356 research outputs found

    Engineering three-dimensionally electrodeposited Si-on-Ni inverse opal structure for high volumetric capacity Li-ion microbattery anode.

    Get PDF
    Aiming at improving the volumetric capacity of nanostructured Li-ion battery anode, an electrodeposited Si-on-Ni inverse opal structure has been proposed in the present work. This type of electrode provides three-dimensional bi-continuous pathways for ion/electron transport and high surface area-to-volume ratios, and thus exhibits lower interfacial resistance, but higher effective Li ions diffusion coefficients, when compared to the Si-on-Ni nanocable array electrode of the same active material mass. As a result, improved volumetric capacities and rate capabilities have been demonstrated in the Si-on-Ni inverse opal anode. We also show that optimization of the volumetric capacities and the rate performance of the inverse opal electrode can be realized by manipulating the pore size of the Ni scaffold and the thickness of the Si deposit

    Multiple Pregnancy after Gonadotropin-Intrauterine Insemination: An Unavoidable Event?

    Get PDF
    Objective. Determine which factors predict multiple pregnancy in gonadotropin-intrauterine insemination cycles so that cancellation criteria might be developed. Study Design. Retrospective chart review of all patients undergoing gonadotropin-intrauterine insemination over a continuous 36 month period. Results. No factors examined were able to predict the occurrence of multiple pregnancy. Conclusion. Multiple pregnancy is an unavoidable complication of gonadotropin-intrauterine insemination treatment

    APLIKASI TEORI PERILAKU TERENCANA: NIAT MELAKUKAN PHYSICAL EXERCISE (LATIHAN FISIK) PADA REMAJA DI SURABAYA

    Get PDF
    Alasan utama untuk rnengangkat topik ini dalarn penelitian ia1ah penulis berrnaksud untuk rneneliti variabel-variabel yang rnelatarbelakangi perilaku physical exercise yang dilakukan remaja di Surabaya. Tujuannya, peneliti ingin rnenguji apakah ada hubungan antara attitude towards behavior (A TB), subjective norm (SN), dan perceived behavioral control (PBC), baik secara bersama-sama maupun secara parsial, dengan niat berperilaku physical exercise (latihan fisik) pada remaja di Surabaya. Metode angket digunakan dalarn penelitian ini, rnenggunakan teknik penskalaan sernantik diferensial. Rernaja baik pria dan wanita (N=336) di kota Surabaya berpartisipasi dalarn penelitian ini. Hasil uji hipotesis rnenujukkan bahwa : {a). Terdapat hubungan yang signifikan antara ATB, SN, dan PBC, secara bersarna-sarna terhadap niat rnelakukan Physical exersice pada remaja (F = 14.233; p = 0,000). Hasil korelasi parsial menunjukkan ATB, dan SN menjadi prediktor paling kuat terhadap niat melaku.kan Physical Exercise, sedangkan PBC tidak

    Spatially resolved texture analysis of Napoleonic War era copper bolts

    Get PDF
    The spatial resolution achievable by a time-of-flight neutron strain scanner has been harnessed using a new data analysis methodology (NyRTex) to determine, nondestructively, the spatial variation of crystallographic texture in objects of cultural heritage. Previous studies on the crystallographic texture at the centre of three Napoleonic War era copper bolts, which demonstrated the value of this technique in differentiating between the different production processes of the different types of bolts, were extended to four copper bolts from the wrecks of HMS Impregnable (completed 1786), HMS Amethyst (1799), HMS Pomone (1805) and HMS Maeander (1840) along with a cylindrical `segment' of a further incomplete bolt from HMS Pomone. These included bolts with works stamps, allowing comparison with documentary accounts of the manufacturing processes used, and the results demonstrated unequivocally that bolts with a `Westwood and Collins' patent stamp were made using the Collins rather than the Westwood process. In some bolts there was a pronounced variation in texture across the cross section. In some cases this is consistent with what is known of the types of hot and cold working used, but the results from the latest study might also suggest that, even in the mature phase of this technology, some hand finishing was sometimes necessary. This examination of bolts from a wider range of dates is an important step in increasing our understanding of the introduction and evolution of copper fastenings in Royal Navy warships

    Plasma membrane recovery kinetics of a microfluidic intracellular delivery platform

    Get PDF
    Intracellular delivery of materials is a challenge in research and therapeutic applications. Physical methods of plasma membrane disruption have recently emerged as an approach to facilitate the delivery of a variety of macromolecules to a range of cell types. We use the microfluidic CellSqueeze delivery platform to examine the kinetics of plasma membrane recovery after disruption and its dependence on the calcium content of the surrounding buffer (recovery time ~5 min without calcium vs. ~30 s with calcium). Moreover, we illustrate that manipulation of the membrane repair kinetics can yield up to 5× improvement in delivery efficiency without significantly impacting cell viability. Membrane repair characteristics initially observed in HeLa cells are shown to translate to primary naïve murine T cells. Subsequent manipulation of membrane repair kinetics also enables the delivery of larger materials, such as antibodies, to these difficult to manipulate cells. This work provides insight into the membrane repair process in response to mechanical delivery and could potentially enable the development of improved delivery methods.National Institutes of Health (U.S.) (Grant RC1 EB011187-02)National Institutes of Health (U.S.) (Grant R01GN101420-01A1)Kathy and Curt Marble Cancer Research FundNational Cancer Institute (U.S.) (Cancer Center Support (Core) Grant P30-CA14051)National Cancer Institute (U.S.) (Cancer Center Support (Core) Grant MPP-09Call-Langer-60

    Pseudopotential study of binding properties of solids within generalized gradient approximations: The role of core-valence exchange-correlation

    Full text link
    In ab initio pseudopotential calculations within density-functional theory the nonlinear exchange-correlation interaction between valence and core electrons is often treated linearly through the pseudopotential. We discuss the accuracy and limitations of this approximation regarding a comparison of the local density approximation (LDA) and generalized gradient approximations (GGA), which we find to describe core-valence exchange-correlation markedly different. (1) Evaluating the binding properties of a number of typical solids we demonstrate that the pseudopotential approach and namely the linearization of core-valence exchange-correlation are both accurate and limited in the same way in GGA as in LDA. (2) Examining the practice to carry out GGA calculations using pseudopotentials derived within LDA we show that the ensuing results differ significantly from those obtained using pseudopotentials derived within GGA. As principal source of these differences we identify the distinct behavior of core-valence exchange-correlation in LDA and GGA which, accordingly, contributes substantially to the GGA induced changes of calculated binding properties.Comment: 13 pages, 6 figures, submitted to Phys. Rev. B, other related publications can be found at http://www.rz-berlin.mpg.de/th/paper.htm

    Resistance, Redistribution and Investor-Friendliness

    Get PDF
    Poor communities sometimes resist private investment and destroy economic surplus even if the government has the willingness and ability to redistribute. We interpret such acts of resistance as demands for redistribution: Destruction contains credible information about how affected groups value surplus, which helps the government in implementing the optimal redistribution policy. Destruction is increasing in the extent of political marginalization of the affected group. While resistance has informational value, it has two distinct costs: it directly reduces surplus and also reduces the investor’s incentives to create surplus. The government uses a tax/subsidy on the investor to maximize weighted social surplus, and we show that the possibility of destruction may force the government to be too soft in its negotiations with the investor. We discuss conditions under which the government should ban resistance or should allow resistance but compensate the investor for its losses incurred in order to enhance social welfare

    Arabidopsis R2R3-MYB transcription factor AtMYB60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (Lactuca sativa)

    Get PDF
    The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches
    corecore