Recent Developments of Microscopic Study for Lanthanide and Manganese Doped Luminescent Materials

Luminescent materials are indispensable for applications in lighting, displays and photovoltaics, which can transfer, absorb, store and utilize light energy. Their performance is closely related with their size and morphologies, exact atomic arrangement, and local configuration about photofunctional centers. Advanced electron microscopy-based techniques have enabled the possibility to study nanostructures with atomic resolution. Especially, with the advanced micro-electro-mechanical systems, it is able to characterize the luminescent materials at the atomic scale under various environments, providing a deep understanding of the luminescent mechanism. Accordingly, this review summarizes the recent achievements of microscopic study to directly image the microstructure and local environment of activators in lanthanide and manganese (Ln/Mn²⁺ )-doped luminescent materials, including: 1) bulk materials, the typical systems are nitride/oxynitride phosphors; and 2) nanomaterials, such as nanocrystals (hexagonal-phase NaLnF₄ and perovskite) and 2D nanosheets (Ca₂ Ta₃ O₁₀ and MoS₂ ). Finally, the challenges and limitations are highlighted, and some possible solutions to facilitate the developments of advanced luminescent materials are provided.

Sporothrix schenckii regulates macrophage inflammatory responses via the c-JUN-induced Dab2 transcription

Macrophages, which serve as a bridge between innate and adaptive immunity, play an important role in sporotrichosis. Sporothrix schenckii infections can produce immune responses such as macrophage polarization and inflammatory factor secretion. In the early stages of inflammation, the expression of DAB2 in macrophages is increased, which controls the secretion of inflammatory factors and affects the polarization of macrophages. However, the expressions and mechanisms of DAB2 in sporotrichosis are not clear. In this study, we examined the expression of DAB2 and its regulation of inflammatory factors under conditions of Sporothrix schenckii infection. Our results indicated that the Sporothrix schenckii infection increased the expression of DAB2 and revealed a mixed M1/M2-like type of gene expression in BMDMs with the inhibited Il6, Il1β and Arg1, and induced Tnfα, Il10 and Mgl1. The deficiency of Dab2 gene suspended the changes of cytokines. In addition, JNK activity in BMDMs was inhibited by Sporothrix schenckii infection, leading to an increase in c-JUN. We also identified c-JUN as a transcription factor for Dab2 through chromatin immunoprecipitation and luciferase reporter assays. In an in vivo mouse model, sporotrichosis induced skin lesions were accompanied with an upregulation of c-JUN and inhibition of JNK activity, which were in accord with findings from in vitro experiments. Taken together, these findings indicate that in the early stages of Sporothrix schenckii infection there is a promotion of DAB2 expression through the JNK/c-JUN pathway, effects which can then control the expression of inflammatory factors.

Electronically and Geometrically Modified Single-Atom Fe Sites by Adjacent Fe Nanoparticles for Enhanced Oxygen Reduction

Fe-N-C materials exhibit excellent activity and stability for oxygen reduction reaction (ORR), as one of the most promising candidates to replace commercial Pt/C catalysts. However, it is challenging to unravel features of the superior ORR activity originating from Fe-N-C materials. In this work, the electronic and geometric structures of the isolated Fe-N-C sites and their correlations with the ORR performance are investigated by varying the secondary thermal activation temperature of a rationally designed NC-supported Fe single-atom catalyst (SAC). The systematic analyses demonstrate the significant role of coordinated atoms of SA and metallic Fe nanoparticles (NPs) in altering the electronic structure of isolated Fe-N-C sites. Meanwhile, strong interaction between isolated Fe-N-C sites and adjacent Fe NPs can change the geometric structure of isolated Fe-N-C sites. Theoretical calculations reveal that optimal regulation of the electronic and geometric structure of isolated Fe-N-C sites by the co-existence of Fe NPs narrows the energy barriers of the rate-limiting steps of ORR, resulting in outstanding ORR performance. This work not only provides the fundamental understanding of the underlying structure-activity relationship, but also sheds light on designing efficient Fe-N-C catalysts.

[Clinicopathological characterization of primary pulmonary and tracheal glomus tumors]

Objective: To investigate the clinical pathological features of primary pulmonary and tracheal glomus tumors. Methods: The clinical and pathological features of 11 cases (4 cases from Shanghai Pulmonary Hospital, Tongji University School of Medicine, China and 7 cases from Fudan University Shanghai Cancer Center, China) of respiratory glomus tumor diagnosed from 2010 to 2019 were analyzed, and reviewed in light of the relevant literature. Results: In the 11 cases, there were 5 males and 6 females, with the onset ages of 29‒66 years (median age of 43). Six tumors were located in the lung, and 5 in the trachea. The tumor diameters ranged 1.0‒7.5 cm, with the average diameter of 2.6 cm. At low magnification, the tumors were diffuse or lobulated in shape. The tumor cells composed of sheets of oval to short spindle cells, with sharply defined cell border and prominent branching thin-walled vessels. Among the 4 benign glomus tumors, one was classified as benign symplastic glomus tumor owing to the hyperchromatic or degeneration nuclei. Two cases were classified as glomus tumors of uncertain malignant potential, on the account of cellular atypia and rare atypical mitotic figures. Five cases were classified as malignant glomus tumors, owing to the tumor necrosis, vascular invasion, marked nuclear atypia, prominent nucleoli and brisk mitoses (2-20/10HPF) including pathological mitotic figures. The tumor cells showed strong immunostaining for SMA, vimentin, type Ⅳ collagen and caldesmon to different extents, while CD34, cytokeratin and S-100 stains were negative. One of the cases was positive for desmin, and one case positive for synaptophysin. Follow-up information was available in 8 patients with the duration ranging from 6 to 95 months. At the end of the follow-up, 6 patients were alive without recurrence or metastasis, and two of the patients with malignant glomus tumors died. Conclusions: Primary pulmonary and tracheal glomus tumors is rare. Among the reported cases, malignant glomus tumor is the most frequent, followed by benign glomus tumors and uncertain malignant potential glomus tumors. Glomus tumors show sheet-like growth pattern and clusters of round epithelioid cells with numerous vascular spaces. They can be easily misdiagnosed as carcinoid tumor. The final diagnosis should be combined with immunohistochemical staining, such as SMA, caldesmon and vimentin.

Pyrolysis Kinetic Study and Reaction Mechanism of Epoxy Glass Fiber Reinforced Plastic by Thermogravimetric Analyzer (TG) and TG-FTIR (Fourier-Transform Infrared) Techniques

TG–FTIR combined technology was used to study the degradation process and gas phase products of epoxy glass fiber reinforced plastic (glass fiber reinforced plastic) under the atmospheres of high purity nitrogen. The pyrolysis characteristics of epoxy glass fiber reinforced plastic were measured under different heating rates (5, 10, 15, 20 °C min⁻¹) from 25 to 1000 °C. The thermogravimetric analyzer (TG) and differential thermogravimetric analyzer (DTG) curves show that the initial temperature, terminal temperature, and temperature of maximum weight loss rate in the pyrolysis reaction phase all move towards high temperature, as the heating rate increases. Epoxy glass fiber reinforced plastic has two stages of thermal weightlessness. The temperature range of the first stage of weight loss is 290–460 °C. The second stage is 460–1000 °C. The above two weight loss stages are caused by pyrolysis of the epoxy resin matrix, and the glass fiber will not decompose. The dynamic parameters of glass fiber reinforced plastic were obtained through the Kissinger-Akahira-Sunose (KAS), Flynn–Wall-Ozawa (FWO) and advanced Vyazovkin methods in model-free and the Coats–Redfern (CR) method in model fitting. FTIR spectrum result shows that the main components of the product gas are CO₂, H₂O, carbonyl components, and aromatic components during its pyrolysis.

Functional metal–organic frameworks as effective sensors of gases and volatile compounds

This review summarizes the recent advances of metal organic framework (MOF) based sensing of gases and volatile compounds.

Metal Organic Frameworks Based Materials for Heterogeneous Photocatalysis

The increase in environmental pollution due to the excessive use of fossil fuels has prompted the development of alternative and sustainable energy sources. As an abundant and sustainable energy, solar energy represents the most attractive and promising clean energy source for replacing fossil fuels. Metal organic frameworks (MOFs) are easily constructed and can be tailored towards favorable photocatalytic properties in pollution degradation, organic transformations, CO₂ reduction and water splitting. In this review, we first summarize the different roles of MOF materials in the photoredox chemical systems. Then, the typical applications of MOF materials in heterogeneous photocatalysis are discussed in detail. Finally, the challenges and opportunities in this promising field are evaluated.

Luminescent Lanthanide MOFs: A Unique Platform for Chemical Sensing

In recent years, lanthanide metal-organic frameworks (LnMOFs) have developed to be an interesting subclass of MOFs. The combination of the characteristic luminescent properties of Ln ions with the intriguing topological structures of MOFs opens up promising possibilities for the design of LnMOF-based chemical sensors. In this review, we present the most recent developments of LnMOFs as chemical sensors by briefly introducing the general luminescence features of LnMOFs, followed by a comprehensive investigation of the applications of LnMOF sensors for cations, anions, small molecules, nitroaromatic explosives, gases, vapors, pH, and temperature, as well as biomolecules.

An ideal detector composed of a 3D Gd-based coordination polymer for DNA and Hg2+ ion

A 3D Gd-based CP was employed as an effective fluorescent sensing platform for DNA and Hg²⁺ ion detection with sensitivity and selectivity, due to its ability to highly quench fluorescence and its different affinities toward ssDNA and dsDNA.

A Temperature-Responsive Smart Europium Metal-Organic Framework Switch for Reversible Capture and Release of Intrinsic Eu3+ Ions

Stimuli-responsive structural transformations are emerging as a scaffold to develop a charming class of smart materials. A EuL metal-organic framework (MOF) undergoes a reversible temperature-stimulated single-crystal to single-crystal transformation, showing a specific behavior of fast capture/release of free Eu3+ in the channels at low and room temperatures. At room temperature, compound 1a is obtained with one free carboxylate group severing as further hook, featuring one-dimensional square channels filled with intrinsic free europium ions. Trigged by lowering the ambient temperature, 1b is gained. In 1b, the intrinsic free europium ions can be fast captured by the carboxylate-hooks anchored in the framework, resulting in the structural change and its channel distortion. To the best of our knowledge, this is the first report of such a rapid and reversible switch stemming from dynamic control between noncovalent and covalent Eu-ligand interactions. Utilizing EuL MOF to detect highly explosive 2,4,6-trinitrophenol at room temperature and low temperature provides a glimpse into the potential of this material in fluorescence sensors.

A tetranuclear copper cluster-based MOF with sulfonate–carboxylate ligands exhibiting high proton conduction properties

A tetranuclear copper cluster-based MOF with sulfonate–carboxylate ligands has been synthesized. It possesses 1D irregular channels lined with sulfonate, carboxylate, and DMF molecules, which show a high proton conductivity of 7.4 × 10⁻⁴ S cm⁻¹ at 95 °C and 95% relative humidity.

Assembly of three coordination polymers based on a sulfonic–carboxylic ligand showing high proton conductivity

Three MOFs with different structures all exhibit proton conduction behavior, especially for the Cu compound with a proton conductivity of 3.46 × 10⁻³ S cm⁻¹ at 368 K and 95% RH.

Highly thermostable lanthanide metal–organic frameworks exhibiting unique selectivity for nitro explosives

The solvent-free Eu-MOF with high red emission intensity and the microporous instinct exhibits high sensitivity for 2,4,6-trinitrophenol with K_sv constant 6.24 × 10⁴ M⁻¹.

A stable, pillar-layer metal–organic framework containing uncoordinated carboxyl groups for separation of transition metal ions

A 3D pillar-layer framework with uncoordinated carboxyl groups can selectively adsorb Cu²⁺ ions and has been applied as a chromatographic column for separating Cu²⁺/Co²⁺ ions.

[Studies on the chemical constituents of Excoecaria cochinchinensis Lour. var. viridis Merr]

Eight compounds have been obtained from the root and stem of Excoecaria cochinchinensis var. viridis growing in Tonghai county of Yunnan province. According to their spectroscopic analyses and physicochemical constants, they have been identified as: shikimic acid, 1-cyclohexene-1-carboxylic acid-5-hydroxy-3,4-isopropylidene-dioxy, oxy-bis(5-methylene-2-furaldehyde), beta-sitosterol, tetracosanoic acid, palmic acid, steric acid and hentriacontane.