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The efficiency of silicon solar cells is still lower than theoretical values, partly due to their inability to utilize the ultraviolet and infrared portions of the solar spectrum. Herein, a novel method using a KCa2Mg2(VO4)3 phosphor with a down-shift effect to improve the photovoltaic performance of silicon solar cells and enhance the utilization of UV light in standard p-type silicon solar cells is proposed. The synthesized phosphors were mixed with an ethylene vinyl acetate (EVA) copolymer and pressed into a film, which was subsequently encapsulated in monocrystalline silicon solar cells. The results show that the addition of this film notably enhanced the photovoltaic performance of the silicon solar cells; the current density was increased by 2.89% (from 33.20 to 34.16 mA cm-2), and the photovoltaic conversion efficiency was improved by 5.69% (from 15.11% to 15.97%) at the optimal concentration compared to bare cells.
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The detection of antibiotic residues is of great significance in monitoring their overuse in healthcare, livestock and poultry farming, and agricultural production. Herein, EuCl3 and 4,4'-dicarboxyl-diphenoxyethene (H2DPOE) ionothermally reacted in 1-methyl-3-butylimidazolium chloride to give a europium metal-organic framework (Eu-DPOE). Eu-DPOE shows different fluorescence quenching rates for sensing eight antibiotics under different excitation wavelengths. Eu-DPOE displays a fast response, high selectivity, and sensitivity in antibiotic detection by fluorescence quenching. Eu-DPOE can sensitively detect TCs (tetracyclines), NOR (norfloxacin), NFT (furazolidone), ODZ (ornidazole), SDZ (sulfadiazine), and CHL (chloramphenicol) with limits of detection below 0.5 µmol/L. It provides a convenient and rapid tool for sensing antibiotics in aqueous solution. The detection mechanism is a competition absorption between DPOE2- and antibiotics with the supports from powder X-ray diffraction (PXRD), UV-vis spectra, and fluorescence lifetime. With a composite membrane of poly(vinylidene fluoride) (PVDF) matrix loading Eu-DPOE (Eu-DPOE@PVDF), Eu-DPOE@PVDF exhibits a visual fluorescence response to NOR under a 254 nm UV lamp and NFT and CTC under 365 nm. Eu-DPOE@PVDF is applied in the quantitative detection of CTC, NOR, and NFT in lake water with recovery rates ranging from 88.37 to 113.8%. Totally, fluorescence-quenched Eu-DPOE@PVDF exhibits a fast response, high selectivity, and sensitivity in sensing CTC, NOR, and NFT.
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Antibacterianos , Estructuras Metalorgánicas , Estructuras Metalorgánicas/química , Europio/química , Polímeros , Lagos , AguaRESUMEN
A novel zeolite-like topology oxonitridosilicate La3.6Ba1.7Si5N10O2.1 with the space group Amm2 (no. 38) and lattice parameters a = 9.5193 (3) Å, b = 16.7011 (5) Å, c = 26.0279 (8) Å, and Z = 12 has been synthesized by a high-temperature solid-state reaction. The crystal structure of La3.6Ba1.7Si5N10O2.1 has four different kinds of tiling, and the cages in the structure are filled with La, Ba, and O atoms. The presence of a noncentrosymmetric space group further suggests its potential for nonlinear optical (NLO) applications, and La3.6Ba1.7Si5N10O2.1 demonstrated a stronger second-harmonic generation (SHG) response than that of SiO2.
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The exploration of transition metal oxynitrides has garnered significant interest due to their intriguing property diversity. Herein, we present a promising new transition metal oxynitride BaLa5V2O3N7, which features an anti-perovskite structure type. This unique structural configuration endows the material with remarkable conductivity, particularly at low temperatures, paving the way for the material to be used in a wide range of technological applications.
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Lithium-sulfur (Li-S) batteries demonstrate great potential for next-generation electrochemical energy storage systems because of their high specific energy and low-cost materials. However, the shuttling behavior and slow kinetics of intermediate polysulfide (PS) conversion pose a major obstacle to the practical application of Li-S batteries. Herein, CrP within a porous nanopolyhedron architecture derived from a metal-organic framework (CrP@MOF) is developed as a highly efficient nanocatalyst and S host to address these issues. Theoretical and experimental analyses demonstrate that CrP@MOF has a remarkable binding strength to trap soluble PS species. In addition, CrP@MOF shows abundant active sites to catalyze the PS conversion, accelerate Li-ion diffusion, and induce the precipitation/decomposition of Li2S. As a result, the CrP@MOF-containing Li-S batteries demonstrate over 67% capacity retention over 1000 cycles at 1 C, â¼100% Coulombic efficiency, and high rate capability (674.6 mAh g-1 at 4 C). In brief, CrP nanocatalysts accelerate the PS conversion and improve the overall performance of Li-S batteries.
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The utilization of lignin, the most abundant aromatic biomass component, is at the forefront of sustainable engineering, energy, and environment research, where its abundance and low-cost features enable widespread application. Constructing lignin into material parts with controlled and desired macro- and microstructures and properties via additive manufacturing has been recognized as a promising technology and paves the way to the practical application of lignin. Considering the rapid development and significant progress recently achieved in this field, a comprehensive and critical review and outlook on three-dimensional (3D) printing of lignin is highly desirable. This article fulfils this demand with an overview on the structure of lignin and presents the state-of-the-art of 3D printing of pristine lignin and lignin-based composites, and highlights the key challenges. It is attempted to deliver better fundamental understanding of the impacts of morphology, microstructure, physical, chemical, and biological modifications, and composition/hybrids on the rheological behavior of lignin/polymer blends, as well as, on the mechanical, physical, and chemical performance of the 3D printed lignin-based materials. The main points toward future developments involve hybrid manufacturing, in situ polymerization, and surface tension or energy driven molecular segregation are also elaborated and discussed to promote the high-value utilization of lignin.
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Oxygen-depleted samples [Y2Ti2O7-x ]2x+(2xe-) (0 ≤ x ≤ 1.0) were prepared by reducing Y2TiO7 powders at 500 °C to 650 °C using CaH2 as a reductive agent, where x represents the content of , which was determined by thermogravimetric analysis. Powder X-ray diffraction patterns illustrate that the pure pyrochlore phase is kept for the samples with x ≤ 1.0, whereas the apparent x values surpass 1.0, and the impurity phase Y2O3 appears. The electride [Y2Ti2O7-x ]2x+(2xe-) (x ≈ 1.0) can be obtained under a reductive condition, in which the concentration of VO is 7.75 × 1021 cm-3. The electron paramagnetic resonance measurements gave the concentration of unpaired electrons in the electride as 1.30 × 1021 cm-3, indicating that the degree of the ionization of is less than 10%. Conductivity measurements for a sintered pellet sample (relative density â¼ 70%) indicate that the electride has quite high conductivity (â¼1.09 S cm-1 at 300 K). The conduction was interpreted by using the variable range hopping mechanisms.
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This work presents three series of Eu/Tb metal-organic frameworks (MOFs) containing benzophenone-4,4'-dicarboxylic acid (H2BPNDC), 4,4'-dicarboxydiphenyl ether (H2OBA), and terephthalic acid (H2BDC) as the ligands. Eu/Tb MOFs have the same structural features in that their 3D frameworks are simplified as 2,3,10-connected {42.6}2{46.618.819.102}{4}2 topological networks. The solid-state fluorescence spectra of three Eu/Tb MOF series are attributed to the combined emissions of 5D0 â 7FJ (J = 1-4) transitions in Eu3+ and 5D4 â 7FJ (J = 6-5) transitions in Tb3+. The nEu:nTb of Eu/Tb MOFs is optimized as 1:69 based on the relationships between ITb(545)/IEu(614) and nEu:nTb; that is, Eu0.0143Tb0.9857-L (L = BPNDC2-, OBA2-, and BDC2-) were selected to carry out the following temperature (T)-sensing tests. The fluorescence mechanism of Eu0.0143Tb0.9857-L can be explained by a ligand-to-metal charge transfer combined with an intermetallic Tb3+ â Eu3+ energy transfer. The T-dependent fluorescence indicates linear relationships with sensitivities of 1.85% K-1 for Eu0.0143Tb0.9857-BPNDC, 6.49% K-1 for Eu0.0143Tb0.9857-OBA, and 0.28% K-1 for Eu0.0143Tb0.9857-BDC. The influence of T on the lowest excited triplet energy levels (T1 values) of the ligands reveals that the ligand energy regulation impacts their fluorescence properties, including the sensitivity, fluorescence quenching rate, quantum yield, and fluorescence lifetime. This shows that Eu0.0143Tb0.9857-BPNDC is sufficiently sensitive to T, making it applicable in noncontact T measurements.
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Panacis Quinquefolii Radix is the dry root of Panax quinquefolium, which is a perennial plant of Araliaceae. The plant has a long growth cycle and serious growth barrier problem, which leads to the use of pesticides. As a result, the pesticide residues in Panacis Quinquefolii Radix are arousing great concern. This paper reviews the research findings on the investigation, detection methods, content analysis and risk assessment of pesticide residues in Panacis Quinquefolii Radix since 1993, and compares the pesticide residue limit standards of different countries and regions. The pesticide residues in Panacis Quinquefolii Radix have been changing from organochlorines with high toxicity to triazines and triazoles with low toxicity. The pesticide residues are generally low, while the pollution of pentachloronitrobenzene and other pesticides still exist. The detection method has evolved from chromatography to chromatography-mass spectrometry. There are no reports of health risks caused by pesticide residues of Panacis Quinquefolii Radix. Pesticide residue is a major factor restricting the sound development of Panacis Quinquefolii Radix industry in China. Therefore, we suggest to improve the registration of pesticides applied to the plant, popularize mature ecological planting mode and supporting technology, and strengthen the research on the risk assessment and limit standard of pesticide residue in Panacis Quinquefolii Radix.
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Medicamentos Herbarios Chinos , Ginsenósidos , Panax , Residuos de Plaguicidas , Medicamentos Herbarios Chinos/química , Ginsenósidos/análisis , Espectrometría de Masas , Panax/química , Residuos de Plaguicidas/análisisRESUMEN
Flux synthesis is an effective method to discover large crystals of new compounds. In this paper, a solid-state reaction in Li flux produced a new nitridolithosilicate La4Ba3Li3Si9N19 in the orthorhombic space group Cmcm (No. 63) with lattice parameters of a = 9.7263(1), b = 18.2746(2), c = 11.2929(1) Å, and Z = 4. The La4Ba3Li3Si9N19 exhibits a 3-D framework based on triangular clusters (3-rings) formed by vertex-sharing SiN4 tetrahedra. The rare earth Pr3+-doped La4Ba3Li3Si9N19 emits a narrow-band red emission peaking at approximately 640 nm with a full width at half-maximum of 50 nm when excited under ultraviolet light.
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Traditional fluorescent materials used in the anti-counterfeiting field usually exhibit monochromatic luminescence at a single-wavelength excitation, which is easily forged by sophisticated counterfeiters. In this work, Zn2GeO4:Mn,x%Li (x = 0 and 20), Zn2GeO4-NaLiGe4O9:Mn,x%Li (x = 50 and 70) and NaLiGe4O9:Mn micro-phosphors with multi-chromatic and multi-mode luminescence have been successfully synthesized via a hydrothermal approach followed by an annealing treatment. As expected these Li+ doped Zn2GeO4:Mn and Zn2GeO4-NaLiGe4O9:Mn phosphors exhibit a double peak emission including a long green afterglow (â¼540 nm) and red photoluminescence (â¼668 nm). By tuning Li+ doping concentrations, a gradual colour output and a tuneable afterglow duration are achieved. In particular, the Zn2GeO4:Mn,Li and NaLiGe4O9:Mn phosphors exhibit excellent performance as security inks for printing luminescent numbers and anti-counterfeiting patterns, which show an afterglow time-dependent or excitation wavelength-dependent luminescence colour evolution. This work proves the feasibility of the Li+ doping strategy in emission tuning, which can stimulate further studies on multi-mode luminescent materials for anti-counterfeiting applications.
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PURPOSE: This study aims to examine the changes of glucose metabolism, glucose variability (GV), and ghrelin secretion within 1 week following SG in Chinese patients with obesity. MATERIALS AND METHODS: Forty-nine patients with obesity (15 with type 2 diabetes) were enrolled to undergo SG. Within 1 week before and after surgery, liquid meal tests were performed in all subjects, and continuous glucose monitoring (CGM) was performed in diabetic patients. Blood samples were collected at 0, 15, 30, 45, 60, 120, and 180 min for glucose, C-peptide, insulin, and ghrelin analysis in liquid meal test. Mean amplitude of glucose excursions (MAGE), standard deviations (SD), and percent time-in-range (%TIR) determined by CGM were analyzed. RESULTS: Both in diabetic and non-diabetic groups, significant decrease was observed in glucose, insulin, C-peptide, and ghrelin. Homeostasis model assessment-insulin resistance and liver fat content was decreased. In diabetic group, MAGE and SD were decreased significantly, and the percent time-in-range was higher. The decrease in blood glucose was positively correlated with the decrease in ghrelin concentration in non-diabetic group. CONCLUSION: Within 1 week after SG, both glucose metabolism and glucose variability were improved significantly. Suppression of ghrelin secretion postoperatively might be a driver of this early improved glycemia homeostasis.
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Diabetes Mellitus Tipo 2 , Obesidad Mórbida , Glucemia , Automonitorización de la Glucosa Sanguínea , Diabetes Mellitus Tipo 2/cirugía , Gastrectomía , Ghrelina , Glucosa , Humanos , Insulina , Obesidad Mórbida/cirugíaRESUMEN
While soil erosion drives land degradation, the impact of erosion on soil microbial communities and multiple soil functions remains unclear. This hinders our ability to assess the true impact of erosion on soil ecosystem services and our ability to restore eroded environments. Here we examined the effect of erosion on microbial communities at two sites with contrasting soil texture and climates. Eroded plots had lower microbial network complexity, fewer microbial taxa, and fewer associations among microbial taxa, relative to non-eroded plots. Soil erosion also shifted microbial community composition, with decreased relative abundances of dominant phyla such as Proteobacteria, Bacteroidetes, and Gemmatimonadetes. In contrast, erosion led to an increase in the relative abundances of some bacterial families involved in N cycling, such as Acetobacteraceae and Beijerinckiaceae. Changes in microbiota characteristics were strongly related with erosion-induced changes in soil multifunctionality. Together, these results demonstrate that soil erosion has a significant negative impact on soil microbial diversity and functionality.
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Microbiota , Suelo , Bacterias/genética , Humanos , Consorcios Microbianos , Microbiología del SueloRESUMEN
The new oxonitridosilicates Ln4-xSr2+xSi5N12-xOx (Ln = La, Ce) were synthesized by high temperature solid-state reactions. The crystal structures were solved and refined from both single-crystal and powder X-ray diffraction data. These oxonitridosilicate compounds crystallize in the monoclinic space group P21/n (no. 14) and exhibit a double-layer structure made up of corner-sharing Si(O/N)4 tetrahedra. When excited with near-UV and blue light, the Pr3+ doped La2.31Sr3.69Si5N10.31O1.69 phosphor shows a narrow-band red emission peaking at 625 nm with a full width at half-maximum of 40 nm.
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The detection of pH and water is of significance in natural and production processes. The ionothermal reactions of 4,4'-oxybisbenzoic acid (H2OBA) with Eu3+ and Tb3+ produced [M(OBA)(H2O)Cl] (M = Eu3+ (1) and Tb3+ (2)) and heteronuclear [Eu0.05Tb0.95(OBA)(H2O)Cl] (3). 3 emits the combined characteristic transitions of Eu3+ and Tb3+. Its energy transition processes can be disturbed by pH and water. The emission colors of 3 follow pH changes. It emits blue light when pH = 1-2, in which OBA2- turns into H2OBA based on the acid-base equilibrium. When pH = 3-11, the emission colors change from green to orange and ITb/IEu exhibits a linearity of ITb/IEu = 6.7482-0.5971·pH; the emissions are quenched at pH = 12-13, due to OH- destroying the delocalized conjugated system of 3. 3 shows a fluorescence response to water with a linearity of ITb/IEu = 0.30353 + 0.15042·VH2O% within 0-0.8% VH2O%. The green (G) and red (R) color intensities of the paper-based MOF sensor of 3 reveal a trinomial fitting equation of G/R = 4.16334 - 1.23014·pH + 0.14036·pH2- 0.00551·pH3 when pH = 3-11. 3 can be used as a ratiometric fluorescent sensor to detect pH and water and the paper-based MOF sensor can also be used in on-site pH detection.
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Benzoatos/química , Europio/química , Concentración de Iones de Hidrógeno , Estructuras Metalorgánicas/química , Terbio/química , Agua/análisis , Colorimetría , Fluorescencia , FluorometríaRESUMEN
Fabricating highly efficient electrocatalysts for electrochemical hydrogen generation is a top priority to relief the global energy crisis and environmental contamination. Herein, a rational synthetic strategy is developed for constructing well-defined FeP-CoMoP hierarchical nanostructures (HNSs). In general terms, the self-supported Co nanorods (NRs) are grown on conductive carbon cloth and directly serve as a self-sacrificing template. After solvothermal treatment, Co NRs are converted into well-ordered Co-Mo nanotubes (NTs). Subsequently, the small-sized Fe oxyhydroxide nanorods arrays are hydrothermally grown on the surface of Co-Mo NTs to form Fe-Co-Mo HNSs, which are then converted into FeP-CoMoP HNSs through a facile phosphorization treatment. FeP-CoMoP HNSs display high activity for hydrogen evolution reaction (HER) with an ultralow cathodic overpotential of 33â mV at 10â mA cm-2 and a Tafel slope of 51â mV dec-1 . Moreover, FeP-CoMoP HNSs also possess an excellent electrochemical durability in alkaline media. First-principles density functional theory (DFT) calculations demonstrate that the remarkable HER activitiy of FeP-CoMoP HNSs originates from the synergistic effect between FeP and CoMoP.
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A novel red oxyfluoride phosphor K3TaO2F4:Mn4+ has been prepared by a simple two-step synthesis method. The structure, composition, and luminescence properties of K3TaO2F4:Mn4+ phosphors were investigated and discussed in detail. The real structure of K3TaO2F4 was carefully studied through X-ray powder diffraction data Rietveld refinement. K3TaO2F4 holds a D4 h group symmetry [TaO2F4]3- octahedron with the oxygen occupying the para-position. Under ultraviolet (UV) and blue light excitation, K3TaO2F4:Mn4+ phosphor emits a narrow band red emission peaking at 630 nm. High-performance warm white-light-emitting diodes (WLEDs) were fabricated using a blue LED chip, YAG:Ce3+ yellow phosphor, and K3TaO2F4:Mn4+ red phosphor. This device exhibits high color quality (CCT = 3488 K, Ra = 93.0, R9 = 90.0), which indicates that Mn4+-doped K3TaO2F4 would be a promising red phosphor for WLED applications.
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OBJECTIVES: A significant number of researches have evidenced that occupational lead (Pb) exposure increased risks of cardiovascular disease. However, evidences about the potential effects of Pb on the cardiac conduction system are sparse and inconclusive. Besides, ryanodine receptors (RyRs) induced dysfunction of cardiac excitation contraction coupling which is considered to be one of the mechanisms in cardiovascular diseases. Therefore, we examined the association between occupational Pb exposure and ECG conduction abnormalities, as well as RyRs in Pb-induced ECG abnormalities. METHODS: We investigated 529 Pb smelter workers, and measured blood lead (BPb), zinc protoporphyrin (ZPP), ECG outcomes and RyR expression levels. Based on BPb levels, the workers were divided into three groups: the BPb not elevated group, the BPb elevated group and the Pb poisoning group. Descriptive and multivariable analyses were performed. RESULTS: Compared with the BPb not elevated group, the Pb poisoning group had a higher incidence of high QRS voltage, and a lower level of RyR1 gene expression (p<0.05). Further unconditional multivariable logistic regression analyses showed that high QRS voltage was positively related to BPb (OR=1.045, 95% CI 1.014 to 1.078) and inversely associated with RyR1 expression (OR=0.042, 95% CI 0.002 to 0.980) after adjusting for potential confounders. In addition, multiple linear regression analyses showed that the QTc interval was positively associated with ZPP (ß=0.299, 95% CI 0.130 to 0.468) after adjusting for potential confounders. CONCLUSIONS: Our study provided evidences that occupational exposure to Pb may be associated with worse ECG outcomes (high QRS voltage), which might be related to decreased levels of RyR1.
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Intoxicación por Plomo/genética , Intoxicación por Plomo/fisiopatología , Plomo/sangre , Exposición Profesional , Canal Liberador de Calcio Receptor de Rianodina/genética , Adulto , Estudios Transversales , Electrocardiografía , Sistema de Conducción Cardíaco/fisiopatología , Humanos , Intoxicación por Plomo/sangre , Modelos Lineales , Modelos Logísticos , Síndrome de QT Prolongado/inducido químicamente , Síndrome de QT Prolongado/diagnóstico , Masculino , Análisis Multivariante , Protoporfirinas/sangre , Adulto JovenRESUMEN
A large number of studies have evidenced that developmental neurotoxicity induced by lead (Pb) is related to oxidative injury. Furthermore, recent studies have found that developmental Pb exposure can induce neurodegeneration in old age. Because of the common presence of Pb in the environment, humans are exposed to this metal throughout their lifetime. However, few studies have explored the changes in lifespan profiles of neurotoxicity, as well as oxidative stress following lifetime Pb exposure. In the present study, rats were exposed to lead acetate from their embryonic stage to old age. Dynamic changes in neurodegeneration, oxidative stress, and endoplasmic reticulum (ER) stress in the brains at postnatal week 3 (PNW3, weaning), 41 weeks (PNW41, adulthood) and 70 weeks (PNW70, old age) were investigated. Pb exposure resulted in neurodegeneration with decreased neuronal densities and brain volumes in PNW3 and PNW70 rats; however, no significant changes occurred in PNW41 rats based on thionine stain analysis and magnetic resonance imaging (MRI) scans. Expression of the ER stress protein glucose-regulated protein 78 (GRP78) increased in Pb-exposed rats, which was associated with high levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in rat brains after Pb exposure in PNW3 and PNW70 rats. Our findings suggested that lifetime Pb exposure induced neurodegenerative injuries that began to occur in infancy, were relieved in adulthood, but intensified in old age. The critical periods for prevention or intervention in neurodegenerative diseases induced by Pb exposure occurred in early life.
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Encéfalo/patología , Intoxicación del Sistema Nervioso por Plomo/patología , Enfermedades Neurodegenerativas/inducido químicamente , Enfermedades Neurodegenerativas/patología , Estrés Oxidativo/efectos de los fármacos , 8-Hidroxi-2'-Desoxicoguanosina , Envejecimiento , Animales , Encéfalo/diagnóstico por imagen , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Chaperón BiP del Retículo Endoplásmico , Estrés del Retículo Endoplásmico/efectos de los fármacos , Femenino , Regulación de la Expresión Génica/efectos de los fármacos , Plomo/sangre , Plomo/metabolismo , Intoxicación del Sistema Nervioso por Plomo/diagnóstico por imagen , Imagen por Resonancia Magnética , Masculino , Enfermedades Neurodegenerativas/diagnóstico por imagen , Neuronas/patología , Embarazo , Efectos Tardíos de la Exposición Prenatal/patología , Ratas , Ratas Sprague-DawleyRESUMEN
We report a novel narrow-band blue emitting phosphor Sr7.92Mg7Si9N22:0.08Eu2+. The crystal structure of Sr8Mg7Si9N22 is composed of corner-sharing and edge-sharing [SiN4] tetrahedra and distorted square-pyramid [MgN5] polyhedra. Under 350 nm excitation, Eu2+ doped Sr8Mg7Si9N22 emits narrow-band blue light with maximum intensity at 450 nm and a fwhm of 38 nm.