bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal preservation of the shark retina for ultrastructural analysis: An assessment of chemical, microwave, and high‐pressure freezing fixation techniques
Authors: Harahush Blake K. , Green Kathryn , Webb Rick , Hart Nathan S. , Collin Shaun P. 
Published: May 2012

AbstractRecent advances in microwave chemical fixation (MCF) and/or high pressure freezing (HPF) combined with transmission electron microscopy have resulted in superior ultrastructural detail in a variety of tissue types. To date, selachian tissue has been fixed and processed using only standard chemical fixation (CF) methods, and the resulting ultrastructure has been less than ideal. In this study, we compared the ultrastructure of the fragile retinal tissue from the brown banded bamboo shark, Chiloscyllium punctatum, obtained using CF, MCF, and HPF methods. For all fixation protocols, ultrastructural preservation was improved by keeping the tissue in oxygenated Ringer solution until the time of fixation. Both MCF and HPF produced superior retinal ultrastructure compared to conventional CF. Although HPF occasionally resulted in very high quality ultrastructure, microwave fixation was almost comparable, quicker and far more consistent. Microsc. Res. Tech. 75:1218–1228, 2012. © 2012 Wiley Periodicals, Inc.
Macroscopic and microscopic analysis of the tongue of the common opossum (Didelphis marsupialis)
Authors: Mançanares Celina A.F. , Santos Amilton C. , Piemonte Maria V. , Vasconcelos Bruno G. , Carvalho Ana F. , Miglino Maria A. , Ambrósio Carlos E. , Neto Antônio C. Assis 
Published: May 2012

AbstractWe performed a macroscopic and microscopic study of the tongues of common opossums, Didelphis marsupialis, from South America. We studied two males and two females. We collected morphometric data on the tongue with precision calipers. For the light microscopy and scanning electron microscopy analyses, we fixed tissue fragments in 10% formaldehyde and 2.5% glutaraldehyde, respectively. The opossum tongues averaged 5.87 ± 0.20 cm in length, 3.27 ± 0.15 cm in width at the lingual body, and 3.82 ± 0.15 cm in width at the root. The mean thickness of the lingual body was 1.8 ± 0.1 cm, and the thickness of the root was 3.82 ± 0.15 cm. Sharp filiform papillae were scattered across the entire tongue; conical filiform papillae occurred on the lingual body and tongue tip; fungiform papillae were scattered among the filiform papillae on the lingual body and tongue tip; and there were three vallate papillae at the root of the tongue. We found two strands of papillary projections in the tongue root. Despite the low variability observed in the lingual papillae, the morphological data obtained in this study may be related to the opossum's diverse food habits and the extensive geographic distribution of the species throughout America. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
Extract of white button mushroom affects skin healing and angiogenesis
Authors: Lam W.P. , Wang C.M. , Tsui T.Y. , Wai M.S , Tang H.C. , Wong Y.W. , Lam L.H. , Hui L.K. , Yew D.T. 
Published: May 2012

AbstractWhite button mushroom extract was examined in this study on (1) its potential effect on angiogenesis in chorioallantoic culture and (2) its recovering effect on the skin after injury in the ICR mice. Methods used included TUNEL assay on apoptosis, immunohistochemistry for vascular endothelial growth factor (VEGF), proliferative cell nuclear antigen (PCNA), epidermal growth factor (EGF), transforming growth factor β (TGF‐β), and immune factor CD4 and western blotting. The results of chorioallantoic culture showed that the mushroom treatment led to significant increase in densities of VEGF sites. In the skin injury, ICR mice model increased EGF, PCNA, and collagen fibers, along with decrease of TUNEL positive apoptotic cells and limited reaction of TGF‐β and CD4 indicated that white button mushroom extract appeared to have beneficial effects on skin in regeneration and after injury. Microsc. Res. Tech. 2012. © 2012 Wiley Periodicals, Inc.
QUANTITATIVE ASSESSMENT OF DEGRADATION CLASSIFICATIONS for DEGRADED ALPINE MEADOWS (HEITUTAN), SANJIANGYUAN, WESTERN CHINA
Authors: Li X.‐L. , Perry G. L. W. , Brierley G. , Sun H.‐Q. , Li C.‐H. , Lu G.‐X. 
Published: May 2012

ABSTRACTImproving our understanding of abiotic and biotic thresholds that are transgressed during ecosystem degradation is vital for effective landscape‐level restoration. Establishing logical and consistent typologies of degradation is an important first‐step in this process. Areas of degraded alpine meadow in western China are referred to as Heitutan (or ‘black soil beach’) and cover vast areas. Previously, four classes of grassland degradation have been differentiated in this large area: non‐degraded alpine meadow and moderate, severe and extreme Heitutan. We evaluated existing field‐based classifications of Heitutan in the Sanjiangyuan region, and examined the criteria on which these classifications are made, by using multivariate statistical approaches. First, we asked whether existing qualitative classifications, based on vegetation cover and the abundance of impalatable plant species, adequately describe the nature of degradation at different locations. We then used a suite of vegetation and soil measures collected across 175 sites spanning a range of degradation conditions to develop a new quantitative assessment of degradation across the alpine meadows of the Qinghai‐Tibetan Plateau. Hierarchical classification highlights two broad classes of degradation: non‐degraded alpine meadow and degraded Heitutan. The non‐degraded category effectively combines the non‐degraded grassland and moderate classes, whereas the degraded Heitutan combines the severe and extreme Heitutan classes. Ordination analyses suggest that the four previously recognized classes of degradation intergrade. Of the 14 biophysical variables used to classify subsites on the basis of their degradation, bare ground area and vegetation cover are the two most useful predictors of grassland condition and associated ecological threshold conditions. Copyright © 2012 John Wiley & Sons, Ltd.
ASSESSING THE IMPACT OF THE SLOPING LAND CONVERSION PROGRAMME ON RURAL SUSTAINABILITY IN GUYUAN, WESTERN CHINA
Authors: König H. J. , Zhen L. , Helming K. , Uthes S. , Yang L. , Cao X. , Wiggering H. 
Published: May 2012

ABSTRACTThe goal of China's sloping land conversion programme (SLCP) is to combat soil erosion and to reduce rural poverty. An ex‐ante assessment of possible SLCP impacts was conducted with a focus on rural sustainability, taking the drought‐prone region of Guyuan in Western China as an example. The Framework for Participatory Impact Assessment (FoPIA) was used to conduct two complementary impact assessments, one assessing SLCP impacts at regional level and a second one assessing alternative forest management options, to explore possible trade‐offs among the economic, social and environmental dimensions of sustainability. Regional stakeholders assessed the SLCP to be capable of reducing soil erosion but felt it negatively affected rural employment, and a further continuation of the Programme was advocated. Assessment of three forest management scenarios by scientists showed that an orientation towards energy forests is potentially beneficial to all three sustainability dimensions. Ecological forests had disproportionate positive impacts on environmental functions and adverse impact on the other two sustainability dimensions. Economic forests were assessed to serve primarily the economic and social sustainability dimensions, while environmental impacts were still tolerable. The FoPIA results were evaluated against the available literature on the SLCP. Overall, the assessment results appeared to be reasonable, but the results of the regional stakeholders appeared to be too optimistic compared with the more critical assessment of the scientists. The SLCP seems to have the potential to tackle soil erosion but requires integrated forest management to minimize the risk of water stress while contributing to economic and social benefits in Guyuan. Copyright © 2012 John Wiley & Sons, Ltd.
A FUZZY RULE BASE APPROACH FOR DEVELOPING A SOIL PROTECTION INDEX MAP: A CASE STUDY in the UPPER AWASH BASIN, ETHIOPIAN HIGHLANDS
Authors: Oinam B. C. , Marx W. , Scholten T. , Wieprecht S. 
Published: May 2012

ABSTRACTLand use practices and vegetation cover distribution are considered to be the most important dynamic factors that influence the land degradation or the soil erosion of a region. In this study, a Soil Protection Index (SPI) is defined as a function of land use practices and intensity of vegetation cover. This index is used to map the relative degree of protection of topsoil from being eroded by external effects such as rainfall and overland flow. A fuzzy rule‐based model integrated within ArcGIS® has been set‐up and tested with the aim to develop SPI maps. The amount of vegetation cover distribution, that is, Normalized Difference Vegetation Index as proxy parameter and Land Use–Land Cover map are chosen as fuzzy input parameters for the SPI as the desired system output. The approach was tested in the Upper Awash basin in Ethiopia. The output SPI map was qualitatively evaluated against the expert‐defined land degradation risk class, and it was found that locations that are mapped with ‘low and very low’ SPI classes at different time periods of the year have a high potential land degradation risk. Furthermore, socio‐economic data (‘population and livestock densities’) and environmental parameters (‘altitude and soil erodibility’) for the region are used to correlate with the SPI map as an indirect method of evaluation. It is found that population and livestock density explained 68 per cent of the spatial distribution pattern of predicted SPI and an adjusted R‐squared value of 0·681 (p < 0·05) was obtained. It was also found that the SPI distribution over the region for two different time periods, that is, January and July 2001, correlated positively (R2 = 0·41 and R2 = 0·51) with the soil erodibility of the region. The transferability and applicability of the model for different environmental settings or landscapes were tested by mapping the SPI of Italy. This SPI map of Italy was compared with the soil erosion map of Italy produced by the European Soil Bureau. It can be concluded that the SPI map reflects the potential land degradation risk distribution of the case‐study region. Results show that a fuzzy rule‐based model can provide useful preliminary information even without detailed and precise data information for developing appropriate strategies for land degradation assessment vital for sustainable land use management. Copyright © 2012 John Wiley & Sons, Ltd.
Analysis of a liquid‐assisted molding process for coating microchannels with an ultraviolet curable polymer
Authors: Boehm Michael W. , Koelling Kurt W. 
Published: May 2012

AbstractInjection molding can be altered to form hollow parts by partially pre‐filling a mold with polymer melt and then injecting a gas into the mold before cooling. The gas will core the center section and in the process force melt into the unfilled portions of the mold. This process is called gas‐assisted injection molding (GAIM) and is a thoroughly studied polymer processing technique. Liquid‐assisted molding follows the same principles as GAIM, except the coring fluid is a liquid of low viscosity. Liquid‐assisted molding of an ultraviolet (UV) curable polymer can be used to coat microchannels, the benefit of which being a smooth and circular cross‐section. Presented here are experiments of the controlled microchannel flow of a long, immiscible liquid thread through a viscous UV curable polymer. The roles of channel geometry and bubble velocity are discussed for square, rectangular, and circular microchannels. Finally, a quasi‐analytical model for calculating the Newtonian coating fluid thickness, when the coring fluid is driven by a constant pressure, was developed using the equation for Poiseuille‐like flow within a square channel. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Effect of volume ratio of acetonitrile to water on the morphology and property of polypyrrole prepared by chemical oxidation method
Authors: Huang Zhenhao , Hu Shuchun , Zhang Nan , Chen Xiaolang , Chen Dan , Jin Qian , Jian Xian 
Published: May 2012

AbstractPolypyrrole (PPY) was prepared by the method of chemical oxidation polymerization in ice bath, and a series of products with different morphology or particle size were obtained through changing volume ratio of acetonitrile to water (VRAW) in the mixed reaction solvents. The structures, morphologies, yield, and conductivities of the as‐prepared PPY were characterized by FTIR, SEM, electronic balance, and Four‐probe conductivity meter. Furthermore, the effect of VRAW on the morphology of the obtained PPY was investigated in detail. As shown from the corresponding results, PPY's average diameter decreased with the increase of VRAW in the range of 1:9 to 4:6, with particle morphology; the film‐shaped PPY was obtained when VRAW was in the scope of 5:5 to 7:3. According to the analysis on the polymerization mechanism of pyrrole in the reaction mixture, the change of PPY's morphology was attributed to the structure change of acetonitrile micelle from spherical structure to double layered structure. As the further study shown, the PPY synthesized at a VRAW of 1:9 shows higher yield and conductivity than which prepared in pure water without acetonitrile; however, the further increase of VRAW results in the decrease of the yield and conductivity. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Influence of carbon nanofibers reinforcement on thermal and electrical behavior of polysulfone nanocomposites
Authors: Nayak L. , Khastgir D. , Chaki T.K. 
Published: May 2012

AbstractCarbon nanofiber (CNF) based polysulfone (PSU) nanocomposites have been developed successfully by a innovative solution mixing technique to explore the effect of state of dispersion and wt% loading of CNFs on different properties of PSU. In order to enhance the interfacial adhesion between CNFs and PSU, CNFs were functionalized by air oxidation. Thermal properties were characterized by using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and it was seen that thermal stability of PSU was increased with increase in CNFs loading. The state of dispersion of CNFs throughout the PSU matrix and PSU–CNFs interaction were confirmed using field emission scanning electron microscopy (FESEM) and high resolution transmission electron microscopy (HRTEM) study. The electrical properties of nanocomposites were studied from direct current (DC) and alternating current (AC) resistivity measurement. DC resistivity registered a very low percolation threshold in‐between 0.5–1 wt% of CNFs loading. DC resistivity of PSU was decreased by nine orders of magnitude with the addition of 1 wt% CNFs loading. Dielectric constant and dissipation factor of nanocomposites were significantly increased with increase in CNFs content in nanocomposites. The enhancement in these properties suggests a great potential application of the resulting nanocomposites as multifunctional materials in various electronics industries. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
High‐performance heat‐sink composites incorporating micron‐sized inorganic fillers and Sn/In metal particles
Authors: Hong Jung‐Pyo , Yoon Sung‐Woon , Hwang Taeseon , Oh Joon‐Suk , Hong Seung‐Chul , Lee Youngkwan , Nam Jae‐Do , Bhuiya Md Mainul Hossain , Kim Kwang J. 
Published: May 2012

AbstractA novel thermal‐barrier composite system was developed by incorporating fusible metal particles in the epoxy matrix system. Using the latent heat of melting, the Sn/In metal particles having melting temperature at 125°C were imbedded in the polymer matrix to suppress the thermal shock and transient temperature variation. The high‐density metal particles were successfully dispersed in the polymer matrix without sinking by incorporating inorganic particles of aluminum nitride (AlN) and boron nitride (BN), which desirably facilitated the heat dissipation to give a high thermal conductivity at around 10 W/m‐K. Under the repeated melting and cooling cycles, the spherical shape of metal particles and the latent heat of melting were retained demonstrating the reversible thermal‐barrier capability of the developed composite system. Under the constant‐heating conditions, it was validated that the temperature rise was delayed by the endothermic melting of Sn/In particles. The developed composite system could find various applications since it could minimize damages caused by the repeated thermal fatigue and/or accidental thermal shock. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Properties and structures of novel cyanate ester/organic rectorite nanocomposites
Authors: Yuan Li , Gu Aijuan , Liang Guozheng , Ma Xiaoyan , Lin Chao , Chen Feng 
Published: May 2012

AbstractOrganic rectorite (OREC) was applied to bisphenol A dicyanate ester (BADCy) resin to develop a novel BADCy/OREC system. The influence of OREC on the reactivity of BADCy was discussed. The morphologies of cured BADCy/OREC systems were investigated by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The static and dynamic mechanical properties as well as the hot water resistance of cured BADCy/OREC systems were evaluated. Results indicate that the addition of OREC can catalyze the reaction of BDACy resin. The intercalated structure and exfoliated structure of silicate platelets may be formed in the cured BADCy/OREC composites. The suitable amount of OREC canimprove the flexural strength, the impact resistance and the hot water resistance of cured BADCy. OREC can maintain the glass transition temperature (Tg) and have slight influence on the dielectric property of cured BADCy. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Mesua ferrea L. seed oil‐based hyperbranched shape memory polyurethanes: Effect of multifunctional component
Authors: Kalita Hemjyoti , Karak Niranjan 
Published: May 2012

AbstractThe bio‐based hyperbranched polyurethanes (HBPUs) have generated immense interest as advanced shape memory materials. In the present investigation, HBPUs were synthesized from poly(ε‐caprolactone)diol as a macroglycol, butanediol as a chain extender, monoglyceride of Mesua ferrea L. seed oil as a bio‐based chain extender, triethanolamine as a branch‐generating moiety (at different percentages), and toluene diisocyanate by a prepolymerization technique using A2 + B3 approach. The structure of the synthesized HBPU was characterized by different techniques. Nuclear magnetic resonance (proton) study indicated the formation of highly branched structure with degree of branching 0.9. The increment of thermal stability from 225 to 260°C and melting point from 50 to 53.5°C with the increase of triethanolamine content was observed. Tensile strength 4–8 MPa, elongation at break 614–814%, impact resistance 0.8–0.95 m, and scratch hardness 2–6 kg increased with the increase of multifunctional moiety content from 0 to 5 wt%. The shape recovery ratio increased with the increase of multifunctional moiety content from 0.21 to 0.95. Thus, the studied HBPUs have the potential to be used as advanced thermoresponsive shape memory materials. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Synthesis of modified silica spheres used for the preparation of dual ultraviolet‐ and thermo‐cured epoxyacrylate/silica composites
Authors: Su Yu‐Chieh , Cheng Liao‐Ping , Don Trong‐Ming 
Published: May 2012

AbstractTo investigate the interfacial effect on properties of epoxyacrylate–silica composites, submicron‐sized silica spheres were synthesized by sol–gel reaction under a basic environment and their surfaces were endowed with vinyl functional groups by further modification with 3‐methacryloxypropyl trimethoxy silane. The pure silica (PS) and the modified silica (MPS) spheres were characterized by Fourier transform infrared, 29Si‐ and 13C‐nuclear magnetic resonance (NMR), scanning electron microscope (SEM), and particle size analyzer. The silica spheres were then added to the presynthesized difunctional epoxyacrylate resin with one vinyl group and one epoxide group at each end, in addition to the photo‐ and thermo‐curing agents. After cure, thermal and mechanical properties of the obtained epoxyacrylate–silica composites were measured and compared. Tensile mechanical properties including initial modulus, ultimate tensile strength, and elongation at break, as well as the fracture energy of the epoxyacrylate–silica composite were all increased by increasing the content of silica spheres. Moreover, the composites filled with MPS had stronger interfacial strength between silica sphere and matrix than those with PS and thus exhibited an additional increase of tensile mechanical properties and fracture toughness. The increase of fracture toughness was owing to the crack deflection and particle–matrix debonding as evidenced by SEM pictures on the fracture surface. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Role of 2‐hydroxyethyl end group on the thermal degradation of poly(ethylene terephthalate) and reactive melt mixing of poly(ethylene terephthalate)/poly(ethylene naphthalate) blends
Authors: Blanco Ignazio , Cicala Gianluca , Restuccia Carmelo Luca , Latteri Alberta , Battiato Salvatore , Scamporrino Andrea , Samperi Filippo 
Published: May 2012

AbstractIn an attempt to minimize the acetaldehyde formation at the processing temperatures (280–300°C) and the outer–inner transesterification reactions in the poly (ethylene terephthalate) (PET)–poly(ethylene naphthalate) (PEN) melt‐mixed blends, the hydroxyl chain ends of PET were capped using benzoyl chloride. The thermal characterization of the melt‐mixed PET–PEN blends at 300°C, as well as that of the corresponding homopolymers, was performed. Degradations were carried out under dynamic heating and isothermal conditions in both flowing nitrogen and static air atmosphere. The initial decomposition temperatures (Ti) were determined to draw useful information about the overall thermal stability of the studied compounds. Also, the glass transition temperature (Tg) was determined by finding data, indicating that the end‐capped copolymers showed a higher degradation stability compared to the unmodified PET and, when blended with PEN, seemed to be efficient in slowing the kinetic of transesterification leading to, for a finite time, the formation of block copolymers, as determined by 1H‐NMR analysis. This is strong and direct evidence that the end‐capping of the OH chain ends influences the mechanism and the kinetic of transesterification. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers