1,081 research outputs found

    ThreeĂą dimensional imaging of shear bands in bulk metallic glass composites

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/134811/1/jmi12443_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/134811/2/jmi12443.pd

    Reporter bacteriophage T7NLC utilizes a novel NanoLuc::CBM fusion for the ultrasensitive detection of Escherichia coli in water.

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    Rapid detection of bacteria responsible for foodborne diseases is a growing necessity for public health. Reporter bacteriophages (phages) are robust biorecognition elements uniquely suited for the rapid and sensitive detection of bacterial species. The advantages of phages include their host specificity, ability to distinguish viable and non-viable cells, low cost, and ease of genetic engineering. Upon infection with reporter phages, target bacteria express reporter enzymes encoded within the phage genome. In this study, the T7 coliphage was genetically engineered to express the newly developed luceriferase, NanoLuc (NLuc), as an indicator of bacterial contamination. While several genetic approaches were employed to optimize reporter enzyme expression, the novel achievement of this work was the successful fusion of the NanoLuc reporter to a carbohydrate binding module (CBM) with specificity to crystalline cellulose. This novel chimeric reporter (nluc::cbm) bestows the specific and irreversible immobilization of NanoLuc onto a low-cost, widely available crystalline cellulosic substrate. We have shown the possibility of detecting the immobilized fusion protein in a filter plate which resulted from a single CFU of E. coli. We then demonstrated that microcrystalline cellulose can be used to concentrate the fusion reporter from 100 mL water samples allowing a limit of detection of \u3c10 CFU mL-1 E. coli in 3 hours. Therefore, we conclude that our phage-based detection assay displays significant aptitude as a proof-of-concept drinking water diagnostic assay for the low-cost, rapid and sensitive detection of E. coli. Additional improvements in the capture efficiency of the phage-based fusion reporter should allow a limit of detection of \u3c10 CFU per 100 mL

    Avalanche dynamics, surface roughening and self-organized criticality - experiments on a 3 dimensional pile of rice

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    We present a two-dimensional system which exhibits features of self-organized criticality. The avalanches which occur on the surface of a pile of rice are found to exhibit finite size scaling in their probability distribution. The critical exponents are τ\tau = 1.21(2) for the avalanche size distribution and DD = 1.99(2) for the cut-off size. Furthermore the geometry of the avalanches is studied leading to a fractal dimension of the active sites of dBd_B = 1.58(2). Using a set of scaling relations, we can calculate the roughness exponent α=D−dB\alpha = D - d_B = 0.41(3) and the dynamic exponent z=D(2−τ)z = D(2 - \tau) = 1.56(8). This result is compared with that obtained from a power spectrum analysis of the surface roughness, which yields α\alpha = 0.42(3) and zz = 1.5(1) in excellent agreement with those obtained from the scaling relations.Comment: 7 pages, 8 figures, accepted for publication in PR

    Probing Sub-Micron Forces by Interferometry of Bose-Einstein Condensed Atoms

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    We propose a technique, using interferometry of Bose-Einstein condensed alkali atoms, for the detection of sub-micron-range forces. It may extend present searches at 1 micron by 6 to 9 orders of magnitude, deep into the theoretically interesting regime of 1000 times gravity. We give several examples of both four-dimensional particles (moduli), as well as higher-dimensional particles -- vectors and scalars in a large bulk-- that could mediate forces accessible by this technique.Comment: 32 pages, 5 figures, RevTeX4, expanded discussion of interactions, references added, to appear in PR

    Seven fatalities associated with ethylphenidate

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    Ethylphenidate is a stimulant novel psychoactive substance that is an analogue of the prescription drug methylphenidate (RitalinÂź). Methylphenidate is used commonly for the treatment of attention deficit hyperactivity disorder. Due to its stimulant effects ethylphenidate is being abused. There is a single case report of a death associated with ethylphenidate in Germany, and a case series of 19 deaths in the East of Scotland, but otherwise, the contribution of ethylphenidate to death is poorly documented. We report the analytical results of 7 cases (between February 2013 and January 2015) in which ethylphenidate was detected and quantitated with a validated liquid chromatography tandem mass spectrometry method (LC-MS/MS). The individuals (all male) ranged in age from 23 to 49 years (median 25 years). The concentration of ethylphenidate in the cases ranged from 0.026mg/L to 2.18mg/L in unpreserved post-mortem femoral blood. Only one case had ethylphenidate present as a sole drug. All other cases had at least 2 other drug classes present (benzodiazepines, heroin, methadone antipsychotics, other new psychoactive compounds). Ethylphenidate toxicity was the sole contribution to the cause of death in one case. Hanging was the cause of death in 2 cases, with the other 4 cases being reported as having occurred due to mixed drug toxicity. These data will further help with the interpretation of post-mortem ethylphenidate levels

    Gravitational radiation from gamma-ray bursts as observational opportunities for LIGO and VIRGO

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    Gamma-ray bursts are believed to originate in core-collapse of massive stars. This produces an active nucleus containing a rapidly rotating Kerr black hole surrounded by a uniformly magnetized torus represented by two counter-oriented current rings. We quantify black hole spin-interactions with the torus and charged particles along open magnetic flux-tubes subtended by the event horizon. A major output of Egw=4e53 erg is radiated in gravitational waves of frequency fgw=500 Hz by a quadrupole mass-moment in the torus. Consistent with GRB-SNe, we find (i) Ts=90s (tens of s, Kouveliotou et al. 1993), (ii) aspherical SNe of kinetic energy Esn=2e51 erg (2e51 erg in SN1998bw, Hoeflich et al. 1999) and (iii) GRB-energies Egamma=2e50 erg (3e50erg in Frail et al. 2001). GRB-SNe occur perhaps about once a year within D=100Mpc. Correlating LIGO/Virgo detectors enables searches for nearby events and their spectral closure density 6e-9 around 250Hz in the stochastic background radiation in gravitational waves. At current sensitivity, LIGO-Hanford may place an upper bound around 150MSolar in GRB030329. Detection of Egw thus provides a method for identifying Kerr black holes by calorimetry.Comment: to appear in PRD, 49

    Non-Small-Cell Lung Cancer Patients with a High Predicted Risk of Irradical Resection: Can Chemoradiotherapy Offer Similar Survival?

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    Purpose: Irradical resection of non-small-cell lung cancer (NSCLC) is a detrimental prognostic factor. Recently, Rasing et al. presented an internationally validated risk score for pre-treatment prediction of irradical resection. We hypothesized that chemoradiation therapy (CRT) could serve as an alternative approach in patients with a high risk score and compared overall survival (OS) outcomes between surgery and CRT. Methods: Patients from a population-based cohort with stage IIB–III NSCLC between 2015 and 2018 in The Netherlands were selected. Patients with a ‘Rasing score’ > 4 who underwent surgery were matched with patients who underwent CRT using 1:1 nearest-neighbor propensity score matching. The primary endpoint of OS was compared using a Kaplan–Meier analysis. Results: In total, 2582 CRT and 638 surgery patients were eligible. After matching, 523 well-balanced pairs remained. Median OS in the CRT group was 27.5 months, compared with 45.6 months in the surgery group (HR 1.44, 95% CI 1.23–1.70, p < 0.001). The 114 surgical patients who underwent an R1–2 resection (21.8%) had a worse median OS than the CRT group (20.2 versus 27.5 months, HR 0.77, 95% CI 0.61–0.99, p = 0.039). Conclusion: In NSCLC patients at high predicted risk of irradical resection, CRT appears to yield inferior survival compared with surgery. Therefore, choosing CRT instead of surgery cannot solely be based on the Rasing score. Since patients receiving an R1–2 resection do have detrimental outcomes compared with primary CRT, the treatment decision should be based on additional information, such as imaging features, comorbidities, patient preference, and the surgeon’s confidence in achieving an R0 resection

    Alteration in the plasma concentration of a DAAO inhibitor, 3-methylpyrazole-5-carboxylic acid, in the ketamine-treated rats and the influence on the pharmacokinetics of plasma d-tryptophan

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    A determination method for 3-methylpyrazole-5-carboxylic acid (MPC), an inhibitor of d-amino acid oxidase (DAAO), in rat plasma was developed by using high-performance liquid chromatography-mass spectrometry (LC-MS). The structural isomer of MPC, 3-methylpyrazole-4-carboxylic acid, was used as an internal standard, and the intra- and inter-day accuracies and precisions were satisfactory for the determination of plasma MPC

    Interstellar MHD Turbulence and Star Formation

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    This chapter reviews the nature of turbulence in the Galactic interstellar medium (ISM) and its connections to the star formation (SF) process. The ISM is turbulent, magnetized, self-gravitating, and is subject to heating and cooling processes that control its thermodynamic behavior. The turbulence in the warm and hot ionized components of the ISM appears to be trans- or subsonic, and thus to behave nearly incompressibly. However, the neutral warm and cold components are highly compressible, as a consequence of both thermal instability in the atomic gas and of moderately-to-strongly supersonic motions in the roughly isothermal cold atomic and molecular components. Within this context, we discuss: i) the production and statistical distribution of turbulent density fluctuations in both isothermal and polytropic media; ii) the nature of the clumps produced by thermal instability, noting that, contrary to classical ideas, they in general accrete mass from their environment; iii) the density-magnetic field correlation (or lack thereof) in turbulent density fluctuations, as a consequence of the superposition of the different wave modes in the turbulent flow; iv) the evolution of the mass-to-magnetic flux ratio (MFR) in density fluctuations as they are built up by dynamic compressions; v) the formation of cold, dense clouds aided by thermal instability; vi) the expectation that star-forming molecular clouds are likely to be undergoing global gravitational contraction, rather than being near equilibrium, and vii) the regulation of the star formation rate (SFR) in such gravitationally contracting clouds by stellar feedback which, rather than keeping the clouds from collapsing, evaporates and diperses them while they collapse.Comment: 43 pages. Invited chapter for the book "Magnetic Fields in Diffuse Media", edited by Elisabete de Gouveia dal Pino and Alex Lazarian. Revised as per referee's recommendation
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