421 research outputs found

    The Extraction and Assay of 1-Kestose:Sucrose Fructosyl Transferase from Leaves of Wheat

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    Anorpiment, As_(2)S_(3), the triclinic dimorph of orpiment

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    The new mineral anorpiment, As_(2)S_(3), the triclinic dimorph of orpiment, has space group P1 and cell parameters a = 5.7577(2), b = 8.7169(3), c = 10.2682(7) Å, α = 78.152(7), β = 75.817(7), γ = 89.861(6)º, V = 488.38(4) Å^3 and Z = 4. It occurs at the Palomo mine, Castrovirreyna Province, Huancavelica Department, Peru. It is a low-temperature hydrothermal mineral associated with dufrénoysite, muscovite, orpiment, pyrite and realgar. It occurs in drusy crusts of wedge-shaped, transparent, greenish yellow crystals. The streak is yellow. The lustre is resinous on crystal faces, but pearly on cleavage surfaces. The Mohs hardness is about 1½. The mineral is sectile with an irregular fracture and one perfect and easy cleavage on {001}. The measured and calculated densities are 3.33 and 3.321 g cm^(-3), respectively. All indices of refraction are greater than 2. The mineral is optically biaxial (—) with 2V = 35-40º and no observed dispersion. The acute bisectrix (X) is approximately perpendicular to the {001} cleavage. Electron microprobe analyses yielded the averages and ranges in wt.%: As 58.21 (57.74-59.03), S 38.72 (38.33-39.00), total 96.94 (96.07-97.75), providing the empirical formula (based on 5 atoms) As_(1.96)S_(3.04). The strongest powder X-ray diffraction lines are [d (hkl) I] 4.867(002) 97, 4.519 (110,111) 77, 3.702 (111) 46, 3.609 (022,112) 82, 2.880 (201,022,121,023) 75, 2.552 (113,131,132) 100, 2.469 (114,130,131) 96. The structure of anorpiment [R_1 = 0.021 for 1484 reflections with F_o > 4σ(F)] consists of layers of covalently bonded As and S atoms. Each S atom bonds to two As atoms at As-S-As angles between 100.45 and 104.15º. Each As atom is strongly bonded to three S atoms at S-As-S angles between 91.28 and 103.59º, forming an AsS_3 pyramid with As at its apex. The As-S linkages within the layers form rings of six AsS_3 pyramids. Interlayer bonding forces are interpreted as van der Waals. The structure of anorpiment is similar to that of orpiment in that it is composed of layers of As2S_3 macromolecules, but arranged in a different stacking sequence

    Ionizing beam-induced adhesion enhancement and interface chemistry for Au-GaAs

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    MeV ion beam-induced adhesion enhancement of Au-films (∼500 Å thick) on p-type and n-type GaAs substrates has been studied by the scratch test, ESCA, and nuclear reaction hydrogen profiling. For films resistively deposited in a diffusion pumped chamber at 2−5×10^(−6)torr, the data indicate that the adhesion enhancement is associated with oxide layers on the substrate surface adsorbed before the film deposition. The ESCA data suggest that water vapour dissociates and forms Ga(OH)_3 at the interface layers under ionizing radiation. The oxide concentration at the interface varies with substrate electronic properties and gives a large difference in the adhesion enhancement. However, the data obtained so far on the hydrogen concentration at the interface indicate that within our range of sensitivity it is about the same for substrates with different electronic properties. Our data demonstrate the importance of a thin absorbed (impurity) layer for the interface chemistry and adhesion enhancement by ionizing radiation

    Membership categorization, culture and norms in action

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    In this article, we examine the extent to which membership categorization analysis (MCA) can inform an understanding of reasoning within the public domain where morality, policy and cultural politics are visible (Smith and Tatalovich, 2003). Through the examination of three examples, we demonstrate how specific types of category device(s) are a ubiquitous feature of accountable practice in the public domain where morality matters and public policy intersect. Furthermore, we argue that MCA provides a method for analysing the mundane mechanics associated with everyday cultural politics and democratic accountability assembled and presented within news media and broadcast settings

    A ratchet mechanism for amplification in low-frequency mammalian hearing

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    The sensitivity and frequency selectivity of hearing result from tuned amplification by an active process in the mechanoreceptive hair cells. In most vertebrates the active process stems from the active motility of hair bundles. The mammalian cochlea exhibits an additional form of mechanical activity termed electromotility: its outer hair cells (OHCs) change length upon electrical stimulation. The relative contributions of these two mechanisms to the active process in the mammalian inner ear is the subject of intense current debate. Here we show that active hair-bundle motility and electromotility can together implement an efficient mechanism for amplification that functions like a ratchet: sound-evoked forces acting on the basilar membrane are transmitted to the hair bundles whereas electromotility decouples active hair-bundle forces from the basilar membrane. This unidirectional coupling can extend the hearing range well below the resonant frequency of the basilar membrane. It thereby provides a concept for low-frequency hearing that accounts for a variety of unexplained experimental observations from the cochlear apex, including the shape and phase behavior of apical tuning curves, their lack of significant nonlinearities, and the shape changes of threshold tuning curves of auditory nerve fibers along the cochlea. The ratchet mechanism constitutes a general design principle for implementing mechanical amplification in engineering applications.Comment: 6 pages, 4 figures, plus Supplementary Information. Animation available on the PNAS website (http://dx.doi.org/10.1073/pnas.0914345107)

    Measuring health related quality of life of care home residents, comparison of self-report with staff proxy responses for EQ-5D-5L and HowRu: protocol for assessing proxy reliability in care home outcome testing

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    Introduction Research into interventions to improve health and wellbeing for older people living in care homes is increasingly common. Health-Related Quality of Life (HRQoL) is frequently used as an outcome measure but collecting both self-reported and proxy HRQoL measures is challenging in this setting. This study will investigate the reliability of UK care home staff as proxy respondents for the EQ-5D-5L and HowRu measures. Methods and Analysis This is a prospective cohort study of a sub-population of care home residents recruited to the larger Proactive Healthcare for Older People in Care Homes (PEACH) study. It will recruit residents ≥ 60 years across 24 care homes and not receiving short stay or respite care. The sample size is 160 participants. Resident and care home staff proxy EQ-5D-5L and HowRu responses will be collected monthly for three months. Weighted kappa statistics and intraclass correlation adjusted for clustering at the care home level will be used to measure agreement between resident and proxy responses. The extent to which staff variables (gender, age group, length of time caring, role, how well they know the resident, length of time working in care homes and in specialist gerontological practice) influence the level of agreement between self-reported and proxy responses will be considered using a multilevel mixed-effect regression model. Ethics and Dissemination The PEACH study protocol was reviewed by the UK Health Research Authority and University of Nottingham Research Ethics Committee and was determined to be a service development project. We will publish this study in a peer-reviewed journal with international readership and disseminate it through relevant national stakeholder networks and specialist societies

    Techniques of disinformation: constructing and communicating "soft facts" after terrorism

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    Informed by social media data collected following four terror attacks in the UK in 2017, this article delineates a series of “techniques of disinformation” used by different actors to try and influence how the events were publicly defined and understood. By studying the causes and consequences of misleading information following terror attacks, the article contributes empirically to the neglected topic of social reactions to terrorism. It also advances scholarship on the workings of disinforming communications, by focusing on a domain other than political elections, which has been the empirical focus for most studies of disinformation to date. Theoretically, the analysis is framed by drawing an analogy with Gresham Sykes and David Matza's (1957) account of the role of “techniques of neutralization” originally published in the American Sociological Review. The connection being that where they studied deviant behaviour, a similar analytic lens can usefully be applied to disinformation cast as “deviant” information

    Combinatorial immunotherapies overcome MYC-driven immune evasion in triple negative breast cancer

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    Few patients with triple negative breast cancer (TNBC) benefit from immune checkpoint inhibitors with complete and durable remissions being quite rare. Oncogenes can regulate tumor immune infiltration, however whether oncogenes dictate diminished response to immunotherapy and whether these effects are reversible remains poorly understood. Here, we report that TNBCs with elevated MYC expression are resistant to immune checkpoint inhibitor therapy. Using mouse models and patient data, we show that MYC signaling is associated with low tumor cell PD-L1, low overall immune cell infiltration, and low tumor cell MHC-I expression. Restoring interferon signaling in the tumor increases MHC-I expression. By combining a TLR9 agonist and an agonistic antibody against OX40 with anti-PD-L1, mice experience tumor regression and are protected from new TNBC tumor outgrowth. Our findings demonstrate that MYC-dependent immune evasion is reversible and druggable, and when strategically targeted, may improve outcomes for patients treated with immune checkpoint inhibitors. The oncoprotein c-Myc is often overexpressed in triple negative breast cancer and has a role in tumor progression and resistance to therapy. Here the authors show that elevated MYC expression is correlated with low immune infiltration, diminished MHC-I pathway expression and that CpG/aOX40 treatment could overcome resistance to PD-L1 blockade in MYC-high breast tumors.Peer reviewe

    Plasma levels of alpha1-antichymotrypsin and secretory leukocyte proteinase inhibitor in healthy and chronic obstructive pulmonary disease (COPD) subjects with and without severe α1-antitrypsin deficiency

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    BACKGROUND: Individuals with severe Z α1-antitrypsin (AAT) deficiency have a considerably increased risk of developing chronic obstructive lung disease (COPD). It has been hypothesized that compensatory increases in levels of other protease inhibitors mitigate the effects of this AAT deficiency. We analysed plasma levels of AAT, α1-antichymotrypsin (ACT) and secretory leukocyte protease inhibitor (SLPI) in healthy (asymptomatic) and COPD subjects with and without AAT deficiency. METHODS: Studied groups included: 71 asymptomatic AAT-deficient subjects (ZZ, n = 48 and SZ, n = 23, age 31 ± 0.5) identified during Swedish neonatal screening for AAT deficiency between 1972 and 1974; age-matched controls (MM, n = 57, age 30.7 ± 0.6); older asymptomatic ZZ (n = 10); healthy MM (n = 20, age 53 ± 9.6); and COPD patients (ZZ, n = 10, age 47.4 ± 11 and MM, n = 10, age 59.4 ± 6.7). Plasma levels of SLPI, AAT and ACT were analysed using ELISA and immunoelectrophoresis. RESULTS: No significant difference was found in plasma ACT and SLPI levels between the healthy MM and the ZZ or SZ subjects in the studied groups. Independent of the genetic variant, subjects with COPD (n = 19) had elevated plasma levels of SLPI and ACT relative to controls (n = 153) (49.5 ± 7.2 vs 40.7 ± 9.1 ng/ml, p < 0.001 and 0.52 ± 0.19 vs 0.40 ± 0.1 mg/ml, p < 0.05, respectively). CONCLUSION: Our findings show that plasma levels of ACT and SLPI are not elevated in subjects with genetic AAT deficiency compared MM controls and do not appear to compensate for the deficiency of plasma AAT

    Objectively measured physical activity and sedentary behaviour and ankle brachial index: Cross-sectional and longitudinal associations in older men

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    AbstractBackgroundAssociations between bouts of physical activity (PA), sedentary behaviour (SB) and cardiovascular disease, and their mutual independence are not well defined. A low ankle brachial index (ABI ≤0.9) indicates peripheral arterial disease (PAD) and is predictive of cardiovascular events and functional impairment. We investigated the independence of PA and SB and the importance of bout duration in relation to ABI using objective measures.Methods945 men from the British Regional Heart Study, mean age 78.4 y, had concurrent measurements of ABI (Vicorder) and physical activity (Actigraph GT3X accelerometer); 427 men also had accelerometer measurements one year previously and contributed data to longitudinal analyses.Results and conclusionIn cross-sectional analyses, after adjusting for covariates each extra 10 min of moderate and vigorous PA per day was associated with an OR of 0.81 (95% CI 0.72, 0.91) for a low ABI, a stronger association than for light PA (OR 0.85, 95% CI 0.75, 0.98). Each extra 30 min of SB was associated with an OR of 1.19 (95% CI 1.07, 1.33) for a low ABI. Associations between moderate and vigorous PA and ABI persisted after adjustment for light PA or SB. Bout lengths for PA and SB were not associated with a low ABI. One year changes in PA or SB were not associated with low ABI.All physical activity and lower levels of SB, regardless of bout duration were inversely associated with ABI; more intense PA showed a stronger association. No associations between changes in PA and ABI were observed, but power may have been limited
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