297 research outputs found

    Advance Care Planning in China

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    Objectives • Describe the interprofessional components of this project. • Describe the attitude of advance care planning among Chinese healthcare professionals

    Animal Perception of Seasonal Thresholds: Changes in Elephant Movement in Relation to Rainfall Patterns

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    Background: The identification of temporal thresholds or shifts in animal movement informs ecologists of changes in an animal\u2019s behaviour, which contributes to an understanding of species\u2019 responses in different environments. In African savannas, rainfall, temperature and primary productivity influence the movements of large herbivores and drive changes at different scales. Here, we developed a novel approach to define seasonal shifts in movement behaviour by examining the movements of a highly mobile herbivore (elephant; Loxodonta africana), in relation to local and regional rainfall patterns. Methodology/Principal Findings: We used speed to determine movement changes of between 8 and 14 GPS-collared elephant cows, grouped into five spatial clusters, in Kruger National Park, South Africa. To detect broad-scale patterns of movement, we ran a three-year daily time-series model for each individual (2007\u20132009). Piecewise regression models provided the best fit for elephant movement, which exhibited a segmented, waveform pattern over time. Major breakpoints in speed occurred at the end of the dry and wet seasons of each year. During the dry season, female elephant are constrained by limited forage and thus the distances they cover are shorter and less variable. Despite the inter-annual variability of rainfall, speed breakpoints were strongly correlated with both local and regional rainfall breakpoints across all three years. Thus, at a multi-year scale, rainfall patterns significantly affect the movements of elephant. The variability of both speed and rainfall breakpoints across different years highlights the need for an objective definition of seasonal boundaries. Conclusions/Significance: By using objective criteria to determine behavioural shifts, we identified a biologically meaningful indicator of major changes in animal behaviour in different years. We recommend the use of such criteria, from an animal\u2019s perspective, for delineating seasons or other extrinsic shifts in ecological studies, rather than arbitrarily fixed definitions based on convention or common practice

    Optimization of atmospheric plasma treatment of LDPE films: Influence on adhesive properties and ageing behavior

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    One of the major disadvantages of low density polyethylene (LDPE) films is their poor adhesive properties. Therefore, LDPE films have been treated with atmospheric pressure air plasma in order to improve their surface properties. So as to simulate the possible conditions in an industrial process, the samples have been treated with two different sample distances (6 and 10 mm), and treatment rates between 100 and 1000 mm s-1. The different sample distances are the distance of the sample from the plasma source. The variation of the surface properties and adhesion characteristics of the films were investigated for different aging times after plasma exposure (up to 21 days) using contact angle measurement, atomic force microscopy, weight loss measurements and shear test. Results show that the treatment increases the polar component () and these changes improve adhesive properties of the material. After the twenty-first day, the ageing process causes a decrease of wettability and adhesive properties of the LDPE films (up to 60%).Fombuena Borrás, V.; García Sanoguera, D.; Sánchez Nacher, L.; Balart Gimeno, RA.; Boronat Vitoria, T. (2014). Optimization of atmospheric plasma treatment of LDPE films: Influence on adhesive properties and ageing behavior. Journal of Adhesion Science and Technology. 28(1):97-113. doi:10.1080/01694243.2013.847045S97113281Achilias, D. S., Roupakias, C., Megalokonomos, P., Lappas, A. A., & Antonakou, Ε. V. (2007). Chemical recycling of plastic wastes made from polyethylene (LDPE and HDPE) and polypropylene (PP). Journal of Hazardous Materials, 149(3), 536-542. doi:10.1016/j.jhazmat.2007.06.076Friedman, M., & Walsh, G. (2002). High performance films: Review of new materials and trends. Polymer Engineering & Science, 42(8), 1756-1788. doi:10.1002/pen.11069Wiles, D. M., & Scott, G. (2006). Polyolefins with controlled environmental degradability. Polymer Degradation and Stability, 91(7), 1581-1592. doi:10.1016/j.polymdegradstab.2005.09.010Gao, J., Lei, J., Li, Q., & Ye, S. (2004). Functionalized low-density polyethylene via a novel photografting method and its adhesion properties. Journal of Adhesion Science and Technology, 18(2), 195-203. doi:10.1163/156856104772759403Shenton, M. J., Lovell-Hoare, M. C., & Stevens, G. C. (2001). Adhesion enhancement of polymer surfaces by atmospheric plasma treatment. Journal of Physics D: Applied Physics, 34(18), 2754-2760. doi:10.1088/0022-3727/34/18/307Belgacem, M. N., Salon-Brochier, M. C., Krouit, M., & Bras, J. (2011). Recent Advances in Surface Chemical Modification of Cellulose Fibres. Journal of Adhesion Science and Technology, 25(6-7), 661-684. doi:10.1163/016942410x525867Friedrich, J., Unger, W., & Lippitz, A. (1995). Plasma modification of polymer surfaces. Macromolecular Symposia, 100(1), 111-115. doi:10.1002/masy.19951000118Ladizesky, N. H., & Ward, I. M. (1989). The adhesion behaviour of high modulus polyethylene fibres following plasma and chemical treatment. Journal of Materials Science, 24(10), 3763-3773. doi:10.1007/bf02385768Nardin, M., & Ward, I. M. (1987). Influence of surface treatment on adhesion of polyethylene fibres. Materials Science and Technology, 3(10), 814-826. doi:10.1179/mst.1987.3.10.814Villagra Di Carlo, B., Gottifredi, J. C., & Habert, A. C. (2010). Synthesis and characterization of composite membrane by deposition of acrylic acid plasma polymer onto pre-treated polyethersulfone support. Journal of Materials Science, 46(6), 1850-1856. doi:10.1007/s10853-010-5012-4Matsunaga, M., & Whitney, P. J. (2000). Surface changes brought about by corona discharge treatment of polyethylene film and the effect on subsequent microbial colonisation. Polymer Degradation and Stability, 70(3), 325-332. doi:10.1016/s0141-3910(00)00105-1Novák, I., Pollák, V., & Chodák, I. (2006). Study of Surface Properties of Polyolefins Modified by Corona Discharge Plasma. Plasma Processes and Polymers, 3(4-5), 355-364. doi:10.1002/ppap.200500163Arpagaus, C., Rossi, A., & Rudolf von Rohr, P. (2005). Short-time plasma surface modification of HDPE powder in a Plasma Downer Reactor – process, wettability improvement and ageing effects. Applied Surface Science, 252(5), 1581-1595. doi:10.1016/j.apsusc.2005.02.099Morra, M., Occhiello, E., Marola, R., Garbassi, F., Humphrey, P., & Johnson, D. (1990). On the aging of oxygen plasma-treated polydimethylsiloxane surfaces. Journal of Colloid and Interface Science, 137(1), 11-24. doi:10.1016/0021-9797(90)90038-pKim, K. S., Ryu, C. M., Park, C. S., Sur, G. S., & Park, C. E. (2003). Investigation of crystallinity effects on the surface of oxygen plasma treated low density polyethylene using X-ray photoelectron spectroscopy. Polymer, 44(20), 6287-6295. doi:10.1016/s0032-3861(03)00674-8Kim, S. H., Ha, H. J., Ko, Y. K., Yoon, S. J., Rhee, J. M., Kim, M. S., … Khang, G. (2007). Correlation of proliferation, morphology and biological responses of fibroblasts on LDPE with different surface wettability. Journal of Biomaterials Science, Polymer Edition, 18(5), 609-622. doi:10.1163/156856207780852514Borcia, G., Anderson, C. A., & Brown, N. M. D. (2004). The surface oxidation of selected polymers using an atmospheric pressure air dielectric barrier discharge. Part I. Applied Surface Science, 221(1-4), 203-214. doi:10.1016/s0169-4332(03)00879-1Pascual, M., Calvo, O., Sanchez-Nácher, L., Bonet, M. A., Garcia-Sanoguera, D., & Balart, R. (2009). Optimization of adhesive joints of low density polyethylene (LDPE) composite laminates with polyolefin foam using corona discharge plasma. Journal of Applied Polymer Science, 114(5), 2971-2977. doi:10.1002/app.30906Encinas, N., Díaz-Benito, B., Abenojar, J., & Martínez, M. A. (2010). Extreme durability of wettability changes on polyolefin surfaces by atmospheric pressure plasma torch. Surface and Coatings Technology, 205(2), 396-402. doi:10.1016/j.surfcoat.2010.06.069Takke, V., Behary, N., Perwuelz, A., & Campagne, C. (2009). Studies on the atmospheric air-plasma treatment of PET (polyethylene terephtalate) woven fabrics: Effect of process parameters and of aging. Journal of Applied Polymer Science, 114(1), 348-357. doi:10.1002/app.30618Awaja, F., Gilbert, M., Kelly, G., Fox, B., & Pigram, P. J. (2009). Adhesion of polymers. Progress in Polymer Science, 34(9), 948-968. doi:10.1016/j.progpolymsci.2009.04.007Garcia, D., Sanchez, L., Fenollar, O., Lopez, R., & Balart, R. (2008). Modification of polypropylene surface by CH4–O2 low-pressure plasma to improve wettability. Journal of Materials Science, 43(10), 3466-3473. doi:10.1007/s10853-007-2322-2Guimond, S., & Wertheimer, M. R. (2004). Surface degradation and hydrophobic recovery of polyolefins treated by air corona and nitrogen atmospheric pressure glow discharge. Journal of Applied Polymer Science, 94(3), 1291-1303. doi:10.1002/app.21134Pascual, M., Balart, R., Sánchez, L., Fenollar, O., & Calvo, O. (2008). Study of the aging process of corona discharge plasma effects on low density polyethylene film surface. Journal of Materials Science, 43(14), 4901-4909. doi:10.1007/s10853-008-2712-0Sanchis, R., Fenollar, O., García, D., Sánchez, L., & Balart, R. (2008). Improved adhesion of LDPE films to polyolefin foams for automotive industry using low-pressure plasma. International Journal of Adhesion and Adhesives, 28(8), 445-451. doi:10.1016/j.ijadhadh.2008.04.002Fresnais, J., Chapel, J. P., Benyahia, L., & Poncin-Epaillard, F. (2009). Plasma-Treated Superhydrophobic Polyethylene Surfaces: Fabrication, Wetting and Dewetting Properties. Journal of Adhesion Science and Technology, 23(3), 447-467. doi:10.1163/156856108x370127Abenojar, J., Colera, I., Martínez, M. A., & Velasco, F. (2010). Study by XPS of an Atmospheric Plasma-Torch Treated Glass: Influence on Adhesion. Journal of Adhesion Science and Technology, 24(11-12), 1841-1854. doi:10.1163/016942410x507614Lommatzsch, U., Pasedag, D., Baalmann, A., Ellinghorst, G., & Wagner, H.-E. (2007). Atmospheric Pressure Plasma Jet Treatment of Polyethylene Surfaces for Adhesion Improvement. Plasma Processes and Polymers, 4(S1), S1041-S1045. doi:10.1002/ppap.200732402Balu, B., Berry, A. D., Patel, K. T., Breedveld, V., & Hess, D. W. (2011). Directional Mobility and Adhesion of Water Drops on Patterned Superhydrophobic Surfaces. Journal of Adhesion Science and Technology, 25(6-7), 627-642. doi:10.1163/016942410x525849Bhattacharya, S., Singh, R. K., Mandal, S., Ghosh, A., Bok, S., Korampally, V., … Gangopadhyay, S. (2010). Plasma Modification of Polymer Surfaces and Their Utility in Building Biomedical Microdevices. Journal of Adhesion Science and Technology, 24(15-16), 2707-2739. doi:10.1163/016942410x511105Das, S., Neogi, S., Chainy, G. B. N., & Guha, S. K. (2011). A Novel Two-Step Procedure for Plasma Surface Modification of Low-Density Polyethylene for Improved Drug Adhesion in Intra Uterine Devices (IUDs). Journal of Adhesion Science and Technology, 25(1-3), 151-167. doi:10.1163/016942410x503285Schulz, U., Munzert, P., & Kaiser, N. (2010). Plasma Surface Modification of PMMA for Optical Applications. Journal of Adhesion Science and Technology, 24(7), 1283-1289. doi:10.1163/016942409x12561252292026Silverstein, M. S., Breuer, O., & Dodiuk, H. (1994). Surface modification of UHMWPE fibers. Journal of Applied Polymer Science, 52(12), 1785-1795. doi:10.1002/app.1994.070521213Inagaki, N., Narushim, K., Tuchida, N., & Miyazaki, K. (2004). Surface characterization of plasma-modified poly(ethylene terephthalate) film surfaces. Journal of Polymer Science Part B: Polymer Physics, 42(20), 3727-3740. doi:10.1002/polb.20234Nakamatsu, J., Delgado-Aparicio, L. F., Da Silva, R., & Soberon, F. (1999). Ageing of plasma-treated poly(tetrafluoroethylene) surfaces. Journal of Adhesion Science and Technology, 13(7), 753-761. doi:10.1163/156856199x00983Yun, Y. I., Kim, K. S., Uhm, S.-J., Khatua, B. B., Cho, K., Kim, J. K., & Park, C. E. (2004). Aging behavior of oxygen plasma-treated polypropylene with different crystallinities. Journal of Adhesion Science and Technology, 18(11), 1279-1291. doi:10.1163/1568561041588200Morent, R., De Geyter, N., Leys, C., Gengembre, L., & Payen, E. (2007). Study of the ageing behaviour of polymer films treated with a dielectric barrier discharge in air, helium and argon at medium pressure. Surface and Coatings Technology, 201(18), 7847-7854. doi:10.1016/j.surfcoat.2007.03.018Zhao, B., & Kwon, H. J. (2011). Adhesion of Polymers in Paper Products from the Macroscopic to Molecular Level — An Overview. Journal of Adhesion Science and Technology, 25(6-7), 557-579. doi:10.1163/016942410x52582

    Distance-Based and Low Energy Adaptive Clustering Protocol for Wireless Sensor Networks

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    A wireless sensor network (WSN) comprises small sensor nodes with limited energy capabilities. The power constraints of WSNs necessitate efficient energy utilization to extend the overall network lifetime of these networks. We propose a distance-based and low-energy adaptive clustering (DISCPLN) protocol to streamline the green issue of efficient energy utilization in WSNs. We also enhance our proposed protocol into the multi-hop-DISCPLN protocol to increase the lifetime of the network in terms of high throughput with minimum delay time and packet loss. We also propose the mobile-DISCPLN protocol to maintain the stability of the network. The modelling and comparison of these protocols with their corresponding benchmarks exhibit promising results

    Properties of Graphene: A Theoretical Perspective

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    In this review, we provide an in-depth description of the physics of monolayer and bilayer graphene from a theorist's perspective. We discuss the physical properties of graphene in an external magnetic field, reflecting the chiral nature of the quasiparticles near the Dirac point with a Landau level at zero energy. We address the unique integer quantum Hall effects, the role of electron correlations, and the recent observation of the fractional quantum Hall effect in the monolayer graphene. The quantum Hall effect in bilayer graphene is fundamentally different from that of a monolayer, reflecting the unique band structure of this system. The theory of transport in the absence of an external magnetic field is discussed in detail, along with the role of disorder studied in various theoretical models. We highlight the differences and similarities between monolayer and bilayer graphene, and focus on thermodynamic properties such as the compressibility, the plasmon spectra, the weak localization correction, quantum Hall effect, and optical properties. Confinement of electrons in graphene is nontrivial due to Klein tunneling. We review various theoretical and experimental studies of quantum confined structures made from graphene. The band structure of graphene nanoribbons and the role of the sublattice symmetry, edge geometry and the size of the nanoribbon on the electronic and magnetic properties are very active areas of research, and a detailed review of these topics is presented. Also, the effects of substrate interactions, adsorbed atoms, lattice defects and doping on the band structure of finite-sized graphene systems are discussed. We also include a brief description of graphane -- gapped material obtained from graphene by attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic

    High-Utilisation Nanoplatinum Catalyst (Pt@cPIM) Obtained via Vacuum Carbonisation in a Molecularly Rigid Polymer of Intrinsic Microporosity

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    Polymers of intrinsic microporosity (PIM or here PIM-EA-TB) offer a highly rigid host environment into which hexachloroplatinate(IV) anions are readily adsorbed and vacuum carbonised (at 500 °C) to form active embedded platinum nanoparticles. This process is characterised by electron and optical microscopy, atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and electrochemical methods, which reveal that the PIM microporosity facilitates the assembly of nanoparticles of typically 1.0 to 2.5-nm diameter. It is demonstrated that the resulting carbonised “Pt@cPIM” from drop-cast films of ca. 550-nm average thickness, when prepared on tin-doped indium oxide (ITO), contain not only fully encapsulated but also fully active platinum nanoparticles in an electrically conducting hetero-carbon host. Alternatively, for thinner films (50–250 nm) prepared by spin coating, the particles become more exposed due to additional loss of the carbon host. In contrast to catalyst materials prepared by vacuum-thermolysed hexachloroplatinate(IV) precursor, the platinum nanoparticles within Pt@cPIM retain high surface area, electrochemical activity and high catalyst efficiency due to the molecular rigidity of the host. Data are presented for oxygen reduction, methanol oxidation and glucose oxidation, and in all cases, the high catalyst surface area is linked to excellent catalyst utilisation. Robust transparent platinum-coated electrodes are obtained with reactivity equivalent to bare platinum but with only 1 μg Pt cm−2 (i.e. ~100% active Pt nanoparticle surface is maintained in the carbonised microporous host). [Figure not available: see fulltext.

    RNA Interference of Four Genes in Adult Bactrocera dorsalis by Feeding Their dsRNAs

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    BACKGROUND: RNA interference (RNAi) is a powerful method to inhibit gene expression in a sequence specific manner. Recently silencing the target gene through feeding has been successfully carried out in many insect species. METHODOLOGY/PRINCIPAL FINDINGS: Escherichia coli strain HT115 was genetically engineered to express dsRNA targeting genes that encode ribosomal protein Rpl19, V type ATPase D subunit, the fatty acid elongase Noa and a small GTPase Rab11. qRT-PCR showed that mRNA level of four target genes was reduced compared to ds-egfp control by feeding either engineered bacteria or dsRNAs. The maximum down-regulation of each gene varied from 35% to 100%. Tissue specific examination indicated that RNAi could be observed not only in midgut but also in other tissues like the ovary, nervous system and fat body. Silencing of rab11 through ingestion of dsRNA killed 20% of adult flies. Egg production was affected through feeding ds-noa and ds-rab11 compared to ds-egfp group. Adult flies were continuously fed with dsRNA and bacteria expressing dsRNA for 14 days and up-regulations of target genes were observed during this process. The transcripts of noa showed up-regulation compared to ds-egfp control group in four tissues on day 7 after continuous feeding either dsRNA or engineered bacteria. The maximum over-expression is 21 times compared to ds-egfp control group. Up-regulation of rab11 mRNA level could be observed in testes on day 7 after continuous bacteria treatment and in midgut on day 2 after ds-rab11 treatment. This phenomenon could also be observed in rpl19 groups. CONCLUSIONS: Our results suggested that it is feasible to silence genes by feeding dsRNA and bacteria expressing dsRNA in Bactrocera dorsalis. Additionally the over-expression of the target gene after continuously feeding dsRNA or bacteria was observed

    Elevated 17β-Estradiol Protects Females from Influenza A Virus Pathogenesis by Suppressing Inflammatory Responses

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    Studies of the 1918 H1N1 influenza pandemic, the H5N1 avian influenza outbreak, and the 2009 H1N1 pandemic illustrate that sex and pregnancy contribute to severe outcome from infection, suggesting a role for sex steroids. To test the hypothesis that the sexes respond differently to influenza, the pathogenesis of influenza A virus infection was investigated in adult male and female C57BL/6 mice. Influenza infection reduced reproductive function in females and resulted in greater body mass loss, hypothermia, and mortality in females than males. Whereas lung virus titers were similar between the sexes, females had higher induction of proinflammatory cytokines and chemokines, including TNF-α, IFN-γ, IL-6, and CCL2, in their lungs than males. Removal of the gonads in both sexes eliminated the sex difference in influenza pathogenesis. Manipulation of testosterone or dihydrotestosterone concentrations in males did not significantly impact virus pathogenesis. Conversely, females administered high doses of estradiol had a ≥10-fold lower induction of TNF-α and CCL2 in the lungs and increased rates of survival as compared with females that had either low or no estradiol. The protective effects of estradiol on proinflammatory cytokines and chemokines, morbidity, and mortality were primarily mediated by signaling through estrogen receptor α (ERα). In summary, females suffer a worse outcome from influenza A virus infection than males, which can be reversed by administration of high doses of estradiol to females and reflects differences in the induction of proinflammatory responses and not in virus load

    Serum-Dependent Selective Expression of EhTMKB1-9, a Member of Entamoeba histolytica B1 Family of Transmembrane Kinases

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    Entamoeba histolytica transmembrane kinases (EhTMKs) can be grouped into six distinct families on the basis of motifs and sequences. Analysis of the E. histolytica genome revealed the presence of 35 EhTMKB1 members on the basis of sequence identity (≥95%). Only six homologs were full length containing an extracellular domain, a transmembrane segment and an intracellular kinase domain. Reverse transcription followed by polymerase chain reaction (RT-PCR) of the kinase domain was used to generate a library of expressed sequences. Sequencing of randomly picked clones from this library revealed that about 95% of the clones were identical with a single member, EhTMKB1-9, in proliferating cells. On serum starvation, the relative number of EhTMKB1-9 derived sequences decreased with concomitant increase in the sequences derived from another member, EhTMKB1-18. The change in their relative expression was quantified by real time PCR. Northern analysis and RNase protection assay were used to study the temporal nature of EhTMKB1-9 expression after serum replenishment of starved cells. The results showed that the expression of EhTMKB1-9 was sinusoidal. Specific transcriptional induction of EhTMKB1-9 upon serum replenishment was further confirmed by reporter gene (luciferase) expression and the upstream sequence responsible for serum responsiveness was identified. EhTMKB1-9 is one of the first examples of an inducible gene in Entamoeba. The protein encoded by this member was functionally characterized. The recombinant kinase domain of EhTMKB1-9 displayed protein kinase activity. It is likely to have dual specificity as judged from its sensitivity to different kinase inhibitors. Immuno-localization showed EhTMKB1-9 to be a surface protein which decreased on serum starvation and got relocalized on serum replenishment. Cell lines expressing either EhTMKB1-9 without kinase domain, or EhTMKB1-9 antisense RNA, showed decreased cellular proliferation and target cell killing. Our results suggest that E. histolytica TMKs of B1 family are functional kinases likely to be involved in serum response and cellular proliferation
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