A dual-porous, three-dimensional, metal–organic framework Zn4O(2,6-NDC)(BTB)4/3 (MOF-205, BET = 4200 m2/g) has been synthesized using microwave power as an alternative energy source for the first ...time, and its catalytic activity has been exploited for CO2–epoxide coupling reactions to produce five-membered cyclic carbonates under solvent-free conditions. Microwave synthesis was performed at different time intervals to reveal the formation of the crystals. Significant conversion of various epoxides was obtained at room temperature, with excellent selectivity toward the desired five-membered cyclic carbonates. The importance of the dual porosity and the synergistic effect of quaternary ammonium salts on efficiently catalyzed CO2 conversion were investigated using various experimental and physicochemical characterization techniques, and the results were compared with those of the solvothermally synthesized MOF-205 sample. On the basis of literature and experimental inferences, a rationalized mechanism mediated by the zinc center of MOF-205 for the CO2–epoxide cycloaddition reaction has been proposed.
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•Multi-variate metal organic frameworks by incorporating different ligands.•MOF-5-MIX was found to be catalytically efficient toward the coupling reaction.•Presence of the OH ...functional group accelerating the epoxide ring opening.•MOF-5-MIX demonstrates excellent recyclability.
The synthesis of heterogeneous catalysts with multiple active sites for the synthesis of cyclic carbonate from epoxide and CO2 has long been of great interest. Herein, we synthesized zinc metal-based multi-variate metal organic frameworks (MOFs) by incorporating different functionalized ligands into a single framework. Chemically functionalized 1,4-benzenedicarboxylic acid (BDC) in the forms of 2-aminoterephthalic acid (NH2-BDC) and 2-hydroxyterephthalic acid (OH-BDC) were combined to form different sets of multi-variate MOFs. The heterogeneous multi-variate MOF, denoted as MOF-5-MIX, was found to be catalytically efficient toward the coupling reaction between epoxide and CO2 under moderate reaction conditions, with >99% selectivity toward cyclic carbonates under solvent-free conditions in a gas-liquid-solid reactor. Herein we demonstrated the advantages of functional groups in the multi-variate framework, which could provide efficient synergistic sites in accelerating the epoxide-CO2 cycloaddition reaction. The MOF-5-MIX exhibited higher catalytic activity (ECH conversion: 98%, temperature: 50 °C, time: 6 h) than other prepared catalysts (MOF-5, MOF-5-NH2, MOF-5-OH). MOF-5-MIX is a promising catalyst system which is capable to catalyze the synthesize of cyclic carbonates under high reaction temperatures (120 °C) without the presence of TBAB as well as at the lower reaction temperature (50 °C) in the presence of TBAB. Comparison with recently reported MOF catalysts revealed that MOF-5-MIX had better catalytic potential. In addition, a plausible reaction mechanism for the MOF-5-MIX catalyzed reaction is proposed that is supported by previously reported experimental results.
A facile approach for modifying the UiO‐66‐NH2 metal–organic framework by incorporating imidazolium‐based ionic liquids (ILs) to form bifunctional heterogeneous catalysts for the cycloaddition of ...epoxides to CO2 is reported. Methylimidazolium‐ and methylbenzimidazolium‐based IL units (ILA and ILB, respectively) were introduced into the pore walls of the UiO‐66‐NH2 framework through a condensation reaction to generate ILA@U6N and ILB@U6N catalysts, respectively. The resultant heterogeneous catalysts, especially ILA@U6N, exhibited excellent CO2 adsorption capability, which makes them effective for cycloaddition reactions producing cyclic carbonates under mild reaction conditions in the absence of any cocatalyst or solvent. The significantly enhanced activity of ILA@U6N is attributed to the synergism between the coordinately unsaturated Lewis acidic Zr4+ centers and Br− ions in the bifunctional heterogeneous catalysts. The size effect of the ILs on coupling between the epoxide and CO2 was also studied for ILA@U6N and ILB@U6N. A periodic DFT study was performed to provide evidence of possible intermediates, transition states, and pathways, as well as to gain deeper insight into the mechanism of the ILA@U6N‐catalyzed cycloaddition reaction between epichlorohydrin and CO2.
IL@MOF catalysts: Metal–organic framework (MOF) UiO‐66‐NH2 is modified by incorporating imidazolium‐based ionic liquids (ILs) into the pore walls to form heterogeneous catalyst for cycloaddition of epoxides to CO2 under mild conditions in the absence of cocatalyst or solvent. The enhanced catalytic activity is attributed to synergism between the coordinately unsaturated Lewis acidic Zr4+ centers and Br− ions in the bifunctional catalysts.
Chlorogenic acid (CGA), an ester of caffeic acid and quinic acid, is among the phenolic acid compounds which can be naturally found in green coffee extract and tea. CGA has been studied since it ...displays significant pharmacological properties. The aim of this study was to investigate the effects of CGA on cognitive function and neuroprotection including its mechanisms in the hippocampus following transient forebrain ischemia in gerbils. Memory and learning following the ischemia was investigated by eight-arm radial maze and passive avoidance tests. Neuroprotection was examined by immunohistochemistry for neuronal nuclei-specific protein and Fluoro-Jade B histofluorescence staining. For mechanisms of the neuroprotection, alterations in copper, zinc-superoxide dismutase (SOD1), SOD2 as antioxidant enzymes, dihydroethidium and 4-hydroxy-2-nonenal as indicators for oxidative stress, and anti-inflammatory cytokines (interleukin (IL)-4 and IL-13) and pro-inflammatory cytokines (tumor necrosis factor α (TNF-α) and IL-2) were examined by Western blotting and/or immunohistochemistry. As a result, pretreatment with 30 mg/kg CGA attenuated cognitive impairment and displayed a neuroprotective effect against transient forebrain ischemia (TFI). In Western blotting, the expression levels of SOD2 and IL-4 were increased due to pretreatment with CGA and, furthermore, 4-HNE production and IL-4 expressions were inhibited by CGA pretreatment. Additionally, pretreated CGA enhanced antioxidant enzymes and anti-inflammatory cytokines and, in contrast, attenuated oxidative stress and pro-inflammatory cytokine expression. Based on these results, we suggest that CGA can be a useful neuroprotective material against ischemia-reperfusion injury due to its antioxidant and anti-inflammatory efficacies.
A facile approach for modifying the UiO-66-NH
metal-organic framework by incorporating imidazolium-based ionic liquids (ILs) to form bifunctional heterogeneous catalysts for the cycloaddition of ...epoxides to CO
is reported. Methylimidazolium- and methylbenzimidazolium-based IL units (ILA and ILB, respectively) were introduced into the pore walls of the UiO-66-NH
framework through a condensation reaction to generate ILA@U6N and ILB@U6N catalysts, respectively. The resultant heterogeneous catalysts, especially ILA@U6N, exhibited excellent CO
adsorption capability, which makes them effective for cycloaddition reactions producing cyclic carbonates under mild reaction conditions in the absence of any cocatalyst or solvent. The significantly enhanced activity of ILA@U6N is attributed to the synergism between the coordinately unsaturated Lewis acidic Zr
centers and Br
ions in the bifunctional heterogeneous catalysts. The size effect of the ILs on coupling between the epoxide and CO
was also studied for ILA@U6N and ILB@U6N. A periodic DFT study was performed to provide evidence of possible intermediates, transition states, and pathways, as well as to gain deeper insight into the mechanism of the ILA@U6N-catalyzed cycloaddition reaction between epichlorohydrin and CO
.
The diagnostic yield of endomyocardial biopsy in cardiac sarcoidosis (CS) is quite low because of the patchy involvement, and for the diagnosis of CS, existing guidelines required histological ...confirmation. Therefore, especially for isolated CS, diagnosis consistent with the guidelines cannot be made in a large number of patients. With recent developments in imaging modalities such as cardiac magnetic resonance and 18-fluorodeoxyglucose positron emission tomography, diagnosing CS has become easier and diagnostic criteria for CS not compulsorily requiring histological confirmation have been suggested. Despite significant advances in diagnostic tools, large-scale studies that can guide treatment plans are still lacking, and treatment has relied on the experience accumulated over the past years and the consensus of experts. However, opinions vary, depending on the situation, which is quite puzzling for the physician treating CS. Moreover, with the advent of new immunosuppressant agents, these new drugs have been applied under the assumption that the effect of immunosuppression is not much different from that of other well-known autoimmune diseases that require immunosuppression. However, we should wait to see the beneficial effects of these new immunosuppressants before we attempt to apply these agents in our clinical practice. This review summarises the widely used diagnostic criteria, current diagnostic modalities and recommended treatments for sarcoidosis. We have added our opinions on selecting or modifying diagnostic and treatment plans from the diverse current recommendations.
Background
There is a close link between
Fusobacterium nucleatum
and colorectal cancer (CRC) tumorigenesis and chemoresistance. However, the genetic characteristics and clinical significance of CRC ...related with
F. nucleatum
remains unclear. This study evaluated the relationship between
F. nucleatum
, pathway mutation, and patient prognosis.
Methods
Fusobacterium nucleatum
amount in the tumor tissue and adjacent normal tissue were measured by quantitative polymerase chain reaction in adjuvant (
N
= 128) and metastatic (
N
= 118) cohorts. Patients were divided into binary (
F. nucleatum
-high and
F. nucleatum
-low) according to
F. nucleatum
amount. Targeted next-generation sequencing of 40 genes included in the 5 critical pathways (WNT, P53, RTK-RAS, PI3 K, and TGF-β) was performed in the adjuvant cohort.
Results
Patients with MSI-H and CIMP-H had higher amount of
F. nucleatum
in tumor tissue.
Fusobacterium nucleatum
-high patients had higher rates of transition mutation and C to T (G to A) nucleotide change regardless of MSI status. In addition, mutation rate of
AMER1
and
ATM
genes, and TGF-β pathway was higher in
F. nucleatum
-high patients.
Fusobacterium nucleatum
-high was associated with poor overall survival (OS) in the palliative cohort (26.4 vs. 30.7 months,
p
= 0.042). Multivariate analysis revealed
F. nucleatum
-high as an independent negative prognostic factor for OS adjusted hazard ratio of 1.69 (95% confidence interval 1.04–2.75),
p
= 0.034. However,
F. nucleatum
amount was not associated with recurrence in the adjuvant cohort.
Conclusions
F. nucleatum
-high was associated with poor survival in metastatic CRC. In addition, we identified mutational characteristics of colorectal cancer according to
F. nucleatum
amount.
This study investigated the clinical value of interleukin-6 (IL-6), pentraxin 3 (PTX3), and procalcitonin (PCT) in patients with sepsis and septic shock diagnosed according to the Third International ...Consensus Definitions for Sepsis and Septic Shock (Sepsis-3).
Serum levels of IL-6, PTX3, and PCT were measured in 142 enrolled subjects (51 with sepsis, 46 with septic shock, and 45 as controls). Follow-up IL-6 and PTX3 levels were measured in patients with initial septic shock within 24 h of hospital discharge. Optimal cut-off values were determined for sepsis and septic shock, and prognostic values were evaluated.
Serum IL-6 levels could discriminate sepsis (area under the curve AUC, 0.83-0.94, P < 0.001; cut-off value, 52.60 pg/mL, 80.4% sensitivity, 88.9% specificity) from controls and could distinguish septic shock (AUC, 0.71-0.89; cut-off value, 348.92 pg/mL, 76.1% sensitivity, 78.4% specificity) from sepsis. Twenty-eight-day mortality was significantly higher in the group with high IL-6 (≥ 348.92 pg/mL) than in the group with low IL-6 (< 348.92 pg/mL) (P = 0.008). IL-6 was an independent risk factor for 28-day mortality among overall patients (hazard ratio, 1.0004; 95% confidence interval, 1.0003-1.0005; p = 0.024). In septic shock patients, both the initial and follow-up PTX3 levels were consistently significantly higher in patients who died than in those who recovered (initial p = 0.004; follow-up P < 0.001).
The diagnostic and prognostic value of IL-6 was superior to those of PTX3 and PCT for sepsis and septic shock.
We synthesized two new adenine-based Zn(II)/Cd(II) metal–organic frameworks (MOFs), namely, Zn2(H2O)(stdb)2(5H-Ade)(9H-Ade)2 n (PNU-21) and Cd2(Hstdb)(stdb)(8H-Ade)(Ade) n (PNU-22), containing ...auxiliary dicarboxylate ligand (stdb = 4,4′-stilbenedicarboxylate). Both MOFs were characterized by multiple analytical techniques such as single-crystal X-ray diffraction (SXRD), powder X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, scanning electron microscopy, as well as temperature program desorption and Brunauer–Emmett–Teller measurements. Both MOFs were structurally robust and possessed unsaturated Lewis acidic metal centers Zn(II) and Cd(II) and free basic N atoms of adenine molecules. They were used as heterogeneous catalysts for the fixation of CO2 into five-membered cyclic carbonates. Significant conversion of epichlorohydrin (ECH) was attained at a low CO2 pressure (0.4 MPa) and moderate catalyst (0.6 mol %)/cocatalyst (0.3 mol %) amounts, with over 99% selectivity toward the ECH carbonate. They showed comparable or even higher catalytic activity than other previously reported MOFs. Because of high thermal stability and robust architecture of PNU-21/PNU-22, both catalysts could be reused with simple separation up to five successive cycles without any considerable loss of their catalytic activity. Densely populated acidic and basic sites in both Zn(II)/Cd(II) MOFs facilitated the conversion of ECH to ECH carbonate in high yields. The reaction mechanism of the cycloaddition reaction between ECH and CO2 is described by possible intermediates, transition states, and pathways, from the density functional theory calculation in correlation with the SXRD structure of PNU-21.
We present the results of simultaneous multifrequency imaging observations at 22, 43, 86, and 129 GHz of OJ 287. We used the Korean Very Long Baseline Interferometry Network as part of the ...Interferometric Monitoring of Gamma-ray Bright active galactic nuclei (iMOGABA). The iMOGABA observations were performed during 31 epochs from 2013 January 16 to 2016 December 28. We also used 15 GHz OVRO and 225 GHz SMA flux density data. We analyzed four flux enhancements in the light curves. The estimated timescales of three flux enhancements were similar with timescales of ∼50 days at two frequencies. A fourth flux enhancement had a variability timescale approximately twice as long. We found that 225 GHz enhancements led the 15 GHz enhancements by a range of 7-30 days in the time delay analysis. We found the fractional variability did not change with frequency between 43 and 86 GHz. We could reliably measure the turnover frequency, , of the core of the source in three epochs. This was measured to be in a range from 27 to 50 GHz and a flux density at the turnover frequency, , ranging from 3 to 6 Jy. The derived SSA magnetic fields, , are in a range from 0.157 0.104 to 0.255 0.146 mG. We estimated the equipartition magnetic field strengths to be in a range from 0.95 0.15 to 1.93 0.30 mG. The equipartition magnetic field strengths are up to a factor of 10 higher than the values of . We conclude that the downstream jet may be more particle energy dominated.
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