5,263 research outputs found
Indolylarylsulfones, a fascinating story of highly potent human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors
Indolylarylsulfones are a potent class of human immunodeficiency virus type 1 non-nucleoside reverse transcriptase inhibitors. In this review, the structure activity relationship (SAR) studies to improve the profile of sulfone L-737,126 discovered by Merck AG have been analysed with focus on introduction of the 3',5'-dimethyl groups at the 3-phenylsulfonyl moiety, the 2-hydroxyethyl tail at the indole-2-carboxamide nitrogen, coupling of the carboxamide nitrogen with one or two glycinamide and alaninamide units, a fluorine atom at position 4 of the indole ring and correlation between configuration of the asymmetric centre and linker length. IAS derivatives look like promising drug candidates for the treatment of AIDS and related infections in combination with other antiretroviral agents
Constraints on Extragalactic Point Source Flux from Diffuse Neutrino Limits
We constrain the maximum flux from extragalactic neutrino point sources by
using diffuse neutrino flux limits. We show that the maximum flux from
extragalactic point sources is E^2(dN/dE) < 1.4 x 10^-9 (L_nu/2x10^43
erg/s)^1/3 GeV cm-^2 s^-1 from individual point sources with average neutrino
luminosity per decade, L_nu. It depends only slightly on factors such as the
inhomogeneous matter density distribution in the local universe, the luminosity
distribution, and the assumed spectral index. The derived constraints are at
least one order of magnitude below the current experimental limits from direct
searches. Significant constraints are also derived on the number density of
neutrino sources and on the total neutrino power density.Comment: 7 pages, 3 figures, and 2 table
Influence of Beams Distribution on the Dynamic and Seismic Linear Response of RC Frame Buildings
The present study compares the dynamic properties and seismic performances offered by reinforced concrete frame structures characterized by different beams distribution. The understanding of the influence of beams distribution on spatial frames is not only useful when dealing with the seismic vulnerability assessment of existing buildings that may show unusual layouts of beams, such as alternating beams at each storey, but also when facing the design of new buildings with fluid viscous dampers for which some structural flexibility is required. A systematic study is described in this paper. Four (2-, 3-, 6-, and 10-storey) regular frame buildings with rectangular plan are considered as reference structures. Different models are developed according to various layouts of the primary beams, exploring alternatives to the full three-dimensional organisation of beams and frames. For instance: beams placed along the longitudinal direction at the odd storeys and placed along the transversal direction at the even storeys, and vice versa; alternating beams every one and two storeys; beams just placed along one direction. Modal analysis has been conducted to evaluate the influence of beams distribution on the dynamic properties (periods of vibration and modal participating mass ratios). Response spectrum analysis and linear time-history dynamic analysis have been carried out to assess the effects of beams distribution on the fundamental seismic response parameters (shear forces, bending moments, top-storey displacements, interstorey drifts, and floor accelerations). On the contrary of what could be expected, the results indicate that structures with beams alternating every storey may show interesting advantages in terms of reduced total base shear, almost comparable bending moments and accelerations, within a still balanced overall behaviour along the two directions, with respect to the complete three-dimensional frame. Two effects are recognized: the period effect and the static scheme effect. The former acting basically on the storey shear forces; the latter acting mainly on the bending moments
Chiral Anomalies via Classical and Quantum Functional Methods
In the quantum path integral formulation of a field theory model an anomaly
arises when the functional measure is not invariant under a symmetry
transformation of the Lagrangian. In this paper, generalizing previous work
done on the point particle, we show that even at the classical level we can
give a path integral formulation for any field theory model. Since classical
mechanics cannot be affected by anomalies, the measure of the classical path
integral of a field theory must be invariant under the symmetry. The classical
path integral measure contains the fields of the quantum one plus some extra
auxiliary ones. So, at the classical level, there must be a sort of
"cancellation" of the quantum anomaly between the original fields and the
auxiliary ones. In this paper we prove in detail how this occurs for the chiral
anomaly.Comment: 26 pages, Latex, misprint fixed, a dedication include
LP 400-22, A very low-mass and high-velocity white dwarf
We report the identification of LP 400-22 (WD 2234+222) as a very low-mass
and high-velocity white dwarf. The ultraviolet GALEX and optical photometric
colors and a spectral line analysis of LP 400-22 show this star to have an
effective temperature of 11080+/-140 K and a surface gravity of log g =
6.32+/-0.08. Therefore, this is a helium core white dwarf with a mass of 0.17
M_solar. The tangential velocity of this white dwarf is 414+/-43 km/s, making
it one of the fastest moving white dwarfs known. We discuss probable
evolutionary scenarios for this remarkable object.Comment: accepted for publication in ApJ Letters, made minor correction
Parent and self-report health-related quality of life measures in young patients with Tourette syndrome
Tourette syndrome is a neurodevelopmental disorder characterized by tics and comorbid behavioral problems. This study compared child- and parent-reported quality of life and everyday functioning. We assessed 75 children with Tourette syndrome, of which 42 (56%) had comorbid conditions (obsessive-compulsive disorder = 25; attention-deficit hyperactivity disorder = 6; both comorbidities = 4). All patients completed psychometric instruments, including the Gilles de la Tourette Syndrome-Quality of Life Scale for Children and Adolescents (child report) and the Child Tourette's Syndrome Impairment Scale (parent report). Data were compared for patients with pure Tourette syndrome, Tourette syndrome + obsessive-compulsive disorder, Tourette syndrome + attention-deficit hyperactivity disorder, and Tourette syndrome + both comorbidities. There were no group differences in quality of life. However, there were differences for total, school, and home activities impairment scores. Children and parents may not share similar views about the impact of Tourette syndrome on functioning. The measurement of health-related quality of life in Tourette syndrome is more complex in children than adults
Fusobacterium nucleatum: a rare cause of bacteremia in neutropenic patients with leukemia and lymphoma
Although anaerobic bacteremias are uncommon in oncohematologic patients, nevertheless they have been considered an emergent problem in the last few years. Fusobacterium nucleatum is an anaerobic Gram-negative bacillus commonly present in the oral cavity and in the respiratory and genito-urinary tracts. Over a 10-year period 18 episodes of F. nucleatum bacteremia in patients with hematological malignances (15 leukemias and 3 lymphomas) have been observed in our Department of Hematology. Predisposing factors included oropharyngeal mucositis and severe neutropenia owing to intensive chemotherapy. In our experience no septic shock occurred and the outcome of bacteremias caused by F. nucleatum was favorable
A Network Tomography Approach for Traffic Monitoring in Smart Cities
Traffic monitoring is a key enabler for several planning and management activities of a Smart City. However, traditional techniques are often not cost efficient, flexible, and scalable. This paper proposes an approach to traffic monitoring that does not rely on probe vehicles, nor requires vehicle localization through GPS. Conversely, it exploits just a limited number of cameras placed at road intersections to measure car end-to-end traveling times. We model the problem within the theoretical framework of network tomography, in order to infer the traveling times of all individual road segments in the road network. We specifically deal with the potential presence of noisy measurements, and the unpredictability of vehicles paths. Moreover, we address the issue of optimally placing the monitoring cameras in order to maximize coverage, while minimizing the inference error, and the overall cost. We provide extensive experimental assessment on the topology of downtown San Francisco, CA, USA, using real measurements obtained through the Google Maps APIs, and on realistic synthetic networks. Our approach provides a very low error in estimating the traveling times over 95% of all roads even when as few as 20% of road intersections are equipped with cameras
An incremental prefix filtering approach for all pairs similarity search
Given a set of records, a threshold value t and a similarity function, we investigate the problem of finding all pairs of records such that similarity between each pair is above t. We propose several optimizations on the existing approaches to solve the problem. Our algorithm outperforms the state-of-the-art algorithms in the case with large and high-dimensional datasets. The speedup we achieved varied from 30% to 4-x depending on the similarity threshold and the dataset properties
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