bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and Characterization of Bifunctional SiO2@(Y0.95–xGdxEu0.05)2O3 Nanocomposites for Magnetic Resonance and Optical Imaging
Authors: Liu Huan , Li Li , Tian Xiu‐Mei , Hu Wen‐Yong , Kuang Xiao‐Yan , Shao Yuan‐Zhi 
Published: October 2012

AbstractThe development of multimodal contrast agents for magnetic resonance (MR) optical imaging has attracted considerable attention due to the combination of both high spatial and temporal resolution of MR imaging with the sensitivity of optical imaging. In this work, a form of dual functional nanocomposites SiO2@(Y0.95–xGdxEu0.05)2O3 (x = 0–0.95) with core–shell structures have been synthesized for magnetic resonance and optical imaging. Based on the results of transmission electron microscopy (TEM), (Y0.95–xGdxEu0.05)2O3 nanoshells of around 8 nm were successfully coated onto amorphous SiO2 nanocores (ca. 115 nm in diameter). The XRD patterns indicate that the shell is crystalline after annealing. Under excitation with UV light (250 nm), the Eu3+ ions in the core–shell nanocomposites of SiO2@(Y0.95–xGdxEu0.05)2O3 mainly exhibit their characteristic red emission (612 nm, 5D0–7F2); increasing the content of Gd increased the luminescent intensity of the nanocomposites significantly. The relationship between T1‐weighted MR imaging and the amount of doped Gd (x) was also investigated. It was found that the highest MR imaging signal intensity was obtained at x = 0.45. In vitro fluorescence imaging indicated that the monodisperse nanoparticles of SiO2@(Y0.95–xGdxEu0.05)2O3 were successfully internalized by RAW 264.7 cells and that they show bright intracellular luminescence. Furthermore, this facile precipitation method may be readily extended to the synthesis of SiO2@(Y0.7Yb0.18Er0.02Gd0.1)2O3 nanocomposites, which present both up‐conversion luminescence and MR contrast properties. The nanocomposites investigated in this study have a certain potential to serve as a versatile material for multimodal imaging probes.
Atropisomeric Chiral Probes to Study the Supramolecular Organization in Porphyrin Self‐Assemblies
Authors: Chappaz‐Gillot Cyril , Canard Gabriel , Andreoli Federico , Vanthuyne Nicolas , Giorgi Michel , Naubron Jean‐Valère , Monnier Valérie , Rosas Roselyne , Roussel Christian , Balaban Teodor Silviu 
Published: October 2012

AbstractA noncatalysed nucleophilic aromatic substitution was used to prepare the (bacterio)chlorophyll mimics 2‐Zn, 3‐Zn, 4‐Zn and 5‐Zn. The localisation of the two recognition groups on the same side of the porphyrin macrocycles in 2‐Zn, 4‐Zn and 5‐Zn produces, through metal–ligand interactions, oligomers that display both H‐ and J‐type aggregates. These supramolecular architectures were confirmed by the introduction of optically pure atropisomers in 5‐Zn, which produces chiral aggregates. The UV/Vis and electronic circular dichroism spectra of all aggregates are used to propose an excitonic splitting mode that would correspond to this dual type of chromophoric self‐assembly.
A Diels–Alder/Retro‐Diels–Alder Approach for the Enantioselective Synthesis of Microbial Butenolides
Authors: Citron Christian A. , Wickel Susanne M. , Schulz Barbara , Draeger Siegfried , Dickschat Jeroen S. 
Published: October 2012

AbstractSeveral volatile lactones have been identified from the endophytic fungus Geniculosporium sp. isolated from the rockrose Cistus monspeliensis, commonly known as Montpelier cistus. The fungal volatiles were collected from agar‐plate cultures by using a closed‐loop stripping apparatus and the headspace extracts were analysed by GC–MS. Structures for these lactones were proposed from their mass spectral data. The suggested structures were verified by synthesis of reference compounds through a Diels–Alder/retro‐Diels–Alder approach. This synthetic method was also successfully applied in the synthesis of butenolides that are signalling molecules from streptomycetes. For the enantioselective synthesis of these butenolides a modified route including an enantioselective Diels–Alder reaction was used.
A Microwave‐Assisted Domino Benzannulation Reaction towards Functionalized Naphthalenes, Quinolines, and Isoquinolines
Authors: Wang Yuqin , Tan Cun , Zhang Xiaofei , He Qian , Xie Yuyuan , Yang Chunhao 
Published: October 2012

AbstractAn efficient palladium/copper‐catalyzed domino reaction was developed to yield functionalized naphthalenes, quinolines, and isoquinolines. The reactions of various substituted 1‐phenylprop‐2‐yn‐1‐ols containing electron‐donating (EDG) and electron‐withdrawing (EWG) groups and 1‐heteroarylprop‐2‐yn‐1‐ols worked well with this procedure. Both electron‐rich and ‐deficient aryl halides were satisfactory substrates for this reaction. This domino benzannulation process involves a Sonogashira cross‐coupling reaction, followed by isomerization to a chalcone, and finally an intramolecular condensation reaction.
Spectrally selective and adaptive surfaces for protection against radiative heating: ITO and VO2
Authors: Försth Michael , Zhao Shuxi , Roos Arne 
Published: October 2012

SUMMARYTwo surface materials for reducing absorptivity of heat radiation from fires have been investigated. The first is VO2, which is a thermochromic material. When the temperature of a VO2 surface increases over a certain temperature, it switches, ideally, from infrared (IR)‐absorbing to IR‐reflecting. VO2 window coatings are still on a research level, yet to be commercialized. In this study, VO2 powder available on the market was investigated. The thermochromic effect could be identified but was not large enough to significantly improve the fire properties of treated surfaces. Some thoughts concerning how to improve the performance of VO2 are discussed. The second investigated material is indium tin oxide (ITO), which is a so called low‐e coating, which means that it has low emissivity and absorptivity in the IR part of the spectrum. ITO is spectrally selective in the sense that it transmits visible light while reflecting a large fraction of the IR radiation, which is a rare property for surfaces in general but a typical property of thin electrically conducting non‐metallic films. It is shown that the application of ITO to poly(methyl methacrylate) (PMMA) significantly improves its fire properties. ITO coating is a mature technology already in widespread use today in the electronics industry. Copyright © 2012 John Wiley & Sons, Ltd.
Seasonal variation in the phytomass, chemical composition and nutritional value of Azolla filiculoides Lam. along the water courses in the Nile Delta, Egypt
Authors: Shaltout Kamal H. , El‐Komi Thanaa M. , Eid Ebrahem M. 
Published: October 2012

AbstractThe present study aims to assess phenological behaviour, phytomass production, chemical composition and nutritional value of Azolla filiculoides in the water courses of the Nile Delta, Egypt. The sampling process was carried out seasonally using twenty‐five plots (each of 1 × 1 m) distributed along 15 irrigation canals and 10 drainage canals in the study area. Sprouting of A. filiculoides had its maximum activity during winter, vegetative growth during spring and summer and withering during autumn. Maximum seasonal phytomass (285.2 g DW m‐2) was found during spring. The annual mean was significantly higher in drainage canals (278.3 g DW m‐2) than in irrigation canals (144.4 g DW m‐2). The concentrations of Ca, Mg and Na in A. filiculoides from drainage canals were significantly higher than in those from irrigation canals. Regarding the type of water courses, there were no significant differences in organic contents and nutritive values between the irrigation and drainage canals. The analysis of growth characteristics indicated that A. filiculoides can grow quite well in drainage canals; its macronutrient (N, Ca, Mg, Na and Fe) contents are high enough to allow it to be used as a bio‐fertilizer. On the other hand, A. filiculoides could be considered as a ‘nutrients and heavy metals remover’ especially in drainage canals for wastewater treatment if the plant is harvested during its maximum phytomass. As feed supplement for animals, this plant could be considered as excellent forage because its high levels of carbohydrate, protein, crude fat, total digestible nutrients and the lower crude fiber contents (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
THE NATURE AND FUNCTION OF THE IN‐FIELD RAINWATER HARVESTING SYSTEM TO IMPROVE AGRONOMIC SUSTAINABILITY
Authors: van Rensburg L. D. , Botha J. J. , Anderson J. J. , Hensley M. 
Published: October 2012

ABSTRACTHensley et al. (2000) proposed an in‐field rainwater harvesting (IRWH) technique for rural farmers located east of Bloemfontein South Africa, a semi‐arid environment. This technique combines the advantages of water harvesting, no‐till and basin tillage to stop ex‐field runoff on high clay soils. The full agronomic potential of the IRWH technique has not, however, been reached because the main cause of water loss is evaporation. Evaporation dominates the hydrological cycle in semi‐arid environments. This paper reviews the nature and design of the IRWH system, specifically the effect of mulch type on evaporation and yield. The effect of mulch type on yield is described by an infiltration ratio of the basin versus the runoff area over a period of three years. The function of the basin and catchment area is also discussed. The function of the basin area was to stop ex‐field runoff completely, to maximize infiltration and to store the collected water in the soil layers beneath the evaporation sensitive zone. The catchment area was designed to promote in‐field runoff and to act as a storage medium for water. Results from this research provide a new perspective on mulch management within water harvesting systems. Copyright © 2012 John Wiley & Sons, Ltd.
IN‐FIELD RAINWATER HARVESTING: MECHANICAL TILLAGE IMPLEMENTS AND SCOPE FOR UPSCALING
Authors: van Rensburg L. D. , Bothma C. B. , Fraenkel C. H. , Le Roux P. A. L. , Hensley M. 
Published: October 2012

ABSTRACTAround the world there is a large difference in crop yields between those obtained by commercial and subsistence farmers. There are many biophysical and socio‐economic reasons for this yield gap. With regard to in‐field rain water harvesting (IRWH), it is considered that crop yields in smallholder farms could be significantly improved by mechanizing the land as part of an IRWH tillage approach. This paper therefore presents the findings of a study that assessed the implements and procedures for applying IRWH. It involved the development of ridge and puddle ploughs. The subsistence farmers who evaluated the performance of the implements were generally satisfied with them. A five‐step procedure was developed for the application of the implements, and valuable lessons were learned with the first large‐scale demonstration of IRWH on croplands. Against the background of these positive results, the scope for upscaling was also explored. It was estimated that IRWH can probably be applied on millions of hectares in sub‐Saharan Africa, and particularly in the Southern African Development Community. Mechanization of IRWH should potentially contribute towards improving food security in sub‐Saharan Africa. Copyright © 2012 John Wiley & Sons, Ltd.
COMPARISON OF ENERGY AVAILABLE FOR EVAPOTRANSPIRATION UNDER IN‐FIELD RAINWATER HARVESTING WITH WIDE AND NARROW RUNOFF STRIPS
Authors: Tesfuhuney Weldemichael A. , Walker Sue , Van Rensburg Leon D. 
Published: October 2012

ABSTRACTThe aim of the study was to quantify the energy balance components and to estimate evapotranspiration (ET) from maize crops under in‐field rainwater harvesting with wide and narrow runoff strip length (RSL) treatments. Based on micrometeorological measurements, energy balance components were compared for selected days under dry and wet conditions. Diurnal changes and daily evaporation flux peaks around midday were analysed. The average fraction of available energy was used to evaluate the efficiency of converting available energy to latent heat flux (LE). The results indicated that LE was higher in wide compared to narrow RSL during dry and wet conditions. However, sensible heat showed lower values on wide RSL during wet conditions due to the advective effect of the runoff area. The wide RSL with a higher basin leaf area ratio (BLAR) of 2.43 had more ET and used more energy on evaporating water compared to narrow runoff with a lower BLAR of 1.42. Wide runoff strips converted the higher available energy more efficiently into a higher biomass production than the narrow RSL. During wet days, the wide RSL used more than 70% of the available energy, while the narrow RSL response to the available energy (63%) was stronger during dry compared to wet days. Copyright © 2012 John Wiley & Sons, Ltd.
AN OVERVIEW OF INDIGENOUS, INDIGENISED AND CONTEMPORARY WATER HARVESTING AND CONSERVATION PRACTICES IN SOUTH AFRICA
Authors: Denison J. A. , Wotshela L. 
Published: October 2012

ABSTRACTA scoping study has found that there are at least 15 water harvesting and conservation methods in use across South Africa, with minor variations and combinations also evident. Some of these are indigenous in that they were developed locally, others are indigenised, meaning they are hybrid solutions incorporating external influences, and finally, there are contemporary practices introduced more recently by scientists or development agencies. The techniques that were identified covered a wide range of scales in differing socio‐economic and agricultural contexts, such as the tens of thousands of hectares of commercially oriented floodwater harvesting in the Northern Cape, called thesaaidam(literally ‘planting‐dam’), to micro‐terracing in Mpumalanga. Our review concluded that while there are some indigenous water harvesting and conservation (WHC) practices, these are notably few compared with other places in the world. This is explained by historical settlement patterns in the wetter part of South Africa, with low land pressure, and an indigenous culture which placed more emphasis on pastoral than cropping practices. Indigenous and indigenised practices, which are locally well adapted, have inherent sustainability and present an opportunistic platform from which to inform new interventions in support of improved agricultural production. Copyright © 2012 John Wiley & Sons, Ltd.
SOCIAL CAPITAL IN A RAINWATER‐HARVESTING PROJECT IN RURAL SOUTH AFRICA
Authors: Esterhuyse Petronella 
Published: October 2012

ABSTRACTThis paper examines social aspects within and amongst households in two selected villages in the Thaba Nchu area in the Free State Province, South Africa. In a semi‐arid environment and low potential for dry croplands, techniques of rainwater harvesting were introduced to enable individual households to improve the level of their food production. This intervention could be seen from a purely biophysical and economic perspective, but the sociocultural domain is just as important for the successful outcome of the intervention. The assumption is that water utilisation and food production are socially embedded in the sense that individuals with different levels of support, are bound together in a situation of risk and uncertainty to collectively find ways to deal with scarcity in resources. The potential for internal conflict and consequent failure or disruption of development projects are real threats to the outcome of any intervention. The paper characterises selected aspects of social capital, namely social support, social networks and cohesion, which are regarded as important factors to consider in the planning and executing of interventions in the field of small‐scale food production. Copyright © 2012 John Wiley & Sons, Ltd.
ALLEVIATING HOUSEHOLD FOOD INSECURITY THROUGH IN‐FIELD RAINWATER HARVESTING
Authors: Botha J. J. , van Rensburg L. D. , Anderson J. J. , Hensley M. , Baiphethi M. N. 
Published: October 2012

ABSTRACTPoverty and food insecurity are generic to the rural communities of poor countries in the sub‐Saharan African region. South Africa, with its huge rural population, is not excluded from poverty. In the Thaba Nchu area of the Free State Province, South Africa, where the study was conducted, 54% of the population was food insecure in 2006 owing partly to high unemployment, low levels of education and collapsed agricultural production, amongst other things. In order to contribute towards the reduction of food insecurity, agricultural techniques, specifically the in‐field rainwater harvesting (IRWH) technique, suited to the climate were introduced and households were encouraged to use these on their homestead gardens. This was done to help improve food production and ensure household food security. This paper reports on the rapid spread of the IRWH technique amongst households in the Thaba Nchu area. Household members obtained the necessary skills to apply the technique in an innovative manner in their homesteads to produce a variety of cash and vegetable crops. Results indicated that excess produce could be sold on local markets, which could promote sustainable livelihoods among the adopting households.
Influence of a layer‐by‐layer‐assembled multilayer of anti‐CD34 antibody, vascular endothelial growth factor, and heparin on the endothelialization and anticoagulation of titanium surface
Authors: Liu Shihui , Liu Tao , Chen Junying , Maitz Manfred , Chen Cheng , Huang Nan 
Published: October 2012

AbstractThe endothelialization of the metal surface of vascular stents came into focus as a new method for improving the biocompatibility of intravascular stents. This article has its focus on building a biofunctional layer on the activated titanium surface with anti‐CD34 antibody, vascular endothelial growth factor (VEGF), and heparin by a layer‐by‐layer (LBL) self‐assembly technique, to promote the endothelialization of the surface. When compared with titanium surface, the number of adhered endothelial progenitor cells (EPCs) on LBLs increased 47.1% after 5 days culture, meanwhile the proliferation rate of EPCs on LBLs during 5 days culture also exhibit significantly improvement. The results of blood compatibility evaluation clearly show that the LBLs reduce the number of adhered and activated blood platelets (adhered: Ti 83% vs. LBL <20% and activated: Ti 57% vs. LBL 19%), and the activated partial thromboplastin time of the LBL surface prolonged about 20 s in compared with platelet‐poor plasma. The assembled LBL thus improves the thromboresistance of the titanium surface. The presented biofunctional multilayer of anti‐CD34, VEGF, and heparin on titanium can significantly improve the blood compatibility and the endothelialization of a medical device. The biofunctional layer supports generation of a new endothelium onto titanium surface by capturing EPCs and oriented differentiation. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.
Polyelectrolyte Complexes: Phase Diagram and Intrinsic Viscosities of the System Water/Poly(2‐vinylpyridinium‐Br)/Poly(styrene sulfonate‐Na)
Authors: Bercea Maria , Nita Loredana‐Elena , Eckelt John , Wolf Bernhard A. 
Published: October 2012

AbstractIn contrast to all earlier work on that subject, measurements are performed at high dilution up to total polymer concentrations wpol of 0.5 wt%. Aqueous solutions of poly(2‐vinylpyridinium‐Br) and of poly(styrene sulfonate‐Na) are only fully miscible if wpol < 0.02 wt%. Decomposition into two liquid phases is observed upon an increase in wpol, where the extension of the miscibility gap is considerably larger at 60 than at 25 °C. Viscosity measurements demonstrate that the formation of the polyelectrolyte complexes may take hours. The intrinsic viscosity of the polyanion turns out to be 20 times larger than that of the polycation and to be much more sensitive toward the addition of extra salt. The [η] values of the blend pass a minimum as a function of its composition.
Evaluation of normal fetal pulmonary veins using B‐flow imaging with spatiotemporal image correlation and by traditional color Doppler echocardiography
Authors: Zhang Ying , Ding Changwei , Fan Miao , Ren Weidong , Guo Yajun , Sun Wei , Cai Ailu 
Published: October 2012

ABSTRACTObjectiveThe purpose of our report is to evaluate the use of color Doppler echocardiography (CDE) with four chamber view (4CV), scanning around left atrium, and four‐dimensional echocardiography with B‐flow imaging and spatiotemporal image correlation (4D BF‐STIC) in detecting fetal pulmonary veins at 17 to 40 weeks’ gestation.MethodsThis was a prospective study. Color Doppler echocardiography with 4CV, scanning around left atrium, and 4D BF‐STIC were used to detect the pulmonary veins in 460 normal fetuses at 17 to 40 weeks of gestation. Routine prenatal screening was used to confirm that the fetuses were in good health with no cardiac or extra cardiac anomalies. All patients underwent follow up at one year. Twenty‐two patients were excluded from the study. The number of pulmonary veins visualized using each method was recorded and then compared in six subgroups according to gestational age.ResultsFour‐dimensional echocardiography with B‐flow imaging and spatiotemporal image correlation was the best method to detect the greatest number of pulmonary veins between 17 and 31 weeks of gestation. Scanning around left atrium detected more pulmonary veins than the traditional 4CV method throughout the gestational period.ConclusionsThe scanning around left atrium method proved to be the most suited for detecting pulmonary veins in clinical practice. 4D BF‐STIC was superior in detecting the greatest number of pulmonary veins before 32 gestational weeks, but had limited clinical usage because it was very time‐consuming and experience‐dependent. The 4D method should be considered as a complement to traditional two‐dimensional sonography, because it facilitates understanding of the anatomy and the spatial relationships of the cardiac structures. © 2012 John Wiley & Sons, Ltd.
Electrospun gelatin/nylon‐6 composite nanofibers for biomedical applications
Authors: Pant Hem Raj , Kim Cheol Sang 
Published: October 2012

AbstractWe describe the preparation and characterization of gelatin‐containing nylon‐6 electrospun fibers and their potential use as a bioactive scaffold for tissue engineering. The physicochemical properties of gelatin/nylon‐6 composite nanofibers were analyzed using field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, TGA and contact angle and tensile measurements. FE‐SEM and TEM images revealed that the nanofibers were well oriented and showed a good incorporation of gelatin. FTIR spectroscopy and TGA also revealed that there was good interaction between the two polymers at the molecular level. The adhesion, viability and proliferation properties of osteoblast cells on the gelatin/nylon‐6 composite nanofibers were analyzed by an in vitro cell compatibility test. Our results suggest that the incorporation of gelatin can increase the cell compatibility of nylon‐6 and therefore the composite mat obtained has great potential in hard tissue engineering. © 2012 Society of Chemical Industry
A new microemulsion approach for producing molecularly imprinted polymers with selective recognition cavities for gallic acid
Authors: Nicolescu Tanta V. , Meouche Walid , Branger Catherine , Margaillan André , Sarbu Andrei , Fruth Victor , Donescu Dan 
Published: October 2012

AbstractBulk and microemulsion systems were studied in order to obtain molecularly imprinted copolymers selective for gallic acid. Both systems contained acrylic acid as the functional monomer and ethylene glycol dimethacrylate as crosslinker. Microemulsion formation was confirmed by refractive index measurements and by conductivity analyses. Simple uptake tests revealed higher affinities for the microemulsion polymers; a 3.55 imprinting factor and a 0.275 g gallic acid (g polymer)–1 adsorption capacity were recorded. Competitive uptake tests, from an oak bark extract, were in agreement with the simple uptake results and BET analyses. Microemulsion polymer particles selectively bind 4.58 times more gallic acid molecules relative to other competitor species.