of lipid profile in children and adolescents is important for early diagnosis of dyslipidemias. Physiological changes might be observed in the concentration of the lipid profile components, according to the stage of sexual maturation.

To evaluate the variation in lipid and lipoprotein concentrations in boys during puberty.

The sample consisted of 570 male adolescents with ages between 10 and 17 years. Weight, height, and body mass index (BMI) were assessed. Total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglyceride (TG) were determined by the enzymatic method, and low-density lipoprotein cholesterol (LDL-C) was calculated. Puberty was classified according to Tanner references. The percentile criterion was adopted for the distribution and identification of lipoprotein levels. The analysis of variance and description tests with p<0.05 was applied.

Participants had similar BMI

Lipid and lipoprotein concentrations tend to undergo changes during puberty in boys. The use of percentile values can be very useful to track variations in lipid and lipoprotein levels during the maturation process.
Production of 111In and
114mIn by proton induced reactions: an update on
excitation functions, chemical separation – purification and
recovery of target material
Authors: Hermanne Alex , Adam-Rebeles Razvan , Van den Winkel Pierre , Tárkányi Ferenc , Takács Sandor
Published: August 2014

In order to update the recommended cross section data of IAEA for
production of 111In and 114m
In through the
112Cd(p,2n) and 114Cd(p,n) reactions new
measurements were performed. In stacked-foil irradiations with
incident proton energy of 36.7 and 25 MeV on highly enriched
112Cd and 114Cd targets, the excitation functions
for 109,110g,110m,111,113m,114m
In were determined, relative
to the monitor reactions
nat
Cu(p,x)62,65Zn. The
results are compared with the available literature values (also
extracted from measurements on
nat
Cd) and with data listed
in the on-line library TENDL-2012 (calculated with the TALYS 1.4
theoretical code).

The industrial, PC-controlled automated dissolution and separation
chemistry apparatus for delivery of large quantities of nca
111In and the recovery of enriched 112Cd from
processed irradiated targets are described.
Technical Challenges for Big Data in Biomedicine and Health: Data Sources, Infrastructure, and Analytics
Authors: Holmes J. H. , Sun J. , Peek N.
Published: August 2014

Objectives: To review technical and methodological challenges for big data research in biomedicine and health.

Methods: We discuss sources of big datasets, survey infrastructures for big data storage and big data processing, and describe the main challenges that arise when analyzing big data. Results: The life and biomedical sciences are massively contributing to the big data revolution through secondary use of data that were collected during routine care and through new data sources such as social media. Efficient processing of big datasets is typically achieved by distributing computation over a cluster of computers. Data analysts should be aware of pitfalls related to big data such as bias in routine care data and the risk of false-positive findings in high-dimensional datasets. Conclusions: The major challenge for the near future is to transform analytical methods that are used in the biomedical and health domain, to fit the distributed storage and processing model that is required to handle big data, while ensuring confidentiality of the data being analyzed.
Trends on Integrating Framework of Applications or Data
Authors: Conchon E. , Bricon-Souf N. ,   Section Editors for the IMIA Yearbook Section on Health and Clinical Management
Published: August 2014

Objective: To summarize current excellent research and trends in the field of Health and Clinical management.

Methods: Synopsis of the articles selected for the IMIA Yearbook 21014

Results: A comprehensive review of papers published in 2013 was performed by querying PubMed. 1079 were reviewed as papers without authors, without abstract or smaller than 4 pages were excluded from the selection. The editors reviewed all papers and 15 papers selected and provided to to international reviewers. Four papers from international peer-reviewed journals were finally selected for the Health and Clinical Management section.

Conclusion: Many telemedicine applications are tested nowadays in medical situation, but the challenges emphasized by the best papers selection focus on the ability of proposing integrative frameworks for applications or data in order to handle efficiency of health and clinical management.
A 2014 Medical Informatics Perspective on Clinical Decision Support Systems: Do We Hit The Ceiling of Effectiveness?
Authors: Lamy J.-B. , Bouaud J. ,   Section Editors for the IMIA Yearbook Section on Decision Support
Published: August 2014

Objective: To summarize recent research and propose a selection of best papers published in 2013 in the field of computer-based decision support in health care.

Method: Two literature reviews were performed by the two section editors from bibliographic databases with a focus on clinical decision support systems (CDSSs) and computer provider order entry in order to select a list of candidate best papers to be peer-reviewed by external reviewers.

Results: The full review process highlighted three papers, illustrating current trends in the domain of clinical decision support. The first trend is the development of theoretical approaches for CDSSs, and is exemplified by a paper proposing the integration of family histories and pedigrees in a CDSS. The second trend is illustrated by well-designed CDSSs, showing good theoretical performances and acceptance, while failing to show a clinical impact. An example is given with a paper reporting on scorecards aiming to reduce adverse drug events. The third trend is represented by research works that try to understand the limits of CDSS use, for instance by analyzing interactions between general practitioners, patients, and a CDSS.

Conclusions: CDSSs can achieve good theoretical results in terms of sensibility and specificity, as well as a good acceptance, but evaluations often fail to demonstrate a clinical impact. Future research is needed to better understand the causes of this observation and imagine new effective solutions for CDSS implementation.
Managing Large-Scale Genomic Datasets and Translation into Clinical Practice
Authors: Soualmia L. F. , Lecroq T. ,   Section Editors for the IMIA Yearbook Section on Bioinformatics and Translational Informatics
Published: August 2014

Objective:To summarize excellent current research in the field of Bioinformatics and Translational Informatics with application in the health domain.

Method: We provide a synopsis of the articles selected for the IMIA Yearbook 2014, from which we attempt to derive a synthetic overview of current and future activities in the field. A first step of selection was performed by querying MEDLINE with a list of MeSH descriptors completed by a list of terms adapted to the section. Each section editor evaluated independently the set of 1,851 articles and 15 articles were retained for peer-review.

Results: The selection and evaluation process of this Yearbook’s section on Bioinformatics and Translational Informatics yielded three excellent articles regarding data management and genome medicine. In the first article, the authors present VEST (Variant Effect Scoring Tool) which is a supervised machine learning tool for prioritizing variants found in exome sequencing projects that are more likely involved in human Mendelian diseases. In the second article, the authors show how to infer surnames of male individuals by crossing anonymous publicly available genomic data from the Y chromosome and public genealogy data banks. The third article presents a statistical framework called iCluster+ that can perform pattern discovery in integrated cancer genomic data. This framework was able to determine different tumor subtypes in colon cancer.

Conclusions: The current research activities still attest the continuous convergence of Bioinformatics and Medical Informatics, with a focus this year on large-scale biological, genomic, and Electronic Health Records data. Indeed, there is a need for powerful tools for managing and interpreting complex data, but also a need for user-friendly tools developed for the clinicians in their daily practice. All the recent research and development efforts are contributing to the challenge of impacting clinically the results and even going towards a personalized medicine in the near future.
Information Technology for Clinical, Translational and Comparative Effectiveness Research
Authors: Choquet R. , Daniel C. ,   Section Editors for the IMIA Yearbook Section on Section on Clinical Research Informatics
Published: August 2014

Objective: To select and summarize key contributions to current research in the field of Clinical Research Informatics (CRI).

Method: A bibliographic search using a combination of MeSH and free terms search over PubMed was performed followed by a blinded review.

Results: The review process resulted in the selection of four papers illustrating various aspects of current research efforts in the area of CRI. The first paper tackles the challenge of extracting accurate phenotypes from Electronic Healthcare Records (EHRs).

Privacy protection within shared de-identified, patient-level research databases is the focus of the second selected paper. Two other papers exemplify the growing role of formal representation of clinical data - in metadata repositories - and knowledge – in ontologies - for supporting the process of reusing data for clinical research.

Conclusions: The selected articles demonstrate how concrete platforms are currently achieving interoperability across clinical research and care domains and have reached the evaluation phase. When EHRs linked to genetic data have the potential to shift the research focus from research driven patient recruitment to phenotyping in large population, a key issue is to lower patient re-identification risks for biomedical research databases.

Current research illustrates the potential of knowledge engineering to support, in the coming years, the scientific lifecycle of clinical research.
Field measurement by fully grouted vibrating wire piezometers
Authors: Wan Michael S. P. , Standing Jamie R.
Published: August 2014

Subsurface instrumentation was installed at a field monitoring site in Hyde Park and bordering Bayswater Road for measuring the ground responses to Crossrail tunnelling near Lancaster Gate. Prior to tunnel construction, pore-water pressures were measured, both in the ‘greenfield' ground and the ground in the vicinity of existing London Underground running tunnels, by three multi-level vibrating-wire piezometer boreholes fully backfilled with cement–bentonite grout. The pore-water pressures in the ‘greenfield' ground were at the same time measured by conventional standpipe piezometers and pushed-in spade cells with built-in vibrating-wire piezometers. This paper investigates the performance of the multi-level vibrating-wire piezometers by comparing their post-installation and steady-state pore-water pressure measurements with those from the other piezometer types. Generally they performed well, providing an efficient means of determining pore-water pressures at several depths within one borehole. One of the ‘greenfield' multi-level vibrating-wire piezometers indicated underdrainage within the London Clay while the other was influenced by inter-connectivity between individual piezometers within the borehole and also the presence of a claystone horizon. One borehole close to the existing tunnel indicated drainage of groundwater into it; this effect is compared with predictions made using a simplistic finite-difference model.
A fast and robust method for estimating the failure probability of structures
Authors: Arab Hamed Ghohani , Ghasemi Mohammad Reza
Published: August 2014

A new approach is presented to estimate quickly and accurately the probability of failure of structures. The approach works by employing first-order reliability methods to determine the closest point to the mean of random variables in a failure region. Then, by presenting sub-intervals in various layers and by grouping the generated samples in a Monte Carlo simulation (MCS), it was possible to reduce the number of structural calculations with controllable error where acceptable accuracy was introduced. Various numerical and engineering examples with complex limit state functions were solved by the proposed approach and the results were compared with those of common reliability methods. The outcome shows the high accuracy of the proposed approach. Furthermore, the number of required structural calculations was significantly reduced compared to normal MCS.
Kelp forest size alters microbial community structure and function on Vancouver Island, Canada
Authors: Clasen J. L. , Shurin J. B.
Published: August 2014

Bacteria are ubiquitous and important components of marine ecosystems, yet the interaction between bacteria and higher trophic levels remain poorly understood. The trophic cascade involving sea otters, urchins, and kelp in the North Pacific is a classic case of altered ecosystem states; however, its impacts on microbial communities are unknown. We investigated the response of microbial communities to variation in kelp abundance between regions with and without sea otter populations along the west coast of Vancouver Island, British Columbia, Canada. We compared bacterial community structure and function between regions with large and small kelp forests, including an subset of the bacterial community that produces alginate lyase, which allows direct utilization of kelp carbon. The abundance and activity of alginate‐lyase‐producing bacteria were 3.2 and 1.4 times higher, respectively, in the region with large kelp forests, and declined rapidly with increasing distance from kelp. Total bacterial abundance was 2.7 times greater, and bacteria grew faster and experienced more zooplankton grazing and viral‐mediated mortality in the presence of large kelp forests. These patterns suggest that larger kelp forests produce more detritus and dissolved organic matter, which stimulate microbial activity. Our results indicate that variation in kelp forest size alters the community structure and productivity of microbes and contributes to the growing evidence that top predators interact with microbes and ecosystem processes through a cascade of indirect effects.
Glycated Albumin and Calprotectin Levels in Gingival Crevicular Fluid From Patients With Periodontitis and Type 2 Diabetes
Authors: Kajiura Yukari , Bando Mika , Inagaki Yuji , Nagata Toshihiko , Kido Jun‐ichi
Published: August 2014

Background: Patients with diabetes mellitus (DM) have a high prevalence of periodontitis. Periodontitis in these patients is characterized by severe inflammation and tissue breakdown, and its diagnosis is important for cures of periodontitis and DM. The purpose of this study is to investigate the levels of glycated albumin (GA), a DM marker, and calprotectin, an inflammatory marker, in gingival crevicular fluid (GCF) from patients with periodontitis and DM (DM‐P).

Methods: The 78 participants in this study were patients with DM, chronic periodontitis (CP), DM‐P, and healthy individuals (H). GCF and blood were collected, and GA and calprotectin in GCF were analyzed using Western blotting and enzyme‐linked immunosorbent assay. Levels were compared among H, DM, CP, and DM‐P groups. Blood GA and glycated hemoglobin (HbA1c) were measured, and the correlation among GCF GA and blood HbA1c or GA levels was investigated. Receiver operating characteristic (ROC) analysis for GCF GA to predict DM was performed.

Results: GA was identified in GCF, and its amount/concentration in GCF samples from DM and DM‐P were significantly higher than those of non‐DM groups (H and CP). Calprotectin amounts in GCF from CP and DM‐P were significantly higher than in H and DM groups. GCF GA level was positively correlated with blood HbA1c and GA level. ROC analysis of GCF GA showed an optimal cutoff value to predict DM.

Conclusions: GA showed a high level in GCF from patients with DM. Examination of GA and calprotectin in GCF may be useful for predicting DM‐P.
Prevalence of Altered Passive Eruption in Orthodontically Treated and Untreated Patients
Authors: Nart Jose , Carrió Neus , Valles Cristina , Solís‐Moreno Carols , Nart Maria , Reñé Ramon , Esquinas Cristina , Puigdollers Andreu
Published: August 2014

Background:Some authors have reported that after orthodontic treatment (OT), a “gummy smile” might develop. Nevertheless, there are no studies in the literature that investigate whether OT increases the presence of altered passive eruption (APE). The primary aim of this cross‐sectional study is to evaluate the prevalence of APE after OT (OT group) and compare it with patients who never received OT (control group). A secondary aim is to identify which variables are related to APE.

Methods:The study population consisted of 190 patients (95 patients each in the control and OT groups), providing 1,140 anterior teeth for the clinical examination. The following clinical parameters were assessed: presence or absence of APE, clinical crown length, and gingival biotype, which was divided into three categories: thin‐scalloped, thick‐flat, and thick‐scalloped.

Results:Twenty‐eight patients (29.5%) were diagnosed with APE in the control group and 40 (42.1%) in the OT group, although this difference was not statistically significant (P= 0.07). Furthermore, 34 (75.6%) patients with thick‐flat biotype were diagnosed with APE, whereas 30 (31.3%) and four (8.2%) with thick‐scalloped and thin‐scalloped biotypes, respectively, had APE. These differences were statistically significant (P<0.001).

Conclusions:It was concluded that: 1) the prevalence of APE is higher after OT but not to a statistically significant degree and 2) APE is more common in individuals with a thick‐flat gingival biotype.
A genetic programming technique for lake level modeling
Authors: Aytek Ali , Kisi Ozgur , Guven Aytac
Published: August 2014

The potential of gene expression programming (GEP) approach for modeling monthly lake levels is investigated. The application of the methodology is presented for the monthly water level data of Van Lake, which is the biggest lake in Turkey. The root mean square errors, mean absolute relative errors, determination coefficient, and modified coefficient of efficiency (EM) are used for evaluating the accuracy of the genetic programming-based models. The results of the proposed models are compared with those of the neuro-fuzzy models. The comparison results indicate that the suggested GEP-based models perform better than the neuro-fuzzy models in forecasting monthly lake levels.
Application of a solid phase extraction-liquid chromatography method to quantify phenolic compounds in woodwaste leachate
Authors: Kamal Najat , Galvez Rosa , Buelna Gerardo
Published: August 2014

Woodwaste produces large volumes of leachate, which often contains high concentrations of phenolic compounds. These compounds are environmental contaminants whose proper management and treatment are mandated to reduce associated environmental impacts. Quality diagnostic and treatment efficiency assessments necessitate the development of rapid, accurate, and reproducible methods of detection and analysis to accurately quantify phenolic compounds. Liquid chromatography (LC) analysis with ultraviolet (UV) detection and solid-phase extraction (SPE) sample preparation on Oasis HLB cartridges were performed and adapted to quantify eight priority phenolic compounds in woodwaste leachate. The method was validated on a synthetic solution simulating the woodwaste leachate, on spiked real woodwaste leachate to 1 μg mL−1, and applied to quantify phenolic compounds in the real woodwaste leachate. Calibration curves were linear for all compounds in the range of 1–30 μg mL−1, and high recoveries varying between 93.5% for 2-chlorophenol and 112.8% for 4-nitrophenol were obtained. Detection limits ranged from 0.06 μg L−1 for 2-chlorophenol to 0.129 μg L−1 for phenol. The proposed method reduced interference, background noise, analysis time, amount of organic solvents and is less costly when compared with other methods.
Feasibility assessment of surface water disinfection by ultrafiltration
Authors: Iannelli R. , Ripari S. , Casini B. , Buzzigoli A. , Privitera G. , Verani M. , Carducci A.
Published: August 2014

Ultrafiltration (UF) has been presented as an alternative to chemical disinfection to obtain safe drinking water, for its ability to remove microbiological contamination. Hollow-fiber UF membranes are designed as an effective barrier to microorganisms, for their high manufacturing integrity and for the ‘potting’ method adopted to seal fibers to the feeding/extraction manifold. While the main advantage over chemical disinfection is the drastic reduction of disinfection-by-product (DBP) formation, some chemicals are still required to control fouling and related sanitary risks. This study aims at an up-to-date assessment of UF use for surface water disinfection by compact, minimally-attended, automated plants. A 3.5 m3/h automated UF pilot-plant was run for 8 months for drinking quality purification of surface water from Pescia stream. Standard drinking water parameters, as well as specific microbiological parameters (Legionella, Mycobacterium, Adenovirus, coliphage) and DBP formation were monitored. Final results highlighted that the plant could reach a good removal of bacteria and a significant reduction of viruses. However, the adopted operation/maintenance policies had a strong impact on energy and water consumption, efficacy of bacterium/virus barrier and DBP formation. Hence, an accurate and competent operation, as well as the assistance of chemical disinfection, are still required for safe drinking water production.
Long-term effects of hydrometeorological and water quality conditions on algal dynamics in the Paldang dam watershed, Korea
Authors: Kim D.-W. , Min J.-H. , Yoo M. , Kang M. , Kim K.
Published: August 2014

The primary goal of this study is to shed light on some important factors that control algal bloom in a large-scale regulated river system. Long-term impacts of environmental conditions on algal dynamics were investigated in the Paldang dam watershed, Korea. Dam inflow, water temperature, chlorophyll-a, TN, PO4-P and TP data collected at five major dams located on the North Han River (NHR) and at four water quality monitoring sites on the South Han River were analyzed for 21 years (1992 to 2012) to examine spatio-temporal variations in each. A pattern of slightly increasing chlorophyll-a and nutrient levels in the NHR since 2001 indicates that algal dynamics were affected by the increased nutrient levels as well as the reduced flow conditions (−10% to −37%). The temporal variations in monthly averaged data collected during summer monsoon seasons (mainly July) over the two decades show that high chlorophyll-a levels observed in both rivers corresponded to the relatively lower flow condition, which means a reduced amount of dam water release due to low or no rainfall over a short period of time, and abnormally high water temperature. This study shows that flow control is most critical for effectively managing algal level in the rivers in the short term, and nutrient management in the watershed is the key to reducing the potential for algal bloom in the long term.