A revolution in lighting Pust, Philipp; Schmidt, Peter J; Schnick, Wolfgang
Nature materials,
05/2015, Letnik:
14, Številka:
5
Journal Article
Recenzirano
Key materials discoveries have prompted the rise of inorganic light-emitting diodes in the lighting industry. Remaining challenges are being addressed to further extend the impact of this technology ...in lighting, displays and other applications.
Observations of the disproportionate incidence of depression in women compared with men have long preceded the recent explosion of interest in sex differences. Nonetheless, the source and ...implications of this epidemiologic sex difference remain unclear, as does the practical significance of the multitude of sex differences that have been reported in brain structure and function. In this article, we attempt to provide a framework for thinking about how sex and reproductive hormones (particularly estradiol as an example) might contribute to affective illness. After briefly reviewing some observed sex differences in depression, we discuss how sex might alter brain function through hormonal effects (both organizational (programmed) and activational (acute)), sex chromosome effects, and the interaction of sex with the environment. We next review sex differences in the brain at the structural, cellular, and network levels. We then focus on how sex and reproductive hormones regulate systems implicated in the pathophysiology of depression, including neuroplasticity, genetic and neural networks, the stress axis, and immune function. Finally, we suggest several models that might explain a sex-dependent differential regulation of affect and susceptibility to affective illness. As a disclaimer, the studies cited in this review are not intended to be comprehensive but rather serve as examples of the multitude of levels at which sex and reproductive hormones regulate brain structure and function. As such and despite our current ignorance regarding both the ontogeny of affective illness and the impact of sex on that ontogeny, sex differences may provide a lens through which we may better view the mechanisms underlying affective regulation and dysfunction.
Abstract Transthyretin amyloidosis is a fatal disorder that is characterized primarily by progressive neuropathy and cardiomyopathy. It occurs in both a mutant form (with autosomal dominant ...inheritance) and a wild-type form (with predominant cardiac involvement). This article guides clinicians as to when the disease should be suspected, describes the appropriate diagnostic evaluation for those with known or suspected amyloidosis, and reviews the interventions currently available for affected patients.
To facilitate the next generation of high-power white-light-emitting diodes (white LEDs), the discovery of more efficient red-emitting phosphor materials is essential. In this regard, the hardly ...explored compound class of nitridoaluminates affords a new material with superior luminescence properties. Doped with Eu(2+), SrLiAl3N4 emerged as a new high-performance narrow-band red-emitting phosphor material, which can efficiently be excited by GaN-based blue LEDs. Owing to the highly efficient red emission at λ(max) ~ 650 nm with a full-width at half-maximum of ~1,180 cm(-1) (~50 nm) that shows only very low thermal quenching (>95% relative to the quantum efficiency at 200 °C), a prototype phosphor-converted LED (pc-LED), employing SrLiAl3N4:Eu(2+) as the red-emitting component, already shows an increase of 14% in luminous efficacy compared with a commercially available high colour rendering index (CRI) LED, together with an excellent colour rendition (R(a)8 = 91, R9 = 57). Therefore, we predict great potential for industrial applications in high-power white pc-LEDs.
We present a conditional space–time proper orthogonal decomposition (POD) formulation that is tailored to the eduction of the average, rare or intermittent events from an ensemble of realizations of ...a fluid process. By construction, the resulting spatio-temporal modes are coherent in space and over a predefined finite time horizon, and optimally capture the variance, or energy of the ensemble. For the example of intermittent acoustic radiation from a turbulent jet, we introduce a conditional expectation operator that focuses on the loudest events, as measured by a pressure probe in the far field and contained in the tail of the pressure signal’s probability distribution. Applied to high-fidelity simulation data, the method identifies a statistically significant ‘prototype’, or average acoustic burst event that is tracked over time. Most notably, the burst event can be traced back to its precursor, which opens up the possibility of prediction of an imminent burst. We furthermore investigate the mechanism underlying the prototypical burst event using linear stability theory and find that its structure and evolution are accurately predicted by optimal transient growth theory. The jet-noise problem demonstrates that the conditional space–time POD formulation applies even for systems with probability distributions that are not heavy-tailed, i.e. for systems in which events overlap and occur in rapid succession.
The isotypic compounds MMg3SiN4 (M = Ca,Sr,Eu) have been synthesized by solid-state reactions in sealed tantalum ampules or in a radio-frequency furnace. The nitridomagnesosilicates crystallize in ...space group I41/a (No. 88). Crystal structures were solved and refined from single-crystal X-ray diffraction data (Z = 16, CaMg3SiN4:Ce3+, a = 11.424(2), c = 13.445(3) Å, R1 = 0.040, wR2 = 0.106; SrMg3SiN4:Eu2+, a = 11.495(2), c = 13.512(3) Å, R1 = 0.036, wR2 = 0.102; EuMg3SiN4, a = 11.511(4), c = 13.552(4) Å, R1 = 0.016, wR2 = 0.039). The nitridomagnesosilicates are isotypic to NaLi3SiO4, containing a condensed tetrahedra network with a high degree of condensation (i.e., atomic ratio (Mg,Si):N) κ = 1. The crystal structures were confirmed by Rietveld refinement, lattice energy (MAPLE) calculations, and further investigated by 29Si-MAS NMR. Ce3+-doped samples of CaMg3SiN4 show yellow emission (λmax = 530 and 585 nm, fwhm ∼3900 cm–1 (∼130 nm)), while SrMg3SiN4:Eu2+ exhibits red luminescence (λmax = 615 nm) with the most narrow red emission of Eu2+-phosphors reported in the literature so far (fwhm ∼1170 cm–1 (∼43 nm)). According to this outstanding narrow red emission, originating from parity allowed 4f65d1 → 4f7 transition in Eu2+, SrMg3SiN4:Eu2+ may point the way to the next generation red phosphor materials for application in illumination-grade white pc-LEDs.
CaLiAl3N4:Eu2+ is an intriguing new narrow-band red-emitting phosphor material with potential for application in high-power phosphor-converted light-emitting diodes (pc-LEDs). With excitation by ...blue InGaN-based LEDs, the compound exhibits an emission maximum at 668 nm with a full width at half maximum of only 1333 cm–1 (∼60 nm). CaLiAl3N4:Eu2+ was synthesized from Ca, LiAlH4, LiN3, AlF3, and EuF3 in weld-shut Ta ampules, and the structure was solved and refined on the basis of single-crystal X-ray diffraction data. After isotypical crystallization with NaLi3SiO4, the compound forms a highly condensed framework of AlN4 and LiN4 tetrahedra I41/a (no. 88), Z = 16, a = 11.1600(16) Å, and c = 12.865(3) Å and can thus by classified as a nitridolithoaluminate. Both types of polyhedra are connected to each other by common edges and corners, yielding a high degree of condensation, κ = 1. The Ca site is positioned in the center of vierer ring channels along 001 and coordinated in a cuboidal manner by eight N atoms. To validate the presence of Li, transmission electron microscopy (TEM) investigations employing electron energy-loss spectroscopy (EELS) were carried out. Furthermore, to confirm the electrostatic bonding interactions and the chemical composition, lattice energy calculations Madelung part of lattice energy (MAPLE) have been performed.
There is considerable evidence from animal studies that the mesolimbic and mesocortical dopamine systems are sensitive to circulating gonadal steroid hormones. Less is known about the influence of ...estrogen and progesterone on the human reward system. To investigate this directly, we used functional MRI and an event-related monetary reward paradigm to study women with a repeated-measures, counterbalanced design across the menstrual cycle. Here we show that during the midfollicular phase (days 4-8 after onset of menses) women anticipating uncertain rewards activated the orbitofrontal cortex and amygdala more than during the luteal phase (6-10 days after luteinizing hormone surge). At the time of reward delivery, women in the follicular phase activated the midbrain, striatum, and left fronto-polar cortex more than during the luteal phase. These data demonstrate augmented reactivity of the reward system in women during the midfollicular phase when estrogen is unopposed by progesterone. Moreover, investigation of between-sex differences revealed that men activated ventral putamen more than women during anticipation of uncertain rewards, whereas women more strongly activated the anterior medial prefrontal cortex at the time of reward delivery. Correlation between brain activity and gonadal steroid levels also revealed that the amygdalo-hippocampal complex was positively correlated with estradiol level, regardless of menstrual cycle phase. Together, our findings provide evidence of neurofunctional modulation of the reward system by gonadal steroid hormones in humans and establish a neurobiological foundation for understanding their impact on vulnerability to drug abuse, neuropsychiatric diseases with differential expression across males and females, and hormonally mediated mood disorders.
The presence of tumor-infiltrating lymphocytes (TILs) is correlated with good prognosis and outcome after (immuno)therapy in triple-negative and HER2-positive breast cancer. However, the role of TILs ...in luminal breast cancer is less clear. Emerging evidence has now demonstrated that genetic aberrations in malignant cells influence the immune landscape of tumors. Phosphatidylinositol 3-kinase (PI3K) is the most common altered pathway in ER-positive breast cancer. It is unknown whether changes in the PI3K pathway result in a different composition of the breast tumor microenvironment. Here we present the retrospective analysis of a prospective randomized trial in ER-positive breast cancer on the prognostic and predictive value of specific tumor-associated lymphocytes in the context of PI3K alterations.
We included 563 ER-positive tumors from a multicenter trial for stage I to III postmenopausal breast cancer patients, who were randomized to tamoxifen or no adjuvant therapy. The amount of CD8-, CD4-, and FOXP3-positive cells was evaluated by immunohistochemistry and quantified by imaging-analysis software. We analyzed the associations between PIK3CA hotspot mutations, PTEN expression, phosphorylated proteins of the PI3K and MAPK pathway (p-AKT, p-ERK1/2, p-4EBP1, p-p70S6K), and recurrence-free interval after adjuvant tamoxifen or no adjuvant treatment.
CD8-positive lymphocytes were significantly more abundant in PIK3CA-mutated tumors (OR = 1.65; 95% CI 1.03-2.68). While CD4 and FOXP3 were not significantly associated with prognosis, patients with tumors classified as CD8-high had increased risk of recurrence (HR = 1.98; 95% CI 1.14-3.41; multivariable model including PIK3CA status, treatment arm, and other standard clinicopathological variables). Lymphocytes were more often present in tumors with increased PI3K downstream phosphorylation. This was most pronounced for FOXP3-positive cells.
These exploratory analyses of a prospective trial in luminal breast cancer suggest high CD8 infiltration is associated with unfavorable outcome and that PI3K pathway alterations might be associated with the composition of the tumor microenvironment.
Oxo- and (oxo)nitridoberyllates show exceptional potential as host lattices for application in illumination grade phosphor converted (pc)LEDs due to their remarkable electronic and structural ...characteristics, allowing highly efficient narrow-band emission upon doping with Eu2+. SrBe6ON4:Eu2+, the first example of an oxonitridoberyllate phosphor, exhibits narrow-band cyan emission (λem = 495 nm; full width at half-maximum, fwhm = 35 nm; ≈1400 cm–1), comparable to the emission of the oxonitridosilicate BaSi2O2N2:Eu2+ (fwhm = 35 nm) or a cyan-emitting primary LED (fwhm = 27 nm). SrBe6ON4:Eu2+ reveals a highly condensed rigid 3D network with a remarkably large degree of condensation i.e., atomic ratio Be:(O,N) of κ = 1.2 that is achieved by interconnection of highly condensed layers of BeN4 tetrahedra by Be2ON6 units via common edges. The crystal structure of SrBe6ON4:Eu2+ was solved on the basis of single-crystal and powder XRD data (C2/c, no. 15, a = 13.9283(14), b = 5.7582(6), c = 4.9908(5) Å, β = 90.195(1)°, Z = 4, R 1 = 0.033, wR 2 = 0.065, GoF = 1.046). SrBe6ON4:Eu2+ shows a close structural relationship to other nitride as well as oxide compounds, and therefore closes a structural gap helping to understand relations in Be-containing solid-state materials. The electronic structure of SrBe6ON4:Eu2+ was characterized by X-ray spectroscopy measurements, supported by density functional theory (DFT) calculations. Due to its excellent emission properties, large band gap, rigid 3D network, as well as chemical and thermal stability, SrBe6ON4:Eu2+ is a promising phosphor to close the cyan gap in efficient high-CRI pcLEDs (CRI, color rendering index).
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