bluuebunny/crossref_metadata_2025_split huggingface dataset:
Is rural migration a threat to environmental sustainability in Southern Burkina Faso?
Authors: Ouedraogo I. , Savadogo P. , Tigabu M. , Cole R. , Odén P. C. , Ouadba J.‐M. 
Published: March 2009

AbstractThere is growing evidence that population pressure on the land has become the most intractable problem in the developing countries where demand for food exceeds the food production capacity of the land. Southern Burkina Faso has experienced rapid population growth, mostly driven by immigration of farmers. This study was carried out in Sissili Province and used satellite images acquired over 31‐year period, census and survey data to capture migration patterns and its impacts on land use change. Results showed that migrant population which accounted for only 3 per cent in the study area in 1976 shifted to 57 per cent in 2007. Migrant people were using improved technology to progressively convert forest land to cropland. Cropland increased at an annualized rate of 0·46 per cent to the detriment of the dense forest and woodland which decreased at 0·57 per cent per annum. Population growth was highly correlated with increasing area of cropland (r2 = 0·95, p = 0·014) and declining dense forest (r2 = 0·78) and woodland (r2 = 0·95) covers. It can be concluded that rural migration, driven by the relatively good soil and rainfall conditions in the recipient area, is accounted for deforestation in the study area. If rural migration is not checked, it will seriously degrade the environment. Copyright © 2009 John Wiley & Sons, Ltd.
How can we control erosion of roadslopes in semiarid mediterranean areas? Soil improvement and native plant establishment
Authors: Bochet E. , García‐Fayos P. , Tormo J. 
Published: March 2009

AbstractRoad building triggers vegetation and soil degradation which affects road safety. We present conclusive results in terms of roadslope protection against erosion from several studies performed on semiarid roadslopes since 2000 (in Eastern Spain). We aim to (1) improve our understanding about slope and vegetation factors which control soil erosion and plant colonisation on semiarid roadslopes; (2) assess the effectiveness of topsoiling, hydroseeding and species selection in the protection of soil against erosion and (3) set scientifically based priorities on ecosystem components that have to be taken into account in future roadslope restoration plans.Erosion and vegetation cover estimations, vegetation surveys, drilling and hydroseeding experiments with commercial and native species were performed on roadslopes, in addition to seed germination and root penetration experiments.Our results indicate that slope type and angle are the main factors controlling soil erosion and plant colonisation on semiarid roadslopes. Microsite availability is more limiting to plant establishment than seed availability. Restoration strategies based on the improvement of soil properties and the appropriate selection of native species, able to overcome harsh hydrological and structural soil conditions, are proposed and tested according to slope characteristics. Drilling proved to be a promising technique for roadcut restoration, whereas topsoiling followed by hydroseeding with a seed mixture of selected native species was the most efficient treatment, in terms of cost and benefit, to control erosion on roadfills.This study clearly shows that ecological knowledge is needed to guide restoration efforts in Mediterranean ecosystems. Moreover, an efficient transfer of scientific knowledge from researchers to the institutions concerned (restorers, policymakers and practitioners) is also needed in the perspective of a more appropriate management of these ecosystems. Copyright © 2009 John Wiley & Sons, Ltd.
The Influence of Counterion Type and Temperature on Flory‐Huggins Binary Interaction Parameter in Polyelectrolyte Hydrogels
Authors: Safronov Alexander P. , Blyakhman Felix A. , Shklyar Tatyana F. , Terziyan Tatyana V. , Kostareva Marina A. , Tchikunov Sergey A. , Pollack Gerald H. 
Published: March 2009

AbstractThe Flory‐Huggins binary interaction parameter and its enthalpy and entropy parts were experimentally determined for polyelectrolyte hydrogels based on poly(acrylic) acid (PAAc) and poly(methacrylic) acid (PMAc) with various mono‐ and divalent counterions. It was shown that water is a poor solvent for acrylic and methacrylic polyelectrolyte hydrogels, as the binary interaction parameter is around 0.8 for mono‐ and 0.6 for divalent counterions. The type of counterion affects the enthalpy‐interaction parameter and according to its increase in PAAc gels, counterions can be placed in the following order: Li+<Ca2+<Mg2+<TMA+<Na+ = K+. For most of the gels studied, the enthalpy interaction parameter was much lower than the entropy contribution.magnified image
Formation of Crystallosolvates from Mixtures of Poly(L‐lactide) and Diphenyl Ether
Authors: Nakajima Hajime , Wataoka Isao , Ohara Hitomi , Kimura Yoshiharu 
Published: March 2009

AbstractPoly(L‐lactide) (PLLA) was mixed homogeneously with diphenyl ether (DE) at high temperature in a range of PLLA/DE compositions from 100/0 to 100/75 in wt.‐%. Cooling of the mixtures yielded white solid products without migration of the liquid DE. Their melting temperature was lowered from 173 to 123 °C as the DE content increased. At an optimum PLLA/DE composition of 100/60, a unique crystallosolvate consisting of large spherulite of PLLA, as detected using polarized optical microscopy, was exclusively generated in powder form. Wide and small angle X‐ray scattering revealed that the PLLA chains form a lamellar structure with a highly ordered crystalline state (α‐form) and that the lamellar spacing is extraordinarily thick, reaching 34 nm. It was therefore suggested that DE partitions into the amorphous layers sandwiched between the crystalline layers and that the specific solvation interaction between DE and PLLA may stabilize the crystallosolvates.magnified image
Copolymerization of Ethylene with 2,7‐Octadienyl Methyl Ether in the Presence of Metallocene and Nickel Diimine Catalysts
Authors: Fernandes Mércia , Kaminsky Walter 
Published: March 2009

AbstractIn this work, copolymers of ethylene with 2,7‐octadienyl methyl ether have been synthesized in the presence of three single‐site catalysts. The obtained copolymers not only have a polar ether function but also a double bond in the side chains that is useful for secondary reactions. The polymers were characterized by GPC, EA, DSC, NMR, and FT‐IR. The catalytic activity depends on the kind of catalysts, the concentration of the polar monomer, and the concentration of the protecting agent. Up to 7.3 wt.‐% of MODE could be incorporated by the metallocene catalyst. These are in average 120 functional side groups in a polymer molecule with a molecular mass of 230 000.magnified image
Synthesis and Characterization of Oxetane‐Functionalized Phosphorescent Ir(III)‐Complexes
Authors: Ulbricht Christoph , Rehmann Nina , Holder Elisabeth , Hertel Dirk , Meerholz Klaus , Schubert Ulrich S. 
Published: March 2009

AbstractIn order to incorporate iridium(III) complexes covalently into an oxetane‐bearing hole‐transporting matrix, a new oxetane‐equipped acetoacetate derivative was introduced as an ancillary ligand. Model complexes with an analogical nonpolymerizable ligand were also prepared in order to perform comparative investigations.Therefore, a series of bis‐cyclometalated Ir(III) complexes, showing orange (C⁁N‐ligand, coumarin 6) and green (C⁁N‐ligand, phenylpyridine) emission were synthesized and fully characterized. The emission maxima are 569 nm for the orange and 518 nm for the green‐emitting Ir(III) complexes. Entirely solution processed devices, based on crosslinkable hole‐conductors, partially doped with the described orange and green Ir(III) emitters, respectively, were fabricated and tested.magnified image
Synthesis of Symmetrical Triblock Copolymers of Styrene and N‐isopropylacrylamide Using Bifunctional Bis(trithiocarbonate)s as RAFT Agents
Authors: Bivigou‐Koumba Achille M. , Kristen Juliane , Laschewsky Andre , Müller‐Buschbaum Peter , Papadakis Christine M. 
Published: March 2009

AbstractSix new bifunctional bis(trithiocarbonate)s were explored as RAFT agents for synthesizing amphiphilic triblock copolymers ABA and BAB, with hydrophilic “A” blocks made from N‐isopropylacrylamide and hydrophobic “B” blocks made from styrene. Whereas the extension of poly(N‐isopropylacrylamide) by styrene was not effective, polystyrene macroRAFT agents provided the block copolymers efficiently. End group analysis by 1H NMR spectroscopy supported molar mass analysis and revealed an unexpected side reaction for certain bis(trithiocarbonate)s, namely a fragmentation to simple trithiocarbonates while extruding ethylenetrithiocarbonate. The amphiphilic block copolymers with short polystyrene blocks are directly soluble in water and self‐organize into thermoresponsive micellar aggregates.magnified image
Defined Comonomer Re‐Feeding During the Metallocene‐Catalyzed Copolymerization of 10‐Undecene‐1‐olate with Propene through FTIR In‐Line Monitoring
Authors: Sahre Karin , Schulze Ulrich , Eichhorn Klaus‐J. , Voit Brigitte 
Published: March 2009

AbstractThe consumption of 10‐undecene‐1‐olate (UOA) during its continuous re‐feeding in the metallocene‐catalyzed copolymerization with propene was investigated by ATR‐FTIR spectroscopy in‐line monitoring through evaluation of the integral absorbances of the characteristic IR bands. For the quantitative determination of the comonomer concentration during the copolymerization reaction with and without continuous re‐feeding of UOA, multiple calibration functions based on the chemometric partial least squares method were applied. For the first time, a direct correlation between the consumption of an olefin and the addition of a polar comonomer during a metallocene‐catalyzed copolymerization was demonstrated. By means of this technique, a relatively constant molar stoichiometric ratio of the comonomer and propene over the whole polymerization time was achieved, which is very important in obtaining copolymers with defined random structure and, thus, from the point of view of reaction engineering, constant product quality.magnified image
Synthesis of Folic Acid Functionalized PLLA‐b‐PPEGMA Nanoparticles for Cancer Cell Targeting
Authors: Hu Feixiong , Neoh Koon Gee , Kang En‐Tang 
Published: March 2009

AbstractPoly(L‐lactic acid)‐block‐poly(poly(ethylene glycol) monomethacrylate) (PLLA‐b‐PPEGMA) has been prepared by the ring‐opening polymerization of lactide with a double‐headed initiator, 2‐hydroxyethyl 2′‐methyl‐2′‐bromopropionate (HMBP), followed by atom transfer radical polymerization (ATRP) of poly(ethylene glycol) monomethacrylate (PEGMA). PLLA‐b‐PPEGMA nanoparticles with encapsulated Fe3O4are prepared by a solvent evaporation/extraction technique, and then further functionalized with folic acid, a cancer targeting ligand. Our results show that such functionalized PLLA‐b‐PPEGMA nanoparticles have good potential as carriers for targeted drug delivery in cancer treatment.magnified image
A twisted factorization method for symmetric SVD of a complex symmetric tridiagonal matrix
Authors: Xu Wei , Qiao Sanzheng 
Published: March 2009

AbstractThis paper presents an O(n2) method based on the twisted factorization for computing the Takagi vectors of an n‐by‐n complex symmetric tridiagonal matrix with known singular values. Since the singular values can be obtained in O(n2) flops, the total cost of symmetric singular value decomposition or the Takagi factorization is O(n2) flops. An analysis shows the accuracy and orthogonality of Takagi vectors. Also, techniques for a practical implementation of our method are proposed. Our preliminary numerical experiments have verified our analysis and demonstrated that the twisted factorization method is much more efficient than the implicit QR method, divide‐and‐conquer method and Matlab singular value decomposition subroutine with comparable accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
Mechanical properties and thermal analysis of low‐density polyethylene + polypropylene blends with dialkyl peroxide
Authors: Şirin Kamil , Balcan Mehmet 
Published: March 2009

AbstractPolypropylene + low density polyethylene (PP + LDPE) blends involving 0, 25, 50, 75 and 100 wt% of PP with dialkyl peroxide (DAP) were prepared by melt blending in a single‐screw extruder. The effects of adding dialkyl peroxide on mechanical and thermal properties of PP + LDPE blends have been studied. It was found that at lower concentrations of peroxide (e.g., 0–0.08 wt% of dialkyl peroxide) LDPE component is cross‐linked and Polypropylene (PP) is degraded in all compositions of PP + LDPE blends. Mechanical properties (Tensile strength at break, at yield and elongation at break), Melt flow index (MFI), hardness, Scanning Electron Microscope (SEM) and thermal analyses (DSC) of these blends were examined. Because of serious degradation or cross‐linking the mechanical properties and the crystallinty (%) of those products were decreased as a result of increasing peroxide content. Copyright © 2009 John Wiley & Sons, Ltd.
Fibrillin‐1 staining anomalies are associated with increased staining for TGF‐β and elastic fibre degradation; new clues to the pathogenesis of emphysema
Authors: Koenders Mieke MJF , Wismans Ronnie G , Starcher Barry , Hamel Ben CJ , Dekhuijzen Richard PN , van Kuppevelt Toin H 
Published: March 2009

AbstractWe recently demonstrated aberrant staining of fibrillin‐1 in lung tissue specimens with emphysematous lesions. In this study, we have extended this observation by an elaborate analysis of the elastic fibre. Using domain‐specific antibodies to fibrillin‐1, and to other elastin fibre‐associated molecules, lung tissue derived from patients without obvious clinical emphysema, but harbouring various degrees of microscopical emphysematous lesions, was analysed. In addition, the fibrillin‐regulated growth factor TGF‐β was studied. Electron microscopy and biochemical analysis of desmosine (a marker for elastin) were also performed. Results were compared with lung tissue derived from patients with clinical emphysema. Domain‐specific antibodies recognizing the C‐terminal, N‐terminal, and middle part of fibrillin‐1 showed aberrant staining patterns associated with increasing degrees of microscopical emphysema. Staining for elastin, emilin‐1, and fibulin‐2 was, however, not aberrant. TGF‐β staining was markedly increased. On the electron microscopic, but not light microscopical, level, initial elastic fibre degradation was noticed in specimens with microscopical emphysema. Lung specimens from patients with clinical emphysema also displayed fragmented fibrillin‐1 staining and, in addition, displayed extensive degradation of the elastic fibre. The results suggest that fibrillin‐1 anomalies and TGF‐β overexpression are associated with initial events occurring during the emphysematous process. Based on these and other data, a mechanism for emphysematogenesis is proposed. Copyright © 2009 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Gastrointestinal upset following improvement of HbA1con initiation of pump therapy
Authors: Partridge H , Kerr D 
Published: March 2009

AbstractContinuous subcutaneous insulin infusion therapy is being increasingly used across the world in our armamentarium to improve blood glucose control in type 1 diabetes. Significant and rapid declines in HbA1c can be achieved because of the potential to reduce hypoglycaemic episodes and, whilst this is one of our goals in diabetes management, we must be conscious of the possible adverse effects of this. Here we report a case of transient gastroparesis with small bowel bacterial overgrowth following initiation of insulin pump therapy and a rapid drop in HbA1c. Copyright © 2009 John Wiley & Sons.
Pharmacovigilance in traditional chinese medicine safety surveillance
Authors: Wang Hainan , Ye Xiaofei , Gao Qingbin , Wu Cheng , Qian Yifeng , Luo Baozhang , Sun Yalin , He Jia 
Published: March 2009

AbstractPurposeTo give an overview of the current status including problems and efforts about pharmacovigilance in Traditional Chinese Medicine (TCM) safety surveillance.MethodsIt is based on literature review and publicly available data in China.ResultsTCM led to several adverse drug reactions (ADRs) during the past few years and pharmacovigilance about TCM remained as a problem though great effort had been made to improve it.ConclusionsPharmacovigilance in TCM is still facing many challenges in playing critical roles in China. More attention should be paid to pharmacovigilance in TCM safety surveillance. Copyright © 2009 John Wiley & Sons, Ltd.
A comparison of mycophenolate use in Australia and Northern Europe, and the impact on the pharmaceutical benefits scheme
Authors: Staatz Christine E. , Smith Alesha J. , Tett Susan E. 
Published: March 2009

AbstractPurposeThe aim of this study was to characterise utilisation of mycophenolate in Australian transplant recipients from 2001 to 2007; to identify specific patterns of mycophenolate mofetil and enteric‐coated mycophenolate sodium usage; to examine expenditure on mycophenolate prescription and to compare Australian usage with Danish, Finish and Netherlands populations.MethodsData on mycophenolate usage were obtained from Medicare Australia, Finish and Danish Medicines Agency and Netherlands Healthcare Insurance Board databases. Utilisation of mycophenolate was described as daily defined dose (DDD/per 1000 population/day).ResultsFrom 2001 to 2007, utilisation of mycophenolate in Australia increased approximately 30‐fold. In 2007, mycophenolate sodium accounted for 8.3% of mycophenolate total DDDs. In 2007, AUD$4 890 000 was spent on mycophenolate prescription. In 2006, utilisation of mycophenolate was five‐ to eight‐fold higher in Northern Europe compared to Australia. Renal transplant rates per 1000 population/year were similar across countries.ConclusionsDifferences in the rate of mycophenolate utilisation between Northern Europe and Australia exist and may be due to differences in approved indications between countries, prescribing habits, or because of a more mature market in Europe. If the Australian market increases to that of North Europe the cost of prescribing mycophenolate will eventually be in the vicinity of AUD$20–80 million. Copyright © 2009 John Wiley & Sons, Ltd.
Influence of reaction conditions on the formation of nanotubes/nanoparticles of polyaniline in the presence of 1‐amino‐2‐naphthol‐4‐sulfonic acid and applications as electrostatic charge dissipation material
Authors: Bhandari Hema , Bansal Vineet , Choudhary Veena , Dhawan Sundeep K 
Published: March 2009

AbstractBACKGROUND: Poly(1‐amino‐2‐naphthol‐4‐sulfonic acid) and its copolymers with aniline are a new class of conducting polymers which can acquire intrinsic protonic doping ability, leading to the formation of highly soluble self‐doped homopolymers and copolymers. Free OH and NH2 groups in the polymer chain can combine with other functional groups that could be present in protective paints which can thus be successfully used as antistatic materials.RESULTS: This paper reports the formation of nanotubes of polyaniline on carrying out oxidative polymerization of aniline in the presence of 1‐amino‐2‐naphthol‐4‐sulfonic acid (ANSA) in p‐toluenesulfonic acid (PTSA) as an external dopant. The presence of SO3H groups in the ANSA comonomer allows the copolymer to acquire intrinsic protonic doping ability. The polymerization mechanism was investigated by analysing the 1H NMR, 13C NMR, Fourier transform infrared and X‐ray photoelectron spectra of the copolymers and homopolymers, which revealed the involvement of OH/NH2 in the reaction mechanism. Scanning and transmission electron microscopy showed how the reaction route and the presence of a dopant can affect the morphology and size of the polymers. Static decay time measurements were also carried out on conducting copolymer films prepared by blending of 1 wt% of copolymers of ANSA and aniline with low‐density polyethylene (LDPE) which showed a static decay time of 0.1 to 0.31 s on dissipating a charge from 5000 to 500 V.CONCLUSION: Copolymers of ANSA with aniline were synthesized in different reaction media, leading to the formation of nanotubes and nanoparticles of copolymer. Blends of 1 wt% of PTSA‐ and self‐doped copolymers of ANSA and aniline with LDPE can be formulated into films with effective antistatic properties. Copyright © 2009 Society of Chemical Industry
Cure reaction of multi‐walled carbon nanotubes/diglycidyl ether of bisphenol A/2‐ethyl‐4‐methylimidazole (MWCNTs/DGEBA/EMI‐2,4) nanocomposites: effect of carboxylic functionalization of MWCNTs
Authors: Zhou Tianle , Wang Xin , Wang Tianchi 
Published: March 2009

AbstractBACKGROUND: The aim of this work was to study, using differential scanning calorimetry, the effect of carboxylic functionalization of multi‐walled carbon nanotubes (MWCNTs) on the cure reaction of MWCNTs/diglycidyl ether of bisphenol A/2‐ethyl‐4‐methylimidazole (MWCNTs/DGEBA/EMI‐2,4) nanocomposites. This is important for the practical design, analysis and optimization of novel materials processing.RESULTS: Comparing the influence of non‐functionalized MWCNTs and carboxyl‐functionalized MWCNTs, it was found that, at the initial curing stage, both MWCNTs act as catalyst and COOH functionalization of MWCNTs has a catalytic effect on the curing process. Then, at the later curing stage, non‐functionalized MWCNTs prevent the occurrence of vitrification, whereas COOH functionalization of MWCNTs promotes vitrification. Non‐functionalized MWCNTs decrease the degree of curing, as evidenced by lower total heat of reaction and lower glass transition temperatures of nanocomposites compared to neat epoxy; however, COOH functionalization of MWCNTs increases the degree of curing.CONCLUSION: For the development of composites, COOH functionalization of MWCNTs could bring a positive influence to the composite process. Its acceleration of cure could help shorten pre‐cure time or lower pre‐treatment temperature, and its effect of promoting vitrification could help shorten post‐cure time or lower post‐treatment temperature. Copyright © 2009 Society of Chemical Industry
Hidden chemistry in phenoxyl radical (C6H5O•) coupling reaction mechanism revealed
Authors: Das Tomi Nath 
Published: March 2009

AbstractA novel hidden reaction of the phenoxyl radical (C6H5O•) with a specific daughter is found to significantly alter its hitherto accepted coupling reactions' scheme. Transient characterizations and mechanistic evaluations in highly acidic to strongly alkaline aqueous medium reveal this concurrent reaction competing favorably in nanosecond–microsecond time‐scale with the five distinct C6H5O• + C6H5O• reactions, which produce various phenolic end‐products as reported earlier (M. Ye and R. H. Schuler, J. Phys. Chem. 1989, 93, 1898). Presently, only the symmetric 4,4′‐dioxo transient precursor, OC6H5H5C6O that leads to the stable 4,4′‐biphenol product, gets partially oxidized by a fraction of remaining C6H5O•. The resulting secondary transient •C12H9O2 radical is generated at diffusion‐controlled rate, k > 5.0 × 109 M−1 s−1, and follows an independent chemistry. Consequently, when the previously reported five coupled end product distribution ratios were appropriately updated, the respective fractional values revealed a closer match for the symmetric 2,2′‐ and 4,4′‐biphenols with their suggested coupling reaction branching probabilities based on the atomic spin‐density distributions in the C6H5O• radical (P. Neta, R. W. Fessenden, J. Phys. Chem., 1974, 78, 523). Results also suggest that in the remaining fraction, differential solvation in aqueous medium of various orientation‐related encounter complexes (C6H5O…C6H5O) formed during coupling favors rearrangement only toward 2,4′‐biphenolic product, at the cost of 2‐ and 4‐phenoxyphenolic species. Copyright © 2009 John Wiley & Sons, Ltd.