23,081 research outputs found

    A Bet With My Uncle Luis (A Translation of "Una Apuesta con Mi Tio Luis)

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    Bioremediation with White-Rot Fungi at Fisherville Mill: Analyses of Gene Expression and Number 6 Fuel Oil Degradation

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    Extracellular enzymes that white-rot fungi secrete during lignin decay have been proposed as promising agents for oxidizing pollutants. We investigated the abilities of the white-rot fungi Punctularia strigosozonata, Irpex lacteus, Trichaptum biforme, Phlebia radiata, Trametes versicolor, and Pleurotus ostreatus to degrade Number 6 fuel oil in wood sawdust cultures. Our goals are to advise bioremediation efforts at a brownfield redevelopment site on the Blackstone River in Grafton, Massachusetts and to contribute to the understanding of decay mechanisms in white-rot fungi. All species tested degraded a C10 alkane. When cultivated for 6 months, Irpex lacteus, T. biforme, P. radiata, T. versicolor and P. ostreatus also degraded a C14 alkane and the polycyclic aromatic hydrocarbon phenanthrene. Gene expression analyses of P. strigosozonata indicate differential gene expression in the presence of Number 6 oil and on pine and aspen sawdust

    Characterization of dentine to assess bond strength of dental composites

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    This study was performed to develop alternating dentine adhesion models that could help in the evaluation of a self-bonding dental composite. For this purpose dentine from human and ivory was characterized chemically and microscopically before and after acid etching using Raman and SEM. Mechanical properties of dentine were determined using 3 point bend test. Composite bonding to dentine, with and without use of acid pre-treatment and/or the adhesive, were assessed using a shear bond test. Furthermore, micro gap formation after restoration of 3 mm diameter cavities in dentine was assessed by SEM. Initial hydroxyapatite level in ivory was half that in human dentine. Surface hydroxyapatites decreased by approximately half with every 23 s of acid etch. The human dentine strength (56 MPa) was approximately double that of ivory, while the modulus was almost comparable to that of ivory. With adhesive use, average shear bond strengths were 30 and 26 MPa with and without acid etching. With no adhesive, average bond strength was 6 MPa for conventional composites. This, however, increased to 14 MPa with a commercial flowable "self-bonding" composite or upon addition of low levels of an acidic monomer to the experimental composite. The acidic monomer additionally reduced micro-gap formation with the experimental composite. Improved bonding and mechanical properties should reduce composite failures due to recurrent caries or fracture respectively

    Newly Acquired Fear of Falling Leads to Altered Eye Movement Patterns and Reduced Stepping Safety: A Case Study

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    This opportune case study describes visual and stepping behaviours of an 87 year old female (P8), both prior to, and following two falls. Before falling, when asked to walk along a path containing two stepping guides positioned before and after an obstacle, P8 generally visually fixated the first stepping guide until after foot contact inside it. However, after falling P8 consistently looked away from the stepping guide before completing the step into it in order to fixate the upcoming obstacle in her path. The timing of gaze redirection away from the target (in relation to foot contact inside it) correlated with absolute stepping error. No differences in eyesight, cognitive function, or balance were found between pre- and post-fall recordings. However, P8 did report large increases in fall-related anxiety and reduced balance confidence, supporting previously suggested links between anxiety/increased fear or falling and maladaptive visual/stepping behaviours. The results represent a novel insight into how psychological and related behavioural factors can change in older adults following a fall, and provide a possible partial rationalisation for why recent fallers are more likely to fall again in the following 12 months. These findings highlight novel possibilities for falls prevention and rehabilitation

    A geometrical formulation of the μ-lower bound problem

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    A new problem formulation for the structured singular value μ in the case of purely real (possibly repeated) uncertainties is presented. The approach is based on a geometrical interpretation of the singularity constraint arising in the μ lower bound problem. An interesting feature of this problem formulation is that the resulting parametric search space is independent of the number of times any parameter is repeated in the structured uncertainty matrix. A corresponding lower bound algorithm combining randomisation and optimisation methods is developed, and some probabilistic performance guarantees are derived. The potential usefulness of the proposed approach is demonstrated on two high-order real μ analysis problems from the aerospace and systems biology literature

    Poly[[triaqua­[μ4-N-(4-carboxyl­ato­phenyl)­iminodiacetato]sodium(I)zinc(II)] dihydrate]

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    In the title coordination polymer, {[NaZn(C11H8NO6)(H2O)3]·2H2O}n, the Zn atom is coordinated in a distorted tetra­hedral environment by three carboxyl­ate O atoms from two (4-carboxyl­atophenyl­imino)diacetate ligands and one water mol­ecule; the Na atom is in an distorted octa­hedral coordination environment formed by four carboxyl­ate O atoms from three (4-carboxyl­atophenyl­imino)diacetate ligands and two water mol­ecules. The Zn atoms and Na atoms are linked by (4-carboxyl­atophenyl­imino)diacetate ligands into a three-dimensional framework; the uncoordinated water mol­ecules fill the voids of the skeleton and stabilize it by O—H⋯O hydrogen bonds

    Pharmacological activation of FOXO3 suppresses triple-negative breast cancer in vitro and in vivo

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    Triple-negative breast cancer (TNBC) is the most lethal form of breast cancer. Lacking effective therapeutic options hinders treatment of TNBC. Here, we show that bepridil (BPD) and trifluoperazine (TFP), which are FDA-approved drugs for treatment of schizophrenia and angina respectively, inhibit Akt-pS473 phosphorylation and promote FOXO3 nuclear localization and activation in TNBC cells. BPD and TFP inhibit survival and proliferation in TNBC cells and suppress the growth of TNBC tumors, whereas silencing FOXO3 reduces the BPD- and TFP-mediated suppression of survival in TNBC cells. While BPD and TFP decrease the expression of oncogenic c-Myc, KLF5, and dopamine receptor DRD2 in TNBC cells, silencing FOXO3 diminishes BPD- and TFP-mediated repression of the expression of these proteins in TNBC cells. Since c-Myc, KLF5, and DRD2 have been suggested to increase cancer stem cell-like populations in various tumors, reducing these proteins in response to BPD and TFP suggests a novel FOXO3-dependent mechanism underlying BPD- and TFP-induced apoptosis in TNBC cells

    Lower GWP Refrigerants Compared to R404A for Economizer Style Compressors

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    Two economizer style compressors are explored, where the high pressure liquid is sub-cooled with a heat exchanger while the evaporation side in the heat exchanger is connected to an intermediate port with higher pressure than the suction pressure and lower pressure than the discharge pressure. One of the compressors is a screw compressor and the other one is a scroll compressor. One of the compressors is an open shaft compressor and the other one is a hermetic style compressor. Both compressor styles have been modeled based on test data with R404A and at conditions mainly corresponding to TRU (transport refrigeration unit) applications. Those compressor models have been used to explore lower GWP refrigerants such as R407A, R407F, N-40a, DR7 and DR33. For each compressor model each alternative refrigerant is compared with the baseline refrigerant R404A, based on capacity, coefficient of performance and discharge temperature. GWP of the refrigerants are compared as well. There is also some discussion relative to the indirect GWP and how it can correlate to the compressors coefficient of performance
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