Cytoplasmic SIRT6-mediated ACSL5 deacetylation impedes nonalcoholic fatty liver disease by facilitating hepatic fatty acid oxidation.

Nonalcoholic fatty liver disease (NAFLD) is characterized by excessive hepatic lipid accumulation, which can progress to nonalcoholic steatohepatitis (NASH). Histone deacetylase Sirtuin 6 (SIRT6) regulates NAFLD by regulating metabolism-related gene expression, but an extrachromosomal role for SIRT6 in NAFLD development remains elusive. We investigated whether SIRT6 functions on NAFLD in the cytoplasm. We found that SIRT6 binds saturated fatty acids, especially palmitic acid. This binding leads to its nuclear export, where it deacetylates long-chain acyl-CoA synthase 5 (ACSL5), thereby facilitating fatty acid oxidation. High-fat diet-induced NAFLD is suppressed by ACSL5 hepatic overexpression but is exacerbated by its depletion. As confirmation, overexpression of a deacetylated ACSL5 mimic attenuated NAFLD in Sirt6 liver-specific knockout mice. Moreover, NASH-hepatic tissues from both patients and diet-fed mice exhibited significantly reduced cytoplasmic SIRT6 levels and increased ACSL5 acetylation. The SIRT6/ACSL5 signaling pathway has a critical role in NAFLD progression and might constitute an avenue for therapeutic intervention.

eIF4E plays the role of a pathogenic gene in psoriasis, and the inhibition of eIF4E phosphorylation ameliorates psoriasis-like skin damage.

Psoriasis is a complex inflammatory skin disease with uncertain pathogenesis. eIF4E (eukaryotic translation initiation factor 4E) and its phosphorylation state p-eIF4E are highly expressed in psoriatic tissues. However, the role eIF4E played in psoriasis is still unclear. To investigate the function of eIF4E and p-eIF4E in psoriasis and to figure out whether eFT-508 (Tomivosertib, eIF4E phosphorylation inhibitor) can relieve the disease severity and become a promising candidate for the psoriasis treatment. We first verified the expression of eIF4E and p-eIF4E in psoriasis patients' lesional skin. Then, we demonstrated the effect of eIF4E and p-eIF4E on the abnormal proliferation and inflammatory state of keratinocytes by using eIF4E-specific small interfering RNA (si-eIF4E) and eFT-508. In this study, all cell experiments were performed under the psoriasis-model condition. Moreover, the external application of eFT-508 on imiquimod (IMQ)-induced psoriasis mice was performed to explore its potential clinical value. Results showed that eIF4E and p-eIF4E were significantly overexpressed in skin lesions of psoriasis patients. Knocking down eIF4E or adding eFT-508 can relieve the abnormal proliferation and the excessive inflammatory state of keratinocytes by reducing the expression of cyclin D1, IL-1ß, CXCL10, IL23, Wnt 5a, NBS1 and p-AKT from mRNA or protein levels. Furthermore, these results were consistent with those obtained from the in vitro experiments. Then, we conclude that eIF4E plays the role of the pathogenic gene in psoriasis, and eFT-508 may be a promising candidate for anti-prosoriasis drugs.

LncRNA lnc-SPRR2G-2 contributes to keratinocyte hyperproliferation and inflammation in psoriasis by activating the STAT3 pathway and downregulating KHSRP.

Psoriasis is a chronic inflammatory disease characterized by increased keratinocyte proliferation and local inflammation. Long noncoding RNAs (lncRNAs) play important regulatory roles in many immune-mediated diseases, including psoriasis. In this study, we aimed to investigate the role and mechanism of lnc-SPRR2G-2 (SPRR2G) in M5-treated psoriatic keratinocytes. Fluorescence in situ hybridization and quantitative real-time polymerase chain reaction (qRT-PCR) showed that lnc-SPRR2G-2 was significantly upregulated in psoriasis tissues and psoriatic keratinocytes. In psoriatic keratinocytes, functional and molecular experiment analyses demonstrated that SPRR2G regulated proliferation, cell cycle and apoptosis, and induced the expression of S100 calcium binding protein A7 (S100A7), interleukin (IL)-1ß, IL-8 and C-X-C motif chemokine ligand 10 (CXCL10). The function of SPRR2G in psoriasis is related to the STAT3 signaling pathway and can be inhibited by a STAT3 inhibitor. Moreover, KH-type splicing regulatory protein (KHSRP) was proved to be regulated by lnc-SPRR2G-2 and to control the mRNA decay of psoriasis-related cytokines (p < 0.05). In summary, we reported the functions of lnc-SPRR2G-2 and KHSRP in psoriasis. Our findings provide new insights for the further exploration of the pathogenesis and treatment of psoriasis.

In Situ Synthesis of Copper-Based Metal-Organic Frameworks with Ligand Defects for Electrochemical Reduction of CO2 into C2 Products.

Electrochemical reduction of CO2 into high-value-added products is a potential approach to solving environmental problems but is limited by poor product selectivity and low efficiency. Metal-organic framework (MOF) materials have been considered one of the most promising catalysts, but their application is limited by complicated preparation processes, especially during the synthesis of organic ligands. In this work, a new three-dimensional Cu-MOF (JXUST-301) with high porosity was constructed based on the naphthalene diimide (NDI) ligand. Furthermore, JXUST-301 with ligand defects (JXUST-301D) originating from the missing NDI unit was synthesized via an in situ reaction. The presence of ligand defects endows JXUST-301D with a better CO2RR performance with a FEC2 of 56.7% and a jC2 of -162.4 mA cm-2. Mechanistic studies revealed that the hierarchical pore structure and amino sites are created from the absence of the NDI unit, which promotes the exposure of catalytically active sites and CO2 enrichment. Furthermore, the electronic structure of the Cu sites is modulated to upshift the d-band center, facilitating chemical adsorption and activation of key reaction intermediates. This work provides new insight into the in situ preparation of efficient Cu-MOF catalysts by introducing defects for the CO2RR.

Effect of Substituents in Equatorial Hexaazamacrocyclic Schiff Base Ligands on the Construction and Magnetism of Pseudo D6h Single-Ion Magnets.

Three mononuclear DyIII compounds [DyL1(Ph3SiO)2][BPh4]·MeCN·2H2O (1), [DyL2(Ph3SiO)2][BPh4]·C2H5OH·H2O (2), and [DyL3(Ph3SiO)(OAc)][BPh4]·CH3OH·3H2O (3) and their corresponding YIII diluted analogues [Dy0.0967Y0.9033L1(Ph3SiO)2][BPh4]·MeCN·2H2O (1@Y), [Dy0.2668Y0.7332L2(Ph3SiO)2][BPh4]·C2H5OH·H2O (2@Y), and [Dy0.1260Y0.8740L3(Ph3SiO)(OAc)][BPh4]·CH3OH·3H2O (3@Y) were synthesized with hexaazamacrocyclic Schiff base ligands as an equatorial ligand. The substituents in the equatorial hexaazamacrocyclic Schiff base ligand show a significant effect on the replacement of the axial ligands. Compounds 1, 2, and 3 are typical zero dc field single-molecule magnets with effective energy barriers (Ueff) of 1092(6), 946.1(7), and 150.1(9) K, respectively. Although the effective energy barriers of 1 and 2 are close, the magnetic hysteresis remains open up to 20 K for 1, twice as large as that of 2 (10 K), which is different from the previously reported compounds, probably due to nonplanarity N6 in the equator. Ab initio calculations indicate that the ground states of compounds 1 and 2 exhibit high anisotropy and pure second and third excited states, while compound 3 exhibits pure ground-state anisotropy and highly mixed excited states, leading to the easy occurrence of quantum tunneling of magnetization between the ground and excited states in compound 3. This work indicates that the substituents in equatorial hexaazamacrocyclic Schiff base ligands have a significant effect on the construction and magnetic properties of DyIII SIMs with D6h symmetry.

Catheter ablation of atrial fibrillation in patients with left bundle branch block.

BACKGROUND: Left bundle branch block (LBBB) and atrial fibrillation (AF) are commonly coexisting conditions. The impact of LBBB on catheter ablation of AF has not been well determined. This study aims to explore the long-term outcomes of patients with AF and LBBB after catheter ablation. METHODS: Forty-two patients with LBBB of 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were enrolled as LBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without LBBB were enrolled as non-LBBB group. Late recurrence and a composite endpoint of stroke, all-cause mortality, and cardiovascular hospitalization were compared between the two groups. RESULTS: Late recurrence rate was significantly higher in the LBBB group than that in the non-LBBB group (54.8% vs. 31.5%, p = .034). Multivariate analysis showed that LBBB was an independent risk factor for late recurrence after catheter ablation of AF (hazard ratio [HR] 2.19, 95% confidence interval [CI] 1.09-4.40, p = .031). LBBB group was also associated with a significantly higher incidence of the composite endpoint (21.4% vs. 6.5%, HR 3.98, 95% CI 1.64-9.64, p = .002). CONCLUSIONS: LBBB was associated with a higher risk for late recurrence and a higher incidence of composite endpoint in the patients underwent catheter ablation.

Long-term fasting induced basal thermogenesis flexibility in female Japanese quails.

Male Japanese quails (Coturnix japonica) have been found to exhibit a three-phase metabolic change when subjected to prolonged fasting, during which basal thermogenesis is significantly reduced. A study had shown that there is a significant difference in the body temperature between male and female Japanese quails. However, whether female Japanese quails also show the same characteristic three-phase metabolic change during prolonged fasting and the underlying thermogenesis mechanisms associated with such changes are still unclear. In this study, female Japanese quails were subjected to prolonged starvation, and the body mass, basal metabolic rate (BMR), body temperature, mass of tissues and organs, body fat content, the state-4 respiration (S4R) and cytochrome c oxidase (CCO) activity in the muscle and liver of these birds were measured to determine the status of metabolic changes triggered by the starvation. In addition, the levels of glucose, triglyceride (TG) and uric acid, and thyroid hormones (T3 and T4) in the serum and the mRNA levels of myostatin (MSTN) and avian uncoupling protein (av-UCP) in the muscle were also measured. The results revealed the existence of a three-phase stage similar to that found in male Japanese quails undergoing prolonged starvation. Fasting resulted in significantly lower body mass, BMR, body temperature, tissues masses and most organs masses, as well as S4R and CCO activity in the muscle and liver. The mRNA level of av-UCP decreased during fasting, while that of MSTN increased but only during Phase I and II and decreased significantly during Phase III. Fasting also significantly lowered the T3 level and the ratio of T3/T4 in the serum. These results indicated that female Japanese quails showed an adaptive response in basal thermogenesis at multiple hierarchical levels, from organismal to biochemical, enzyme and cellular level, gene and endocrine levels and this integrated adjustment could be a part of the adaptation used by female quails to survive long-term fasting.

Flicker Noise in Resistive Gas Sensors-Measurement Setups and Applications for Enhanced Gas Sensing.

We discuss the implementation challenges of gas sensing systems based on low-frequency noise measurements on chemoresistive sensors. Resistance fluctuations in various gas sensing materials, in a frequency range typically up to a few kHz, can enhance gas sensing by considering its intensity and the slope of power spectral density. The issues of low-frequency noise measurements in resistive gas sensors, specifically in two-dimensional materials exhibiting gas-sensing properties, are considered. We present measurement setups and noise-processing methods for gas detection. The chemoresistive sensors show various DC resistances requiring different flicker noise measurement approaches. Separate noise measurement setups are used for resistances up to a few hundred kΩ and for resistances with much higher values. Noise measurements in highly resistive materials (e.g., MoS2, WS2, and ZrS3) are prone to external interferences but can be modulated using temperature or light irradiation for enhanced sensing. Therefore, such materials are of considerable interest for gas sensing.

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OBJECTIVES: To investigate the risk factors for bronchopulmonary dysplasia (BPD) in twin preterm infants with a gestational age of <34 weeks, and to provide a basis for early identification of BPD in twin preterm infants in clinical practice. METHODS: A retrospective analysis was performed for the twin preterm infants with a gestational age of <34 weeks who were admitted to 22 hospitals nationwide from January 2018 to December 2020. According to their conditions, they were divided into group A (both twins had BPD), group B (only one twin had BPD), and group C (neither twin had BPD). The risk factors for BPD in twin preterm infants were analyzed. Further analysis was conducted on group B to investigate the postnatal risk factors for BPD within twins. RESULTS: A total of 904 pairs of twins with a gestational age of <34 weeks were included in this study. The multivariate logistic regression analysis showed that compared with group C, birth weight discordance of >25% between the twins was an independent risk factor for BPD in one of the twins (OR=3.370, 95%CI: 1.500-7.568, P<0.05), and high gestational age at birth was a protective factor against BPD (P<0.05). The conditional logistic regression analysis of group B showed that small-for-gestational-age (SGA) birth was an independent risk factor for BPD in individual twins (OR=5.017, 95%CI: 1.040-24.190, P<0.05). CONCLUSIONS: The development of BPD in twin preterm infants is associated with gestational age, birth weight discordance between the twins, and SGA birth.

Highly pH-Responsive Sensor Based on a EuIII Metal-Organic Framework with Efficient Recognition of Arginine and Lysine in Living Cells.

A lanthanide-based three-dimensional metal-organic framework with excellent water, acid/base, and solvent stability, namely {[(CH3)2NH2]0.7[Eu2(BTDBA)1.5(lac)0.7(H2O)2]·2H2O·2DMF·2CH3CN}n (JXUST-29, H4BTDBA = 4',4‴-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis([1,1'-biphenyl]-3,5-dicarboxylic acid), Hlac = lactic acid), has been synthesized and characterized. Since the N atoms of the thiadiazole group will not coordinate with lanthanide ions, JXUST-29 has a free basic N-site accessible to small H+ ions, which allows it to be used as a promising pH fluorescence sensor. Interestingly, the luminescence signal was significantly enhanced, with an approximately 54-fold enhancement in the emission intensity when the pH value was increased from 2 to 5, which is the typical behavior of pH probes. In addition, JXUST-29 can also be used as a luminescence sensor to detect l-arginine (Arg) and l-lysine (Lys) in an aqueous solution through fluorescence enhancement and the blue-shift effect. The detection limits were 0.023 and 0.077 µM, respectively. In addition, JXUST-29-based devices were designed and developed to facilitate detection. Importantly, JXUST-29 is also capable of detecting and sensing Arg and Lys in living cells.

Differential changes in the gut microbiota between extrinsic and intrinsic atopic dermatitis.

Elevated serum level of total and (or) allergen-specific IgE is one of the key features of atopic dermatitis (AD). Previous studies have shown that the gut microbiome mediates interactions between external exposures and the immune system in AD; however, the relationship between the gut microbiota and IgE remains unclear. In the present study, analyses of environmental exposures for 250 AD patients and 138 healthy volunteers revealed an association between hygiene levels in the residential environment and the occurrence of AD and the IgE level. Metagenomic sequencing of the gut microbiota from 68 AD patients and 77 healthy controls showed that AD patients had a distinct gut microbiota composition; moreover, while L-histidine degradation was enriched in healthy controls, L-histidine biosynthesis was enriched in AD patients. Extrinsic and intrinsic AD showed different enrichment patterns of specific microbes and differential associations of functional pathways. Our study indicated that elevated levels of IgE in AD were related to specific microbes in the gut microbiota, which showed extensive interactions with environmental factors.

Chromosome-scale genome assembly and insights into the metabolome and gene regulation of leaf color transition in an important oak species, Quercus dentata.

Quercus dentata Thunb., a dominant forest tree species in northern China, has significant ecological and ornamental value due to its adaptability and beautiful autumn coloration, with color changes from green to yellow into red resulting from the autumnal shifts in leaf pigmentation. However, the key genes and molecular regulatory mechanisms for leaf color transition remain to be investigated. First, we presented a high-quality chromosome-scale assembly for Q. dentata. This 893.54 Mb sized genome (contig N50 = 4.21 Mb, scaffold N50 = 75.55 Mb; 2n = 24) harbors 31 584 protein-coding genes. Second, our metabolome analyses uncovered pelargonidin-3-O-glucoside, cyanidin-3-O-arabinoside, and cyanidin-3-O-glucoside as the main pigments involved in leaf color transition. Third, gene co-expression further identified the MYB-bHLH-WD40 (MBW) transcription activation complex as central to anthocyanin biosynthesis regulation. Notably, transcription factor (TF) QdNAC (QD08G038820) was highly co-expressed with this MBW complex and may regulate anthocyanin accumulation and chlorophyll degradation during leaf senescence through direct interaction with another TF, QdMYB (QD01G020890), as revealed by our further protein-protein and DNA-protein interaction assays. Our high-quality genome assembly, metabolome, and transcriptome resources further enrich Quercus genomics and will facilitate upcoming exploration of ornamental values and environmental adaptability in this important genus.

Near-Room-Temperature Synergetic Response of Magnetism, Dielectricity and Luminescence Based on (C5 NH13 Cl)2 MnBr4.

Multifunctional materials with working temperatures near room temperature are crucial for practical applications. Until now, it is still a great challenge to obtain such materials. In this paper, a complex of (C5 NH13 Cl)2 MnBr4 (1) with a structural phase transition near room temperature is reported. The phase transition induces switchable magnetic properties, dielectric anomalies and luminescent response over the same range of temperatures. It is the first time the synergetic effect of magnetism, dielectricity and luminescence near room temperature have been observed in the same molecular complex.

Synthesis and Structure of an Aqueous Stable Europium-Based Metal-Organic Framework with Ratiometric Fluorescence Sensing for Phosphate and Luminescence Quenching for Salicylaldehyde.

An aqueous stable europium-based metal-organic framework with properties of ratiometric fluorescence sensing, namely, {[(CH3)2NH2][Eu(TCPB)(H2O)2]·DMF}n (Eu-MOF; H4TCPB = 1,2,4,5-tetrakis(4-carboxyphenyl)-benzene), was synthesized under solvothermal conditions and structurally characterized. Crystal structure analysis shows that Eu-MOF is a three-dimensional porous crystal, in which the EuIII ion is an eight-coordinate square inverse prism with eight oxygen atoms. Fluorescence measurements show that Eu-MOF exhibits characteristic emission of the EuIII ion and ligand. Eu-MOF displays good selectivity and sensitivity as a ratiometric fluorescence sensor for phosphate anions with a low detection limit in Tris-HCl buffer solution. Furthermore, Eu-MOF also has a good ability to identify salicylaldehyde through fluorescence quenching with a detection limit of 0.095 ppm. Therefore, it is an excellent fluorescent sensing material for phosphate and organic salicylaldehyde.

Expression and functional analysis of fam76b in zebrafish.

FAM76B is nuclear speckle-localized protein with a molecular weight of 39 kDa. The amino sequence of FAM76B protein is highly conserved among species, suggesting that FAM76B has important biological functions. However, the biological function of FAM76B is currently still unclear. To explore the biological function of FAM76B, we firstly used zebrafish as the experimental model to study the distribution and expression level of Fam76b. The results indicated that fam76b is highly expressed in hematopoiesis and immune systems of zebrafish by real-time quantitative PCR, in situ hybridization and Tg(fam76b: eGFP) transgenic zebrafish. Then, the fam76b gene was knocked out by CRISPR/Cas9 in zebrafish and fam76b rescue in fam76b-/- zebrafish was performed using the TOL2 transposable system. fam76b gene knockout zebrafish exhibit reduced thymus, excessive inflammatory response, and increased mortality. FAM76B was further found to be involved in regulating the development of hematopoiesis and immune system, and participate in the process of inflammatory response. Our findings in the study lay the groundwork for elucidating the function of the new molecule Fam76b and provide new insights into the development of zebrafish hematopoietic and immune system.

Highly Stable Rare Earth Metal-Organic Frameworks for Fluorescence Recognition of Folic Acid, Proton Conduction, and Magnetic Refrigeration.

Four new isostructural rare earth metal-organic frameworks (RE-MOFs) were synthesized and full characterized, namely, {[(CH)2NH2]3[RE2(BTDBA)2(HCOO)]·5H2O·2DMF}n (H4BTDBA = (4',4'''-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis([1,1'-biphenyl]-3,5-dicarboxylic acid); RE = Eu (JXUST-34), Gd (JXUST-35), Tb (JXUST-36), and Dy (JXUST-37)). The single-crystal structures analysis shows that JXUST-34-37 are chain-based three-dimensional structures. Importantly, JXUST-34 exhibits excellent water, organic solvents, and acid-base stability, which can be used as a fluorescence sensor for folic acid and Al3+ with detection limits of 0.02 mM and 0.05 µM, respectively. The presence of free [(CH)2NH2]+ cations in the channels can engage the proton carrier during proton conduction. JXUST-34-37 display good proton conductivity, and the conductivities vary with relative humidity and temperatures, among which JXUST-37 has the highest conductivity of 9.66 × 10-3 S·cm-1 at 60 °C and 98% RH. The magnetic studies show that the -ΔSm of JXUST-35 reaches 16.13 J kg-1 K-1 at 2 K and ΔH = 7 T. JXUST-34-37 show multifunctional properties of fluorescence sensing, high proton conductivity, and magnetic refrigeration, which provides a new clue for the development of fluorescent-responsive, magnetic-refrigerant, and proton-conductive RE-MOF materials.

Ce4+/Ce3+ Redox Effect-Promoted CdS/CeO2 Heterojunction Photocatalyst for the Atom Economic Synthesis of Imines under Visible Light.

The employment of stoichiometric alcohols and amines for imine synthesis under mild and green reaction conditions is still a challenge in the field. In this work, based on our research foundation in the thermocatalytic synthesis of imines over ceria, a CdS/CeO2 heterojunction photocatalyst was constructed and successfully realized the atom-economic synthesis of imines under visible light without additives at room temperature. Mechanistic experiments and corresponding characterizations indicated that the CdS/CeO2 heterojunction can improve the separation efficiency of photogenerated carriers, which can be further enhanced by the Ce4+/Ce3+ redox pair by rapidly combining photogenerated e-. The in situ-reduced Ce3+ can better activate O2 to form Ce-O-O·, which, together with h+, efficiently accelerates alcohol oxidation, which is the rate-determined step for the synthesis of imines via oxidative coupling reaction of alcohol and amine. In addition, our photocatalyst exhibited fairly decent reusability and substrate universality. This work solves problems of using base additives and excess amine or alcohol in the reported photocatalytic systems and provides new insight for designing CeO2-based photocatalytic oxidation catalysts.

Stable Europium(III) Metal-Organic Framework Demonstrating High Proton Conductivity and Fluorescence Detection of Tetracyclines.

A europium(III) metal-organic framework (MOF), namely, {[[(CH3)2NH2]3Eu2(DTTP-2OH)2(HCOO)(H2O)]·4H2O}n (Eu-MOF, H4DTTP-2OH = 2',5'-dihydroxy-[1,1':4',1″-terphenyl]-3,3″,5,5″-tetracarboxylic acid) has been assembled through solvothermal method. The Eu-MOF is a three-dimensional (3D) (4,4,8)-connected topological framework with binuclear Eu(III) clusters as secondary building units, in which a richly ordered hydrogen bonding network formed among the free H2O molecules, dimethylamine cations, and phenolic hydroxyl groups provides a potential pathway for proton conduction. The proton conductivity reaches the category of superionic conductors (σ > 10-4 S cm-1) at room temperature with a maximum conductivity of 1.91 × 10-3 S cm-1 at 60 °C and 98% RH. Moreover, it also can be used as a fluorescence sensor in aqueous solution with detection limits of 0.14 µM for tetracycline, 0.13 µM for oxytetracycline and 0.11 µM for doxycycline. These results pave new methods for constructing MOFs with high proton conductivity and responsive fluorescence.

Mechanochromic and Selective Vapochromic Solid-State Luminescence of a Dinuclear Cuprous Complex.

The unraveling of the stimuli-responsive mechanism is crucial to the design and precise synthesis of stimuli-responsive luminescent materials. We report herein the mechanochromic and selective vapochromic solid-state luminescence properties of a new bimetallic cuprous complex [{Cu(bpmtzH)}2(µ-dppm)2](ClO4)2 (1), and the corresponding response mechanisms are elucidated by investigating its two different solvated polymorphs 1·2CH2Cl2 (1-g) and 1·2CHCl3 (1-c). Green-emissive 1-g and cyan-emissive 1-c can be interconverted upon alternate exposure to CHCl3 and CH2Cl2 vapors, which is principally attributable to a combined alteration of both intermolecular NHbpmtzH···OClO3- hydrogen bonds and intramolecular "triazolyl/phenyl" π···π interactions induced by different solvents. Solid-state luminescence mechanochromism present in 1-g and 1-c is mainly ascribed to the grinding-induced breakage of the NHbpmtzH···OClO3- hydrogen bonds. It is suggested that intramolecular π···π-triazolyl/phenyl interactions are affected by different solvents but not by grinding. The results provide new insights into the design and precise synthesis of multi-stimuli-responsive luminescent materials by the comprehensive use of intermolecular hydrogen bonds and intramolecular π···π interactions.

Solvent- and pH-Stable Eu(III)-Based Metal-Organic Framework with Phosphate-Ratio Fluorescence Sensing and Significant Proton Conduction.

Lanthanide-based metal-organic frameworks show good potential for applications due to their unique structures and functional properties. A highly thermally and acid-base stable Eu-MOF was synthesized by a solvothermal method with the molecular formula {[(CH3)2NH2]2[Eu2(NDDP)2(H2O)2]·H2O}n (Eu-MOF, H4NDDP = 5,5'-(naphthalene-2,6-diyl)diisophthalic acid). Eu-MOF takes a three-dimensional (4,4,8)-connected topology. The water molecules involved in the coordination, free water molecules, and [(CH3)2NH2]+ cations in the pore can be used as proton carriers. The proton conductivity attains 1.25 × 10-4 S cm-1 at room temperature and 2.42 × 10-3 S cm-1 at 70 °C and 98% relative humidity. Combined with the dual-emission properties from the ligands and Eu(III) ions enables Eu-MOF to be used as a ratiometric fluorescent sensor for phosphate efficiently and rapidly, with a limit of detection of 0.12 µM in the Tris-HCl buffer solution. These results provide a new approach for the construction of MOFs with high proton conductivity and a ratiometric fluorescence response.