Boosting the Luminescence of a Europium(III)-ß-Diketonate Complex-Nanoclay Aqueous Solution by Acetylcholine.

It is a challenging task to prepare lanthanide complex-based luminescent materials with high quantum efficiency in aqueous solution, since the excited state of Ln3+ can be significantly quenched by water through the excitation of the O-H vibrations. Herein, we present a simple and environmentally friendly strategy to prepare strongly red-light-emitting lanthanide complex-based luminescent materials by loading 2-thenoyltrifluoroacetate (TTA) on the Eu3+-exchanged nanoclay (Eu3+(TTAn)-NC, NC = nanoclay) and coadsorption of choline chloride (ChCl) or acetylcholine chloride (AChCl) in water. The coadsorbed molecules remarkably boosted the luminescence of Eu3+(TTAn)-NC, which is tentatively ascribed to the removal of waters coordinated in the Eu3+ coordination sphere via the complete coordination of TTA mediated by ChCl or AChCl. Highly luminescent films were facilely prepared by mixing a Eu3+(TTAn)-NC aqueous solution with PVA-ChCl (PVA-AChCl) deep eutectic solvents. This work provides a simple and environmentally friendly way for preparing highly luminescent emitting luminescent materials in aqueous solution.

Spidroin-mimetic Engineered Protein Fibers with High Toughness and Minimized Batch-to-batch Variations through ß-sheets Co-assembly.

Synthetic spidroin fibers have not yet attained the same level of toughness and stability as natural spider silks due to the complexity of composition and hierarchical structure. Particularly, understanding the intricate interactions between spidroin components in spider fiber is still elusive. Herein, we report modular design and preparation of spidroin-mimetic fibers composed of a conservative C-terminus spidroin module, two different natural ß-sheets modules, and a non-spidroin random-coil module. The resulting fibers exhibit a toughness of ~200 MJ/m3, reaching the highest value among the reported artificial spider silks. The interactions between two components of recombinant spidroins facilitate the intermolecular co-assembly of ß-sheets, thereby enhancing the mechanical strength and reducing batch-to-batch variability in the dual-component spidroin fibers. Additionally, the dual-component spidroin fibers offer potential applications in implantable or even edible devices. Therefore, our work presents a generic strategy to develop high-performance protein fibers for diverse translations in different scenarios.

Glucose metabolic reprogramming and its therapeutic potential in obesity-associated endometrial cancer.

Endometrial cancer (EC) is a common gynecological cancer that endangers women health. Although substantial progresses of EC management have been achieved in recent years, the incidence of EC still remains high. Obesity has been a common phenomenon worldwide that increases the risk of EC. However, the mechanism associating obesity and EC has not been fully understood. Metabolic reprogramming as a remarkable characteristic of EC is currently emerging. As the primary factor of metabolic syndrome, obesity promotes insulin resistance, hyperinsulinemia and hyperglycaemia. This metabolic disorder remodels systemic status, which increases EC risk and is related with poor prognosis. Glucose metabolism in EC cells is complex and mediated by glycolysis and mitochondria to ensure energy requirement. Factors that affect glucose metabolism may have an impact on EC initiation and progression. In this study, we review the glucose metabolic reprogramming of EC not only systemic metabolism but also inherent tumor cell metabolism. In particular, the role of glucose metabolic regulation in malignant properties of EC will be focused. Understanding of metabolic profile and glucose metabolism-associated regulation mechanism in EC may provide novel perspective for treatment.

Clusterization-Triggered Room Temperature Phosphorescence Supramolecular Assembly with Extraordinary Stimulus-responsive Features from Nonaromatic Amino Acids.

Achieving stimulus-responsive performance in room-temperature phosphorescence (RTP) materials especially systems without classic conjugated groups is attractive and important but remains a great challenge. Herein we propose a universal approach to construct colors-tunable RTP supramolecular co-assemblies (AC@amino acid) with excitation wavelength-dependent properties through co-assembly of functional aminoclay (AC) and nonconjugated amino acid using environmentally friendly strategy. Experimental and theoretical results successfully disclose that the RTP feature is attributable to space conjugation through effective space electronic communications among different π and n (lone pair) electrons of amino acid molecules and the effective stabilization of their triplet state by AC. Meanwhile, their colors-tunable performances are mainly owing to the co-existence of clusters with different aggregates degree through recrystallization of amino acid taking AC as a template. Importantly, AC@amino acid exhibit sensitive stimulus response features towards water, yet their RTP performance can be maintained in other solvents, such as ethanol (EtOH). By virtue of this unique feature, multilevel information encryption application were demonstrated. This work provides a unique insight and more deep understanding on designing novel RTP systems without classic conjugated groups. Importantly, their extraordinary stimulus-responsive performances endow these RTP systems with a highly promising potential for intelligent information encryption applications.

Room-Temperature Self-Healing Glassy Luminescent Hybrid Film.

The self-healing of glassy polymer materials on site has always been a huge challenge due to their frozen polymer network. We herein report self-repairable glassy luminescent film by assembling a lanthanide-containing polymer with randomly hyperbranched polymers possessing multiple hydrogen (H) bonds. Because of multiple H bonds, the hybrid film exhibits enhanced mechanical strength, with high glass transition temperature (Tg) of 40.3 °C and high storage modulus of 3.52 GPa, meanwhile, dynamic exchange of multiple H bonds enables its rapid room-temperature self-healing ability. This research provides new insights in preparing mechanical robust yet repairable polymeric functional materials.

High-Quantum-Efficiency Blue Phosphors with Superior Thermal Stability Derived from Eu3+-Doped Faujasite Y Zeolite.

Blue phosphors of high efficiency and superior thermal stability constitute the critical component for achieving high-quality white light-emitting diodes (WLEDs). Herein, we report a highly efficient blue-emitting phosphor with superior thermal stability by heating Eu3+-doped Faujasite Y zeolite under a reducing atmosphere. The intensity and peak value of the phosphor are highly dependent on calcination temperature, and the intensity of PLE and PL spectra reaches a maximum at 1100 °C. Under the excitation of 360 nm, the phosphor shows a high quantum efficiency (90%) and thermal stability (the emission intensity at 423 K is about 125% of that at room temperature). WLEDs fabricated using this blue phosphor, a yellow Eu2+-SOD phosphor, and a commercially available red Sr2Si5N8:Eu2+ phosphor exhibit an excellent optical performance with a correlated color temperature of 4359 K and a color rendering index of 97. This work provides a new strategy for the synthesis of phosphors with high thermal stability and luminous efficiency.

Tunable Luminescence of Silver Nanoclusters Confined in SOD/FAU Zeolites and Selective Sensing for Organic Amine.

A series of Ag-zeolite luminescent composites are prepared based on SOD and FAUY zeolites, and the effect of zeolite host particle size on their dynamic luminescent emission properties was discussed for the first time. The relationship between zeolite particle size and the nucleation of silver nanoclusters (AgNCs) is revealed. With the increase of zeolite particle size from nanometers to microns, the luminescent color of both Ag-SOD and Ag-Y composites shows significant blue shift. The observed tunable luminescence can be accounted for the slower nucleation rate of AgNCs in micron-scale zeolites with longer channels, resulting in smaller nuclearity of AgNCs within large-size zeolites, through the characterization of extended X-ray absorption fine structure, implying the important roles played by the zeolite themselves in determining the luminescence properties. Moreover, the composites prepared by us feature simple signal transduction, fast response (30 s), and excellent selectivity and sensitivity for discriminative luminescence detection of triethylamine and ethylamine, and they have good reversible luminescence response after sensing HAc gas, which might imply the potential applications in the volatile organic amine detection and information encryption field.

Stable and Highly Luminescent Silver Nanoclusters in the 13X Zeolite Enabled by Mg2+ Doping and Their Luminescence Tuning by Heating Temperature.

Zeolite-confined silver nanoclusters (Ag-zeolite) have aroused vast interest due to their remarkable luminescence. The countercations within a zeolite play critical roles in determining the luminescent properties of the resulting Ag-zeolite. We observed, in this work, that introducing Mg2+ enabled the Ag-13X zeolite a stable and bright yellow emission with a high PLQY of 94.6%, the first report on the luminescence enhancement of the Ag-13X zeolite by Mg2+, to the best of our knowledge. The formation of specific internal electric fields inside 13X and the structural contraction of the zeolite framework due to the high charge density and the small ionic radius of Mg2+ are believed to be responsible for the enhanced stable and bright yellow emission. The stabilization effect of Mg2+ is removed by increasing the heating temperature above 700 °C, which leads to the variation of silver nanoclusters as a result of the framework collapse of the zeolite. The Ag-zeolite synthesized by us, featured with a broad emission band, a high PLQY of 94.6%, and good thermal stability, can be considered a suitable candidate to replace the traditional commercial yellow-emitting phosphor YAG:Ce3+ for light-based applications. This work contributes to a valuable reference for the rational design of silver nanoclusters confined in zeolites with promising new functionalities and stimulates potential applications as novel phosphors for near-ultraviolet light-emitting diodes (NUV-LEDs).

Variable Luminescence and Chromaticity of Homoleptic Frameworks of the Lanthanides together with Pyridylpyrazolates.

Homoleptic, 3D coordination polymers of the formula 33 ∞ [Ln(3-PyPz)3 ] and 3 ∞ [Ln(4-PyPz)3 ], (3-PyPz)- =3-(3-pyridyl)pyrazolate anion, (4-PyPz)- =3-(4-pyridyl)pyrazolate anion, both C8 H6 N3 - , Ln=Sm, Eu, Gd, Tb, Dy, were obtained as highly luminescent frameworks by reaction of the lanthanide metals (Ln) with the aromatic heterocyclic amine ligands 3-PyPzH and 4-PyPzH. The compounds form two isotypic series of 3D coordination polymers and exhibit fair thermal stability up to 360 °C. The luminescence properties of all ten compounds were determined in the solid state, with an antenna effect through ligand-metal energy transfer leading to high efficiency of the luminescence displayed by good quantum yields of up to 74 %. The emission is mainly based on ion-specific lanthanide-dependent intra 4 f-4 f transitions for Tb3+ : green, Dy3+ : yellow, Sm3+ : orange-red, Eu3+ : red. For the Gd3+ -containing compounds, the yellow emission of ligand triplet-based phosphorescence is observed at room temperature and 77 K. Co doping of the Gd-containing frameworks with Eu3+ and Tb3+ allow further shifting of the chromaticity towards white light emission.

Organic-Inorganic Hybrid Luminescent Hydrogel Glued by a Cationic Polymeric Binder.

Luminescent hydrogels have shown great potential in many fields, such as lighting, display, imaging, and sensing, because of their unique optical properties, biocompatibility, and easy processing. Organic-inorganic hybrid self-assembly can not only enhance the hydrogels' mechanical strength, but also retain their self-healing ability. Herein, a luminescent supramolecular hydrogel is reported, which is formed via self-assembly of the negatively charged Laponite nanosheets and cationic lanthanide coordination polymer. The corresponding results reveal that the multiple binding interaction between Laponite and the polymeric binder is vital for improving the mechanical performance of the obtained luminescent supramolecular hydrogel.

Porcine circovirus type 2 upregulates endothelial-derived IL-8 production in porcine iliac artery endothelial cells via the RIG-I/MDA-5/MAVS/JNK signaling pathway.

BACKGROUND: Dysfunction of endothelial cells and vascular system is one of the most important pathological changes of porcine circovirus disease (PCVD) caused by porcine circovirus type 2 (PCV2). PCV2-infected endothelial cells can upregulate the production of endothelial-derived IL-8, which can inhibit the maturation of dendritic cells. Endothelial-derived IL-8 has different structural and biological characteristics compared with monocyte-derived IL-8. However, the mechanism of endothelial-derived IL-8 production is still unclear. RESULTS: Key molecules of RIG-I-like signaling pathway RIG-I, MDA-5, MAVS and a key molecule of JNK signaling pathway c-Jun in PCV2-infected porcine iliac artery endothelial cells (PIECs) were upregulated significantly detected with quantitative PCR, Western blot and fluorescence confocal microscopy, while no significant changes were found in NF-κB signaling pathway. Meanwhile, the expression of endothelial-derived IL-8 was downregulated after RIG-I, MDA-5, or MAVS genes in PIECs were knocked down and PIECs were treated by JNK inhibitor. CONCLUSIONS: PCV2 can activate RIG-I/MDA-5/MAVS/JNK signaling pathway to induce the production of endothelial-derived IL-8 in PIECs, which provides an insight into the further study of endothelial dysfunction and vascular system disorder caused by PCV2.

A Robust Mixed-Lanthanide PolyMOF Membrane for Ratiometric Temperature Sensing.

Temperature sensors play a significant role in biology, chemistry, and engineering, especially those that can work accurately in a noninvasive manner. We adopted a photoinduced post-synthetic copolymerization strategy to realize a membranous ratiometric luminescent thermometer based on the emissions of two lanthanide ions. This novel mixed-lanthanide polyMOF membrane exhibits not only the integrity and temperature sensing behaviour of the Ln-MOF powder but also excellent mechanical properties, such as flexibility, elasticity, and processability. Moreover, the polyMOF membrane shows remarkable stability under harsh conditions, including high humidity, strong acid and alkali (pH 0-14), which allowed the mapping of temperature distributions in extreme circumstances. This work highlights a simple strategy for polyMOF membrane formation and pushes forward the further practical application of Ln-MOF-based luminescent thermometers in various fields and conditions.

Endothelial IL-8 induced by porcine circovirus type 2 affects dendritic cell maturation and antigen-presenting function.

BACKGROUND: Porcine circovirus (PCV) disease caused by PCV type 2 (PCV2) is mainly attributed to immunosuppression and immune damage. PCV2 can infect vascular endothelial cells and induce high expression of endothelial IL-8. Dendritic cells (DCs), as professional antigen-presenting cells, can not only present antigens but also activate naïve T-cells, causing an immune response. METHODS: To demonstrate whether endothelial IL-8 is the main factor inhibiting the maturation and related functions of dendritic cells during PCV2 infection, monocyte-derived DCs (MoDCs) and porcine iliac artery endothelial cells (PIECs) processed by different methods were co-cultured in two ways. Flow cytometry, molecular probe labeling, fluorescence quantitative PCR, and the MTS assay were used to detect the changes in related functions and molecules of MoDCs. RESULTS: Compared to those in the PIEC-DC group, the endothelial IL-8 upregulation co-culture group showed significantly lower double-positive rates for CD80/86 and MHC-II of MoDCs and significantly increased endocytosis of MoDCs. Meanwhile, the adhesion rate and average fluorescence intensity of MoDCs were significantly downregulated in migration and adhesion experiments. Furthermore, the MHC-I and LAMP7 mRNA levels in MoDCs and the proliferation of MoDC-stimulated T-cells were markedly reduced. However, the changes in MoDCs of the endothelial IL-8 downregulation co-culture group were the opposite. CONCLUSIONS: PCV2-induced endothelial IL-8 reduces the adhesion and migration ability of MoDCs, resulting in a decreased maturation rate of MoDCs, and further inhibits antigen presentation by DCs. These results may explain the immunosuppressive mechanism of PCV2 from the perspective of the interaction between endothelial cells and DCs in vitro.

Ammonia-Responsive Luminescence of Ln3+-ß-diketonate Complex Encapsulated within Zeolite Y.

Assembling Ln3+(HPBAn) (Ln = Eu or Tb, HPBA = N-(2-pyridinyl)benzoylacetamide) in the cavities of zeolite Y (ZY) via the "ship-in-a-bottle" strategy leads to the formation of novel luminescent composite, Ln(HPBAn)@ZY, whose luminescence can be easily modulated by ammonia on the basis of the energy level variation of HPBA after deprotonation process. Additionally the bimetallic complex doping sample, Eu0.5Tb0.5(HPBAn)@ZY, show great potential as self-referencing luminescent sensor for detecting low ammonia concentration of 10-12⁻0.25 wt%.

Loading Photochromic Molecules into a Luminescent Metal-Organic Framework for Information Anticounterfeiting.

Stimuli-responsive photoluminescent materials have attracted considerable attention owing to their potential applications in security protection because the information recorded directly in materials with static luminescent outputs are usually visible under either ambient or UV light. Herein, we realize reversible information anticounterfeiting by loading a photoswitchable diarylethene derivative into a lanthanide metal-organic framework (MOF). Light triggers the open- and closed-form isomerization of the diarylethene unit, which respectively regulates the inactivation and activation of the photochromic FRET process between the diarylethene acceptor and lanthanide donor, resulting in reversible luminescence on-off switching of the lanthanide emitting center in the MOF host. This photoresponsive host-guest system allows for reversible multiple information pattern visible/invisible transformation by simply alternating the exposure to UV and visible light.

Reduced antigen presentation capability and modified inflammatory/immunosuppressive cytokine expression of induced monocyte-derived dendritic cells from peripheral blood of piglets infected with porcine circovirus type 2.

The efficiency of immune responses and host defense against pathogens largely depends on the function of dendritic cells (DCs). Porcine circovirus type 2 (PCV2) infection causes viremia and extensive modulation of immune activities in the blood. The objective of the present study was to investigate the effects of PCV2 infection in vivo on the immunological function of DCs induced from peripheral blood monocytes (MoDCs). At different points after infection with PCV2, peripheral blood monocytes from PCV2-infected pigs were used to induce differentiation of DCs in vitro. Flow cytometry and quantitative real-time reverse transcription PCR were conducted to detect mRNA expression of surface markers related to antigen presentation and inflammatory/immunosuppressive cytokines of the induced MoDCs. The ability of induced MoDCs to stimulate T cells was measured using an MTS assay. In the early phase of infection at 3 days post-inoculation (DPI), IL-10, IL-8 and MIP-1ß in MoDCs were upregulated significantly. By the peak of virus proliferation at 7 DPI, antigen presentation molecules SLA-DR (MHC II) and CD80/86 together with cytokines IL-12 and IL-10 had decreased, accompanied by a rapid reduction of IL-8 and MIP-1ß. The T cell stimulation index of induced MoDCs in PCV2 groups after different infection times declined to some extent, with a significant difference at 7 DPI. PCV2 infection in vivo functionally reduced the antigen presentation capability of induced MoDCs from peripheral blood and modified expression of inflammatory/immunosuppressive cytokines that may be related to PCV2-induced immunosuppression.

Reversible Phase Transition of Robust Luminescent Hybrid Hydrogels.

We report herein on remote control over a reversible phase transition of robust luminescent hybrid hydrogels as enabled by the rational selection and incorporation of photoswitches. Azobenzene units functionalized with a guanidinium group were utilized as the photoswitches and incorporated through a host-guest inclusion method involving α-cyclodextrins functionalized with 2,6-pyridinedicarboxylic acid (PDA) groups. While the guanidinium functional groups bind to the negatively charged Laponite matrix surface to connect organic and inorganic components, the PDA groups enable simultaneous coordination with different lanthanide metal ions, thus rendering the hydrogel broadly luminescent. Owing to its conformation-dependent binding behavior with α-cyclodextrin, the isomerization of azobenzene induced association or dissociation of the inclusion complexes and thus lead to a reversible photocontrolled sol↔gel phase transition of the luminescent hybrid hydrogels.

Effect of porcine circovirus type 2 (PCV2) on the function of splenic CD11c+ dendritic cells in mice.

Porcine circovirus-associated disease (PCVAD) caused by porcine circovirus type 2 (PCV2) is an important disease in the global pig industry. Dendritic cells (DCs) are the primary immune cells capable of initiating adaptive immune responses as well as major target cells of PCV2. To determine whether PCV2 affects the immune functions of DCs, we evaluated the expression of endocytosis and co-stimulatory molecules on DCs (CD11c+) from PCV2-infected mouse spleen by flow cytometry (FCM). We also analyzed the main cytokines secreted by DCs (CD11c+) and activation of CD4+ and CD8+ T cells by DCs (CD11c+) through measurement of cytokine secretion, using ELISA. Compared with control mice, PCV2 did not affect the endocytic activity of DCs but it significantly enhanced TNF-α secretion and markedly decreased IFN-α secretion. Subsets of CD40+, MHCII+ CD40+ and CD137L+ CD86+ DCs did not increase obviously, but MHCII+ CD40- and CD137L- CD80+/CD86+ DCs increased significantly in PCV2-infected mouse spleen. Under the stimulation of DCs from PCV2-infected mouse, secretion of IFN-γ by CD4+ and CD8+ T cells and of IL-12 by CD8+ T cells was significantly lower than in control mice, while secretion of IL-4 by CD4+ T cells was remarkably higher. These results indicate that PCV2 modulates cytokine secretion and co-stimulatory molecule expression of DCs, and alters activation of CD4+ and CD8+ T cells by DCs. The immunomodulatory effects of PCV2 on DCs might be related to the host's immune dysfunction and persistent infection with this virus.

A Red-Emitting Luminescent Material Capable of Detecting Low Water Content in Organic Solvents.

A new red-emitting luminescent material was prepared from a gel formed by simply mixing EuCl3 ⋅6 H2 O and 4'-para-phenylcarboxyl-2,2':6',2''-terpyridine (Hcptpy) in a molar ratio of 1:2 in anhydrous ethanol at room temperature. It shows bright red luminescence dominated by the (5) D0 →(7) F2 transition of Eu(3+) , a long lifetime (1.16 ms), a high absolute quantum yield (48.2 %), and good thermostability (stable up to 500 °C). In addition, the luminescence of the material can be easily quenched by contact with water, which makes it suitable for detecting low contents of water (0.1-1.5 vol %) in common organic solvents such as diethyl ether and THF.

Water-Soluble Luminescent Hybrid Composites Consisting of Oligosilsesquioxanes and Lanthanide Complexes and their Sensing Ability for Cu(2.).

Water-soluble hybrid composites with great potential for selective and sensitive sensing and that are obtained through simple, rapid, and environmentally friendly methods are highly desirable and remain a challenging task. Herein, we present luminescent hybrid composites that were realized by linking Na3 [Ln(dpa)3 ] (dpa=2,6-pyridinedicarboxylic acid) to octa-amino functionalized polyhedral oligomeric silsesquioxane (POSS-NH2 ) through hydrogen-bonding interactions between the oxygen atoms of the carboxylate groups of dpa and the hydrogen-bond-donor amino groups. The resulting hybrid composites Ln(dpa)3 @POSS-NH2 are highly soluble in aqueous solutions and the quantum yield of Eu(dpa)3 @POSS-NH2 is as high as 56.5 % or 46.3 % in the solid state and in aqueous solution, respectively, as determined by using the integrating sphere method. The novel water-soluble luminescent hybrid composites exhibit high thermal and photostability, and the emitted colors of the resulting hybrid composite can be finely tuned by changing the Eu(3+) /Tb(3+) ratio. Interestingly, Eu(dpa)3 @POSS-NH2 hybrid composites exhibited an effective switch-off fluorescence response to Cu(2+) over other common metal ions in aqueous media.