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.

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.

Enhanced Heterogeneous Catalytic Activity of Peroxymonosulfate for Rhodamine B Degradation via a CoII-Based Metal-Organic Framework.

A stable metal-organic framework with the formula {[Co(BBZB)(IPA)]·H2O}n (JXUST-23, BBZB = 4,7-bis(1H-benzimidazole-1-yl)-2,1,3-benzothiadiazole and H2IPA = isophthalic acid) was constructed by incorporating Co2+ ions and two conjugated ligands under solvothermal conditions. JXUST-23 takes a dinuclear cluster-based layer structure with a porosity of 2.7%. In this work, JXUST-23 was used to activate peroxymonosulfate (PMS) to degrade rhodamine B (RhB), a difficult-to-degrade pollutant in water. Compared with pure PMS or JXUST-23, the JXUST-23/PMS system displays the best degradation ability of RhB in neutral solution. When the mass ratio of JXUST-23 to PMS was 2:3, 99.72% of RhB (50 ppm) was removed within 60 min, and the reaction rate was 0.1 min-1. Furthermore, free radical quenching experiments show that SO4•- was the main free radical during the process of RhB degradation. In addition, JXUST-23 exhibits good reusability for the degradation of the organic dye RhB, making it a potential candidate for environmental remediation.

Controllable Synthesis of TbIII Metal-Organic Frameworks with Reversible Luminescence Sensing for Benzaldehyde Vapor.

Two novel lanthanide metal-organic frameworks (MOFs) with the formulas [Tb(bidc)(Hbidc)(H2O)]n (JXUST-20) and {[Tb3(bidc)4(HCOO)(DMF)]·solvents}n (JXUST-21) were synthesized based on 2,1,3-benzothiadiazole-4,7-dicarboxylic acid (H2BTDC) under solvothermal conditions. Interestingly, benzimidazole-4,7-dicarboxylic acid (H2bidc) was formed in situ using H2BTDC as the starting material. The self-assembly process of the targeted MOFs with different topological structures can be controlled by the solvents and concentration of the reactants. Luminescence experiments show that JXUST-20 and JXUST-21 exhibit strong yellow-green emission. JXUST-20 and JXUST-21 can selectively sense benzaldehyde (BzH) via a luminescence quenching effect with detection limits of 15.3 and 1.44 ppm, respectively. In order to expand the practical application of MOF materials, mixed-matrix membranes (MMMs) have been constructed by mixing targeted MOFs and poly(methyl methacrylate) in a N,N-dimethylformamide (DMF) solution, which can also be used for BzH vapor sensing. Therefore, the first case of MMMs derived from TbIII MOFs has been developed for the reversible detection of BzH vapor, providing a simple and efficient platform for the future detection of volatile organic compounds.

A pH-Stable TbIII-Based Metal-Organic Framework as a Turn-On and Blue-Shift Fluorescence Sensor toward Benzaldehyde and Salicylaldehyde in Aqueous Solution.

A new polydentate tetracarboxylic acid with a benzothiadiazole unit (4',4'''-(benzo[c][1,2,5]thiadiazole-4,7-diyl)bis([1,1'-biphenyl]-3,5-dicarboxylic acid), H4BTDBA) has been used to prepare a pH-stable three-dimensional TbIII-based metal-organic framework (MOF) with the formula {[(CH3)2NH2]0.7[Tb2(BTDBA)1.5(lac)0.7(H2O)2]·solvents}n (Hlac = lactic acid, JXUST-19). JXUST-19 exhibits a new (4,4,12)-connected topology based on tetranuclear [Tb4] clusters. JXUST-19 can remain stable when soaked in water for at least 1 week and in aqueous solutions with various pH values (2-12) for 24 h. Fluorescence study indicates JXUST-19 can be employed as a rare turn-on and blue-shift MOF sensor toward benzaldehyde (BZ) and salicylaldehyde (SA). To date, JXUST-19 represents the first TbIII-based turn-on MOF sensor toward salicylaldehyde in aqueous solution, and the fluorescence enhancement and naked-eye detection of BZ have been rarely reported. In addition, JXUST-19 based fluorescent test papers, light-emitting diode lamp beads, and portable composite films were developed to realize naked-eye detection of BZ and SA, which has great potential in practical applications.

A Benzothiadiazole-Based Eu3+ Metal-Organic Framework as the Turn-On Luminescent Sensor toward Al3+ and Ga3+ with Potential Bioimaging Application.

The design and preparation of novel multifunctional lanthanide metal-organic frameworks (Ln-MOFs) have been arisen widespread attention. In particular, Ln-MOFs have shown great luminescence potential in chemical sensing. Herein, a new benzothiadiazole-based Eu-MOF {[(CH3)2NH2][Eu(BTDB)2]·2H2O}n (JXUST-11) was obtained based on 4,4'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)dibenzoic acid (H2BTDB), which exhibits a chain-based three-dimensional framework. Moreover, JXUST-11 is considered as a photoluminescent sensor to identify Al3+ and Ga3+ ions by fluorescence enhancement with the detection limits of 2.9 and 10.2 ppm, severally. Importantly, Al3+ and Ga3+ can be discerned with the naked eye by color change under a natural lamp. In addition, a portable MOF film based on JXUST-11 was developed for Al3+ and Ga3+ detection. This is the first Ln-MOF that can be employed as a naked-eye fluorescent probe to identify Ga3+. Interestingly, JXUST-11 is also capable of detecting Al3+ and Ga3+ in living cells.

Fabrication and DFT Calculation of Amine-Functionalized Metal-Organic Framework as a Turn-On Fluorescence Sensor for Fe3+ and Al3+ Ions.

Due to their important role in biological systems, it is urgent to develop a material that can rapidly and sensitively detect the concentration of Fe3+ and Al3+ ions. In this work, a brand-new CdII-based metal-organic framework [Cd(BTBD)2(AIC)]n (JXUST-18, BTBD = 4,7-bis(1H-1,2,4-triazol-1-yl)-2,1,3-benzothiadiazole and H2AIC = 5-aminoisophthalic acid) with a 4-connected sql topology was designed and synthesized. The symmetrical CdII centers are linked by AIC2- ligands with µ3-η1:η1:η1:η1 coordination mode to form a [Cd2(COO)2] secondary building unit (SBU). The contiguous SBUs are further connected by BTBD ligands to form a two-dimensional (2D) layer structure. JXUST-18 can remain stable in aqueous solutions with pH values of 3-12 or in boiling water. Luminescent experiments suggest that JXUST-18 displays more than eightfold fluorescence enhancement in the presence of Fe3+ and Al3+ ions, and the detection limits for Fe3+ and Al3+ ions are 0.196 and 0.184 µM, respectively. Furthermore, the change in luminescence color is uncomplicatedly distinguishable with the naked eye under ultraviolet light at 365 nm. In addition, a series of devices based on JXUST-18 including fluorescence test strips, lamp beads, and composite films were developed to detect metal ions via visual changes in luminescence color. Significantly, JXUST-18 is a rare MOF-based turn-on fluorescence sensor for the detection of Fe3+ ions. The theoretical calculation suggests that the complexation of Fe3+/Al3+ ions and the -NH2 group contributes to fluorescence enhancement.

A New Small-Molecule Compound, Q308, Silences Latent HIV-1 Provirus by Suppressing Tat- and FACT-Mediated Transcription.

Eliminating the latent HIV reservoir remains a difficult problem for creating an HIV functional cure or achieving remission. The "block-and-lock" strategy aims to steadily suppress transcription of the viral reservoir and lock the HIV promoter in deep latency using latency-promoting agents (LPAs). However, to date, most of the investigated LPA candidates are not available for clinical trials, and some of them exhibit immune-related adverse reactions. The discovery and development of new, active, and safe LPA candidates for an HIV cure are necessary to eliminate residual HIV-1 viremia through the block-and-lock strategy. In this study, we demonstrated that a new small-molecule compound, Q308, silenced the HIV-1 provirus by inhibiting Tat-mediated gene transcription and selectively downregulating the expression levels of the facilitated chromatin transcription (FACT) complex. Strikingly, Q308 induced the preferential apoptosis in HIV-1 latently infected cells, indicating that Q308 may reduce the size of the viral reservoir and thus further prevent viral rebound. These findings highlight that Q308 is a novel and safe anti-HIV-1 inhibitor candidate for a functional cure.

Turn-On Luminescent Sensor toward Fe3+, Cr3+, and Al3+ Based on a Co(II) Metal-Organic Framework with Open Functional Sites.

A novel Co-based metal-organic framework (MOF) with the formula of {[Co3(BIBT)3(BTC)2(H2O)2]·solvents}n (JXUST-2, where JXUST denotes Jiangxi University of Science and Technology, BIBT = 4,7-bi(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole, and H3BTC = 1,3,5-benzenetricarboxylic acid) has been solvothermally prepared, which takes 3D structure with a rare 3,4,6-c topology and contains intramolecular hydrogen bonds. Interestingly, the sensing investigations suggest that JXUST-2 could be considered as a multifunctional fluorescence sensor toward Fe3+, Cr3+, and Al3+ via a turn-on effect with good reusability and detection limits of 0.13, 0.10, and 0.10 µM, respectively. The turn-on effect of JXUST-2 could be ascribed to an absorbance caused enhancement (ACE) mechanism. Notably, JXUST-2 is the first turn-on MOF fluorescent sensor for Fe3+, Cr3+, and Al3+ simultaneously.

Iodine concentration and content measured by dual-source computed tomography are correlated to thyroid hormone levels in euthyroid patients: a cross-sectional study in China.

BACKGROUND: The aim of this study was to investigate the correlation of the dual energy CT measured iodine concentration and total iodine content with blood measured thyroid parameters. METHODS: Forty-three patients with normal thyroid function at our hospital from August 2017 to October 2019 were included in this retrospective study. Dual energy CT was used to scan the neck of thyroid patients. The mean iodine concentration and thyroid tissue volume were measured to calculate the total iodine content of the thyroid. Relevant tests of triiodothyronine (FT3), total triiodothyronine (TT3), total thyroxine (TT4), free thyroxine (FT4), and thyroid hormone (TSH) were conducted. The correlation of the thyroid mean iodine concentration and total iodine content with blood-measured thyroid function was analysed. RESULT: The total iodine content in the thyroid was positively correlated with FT3 but negatively correlated with TSH. The mean iodine concentration of the thyroid was positively correlated with both FT3 and TT3. CONCLUSION: The thyroid iodine content measured by dual energy CT can be used to determine the human iodine nutritional status and evaluate thyroid function, which will facilitate the diagnosis and treatment of thyroid diseases.

HDAC2 hyperexpression alters hippocampal neuronal transcription and microglial activity in neuroinflammation-induced cognitive dysfunction.

BACKGROUND: Inflammation can induce cognitive dysfunction in patients who undergo surgery. Previous studies have demonstrated that both acute peripheral inflammation and anaesthetic insults, especially isoflurane (ISO), are risk factors for memory impairment. Few studies are currently investigating the role of ISO under acute peri-inflammatory conditions, and it is difficult to predict whether ISO can aggravate inflammation-induced cognitive deficits. HDACs, which are essential for learning, participate in the deacetylation of lysine residues and the regulation of gene transcription. However, the cell-specific mechanism of HDACs in inflammation-induced cognitive impairment remains unknown. METHODS: Three-month-old C57BL/6 mice were treated with single versus combined exposure to LPS injected intraperitoneally (i.p.) to simulate acute abdominal inflammation and isoflurane to investigate the role of anaesthesia and acute peripheral inflammation in cognitive impairment. Behavioural tests, Western blotting, ELISA, immunofluorescence, qRT-PCR, and ChIP assays were performed to detect memory, the expressions of inflammatory cytokines, HDAC2, BDNF, c-Fos, acetyl-H3, microglial activity, Bdnf mRNA, c-fos mRNA, and Bdnf and c-fos transcription in the hippocampus. RESULTS: LPS, but not isoflurane, induced neuroinflammation-induced memory impairment and reduced histone acetylation by upregulating histone deacetylase 2 (HDAC2) in dorsal hippocampal CaMKII+ neurons. The hyperexpression of HDAC2 in neurons was mediated by the activation of microglia. The decreased level of histone acetylation suppressed the transcription of Bdnf and c-fos and the expressions of BDNF and c-Fos, which subsequently impaired memory. The adeno-associated virus ShHdac2, which suppresses Hdac2 after injection into the dorsal hippocampus, reversed microglial activation, hippocampal glutamatergic BDNF and c-Fos expressions, and memory deficits. CONCLUSIONS: Reversing HDAC2 in hippocampal CaMKII+ neurons exert a neuroprotective effect against neuroinflammation-induced memory deficits.

A ZnII-Based Metal-Organic Framework with a Rare tcj Topology as a Turn-On Fluorescent Sensor for Acetylacetone.

A ZnII-based metal-organic framework (MOF) with a rare tcj topology has been solvothermally synthesized and displays relatively good thermal and chemical stabilities. Interestingly, the MOF can sensitively and selectively sense acetylacetone (acac) via a fluorescence enhancement effect with a detection limit of 0.10 ppm and good reusability, which demonstrates the first example of a MOF-based turn-on fluorescent sensor for acac.

Rapid Detection of Serratia fonticola by TaqMan Quantitative Real-Time PCR Using Primers Targeting the gyrB Gene.

A gyrB gene is present in the majority of bacterial species, and encodes the ATPase domain of DNA gyraseB-subunit protein, which is essential for transcription and replication of bacteria. The gyrB gene exhibits higher nucleotide sequence variability than the 16S rDNA gene and thus could be more reliable in differentiating Serratia fonticola. A species-specific primer pair and probe were designed for quantitative real-time PCR detection of S. fonticola using gyrB as the target gene. Nine members of the Serratia family (representing nine Serratia species) were chosen to verify the specificity of the primers. Additionally, two species each of Salmonella and Klebsiella, and five other species belonging to five other genera of Enterobacteriaceae, were tested for primer cross-reaction. All the tested strains gave negative results. The limit of detection for S. fonticola using the gyrB gene was 100 copies per PCR reaction. This TaqMan PCR assay provided a specific, rapid, and sensitive method to detect S. fonticola based on its gyrB gene.

Fluorescence sensing and device fabrication with luminescent metal-organic frameworks.

Metal-organic frameworks (MOFs) are a novel class of hybrid porous multi-functional materials consisting of metal ions/clusters and organic ligands. MOFs have exclusive benefits due to their tunable structure and diverse properties. Luminescent MOFs (LMOFs) exhibit both porosity and light emission. They display abundant host and guest responses, making them conducive to sensing. Currently, LMOF sensing research is gaining more depth, with attention given to their device and practical applications. This work reviews recent advancements and device applications of LMOFs as chemical sensors toward ions, volatile organic compounds, biomolecules, and environmental toxins. Furthermore, the detection mechanism and the correlation between material properties and structure are elaborated. This analysis serves as a valuable reference for the preparation and efficient application of targeted LMOFs.

Clinical study of different prediction models in predicting diabetic nephropathy in patients with type 2 diabetes mellitus.

BACKGROUND: Among older adults, type 2 diabetes mellitus (T2DM) is widely recognized as one of the most prevalent diseases. Diabetic nephropathy (DN) is a frequent complication of DM, mainly characterized by renal microvascular damage. Early detection, aggressive prevention, and cure of DN are key to improving prognosis. Establishing a diagnostic and predictive model for DN is crucial in auxiliary diagnosis. AIM: To investigate the factors that impact T2DM complicated with DN and utilize this information to develop a predictive model. METHODS: The clinical data of 210 patients diagnosed with T2DM and admitted to the First People's Hospital of Wenling between August 2019 and August 2022 were retrospectively analyzed. According to whether the patients had DN, they were divided into the DN group (complicated with DN) and the non-DN group (without DN). Multivariate logistic regression analysis was used to explore factors affecting DN in patients with T2DM. The data were randomly split into a training set (n = 147) and a test set (n = 63) in a 7:3 ratio using a random function. The training set was used to construct the nomogram, decision tree, and random forest models, and the test set was used to evaluate the prediction performance of the model by comparing the sensitivity, specificity, accuracy, recall, precision, and area under the receiver operating characteristic curve. RESULTS: Among the 210 patients with T2DM, 74 (35.34%) had DN. The validation dataset showed that the accuracies of the nomogram, decision tree, and random forest models in predicting DN in patients with T2DM were 0.746, 0.714, and 0.730, respectively. The sensitivities were 0.710, 0.710, and 0.806, respectively; the specificities were 0.844, 0.875, and 0.844, respectively; the area under the receiver operating characteristic curve (AUC) of the patients were 0.811, 0.735, and 0.850, respectively. The Delong test results revealed that the AUC values of the decision tree model were lower than those of the random forest and nomogram models (P < 0.05), whereas the difference in AUC values of the random forest and column-line graph models was not statistically significant (P > 0.05). CONCLUSION: Among the three prediction models, random forest performs best and can help identify patients with T2DM at high risk of DN.

A dinuclear CdII cluster-based stable luminescent metal-organic framework for the consecutive and visual detection of H2PO4- and OCN.

Due to their hazard to biological systems, it is urgent to develop materials that can rapidly and sensitively detect the concentration of H2PO4- and OCN- ions. In this work, a new CdII-based luminescent metal-organic framework with the formula [Cd(BTDB)(2,6-BBIP)]n (JXUST-47, H2BTDB = (benzo[c][1,2,5]thiadiazole-4,7-diyl)dibenzoic acid, 2,6-BBIP = 2,6-bis(benzimidazol-1-yl)pyridine) and sql topology was successfully synthesized using a mixed-ligand strategy. JXUST-47 shows good chemical and thermal stability. It also exhibits weak quenching and fluorescence blue shift for H2PO4- and red shift for OCN-, with the detection limits of 0.106 and 0.128 mM, respectively. In addition, considering the demand for H2PO4- and OCN- ion detection, by combining this with the functions of a smartphone, the chroma of photographs have been used to realize the consecutive visual detection of the concentration of these ions.

Reversible single-crystal-to-single-crystal transition in Gd(III) metal-organic frameworks induced by heat and solvents with a significant magnetocaloric effect.

The design and synthesis of a Gd(III) metal-organic framework with the formula [Gd4(BTDI)3(DMF)4]n (JXUST-40, H4BTDI = 5,5'-(benzo[c][1,2,5]thiadiazole-4,7-diyl)diisophthalic acid) are reported hererin. Interestingly, a reversible single-crystal-to-single-crystal transition between JXUST-40 and {[Gd4(BTDI)3(H2O)4]·6H2O}n (JXUST-40a) was achieved under the stimulation of heat and solvents. Both JXUST-40 and JXUST-40a exhibited good stability when soaked in common solvents and aqueous solutions with pH values of 1-12. Magnetic studies showed that JXUST-40a has a larger magnetocaloric effect with -ΔSmaxm = 26.65 J kg-1 K-1 at 2 K and 7 T than JXUST-40 due to its larger magnetic density. Structural analyses indicated that the coordinated solvent molecules play a crucial role in the coordination environment around the Gd(III) ions and the change in the framework, ultimately leading to the changes in the pore size and magnetism between JXUST-40 and JXUST-40a. In addition, both isomorphic [Dy4(BTDI)3(DMF)4]n (JXUST-41) and {[Dy4(BTDI)3(H2O)4]·6H2O}n (JXUST-41a) displayed slow magnetic relaxation behaviour.

Polycomb Repressive Complex 1.1 Component, BCOR, Promotes Syncytiotrophoblast Differentiation in Mice and Humans.

Early defects in placenta development are thought to underlie a range of adverse pregnancy conditions including miscarriage, fetal growth abnormalities, preeclampsia, and stillbirth. Differentiating trophoblast stem cells undergo a choreographed allocation of syncytiotrophoblast and extravillous trophoblast cells in response to signaling cues from the developing fetus and the uterine environment. The expression and activity of transcription factors and chromatin modifying enzymes change during differentiation to appropriately reshape the chromatin landscape in each cell type. We have previously found in mice that extraembryonic loss of BCOR, a conserved component of the epigenetic silencing complex Polycomb Repressive Complex 1.1 (PRC1.1), leads to a reduced labyrinth and expanded trophoblast giant cell population in the placenta. Molecular analysis of wild-type and BCOR loss-of-function male and female placentas by RNA-seq identified gene expression changes as early as E6.5. We found that BCOR is required to down regulate stem cell genes and repress factors that promote alternate lineages which leads to reduced levels of syncytiotrophoblasts. ChIP-seq experiments identified a number of directly bound functional targets including Pdgfa and Wnt7b . In humans, BCOR is mutated in X-linked syndromes involving fetal growth restriction and females with a heterozygous null mutation in BCOR can experience recurrent miscarriages. To establish a direct role for BCOR in human placental development, we used CRISPR/Cas9 to knockout BCOR in male (CT29) and female (CT30) human trophoblast stem cells. Mutant cell lines retained capacity for induced differentiation into syncytiotrophoblast and extravillous trophoblasts and exhibited minimal changes in gene expression. However, in 3D cell culture using trophoblast organoid media, BCOR knockout lines had significantly altered gene expression including homologs of stem cell genes upregulated in Bcor knockout mice. CUT&RUN experiments in self-renewing and 3D cell culture identified genes directly bound by BCOR. Single cell profiling of wild type, knockout, and a P85L pathogenic knock-in BCOR mutation showed a reduced capacity to differentiate into syncytiotrophoblasts after four days of differentiation. Together, these results suggest that BCOR is a conserved regulator of trophoblast development that represses stem cell genes during differentiation and maintains lineage fidelity by repressing genes that promote alternate cell fates.