Correction: Tubular metal organic frameworks from the curvature of 2D-honeycombed metal coordination.

Correction for 'Tubular metal organic frameworks from the curvature of 2D-honeycombed metal coordination' by Junhui Bao et al., Dalton Trans., 2020, 49, 2403-2406, https://doi.org/10.1039/C9DT04668B.

Coplanar binuclear group 4 post-metallocene complexes supported by chelating µ-(σ2-aryl) ligands: characterisation and olefin polymerisation catalysis.

The report concerns expansion of the previously developed M-[O,N,C] [pyridine-2-phenolate-6-(σ-aryl)] catalyst system into rigid, coplanar bimetallic assemblies, which afford metal-metal distances that are predetermined yet amenable for cooperativity, as well as locked-in "syn" orientation of binding sites that offer the same direction of access for substrates. The binuclear complexes are generated in a regioselective manner to yield para hydrogen atoms (not ortho) at the central µ-aryl moiety, and have been characterised by multinuclear NMR spectroscopy. The "anti" (showing opposite directions of access) and mononuclear analogues have also been prepared for comparison purposes. Six syn-type bimetallic derivatives of Ti, Zr and Hf have been characterised by X-ray crystallography, to reveal metal-metal separations of 6.3-6.7 Å. For ethylene and ethylene/1-octene polymerisation reactions in conjunction with trityl borate, the syn-Ti2 catalysts display superior efficiencies and produced polymers with higher Mw values than for the anti and mono-Ti congeners, thus indicating the possibility of favourable enchainment interactions and cooperative reactivity.

Cooperativity in Shape-Persistent Bis-(Zn-salphen) Catalysts for Efficient Cyclic Carbonate Synthesis under Mild Conditions.

A series of conformationally rigid (Zn-salphen)2 complexes with a planar bridging component (xanthene or dibenzofuran) are described. Conformational changes for these assemblies are essentially limited to the axial rotation of the Zn-salphen moieties; however, such geometric constraints crucially permit the subtle tuning of the intermetallic separation and geometry to potentially enhance catalytic activity (and cooperative effects). The complexes have been investigated as catalysts in conjunction with nBu4NI for the coupling of CO2 with epoxides. Selected dibenzofuran derivatives are significantly more active for the production of cyclic carbonate than their mononuclear analogues under identical conditions and concentrations of Zn sites. High initial turnover frequencies (up to 29 000 h-1; 14 500 h-1 per Zn, using 10 bar of CO2 at 95 °C) and excellent efficiencies under mild conditions (1 bar of CO2 at 55 °C) have been achieved. Kinetic studies using in situ (ReactIR) spectroscopy and density functional theory calculations have been performed, which reveal the existence of an intramolecular rate component and a preference for the cooperative pathway as well as transition states that depict the Zn sites operating in tandem. Taken together, these results provide strong evidence of cooperative reactivity in these Zn2 catalysts.

Long-term exposure to air pollution and lung function among children in China: Association and effect modification.

Background: Children are vulnerable to the respiratory effects of air pollution, and their lung function has been associated with long-term exposure to low air pollution level in developed countries. However, the impact of contemporary air pollution level in developing countries as a result of recent efforts to improve air quality on children's lung function is less understood. Methods: We obtained a cross-sectional sample of 617 schoolchildren living in three differently polluted areas in Anhui province, China. 2-year average concentrations of air pollutants at the year of spirometry and the previous year (2017-2018) obtained from district-level air monitoring stations were used to characterize long-term exposure. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and forced expiratory flow between 25 and 75% of FVC (FEF25-75) were determined under strict quality control. Multivariable regression was employed to evaluate the associations between air pollution level and lung function parameters, overall and by demographic characteristics, lifestyle, and vitamin D that was determined by liquid chromatography tandem mass spectrometry. Results: Mean concentration of fine particulate matter was 44.7 µg/m3, which is slightly above the interim target 1 standard of the World Health Organization. After adjusting for confounders, FVC, FEV1, and FEF25-75 showed inverse trends with increasing air pollution levels, with children in high exposure group exhibiting 87.9 [95% confidence interval (CI): 9.5, 166.4] mL decrement in FEV1 and 195.3 (95% CI: 30.5, 360.1) mL/s decrement in FEF25-75 compared with those in low exposure group. Additionally, the above negative associations were more pronounced among those who were younger, girls, not exposed to secondhand smoke, non-overweight, physically inactive, or vitamin D deficient. Conclusions: Our study suggests that long-term exposure to relatively high air pollution was associated with impaired lung function in children. More stringent pollution control measures and intervention strategies accounting for effect modification are needed for vulnerable populations in China and other developing countries.

Precisely Controlled Multidimensional Covalent Frameworks: Polymerization of Supramolecular Colloids.

Rapid and selective removal of micropollutants from water is important for the reuse of water resources. Despite hollow frameworks with specific functionalized porous walls for the selective adsorption based on a series of interactions, tailoring a stable shape of nanometer- and micrometer-sized architectures for the removal of specific pollutants remains a challenge. Here, exactly controlled sheets, tubes, and spherical frameworks were presented from the crosslinking of supramolecular colloids in polar solvents. The frameworks strongly depended on the architecture of original supramolecular colloids. As the entropy of colloids increased, the initial laminar framework rolled up into hollow tubules, and then further curled into hollow spheres. These shape-persistent frameworks showed unprecedented selectivity as well as specific recognition for the shape of pollutants, thus contributing to efficient pollutant separation.

The role of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-3 in esophageal squamous cell carcinoma.

6-phosphofructo-kinase-2/fructose diphosphatase-2 isoenzyme 3 (PFKFB3) is closely related to the growth of many types of cancer cells. Glycolysis not only provides Adenosine triphosphate for the growth of tumor cells, but also protects them from acid products, which is beneficial to the invasion and metastasis of tumors. However, PFKFB3 expression in esophageal squamous cell carcinoma (ESCC) has been scarcely reported. In this study, the role of PFKFB3 was studied in 120 ESCC samples using immunohistochemistry technique (IHC), western blotting, and reverse transcriptase-polymerase chain reaction (RT-PCR). Both PFKFB3 protein and gene expression in ESCC tissues were significantly higher than in adjacent non-tumor tissues (P < .05). Single factor analysis showed that both PFKFB3 protein and gene expression are related to infiltration depth, stage, tumor metastasis, and the degree of tumor differentiation in ESCC. Multifactor Cox survival analysis revealed that PFKFB3 protein expression, tumor location, tumor metastasis, tumor differentiation degree, and tumor stage were independent factors affecting the overall survival of postoperative patients. Multivariate Cox survival analysis showed that PFKFB3 mRNA has a good performance for predicting 3-year survival of patients with ESCC 0.89 (0.79-0.99), with a sensitivity of 0.85 and specificity of 0.77. Encouragingly, the sensitivity and specificity of PFKFB3 in the diagnosis of early ESCC (stage I and stage II) can reach 87.8% and 91.5%. In conclusion, high PFKFB3 protein and gene expression may be associated with the occurrence, development, and prognosis of ESCC. PFKFB3 could be used to help develop new therapeutic and diagnostic strategies for ESCC patients.

MicroRNA-490-3p suppresses hepatocellular carcinoma cell proliferation and migration by targeting the aurora kinase A gene (AURKA).

INTRODUCTION: Hepatocellular carcinoma (HCC) is the most common and prevalent cancer type among liver cancers. In this study, expression of miR-490-3p and aurora kinase A gene (AURKA) was investigated in HCC. Additionally, we explored the microRNA (miR)-490-3p/AURKA relationship as well as the influence on HCC cell proliferation and migration. MATERIAL AND METHODS: The dual luciferase reporter assay serves to verify the target relationship between miR-490-3p and AURKA. miR-490-3p mimics, AURKA siRNA and AURKA cDNA, were transfected into HCC cells. Quantitative real-time polymerase chain reaction and western blot were chosen for examining the relative expression of miR-490-3p and AURKA in HCC tissues, adjacent tissues, HCC cells and normal cells. The study detected the proliferation of HCC cells with the application of MTT assay and colony formation assay. Transwell assay was applied for the observation of migration, and wound healing assay for invasion. RESULTS: The experiment results showed that miR-490-3p expression was down-regulated and AURKA expression was up-regulated in HCC cells and tissues. AURKA was the target gene of miR-490-3p and overexpression of miR-490-3p could inhibit the expression of AURKA in HCC cells. miR-490-3p overexpression could inhibit HCC cell migration and invasion, while AURKA promoted HCC cell migration. All experiment results indicated that miR-490-3p was low-expressed while AURKA was over-expressed in HCC cells and tissues compared to normal liver cells and tissues. CONCLUSIONS: miR-490-3p could down-regulate the expression of AURKA, thus suppressing the proliferation and migration of HCC cells.

Tubular metal organic frameworks from the curvature of 2D-honeycombed metal coordination.

A tubular MOF with adequate active sites is prepared by the bending of metal-coordinated honeycombed frameworks via titration and shows fast catalytic kinetics with lower catalytic loading for CO2 conversion. The TON is observed to be 2300 and the corresponding TOF of up to 173 h-1 is achieved for the first time.

Two-Dimensional Cationic Networks and Their Spherical Curvature with Tunable Opening-Closing.

Despite many cationic nanomaterials that have been developed for efficient adsorption of anionic pollutants, tailoring a stable shape with denser cations on the surface for advanced removal capability remains challenging. Here, a new strategy is presented for fabricating two-dimensional (2D) cationic laminas and their curvature based on cross-linking of 2D supramolecular networks from hydrogen-bonded trimesic amide derivatives. Owing to the distribution of most cations on the surface, two cationic nanostructures from cross-linking of supramolecular networks show fast sorption kinetics for anionic pollutants. Notably, the removal capacity of the capsule-like curvature adsorbent is more than twice that of lamina  adsorbent for sufficient space around cationic sites in hollow aperture. Moreover, the capsule-like adsorbent is triggered to open and spontaneously release the adsorbed pollutants upon the addition of halogen anions, which can be recovered by subsequent dialysis. Strategy of a capsule-like pocket with tunable opening-closing will provide a new insight for storage and adsorption.

Observation of the effect of targeted therapy of 64-slice spiral CT combined with cryoablation for liver cancer.

AIM: To observe the effect of targeted therapy with 64-slice spiral computed tomography (CT) combined with cryoablation for liver cancer. METHODS: A total of 124 patients (142 tumors) were enrolled into this study. According to the use of dual-slice spiral CT or 64-slice spiral CT as a guide technology, patients were divided into two groups: dual-slice group (n = 56, 65 tumors) and 64-slice group (n = 8, 77 tumors). All patients were accepted and received targeted therapy by an argon-helium superconducting surgery system. The guided scan times of the two groups was recorded and compared. In the two groups, the lesion ice coverage in diameter of ≥ 3 cm and < 3 cm were recorded, and freezing effective rate was compared. Hepatic perfusion values [hepatic artery perfusion (HAP), portal vein perfusion (PVP), and the hepatic arterial perfusion index (HAPI)] of tumor tissues, adjacent tissues and normal liver tissues at preoperative and postoperative four weeks in the two groups were compared. Local tumor changes were recorded and efficiency was compared at four weeks post-operation. Adverse events were recorded and compared between the two groups, including fever, pain, frostbite, nausea, vomiting, pleural effusion and abdominal bleeding. RESULTS: Guided scan times in the dual-slice group was longer than that in the 64-slice group (t = 11.445, P = 0.000). The freezing effective rate for tumors < 3 cm in diameter in the dual-slice group (81.58%) was lower than that in the 64-slice group (92.86%) (χ2 = 5.707, P = 0.017). The HAP and HAPI of tumor tissues were lower at four weeks post-treatment than at pre-treatment in both groups (all P < 0.05), and those in the 64-slice group were lower than that in the dual-slice group (all P < 0.05). HAP and PVP were lower and HAPI was higher in tumor adjacent tissues at post-treatment than at pre-treatment (all P < 0.05). Furthermore, the treatment effect and therapeutic efficacy in the dual-slice group were lower than the 64-slice group at four weeks post-treatment (all P < 0.05). Moreover, pleural effusion and intraperitoneal hemorrhage occurred in patients in the dual-slice group, while no complications occurred in the 64-slice group (all P < 0.05). CONCLUSION: 64-slice spiral CT applied with cryoablation in targeted therapy for liver cancer can achieve a safe and effective freezing treatment, so it is worth being used.

Assessment of 64-slice spiral computed tomography with perfusion weighted imaging in the early diagnosis of ground-glass opacity lung cancer.

PURPOSE: To evaluate the use of the 64-slice spiral computed tomography (CT) with perfusion-weighted imaging in the early diagnosis of ground-glass opacity lung cancers. METHODS: 412 patients with ground-glass opacities found by conventional CT scan in our hospital, and deemed highly suspected of being lung cancers, were enrolled in the study between February of 2012 and February of 2015. Sixty four-slice spiral CTs with perfusion-weighted imaging were carried out on all patients, and the latest nodular contrast analysis software, MPR2D, 3D reconstruction technology, MIP technology and perfusion scanning technology were used to analyze lesion types, density, blood supply, peripheral signals, doubling time and tissue perfusion characteristics. This was repeated after one month, and the final pathologic diagnosis was used as a reference. RESULTS: There were 350 (84.95%) patients who were ultimately diagnosed with lung cancer. The main lesion type of lung cancer was quasi-circular, the average CT density was 56.7±5.4 HU, bronchial arterial enhancement increased in the nodule, peripheral signals were mainly irregular burrs, and the average doubling time was 1.2±0.3 s. Comparing these parameters with the ones in the non-cancer group, the differences found were with statistical significance (p<0.05). Importantly, tissue perfusion parameters of blood flow, blood volume, mean transit time and permeability surface in the lung cancer group were all significantly higher than those in non-cancer group (p<0.05). CONCLUSION: From the findings in our study, we propose that 64-slice spiral CT with perfusion-weighted imaging can be used to diagnose ground-glass opacity lung cancer early, by taking into account variables such as lesion type, density, blood supply, peripheral signals, doubling time and tissue perfusion characteristics.