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In this paper, we propose an optimized transmission scheme with energy-harvesting for a diffusion-based molecular communication system composed by nano-devices fed by piezoelectric nanogenerators. To this end, we firstly derive a system model that analytically describes the mean and the variance of the aggregated noise at the output of the receiver and the achievable Bit Error Rate. Then, we formulate an optimization problem that minimizes an objective function defined as a linear combination of the probability that the voltage across the ultra-nanocapacitor of the transmitter goes under a target value and the number of enqueued packets. We solve this problem by considering the actual energy budget, a target Bit Error Rate, and the need to achieve the simplicity of the transmitter as constraints. Finally, we use computer simulations to validate the formulated analytical models and demonstrate the unique ability of the proposed approach to guarantee BER = 5% and BER = 10% for communication distances up to 47 µm and 50 µm , respectively, while registering better results against baseline scenarios.
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Comunicación , Simulación por Computador , DifusiónRESUMEN
Infection by human immunodeficiency virus-1 (HIV-1) is associated with a progressive decrease in CD4 T-cell numbers and the consequent collapse of host immune defenses. The major pathogenic mechanism of AIDS is the massive apoptotic destruction of the immunocompetent cells, including uninfected cells. The latter process, also known as by-stander killing, operates by various mechanisms one of which involves the formation of syncytia which undergo cell death by following a complex pathway. We present here a detailed and curated map of the syncytial apoptosis signaling network, aimed at simplifying the whole mechanism that we have characterized at the molecular level in the last 15 years. The map was created using Systems Biology Graphical Notation language with the help of CellDesigner software and encompasses 36 components (proteins/genes) and 54 interactions. The simplification of this complex network paves the way for the development of novel therapeutic strategies to eradicate HIV-1 infection. Agents that induce the selective death of HIV-1-elicited syncytia might lead to the elimination of viral reservoirs and hence constitute an important complement to current antiretroviral therapies.
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Linfocitos T CD4-Positivos/metabolismo , Células Gigantes/metabolismo , Proteínas gp160 de Envoltorio del VIH/metabolismo , Infecciones por VIH/metabolismo , VIH-1/metabolismo , Transducción de Señal/genética , Apoptosis/genética , Efecto Espectador/genética , Antígenos CD4/genética , Antígenos CD4/metabolismo , Linfocitos T CD4-Positivos/patología , Fusión Celular , Regulación de la Expresión Génica , Células Gigantes/patología , Proteínas gp160 de Envoltorio del VIH/genética , Infecciones por VIH/genética , Infecciones por VIH/patología , Infecciones por VIH/virología , VIH-1/genética , VIH-1/patogenicidad , Interacciones Huésped-Patógeno/genética , Humanos , Mapeo de Interacción de Proteínas , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Receptores Purinérgicos/genética , Receptores Purinérgicos/metabolismoRESUMEN
Cancerogenesis is driven by mutations leading to aberrant functioning of a complex network of molecular interactions and simultaneously affecting multiple cellular functions. Therefore, the successful application of bioinformatics and systems biology methods for analysis of high-throughput data in cancer research heavily depends on availability of global and detailed reconstructions of signalling networks amenable for computational analysis. We present here the Atlas of Cancer Signalling Network (ACSN), an interactive and comprehensive map of molecular mechanisms implicated in cancer. The resource includes tools for map navigation, visualization and analysis of molecular data in the context of signalling network maps. Constructing and updating ACSN involves careful manual curation of molecular biology literature and participation of experts in the corresponding fields. The cancer-oriented content of ACSN is completely original and covers major mechanisms involved in cancer progression, including DNA repair, cell survival, apoptosis, cell cycle, EMT and cell motility. Cell signalling mechanisms are depicted in detail, together creating a seamless 'geographic-like' map of molecular interactions frequently deregulated in cancer. The map is browsable using NaviCell web interface using the Google Maps engine and semantic zooming principle. The associated web-blog provides a forum for commenting and curating the ACSN content. ACSN allows uploading heterogeneous omics data from users on top of the maps for visualization and performing functional analyses. We suggest several scenarios for ACSN application in cancer research, particularly for visualizing high-throughput data, starting from small interfering RNA-based screening results or mutation frequencies to innovative ways of exploring transcriptomes and phosphoproteomes. Integration and analysis of these data in the context of ACSN may help interpret their biological significance and formulate mechanistic hypotheses. ACSN may also support patient stratification, prediction of treatment response and resistance to cancer drugs, as well as design of novel treatment strategies.
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Occupational medicine in the last few years is trying to tune its objectives to the changing needs of the working world. The continuous reduction of incidence of work related diseases progressively substituted with chronic degenerative ones, suggests a different strategy to prevent occupational diseases and to protect workers health. Health surveillance should not be limited only to draw up the work qualification but should be the starting point to plan intervention useful both to workers and to the general population. Corner stone of this endeavour is the epidemiological research focused on the improvement of quality of life.
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Métodos Epidemiológicos , Modelos Estadísticos , Vigilancia de la Población/métodos , HumanosRESUMEN
The Authors refer the Health Surveillance outcomes on 3185 workers of Campania region from 1996 to 2001: CHD frequencies and relationship between the individual (age, BMI, smoking, serum cholesterol) and the occupational risks factors (work strain and shift). All risk factors increase the frequencies of CHD, but the work strain and the shift determinate an upper increase of the relative risk. The Authors suggest far reaching programs of Health Surveillance, useful to define and to control the specific work risks and to improve the worksite health promotion.