1,722 research outputs found

    Group V Mixing Effects in the Structural and Optical Properties of (ZnSi)1/2(P)1/4(As)1/4

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    We present {\it ab initio} total energy and band structure calculations based on Density Funtional Theory (DFT) within the Local Density Aproximation (LDA) on group-V mixing effects in the optoelectronic material (ZnSi)1/2P1/4As3/4(ZnSi)_{1/2}P_{1/4}As_{3/4}. This compound has been recently proposed by theoretical design as an optically active material in the 1.5 μ\mum (0.8 eV) fiber optics frequency window and with a monolithic integration with the Si (001) surface. Our results indicate that alloy formation in the group V planes would likely occur at typical growth conditions. In addition, desired features such as in-plane lattice constant and energy gap are virtually unchanged and the optical oscillator strength for band-to-band transitions is increased by a factor of 6 due to alloying

    BP Reduction, Kidney Function Decline, and Cardiovascular Events in Patients without CKD.

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    BACKGROUND AND OBJECTIVES: In the Systolic Blood Pressure Intervention Trial (SPRINT), intensive systolic BP treatment (target <120 mm Hg) was associated with fewer cardiovascular events and higher incidence of kidney function decline compared with standard treatment (target <140 mm Hg). We evaluated the association between mean arterial pressure reduction, kidney function decline, and cardiovascular events in patients without CKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: We categorized patients in the intensive treatment group of the SPRINT according to mean arterial pressure reduction throughout follow-up: <20, 20 to <40, and ≥40 mm Hg. We defined the primary outcome as kidney function decline (≥30% reduction in eGFR to <60 ml/min per 1.73 m2 on two consecutive determinations at 3-month intervals), and we defined the secondary outcome as cardiovascular events. In a propensity score analysis, patients in each mean arterial pressure reduction category from the intensive treatment group were matched with patients from the standard treatment group to calculate the number needed to treat regarding cardiovascular events and the number needed to harm regarding kidney function decline. RESULTS: In the intensive treatment group, 1138 (34%) patients attained mean arterial pressure reduction <20 mm Hg, 1857 (56%) attained 20 to <40 mm Hg, and 309 (9%) attained ≥40 mm Hg. Adjusted hazard ratios for kidney function decline were 2.10 (95% confidence interval, 1.22 to 3.59) for mean arterial pressure reduction between 20 and 40 mm Hg and 6.22 (95% confidence interval, 2.75 to 14.08) for mean arterial pressure reduction ≥40 mm Hg. In propensity score analysis, mean arterial pressure reduction <20 mm Hg presented a number needed to treat of 44 and a number needed to harm of 65, reduction between 20 and <40 mm Hg presented a number needed to treat of 42 and a number needed to harm of 35, and reduction ≥40 mm Hg presented a number needed to treat of 95 and a number needed to harm of 16. CONCLUSIONS: In the intensive treatment group of SPRINT, larger declines in mean arterial pressure were associated with higher incidence of kidney function decline. Intensive treatment seemed to be less favorable when a larger reduction in mean arterial pressure was needed to attain the BP target.info:eu-repo/semantics/publishedVersio

    Event-related brain potentials in the study of inhibition: cognitive control, source localization and age-related modulations

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    In the previous 15 years, a variety of experimental paradigms and methods have been employed to study inhibition. In the current review, we analyze studies that have used the high temporal resolution of the event-related potential (ERP) technique to identify the temporal course of inhibition to understand the various processes that contribute to inhibition. ERP studies with a focus on normal aging are specifically analyzed because they contribute to a deeper understanding of inhibition. Three time windows are proposed to organize the ERP data collected using inhibition paradigms: the 200 ms period following stimulus onset; the period between 200 and 400 ms after stimulus onset; and the period between 400 and 800 ms after stimulus onset. In the first 200 ms, ERP inhibition research has primarily focused on N1 and P1 as the ERP components associated with inhibition. The inhibitory processing in the second time window has been associated with the N2 and P3 ERP components. Finally, in the third time window, inhibition has primarily been associated with the N400 and N450 ERP components. Source localization studies are analyzed to examine the association between the inhibition processes that are indexed by the ERP components and their functional brain areas. Inhibition can be organized in a complex functional structure that is not constrained to a specific time point but, rather, extends its activity through different time windows. This review characterizes inhibition as a set of processes rather than a unitary process

    Epigenetic regulation of cdh1 is altered after hoxb7-silencing in mda-mb-468 triple-negative breast cancer cells

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    HOXB7 is often overexpressed in breast cancer cells and found to relate to poor prognosis. The search for the HOXB7 targets, as a transcription factor, has led to molecules involved in regulating cell proliferation, migration, invasion, and processes such as angiogenesis and therapy resistance. However, the specific targets affected by the deregulation of HOXB7 in breast cancer remain largely unknown in most molecular sub-types, such as triple-negative breast cancers (TNBC). To unveil the molecular basis behind these aggressive and often untreatable cancers, here we explored the contribution of HOXB7 deregulation for their aggressiveness. To this end, HOXB7 was silenced in TNBC Basal A cells MDA-MB-468, and the phenotype, gene/protein expression, and methylation profile of putative targets were analyzed. Lower migration and invasion rates were detected in HOXB7-silenced cells in comparison with the controls. In addition, these cells expressed more CDH1 and less DNMT3B, and the promoter methylation status of CDH1 diminished. Our data suggest that the HOXB7 transcription factor may act on TNBC Basal A cells by controlling CDH1 epigenetic regulation. This may occur indirectly through the up-regulation of DNMT3B, which then controls DNA methylation of the CDH1 promoter. Thus, future approaches interfering with HOXB7 regulation may be promising therapeutic strategies in TNBC treatment.This research was funded by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE 2020 Operational Programme for Competitiveness and Internationalisation (POCI-01-0145-FEDER-030562), Portugal 2020, and by Portuguese funds through FCT (Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior) in the framework of the project PTDC/BTM-TEC/30562/2017

    {\it Ab initio} 27Al^{27}Al NMR chemical shifts and quadrupolar parameters for Al2O3Al_2O_3 phases and their precursors

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    The Gauge-Including Projector Augmented Wave (GIPAW) method, within the Density Functional Theory (DFT) Generalized Gradient Approximation (GGA) framework, is applied to compute solid state NMR parameters for 27Al^{27}Al in the α\alpha, θ\theta, and κ\kappa aluminium oxide phases and their gibbsite and boehmite precursors. The results for well-established crystalline phases compare very well with available experimental data and provide confidence in the accuracy of the method. For γ\gamma-alumina, four structural models proposed in the literature are discussed in terms of their ability to reproduce the experimental spectra also reported in the literature. Among the considered models, the Fd3ˉmFd\bar{3}m structure proposed by Paglia {\it et al.} [Phys. Rev. B {\bf 71}, 224115 (2005)] shows the best agreement. We attempt to link the theoretical NMR parameters to the local geometry. Chemical shifts depend on coordination number but no further correlation is found with geometrical parameters. Instead our calculations reveal that, within a given coordination number, a linear correlation exists between chemical shifts and Born effective charges

    Towards self-organized service-oriented multi-agent systems

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    The demand for large-scale systems running in complex and even chaotic environments requires the consideration of new paradigms and technologies that provide flexibility, robustness, agility and responsiveness. Multiagents systems is pointed out as a suitable approach to address this challenge by offering an alternative way to design control systems, based on the decentralization of control functions over distributed autonomous and cooperative entities. However, in spite of their enormous potential, they usually lack some aspects related to interoperability, optimization in decentralized structures and truly self-adaptation. This paper discusses a new perspective to engineer adaptive complex systems considering a 3-layer framework integrating several complementary paradigms and technologies. In a first step, it suggests the integration of multi-agent systems with service-oriented architectures to overcome the limitations of interoperability and smooth migration, followed by the use of technology enablers, such as cloud computing and wireless sensor networks, to provide a ubiquitous and reconfigurable environment. Finally, the resulted service-oriented multi-agent system should be enhanced with biologically inspired techniques, namely self-organization, to reach a truly robust, agile and adaptive system
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