1,721,550 research outputs found
PERIODICALLY TIME-MODULATED BISTABLE SYSTEMS - NONSTATIONARY STATISTICAL PROPERTIES
No full textThe relaxation properties of a one-dimensional overdamped system modulated by an external periodic force are studied analytically by means of a perturbation approach. The validity of the ap- proximations introduced is discussed in detail. The nonstationary nature of the process is illustrat- ed by evaluating explicitly the autocorrelation function for the relaxation in a bistable potential. The predictions thus obtained are shown to compare favorably with the results of analogue simula- tion for the case of a quartic double-well potential. The stochastic resonance mechanism is proven to set in only when the periodic perturbation breaks the symmetry of the bistable potential
Tunable MoS2 strain sensor
No full textMolybdenum disulfide (MoS2) is a promising two-dimensional (2D) semiconductor for the realization of electronic devices such as sensors and transducers. Among other mechanical and electronic properties, MoS2 shows piezoresistive effect due to the strain-induced modulation of its electronic band-gap. In this work we present how the piezoresistive property of MoS2 can be exploited to realize a strain gauge. The non-linear response of the sensor is used to tune and enhance the sensitivity of the sensor in a specific strain range. We find that in optimal working conditions we can achieve a gauge factor of-96
Using a Mathematical Model to Evaluate the Efficacy of TB Control Measures
No full textWe evaluated the efficacy of recommended tuberculosis (TB) infection control measures by using a deterministic mathematical model for airborne contagion. We examined the percentage of purified protein derivative conversions under various exposure conditions, environmental control strategies, and respiratory protective devices. We conclude that environmental control cannot eliminate the risk for TB transmission during high-risk procedures; respiratory protective devices, and particularly high-efficiency particulate air masks, may provide nearly complete protection if used with air filtration or ultraviolet irradiation. Nevertheless, the efficiency of these control measures decreases as the infectivity of the source case increases. Therefore, administrative control measures (e.g., indentifying and isolating patients with infectious TB) are the most effective because they substantially reduce the rate of infection
Activity of cytokine-induced killer cells against bone and soft tissue sarcoma
No full textCytokine-induced killer (CIK) cells are T lymphocytes expanded ex vivo that are endowed with MHC-independent tumoricidal activity. We have recently demonstrated, in a preclinical setting, that CIK cells are active against autologous bone and soft tissue sarcomas. In particular, CIK cells killed a putative sarcoma stem cell population that may underlie disease relapse and chemoresistance. © 2014 Landes Bioscience
Piezoelectric buckled beams for random vibration energy harvesting
No full textAmong the main vibration-to-electricity conversion systems, resonant harvesters suffer from a series of strong limits like their narrow frequency response and poor output power at small scale. Most of all, realistic vibration sources are variable in time and abundant at relatively low frequencies. Nonlinear vibration harvesters, on the other hand, are more attractive, thanks to their large bandwidth response and flexibility to convert kinetic energy of the natural frequency of the sources. In particular, bistable oscillators have been proven to show higher global performances when excited by random vibrations. In this paper, such an approach is investigated for piezoelectric beams by exerting an increasing axial compression. An advantage of this technique is the absence of magnetic forces to create bistable dynamics. A thin piezoelectric axially loaded beam is theoretically modelled and experimentally investigated under wideband random vibrations. In the buckled configuration, the device exhibits superior power generation over a large interval of resistive load, with gains up to more than a factor of ten compared to the unbuckled state. The numerical model and experimental results are in good qualitative agreement
Genetically redirected T lymphocytes for adoptive immunotherapy of solid tumors
No full textGenetic engineering of T lymphocytes to confer new antitumor specificities is a fascinating approach that may help the successful clinical translation of adoptive immunotherapy strategies. The recognition of tumor-specific antigens may be obtained inducing the membrane expression of transgene encoded antitumor T cell receptors (TCR) or chimeric antigen receptors (CAR). Few but very informative clinical trials with TCR or CAR redirected T lymphocytes have been attempted in the last years, reporting important clinical results along with disappointing failures and important warnings. In this work, we will focus on TCR and CAR redirected T lymphocytes as adoptive immunotherapy for solid tumors. We will review the main topics of these strategies from the angle of clinical applications, discussing the main issues that emerged from early clinical trials and their impact on next study designs. © 2014 Bentham Science Publishers
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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