1,891 research outputs found
An efficient solution for privacy-preserving, secure remote access to sensitive data
Sharing data that contains personally identifiable or sensitive information, such as medical records, always has privacy and security implications. The issues can become rather complex when the methods of access can vary, and accurate individual data needs to be provided whilst mass data release for specific purposes (for example for medical research) also has to be catered for. Although various solutions have been proposed to address the different aspects individually, a comprehensive approach is highly desirable. This paper presents a solution for maintaining the privacy of data released en masse in a controlled manner, and for providing secure access to the original data for authorized users. The results show that the solution is provably secure and maintains privacy in a more efficient manner than previous solutions
A study on the extraction and purification technology of tea sapogenin
In order to extract and purify tea sapogenin, first the extraction liquid is obtained using mechanically pressed tea-seeds as raw material, which will be decreased by organic solvent. When the conditions like the methanol volume fraction is 75v/v, solid-liquid is 1:4 and the ultrasonic frequency is 25.8 Hz, extract them for 30 min. After this, collect the extraction liquid and slowly add in Hz-841 macroporous resin column, then elute it with 0.3% NaOH. The third step is to elute with ethanol of different concentrations after the coloring pigment is got rid of, and then detect it with thin layer chromatography (TLC). It is discovered that there is only tea sapogenin in the 35 – 95v/v ethanol elution liquid. The last step is to collect the 95% ethanol elution liquid and vacuum condense it; and then tea-Tea sapogenin with a purity of 96% can be obtained
Low-mass lepton pair production at large transverse momentum
We study the transverse momentum distribution of low-mass lepton pairs
produced in hadronic scattering, using the perturbative QCD factorization
approach. We argue that the distribution at large transverse momentum, , with the pair's invariant mass as low as , can be systematically factorized into universal
parton-to-lepton pair fragmentation functions, parton distributions, and
perturbatively calculable partonic hard parts evaluated at a short distance
scale . We introduce a model for the input lepton pair
fragmentation functions at a scale GeV, which are then evolved
perturbatively to scales relevant at RHIC. Using the evolved fragmentation
functions, we calculate the transverse momentum distributions in hadron-hadron,
hadron-nucleus, and nucleus-nucleus collisions at RHIC. We also discuss the
sensitivity of the transverse momentum distribution of low-mass lepton pairs to
the gluon distribution.Comment: 16 pages, 11 figures, revised version to appear in Phys. Rev.
Illuminating cell signaling with genetically encoded FRET biosensors in adult mouse cardiomyocytes.
FRET-based biosensor experiments in adult cardiomyocytes are a powerful way of dissecting the spatiotemporal dynamics of the complicated signaling networks that regulate cardiac health and disease. However, although much information has been gleaned from FRET studies on cardiomyocytes from larger species, experiments on adult cardiomyocytes from mice have been difficult at best. Thus the large variety of genetic mouse models cannot be easily used for this type of study. Here we develop cell culture conditions for adult mouse cardiomyocytes that permit robust expression of adenoviral FRET biosensors and reproducible FRET experimentation. We find that addition of 6.25 µM blebbistatin or 20 µM (S)-nitro-blebbistatin to a minimal essential medium containing 10 mM HEPES and 0.2% BSA maintains morphology of cardiomyocytes from physiological, pathological, and transgenic mouse models for up to 50 h after adenoviral infection. This provides a 10-15-h time window to perform reproducible FRET readings using a variety of CFP/YFP sensors between 30 and 50 h postinfection. The culture is applicable to cardiomyocytes isolated from transgenic mouse models as well as models with cardiac diseases. Therefore, this study helps scientists to disentangle complicated signaling networks important in health and disease of cardiomyocytes
The hot gas distribution, X-ray luminosity and baryon budget in the L-Galaxies semi-analytic model of galaxy formation
Hot ionized gas is important in the baryon cycle of galaxies and contributes
the majority of their ``missing baryons''. Until now, most semi-analytic models
of galaxy formation have paid little attention to hot gaseous haloes and their
X-ray emission. In this paper, we adopt the one-dimensional model from Sharma
et al. instead of the isothermal sphere to describe the radial distribution of
hot gas in the L-Galaxies semi-analytic model. The hot gas halo can be divided
into two parts according to the ratio of the local thermal instability
time-scale and the free-fall time-scale: a cool core with and a stable outer halo with . We update the
prescriptions of cooling, feedback and stripping based on the new hot gas
profiles, and then reproduce several X-ray observational results, like the
radial profiles of hot gas density, and the scaling relations of X-ray
luminosity and temperature. We find: (1) Consistent with observations, flatter
density profiles in halo centers produce lower X-ray emission than an
isothermal sphere; (2) Cool core regions prone to precipitation have higher gas
temperature than the virial temperature, and a larger
ratio in smaller haloes leads to a steeper slope in the
relation; (3) The ionized gas in the unbounded reservoir and low temperature
intergalactic gas in low mass haloes could be the main components of the halo
``missing baryons''. Our model outputs can predict the observations of hot gas
in the nearby universe and produce mock surveys of baryons probed by future
X-ray telescopes.Comment: 18 pages, 15 figures, accepted for publication in MNRA
The hot gas distribution, X-ray luminosity and baryon budget in the L-Galaxies semi-analytic model of galaxy formation
© 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1093/mnras/stac3735Hot ionized gas is important in the baryon cycle of galaxies and contributes the majority of their ``missing baryons''. Until now, most semi-analytic models of galaxy formation have paid little attention to hot gaseous haloes and their X-ray emission. In this paper, we adopt the one-dimensional model from Sharma et al. instead of the isothermal sphere to describe the radial distribution of hot gas in the L-Galaxies semi-analytic model. The hot gas halo can be divided into two parts according to the ratio of the local thermal instability time-scale and the free-fall time-scale: a cool core with and a stable outer halo with . We update the prescriptions of cooling, feedback and stripping based on the new hot gas profiles, and then reproduce several X-ray observational results, like the radial profiles of hot gas density, and the scaling relations of X-ray luminosity and temperature. We find: (1) Consistent with observations, flatter density profiles in halo centers produce lower X-ray emission than an isothermal sphere; (2) Cool core regions prone to precipitation have higher gas temperature than the virial temperature, and a larger ratio in smaller haloes leads to a steeper slope in the relation; (3) The ionized gas in the unbounded reservoir and low temperature intergalactic gas in low mass haloes could be the main components of the halo ``missing baryons''. Our model outputs can predict the observations of hot gas in the nearby universe and produce mock surveys of baryons probed by future X-ray telescopes.Peer reviewe
Street-scale air quality modelling over the West Midlands, United Kingdom:Effect of idealised traffic reduction scenarios
Air pollution is the major environmental risk to human health. Road transport is one of the major sources for air pollution, particularly nitrogen dioxide, in urban areas, and hence traffic control is an important measure in air quality management. A street-scale air quality model, ADMS-Urban, was configured for a case study of the West Midlands, UK to represent a baseline year (2019). Model outputs were evaluated using hourly air pollutant measurement data, and the model demonstrates good performance overall. This modelling tool was then used to explore the effect of five hypothetical traffic reduction scenarios, ranging from 10% to 90% reduction in traffic activity; scenario impacts were analysed over a range of spatial resolutions. The impacts of traffic reduction are highly dependent on spatial resolution (i.e. street scale, electoral ward level and local authority level), which has to be taken into account when formulating policies for managing air quality on local and city-wide scales. There was an almost linear relationship between the predicted annual concentration and traffic reduction for both NO2 and PM2.5. Traffic reduction would principally reduce NO2 concentrations, with even very substantial changes in traffic having more limited effects on reducing PM2.5 concentrations reflecting the importance of regional and non-traffic PM2.5 sources.</p
Spheres and Prolate and Oblate Ellipsoids from an Analytical Solution of Spontaneous Curvature Fluid Membrane Model
An analytic solution for Helfrich spontaneous curvature membrane model (H.
Naito, M.Okuda and Ou-Yang Zhong-Can, Phys. Rev. E {\bf 48}, 2304 (1993); {\bf
54}, 2816 (1996)), which has a conspicuous feature of representing the circular
biconcave shape, is studied. Results show that the solution in fact describes a
family of shapes, which can be classified as: i) the flat plane (trivial case),
ii) the sphere, iii) the prolate ellipsoid, iv) the capped cylinder, v) the
oblate ellipsoid, vi) the circular biconcave shape, vii) the self-intersecting
inverted circular biconcave shape, and viii) the self-intersecting nodoidlike
cylinder. Among the closed shapes (ii)-(vii), a circular biconcave shape is the
one with the minimum of local curvature energy.Comment: 11 pages, 11 figures. Phys. Rev. E (to appear in Sept. 1999
Numerical observation of non-axisymmetric vesicles in fluid membranes
By means of Surface Evolver (Exp. Math,1,141 1992), a software package of
brute-force energy minimization over a triangulated surface developed by the
geometry center of University of Minnesota, we have numerically searched the
non-axisymmetric shapes under the Helfrich spontaneous curvature (SC) energy
model. We show for the first time there are abundant mechanically stable
non-axisymmetric vesicles in SC model, including regular ones with intrinsic
geometric symmetry and complex irregular ones. We report in this paper several
interesting shapes including a corniculate shape with six corns, a
quadri-concave shape, a shape resembling sickle cells, and a shape resembling
acanthocytes. As far as we know, these shapes have not been theoretically
obtained by any curvature model before. In addition, the role of the
spontaneous curvature in the formation of irregular crenated vesicles has been
studied. The results shows a positive spontaneous curvature may be a necessary
condition to keep an irregular crenated shape being mechanically stable.Comment: RevTex, 14 pages. A hard copy of 8 figures is available on reques
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