Ammonothermal Synthesis and Crystal Growth of the Chain‐type Oxonitridosilicate Ca1+xY1–xSiN3–xOx (x > 0)

The oxonitridosilicate Ca1+xY1–xSiN3–xOx (x > 0) was synthesized in custom‐built high‐temperature autoclaves starting from CaH2, intermetallic YSi and NaN3 using supercritical ammonia as solvent at a maximum pressure of 140 MPa and temperature of 1070 K. In situ formed NaNH2 acts as ammonobasic mineralizer and increases the solubility of the other starting materials. Air and moisture sensitive rod‐shaped single crystals of the title compound with length of up to 200 μm were obtained. The crystal structure was solved and refined by single‐crystal X‐ray diffraction. The results are supported by powder X‐ray diffraction, energy dispersive X‐ray spectroscopy and lattice energy (MAPLE) calculations. Ca1+xY1–xSiN3–xOx (x > 0) is isostructural to Ca2PN3 and Eu2SiN3 and crystallizes in the orthorhombic space group Cmce (no. 64) with a = 5.331(2), b = 10.341(4), c = 11.248(4) Å and Z = 8 (R1 = 0.0257, wR2 = 0.0447) and contains infinite zweier single chains running along [100] which are built up from corner sharing Si(N,O)4 tetrahedra

Business Ethics: The Promise of Neuroscience

Recent advances in cognitive neuroscience research portend well for furthering understanding of many of the fundamental questions in the field of business ethics, both normative and empirical. This article provides an overview of neuroscience methodology and brain structures, and explores the areas in which neuroscience research has contributed findings of value to business ethics, as well as suggesting areas for future research. Neuroscience research is especially capable of providing insight into individual reactions to ethical issues, while also raising challenging normative questions about the nature of moral responsibility, autonomy, intent, and free will. This article also provides a brief summary of the papers included in this special issue, attesting to the richness of scholarly inquiry linking neuroscience and business ethics. We conclude that neuroscience offers considerable promise to the field of business ethics, but we caution against overpromise

Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes

Progress and Challenges in the Biology of FNDC5 and Irisin

Abstract In 2002, a transmembrane protein—now known as FNDC5—was discovered and shown to be expressed in skeletal muscle, heart, and brain. It was virtually ignored for 10 years, until a study in 2012 proposed that, in response to exercise, the ectodomain of skeletal muscle FNDC5 was cleaved, traveled to white adipose tissue, and induced browning. The wasted energy of this browning raised the possibility that this myokine, named irisin, might mediate some beneficial effects of exercise. Since then, more than 1000 papers have been published exploring the roles of irisin. A major interest has been on adipose tissue and metabolism, following up the major proposal from 2012. Many studies correlating plasma irisin levels with physiological conditions have been questioned for using flawed assays for irisin concentration. However, experiments altering irisin levels by injecting recombinant irisin or by gene knockout are more promising. Recent discoveries have suggested potential roles of irisin in bone remodeling and in the brain, with effects potentially related to Alzheimer’s disease. We discuss some discrepancies between research groups and the mechanisms that are yet to be determined. Some important questions raised in the initial discovery of irisin, such as the role of the mutant start codon of human FNDC5 and the mechanism of ectodomain cleavage, remain to be answered. Apart from these specific questions, a promising new tool has been developed—mice with a global or tissue-specific knockout of FNDC5. In this review, we critically examine the current knowledge and delineate potential solutions to resolve existing ambiguities

Irisin: Still chasing shadows

Objective Considerable uncertainty remains regarding the veracity of measuring myokine irisin more than seven years after its original description. Unresolved issues include the nature of transcription of the irisin precursor fibronectin type III domain containing 5 (FNDC5) gene across species, the reliability of irisin levels measured with commercial enzyme-linked immunosorbent assays (ELISAs), and the overall validity of the recently published reference values for human serum measured with quantitative mass spectrometry. We utilized multiple species and measures to evaluate the robustness of commonly used reagents and methods for reporting irisin. Methods Amplification of cDNA was used to assess the FNDC5 transcript patterns in humans and mice. The specificity and sensitivity of different irisin antibodies were examined via western blotting. Quantification of circulating native irisin was conducted with mass spectrometry using an absolute quantification peptide for irisin. Results We show that there is a greater transcript diversity of human FNDC5 than currently annotated, but no indication of the expression of transcripts leading to a truncated form of irisin. Available irisin antibodies still bind to patterns of unspecific serum proteins, which compromise reliable measurements of irisin with ELISAs. Absolute quantification of irisin with labeled peptides by mass spectrometry is an advanced method but requires a multi-step sample preparation introducing uncontrollable variations in the measurement. Conclusion Our data represent an explicit warning against measuring circulating irisin using available methods. Measuring irisin is akin to chasing shadows

Oxonitridosilicate Oxides <i>RE</i>₂₆Ba₆[Si₂₂O₁₉N₃₆]O₁₆:Eu²⁺ (<i>RE</i> = Y, Tb) with a Unique Layered Structure and Orange-Red Luminescence for <i>RE</i> = Y

The oxonitridosilicate oxides <i>RE</i>₂₆Ba₆[Si₂₂O₁₉N₃₆]­O₁₆:Eu²⁺ (<i>RE</i> = Y, Tb) were synthesized by high-temperature reaction in a radiofrequency furnace starting from <i>RE</i>F₃, <i>RE</i>₂O₃ (<i>RE</i> = Y, Tb), BaH₂, Si­(NH)₂, and EuF₃. The structure elucidation is based on single-crystal X-ray data. The isotypic materials crystallize in the monoclinic space group <i>Pm</i> (no. 6) [<i>Z</i> = 3, <i>a</i> = 16.4285(8), <i>b</i> = 20.8423(9), <i>c</i> = 16.9257(8) Å, β = 119.006(3)° for <i>RE</i> = Y and <i>a</i> = 16.5465(7), <i>b</i> = 20.9328(9), <i>c</i> = 17.0038(7) Å, β = 119.103(2)° for <i>RE</i> = Tb]. The unique silicate layers are made up from Q¹-, Q²-, and Q³-type Si­(O/N)₄- as well as Q⁴-type SiN₄-tetrahedra, forming three slightly differing types of cages. The corresponding 3-fold superstructure as well as pronounced hexagonal pseudosymmetry complicated the structure elucidation. Rietveld refinement on powder X-ray diffraction data, energy-dispersive X-ray spectroscopy and infrared spectroscopy support the findings from single-crystal X-ray data. When excited with UV to blue light, Y₂₆Ba₆[Si₂₂O₁₉N₃₆]­O₁₆:Eu²⁺ shows broad orange-red luminescence (λ_em = 628 nm, fwhm ≈ 125 nm/3130 cm^–1). An optical band gap of 4.2 eV was determined for the doped compound by means of UV/vis spectroscopy

Unprecedented Deep-Red Ce³⁺ Luminescence of the Nitridolithosilicates Li_38.7<i>RE</i>_3.3Ca_5.7[Li₂Si₃₀N₅₉]O₂F (<i>RE</i> = La, Ce, Y)

Ce³⁺ doped solids find broad application, e.g. in phosphor converted light emitting diodes, utilizing the usually broad blue to yellow-orange emission of the respective phosphors. The red to infrared spectral range was not yet accessible with the activator Ce³⁺, even in nitride host materials. Here, we report on the nitridolithosilicates Li_38.7<i>RE</i>_3.3Ca_5.7[Li₂Si₃₀N₅₉]­O₂F (<i>RE</i> = La, Ce, Y) with unique, red-shifted Ce³⁺ luminescence. The materials were synthesized by solid-state metathesis reactions in tantalum ampules. The isotypic crystal structures exhibit a highly condensed three-dimensional network made up of SiN₄ and LiN₄ tetrahedra. Crystal structures were refined from single-crystal and powder X-ray diffraction data. The results are supported by energy-dispersive X-ray spectroscopy as well as charge distribution, lattice energy, and bond valence sum calculations. Optical band gaps of ≈4 eV were determined from diffuse reflectance UV/vis data using Tauc plots. The nitridolithosilicates are highly excitable from the UV to the green-yellow spectral range with a preferred excitation wavelength of λ_exc ≈ 540 nm. The emission spectra peak is in the deep-red with λ_em = 638–651 nm (fwhm ≈ 3600 cm^–1). According to the unique absorption and emission properties, application as luminescent solar concentrators or in horticultural lighting appears promising

Narrow-Band Yellow-Orange Emitting La_3–<i>x</i>Ca_1.5<i>x</i>Si₆N₁₁:Eu²⁺ (<i>x</i> ≈ 0.77): A Promising Phosphor for Next-Generation Amber pcLEDs

The nitridosilicate La_3–<i>x</i>Ca_1.5<i>x</i>Si₆N₁₁:Eu²⁺ (<i>x</i> ≈ 0.77) was synthesized in a radiofrequency furnace starting from LaF₃, La­(NH₂)₃, CaH₂, Si­(NH)₂, and EuF₃. The crystal structure was solved and refined from single-crystal X-ray data in the tetragonal space group <i>P</i>4<i>bm</i> (no. 100) with <i>a</i> = 10.1142(6), <i>c</i> = 4.8988(3) Å, and <i>Z</i> = 2. Thereby, the so far unknown charge balance mechanism in the system (La,Ca)₃Si₆N₁₁, which is necessary as bivalent Ca²⁺ substitutes trivalent La³⁺, was clarified. Accordingly, charge balance is achieved by incorporation of Ca²⁺ on three cation sites, including an additional third site compared to the homeotypic La₃Si₆N₁₁ structure type. The results are supported by Rietveld refinement on powder X-ray diffraction data as well as energy-dispersive X-ray spectroscopy. Fourier transform infrared spectroscopy indicates absence of N–H bonds. An optical band gap of ≈ 4.0 eV was determined using UV/vis reflectance spectroscopy. The Eu²⁺ doped compound exhibits a remarkably narrow emission in the yellow-orange spectral range (λ_em ≈ 587 nm, fwhm ≈ 60 nm/1700 cm^–1). Because of the intriguing yellow-orange luminescence, La_3–<i>x</i>Ca_1.5<i>x</i>Si₆N₁₁:Eu²⁺ (<i>x</i> ≈ 0.77) is a promising candidate for application in next-generation amber phosphor-converted light emitting diodes

Efficient Yellow-Orange Phosphor Lu₄Ba₂[Si₉ON₁₆]O:Eu²⁺ and Orange-Red Emitting Y₄Ba₂[Si₉ON₁₆]O:Eu²⁺: Two Oxonitridosilicate Oxides with Outstanding Structural Variety

The oxonitridosilicate oxides Y₄Ba₂[Si₉ON₁₆]­O:Eu²⁺ and Lu₄Ba₂[Si₉ON₁₆]­O:Eu²⁺ have been synthesized starting from <i>RE</i>F₃, <i>RE</i>₂O₃ (<i>RE</i> = Y, Lu), BaH₂, Si­(NH)₂, and EuF₃ in a radiofrequency furnace at 1550 °C. The crystal structures were solved and refined from single-crystal X-ray data supported with Rietveld refinement on X-ray powder diffraction data. Both compounds are isotypic and crystallize in monoclinic space group <i>P</i>2₁/<i>c</i> (no. 14) with <i>Z</i> = 4 and <i>a</i> = 6.0756(2), <i>b</i> = 27.0606(9), <i>c</i> = 9.9471(3) Å, and β = 91.0008(8)° for <i>RE</i> = Y and <i>a</i> = 6.0290(3), <i>b</i> = 26.7385(12), <i>c</i> = 9.8503(5) Å, and β = 90.7270(30)° for <i>RE</i> = Lu. The unique crystal structure exhibits a three-dimensional network made up from Q⁴-type SiN₄ and Q³-type SiON₃ tetrahedra. Containing 4-fold bridging N^[4] atoms in star-shaped units [N^[4](SiN₃)₄] next to N^[3], N^[2], O^[1], and noncondensed oxide ions, the title compounds illustrate the vast structural variety in (oxo)­nitridosilicates. Under excitation with UV to blue light, Y₄Ba₂[Si₉ON₁₆]­O:Eu²⁺ shows emission in the orange-red spectral range (λ_max = 622 nm, full width at half-maximum (fwhm) ≈ 2875 cm^–1). Yellow-orange emitting Lu₄Ba₂[Si₉ON₁₆]­O:Eu²⁺ (λ_max = 586 nm, fwhm ≈ 2530 cm^–1) exhibits high internal quantum efficiency (IQE) ≈ 85%. This makes Lu₄Ba₂[Si₉ON₁₆]­O:Eu²⁺ a promising phosphor for low color rendering index (CRI) warm white phosphor converted light emitting diodes (pcLEDs)