The Redox Coupling Effect in a Photocatalytic RuII -PdII Cage with TTF Guest as Electron Relay Mediator for Visible-Light Hydrogen-Evolving Promotion.

A nanocage coupling effect from a redox RuII -PdII metal-organic cage (MOC-16) is demonstrated for efficient photochemical H2 production by virtue of redox-guest modulation of the photo-induced electron transfer (PET) process. Through coupling with photoredox cycle of MOC-16, tetrathiafulvalene (TTF) guests act as electron relay mediator to improve the overall electron transfer efficiency in the host-guest system in a long-time scale, leading to significant promotion of visible-light driven H2 evolution. By contrast, the presence of larger TTF-derivatives in bulk solution without host-guest interactions results in interference with PET process of MOC-16, leading to inefficient H2 evolution. Such interaction provides an example to understand the interplay between the redox-active nanocage and guest for optimization of redox events and photocatalytic activities in a confined chemical nanoenvironment.

Design and Enantioresolution of Homochiral Fe(II)-Pd(II) Coordination Cages from Stereolabile Metalloligands: Stereochemical Stability and Enantioselective Separation.

The stereochemistry of chiral-at-metal complexes is much more abundant, albeit complicated, than chiral-at-carbon compounds, but how to make use of stereolabile metal-centers remains a formidable challenge due to the highly versatile coordination geometry of metal ions and racemization/epimerization problem. We demonstrate herein a stepwise assembly of configurationally stable [Pd6(FeL3)8]28+ (Δ/Λ-MOCs-42) homochiral octahedral cages from unstable D3-symmetry tris-chelate-Fe type metalloligands via strong face-directed stereochemical coupling and facile chiral-induced resolution processes based on stereodifferentiating host-guest dynamics. Kinetic studies reveal that the dissociation rate of MOC-42 cages is 100-fold slower than that of Fe-metalloligands and the racemization is effectively inhibited, making the cages retain their chirality over extended periods of time (>5 months) at room temperature. Recyclable enantioseparation of atropisomeric compounds has been successfully achieved, giving up to 88% ee.

Dual Heterogeneous Catalyst Pd-Au@Mn(II)-MOF for One-Pot Tandem Synthesis of Imines from Alcohols and Amines.

A new Mn(II) metal-organic framework (MOF) 1 was synthesized by the combination of 4,4,4-trifluoro-1-(4-(pyridin-4-yl)phenyl)butane-1,3-dione (L) and Mn(OAc)2 in solution. 1 features a threefold-interpenetrating NbO net containing honeycomb-like channels, in which the opposite Mn(II)···Mn(II) distance is 23.5075(10) Å. Furthermore, 1 can be an ideal platform to support Pd-Au bimetallic alloy nanoparticles to generate a composite catalytic system of Pd-Au@Mn(II)-MOF (2). 2 can be a highly active bifunctional heterogeneous catalyst for the one-pot tandem synthesis of imines from benzyl alcohols and anilines and from benzyl alcohols and benzylamines.

Au@Cu(II)-MOF: Highly Efficient Bifunctional Heterogeneous Catalyst for Successive Oxidation-Condensation Reactions.

A new composite Au@Cu(II)-MOF catalyst has been synthesized via solution impregnation and full characterized by HRTEM, SEM-EDS, XRD, gas adsorption-desorption, XPS, and ICP analysis. It has been shown here that the Cu(II)-framework can be a useful platform to stabilize and support gold nanoparticles (Au NPs). The obtained Au@Cu(II)-MOF exhibits a bifunctional catalytic behavior and is able to promote selective aerobic benzyl alcohol oxidation-Knoevenagel condensation in a stepwise way.

Pd@Cu(II)-MOF-Catalyzed Aerobic Oxidation of Benzylic Alcohols in Air with High Conversion and Selectivity.

A new 3D porous Cu(II)-MOF (1) was synthesized based on a ditopic pyridyl substituted diketonate ligand and Cu(OAc)2 in solution, and it features a 3D NbO motif which is determined by the X-ray crystallography. Furthermore, the Pd NPs-loaded hybrid material Pd@Cu(II)-MOF (2) was prepared based on 1 via solution impregnation, and its structure was confirmed by HRTEM, SEM, XRPD, gas adsorption-desorption, and ICP measurement. 2 exhibits excellent catalytic activity (conversion, 93% to >99%) and selectivity (>99% to benzaldehydes) for various benzyl alcohol substrates (benzyl alcohol and its derivatives with electron-withdrawing and electron-donating groups) oxidation reactions in air. In addition, 2 is a typical heterogeneous catalyst, which was confirmed by hot solution leaching experiment, and it can be recycled at least six times without significant loss of its catalytic activity and selectivity.

Wear Performance of Circular Shim against Cam in Engine Bench Test.

Unlike the conventional engine, the valve train of a certain type of engine uses a circular shim instead of a tappet to wear against the cam. To verify the reliability of the shim, an engine bench test was used to test its wear performance. The total duration of the bench test was 1000 h, which was divided into three stages. In each stage, the test equipment was stopped, and the shims were disassembled to observe the surface morphology during the worn process. Precious long-term data were obtained. With the extension of the bench test time, weight loss increased. The maximum weight loss occurs 1000 h after worn, which is about twice that of 350 h. During the wear process, a plastic flow of material was found on the subsurface, and fatigue wear marks occurred on the surface. With an increase in test time, the wear marks increased, leading to material spalling and the formation of pits. The wear mechanism was the mixed wear of fatigue wear and adhesive wear.

Cage-confined photocatalysis for wide-scope unusually selective [2 + 2] cycloaddition through visible-light triplet sensitization.

Light-induced [2 + 2] cycloaddition is the most straightforward way to generate cyclobutanes, which are core structures of many natural products, drugs and bioactive compounds. Despite continuous advances in selective [2 + 2] cycloaddition research, general method for intermolecular photocatalysis of acyclic olefins with specific regio- and diastereoselectivity, for example, syn-head-to-head (syn-HH) cyclobutane derivatives, is still lack of development but highly desired. Herein, we report a cage-confined photocatalytic protocol to enable unusual intermolecular [2 + 2] cycloaddition for α,ß-unsaturated carbonyl compounds. The syn-HH diastereomers are readily generated with diastereoselectivity up to 99%. The cage-catalyst is highly efficient and robust, covering a diverse substrate range with excellent substituent tolerance. The mimic-enzyme catalysis is proposed through a host-guest mediated procedure expedited by aqueous phase transition of reactant and product, where the supramolecular cage effect plays an important role to facilitate substrates inclusion and pre-orientation, offering a promising avenue for general and eco-friendly cycloaddition photocatalysis with special diastereoselectivity.

Artesunate inhibits epithelial-mesenchymal transition in non-small-cell lung cancer (NSCLC) cells by down-regulating the expression of BTBD7.

In recent years, more and more studies have shown that antiparasitic drugs can affect a variety of biological processes of tumor cells and exhibit a potential anti-tumor activity. Although artesunate (ART), a strong bioactive derivative of artemisinin and widely used clinically against malaria, was found to have an inhibitory effect on tumor cells, it is still unclear whether ART could regulate the tumor malignancy of non-small-cell lung cancer (NSCLC) cells. In this study, we aimed to investigate the effect of ART on migration capacities in NSCLC cell lines of A549 and H1975. Cell migration capacity was remarkably inhibited by ART treatment. The expression of epithelial marker E-cadherin was upregulated, while mesenchymal markers (N-cadherin, vimentin and FN1) were inhibited by ART in both protein and mRNA levels in A549 and H1975 cells, indicating ART could suppress the epidermal interstitial transformation (EMT) of NSCLC cells. Meanwhile, BTBD7 was found highly expressed in tumor tissues of NSCLC patient and associated with poor prognosis. The anti-migration activity of ART was found to be mediated by the inhibition of BTBD7 mRNA expression and was reversed when the cells were transiently transfected with the BTBD7 overexpression plasmid. Our study demonstrated the potent anti-migratory activity of ART, thereby presenting it as a new candidate for clinical therapy in NSCLC.

Visible-light triggered selective reduction of nitroarenes to azo compounds catalysed by Ag@organic molecular cages.

Herein, a new Ag nanoparticle (Ag NP) loaded organic molecular cage is reported. The obtained Ag@1 can act as a highly efficient heterogeneous catalyst for the selective reduction of nitroarenes to azo compounds under visible-light irradiation.

Angiogenesis and Hepatic Fibrosis: Western and Chinese Medicine Therapies on the Road.

Hepatic fibrosis is a common feature of almost all chronic liver diseases. Formation of new vessels (angiogenesis) is a process strictly related to the progressive fibrogenesis which leads to cirrhosis and liver cancer. This review mainly concerns the relationship between angiogenesis and hepatic fibrosis, by considering the mechanism of angiogenesis, cells in angiogenesis, anti-angiogenic and Chinese medicine therapies.

Wrapping of the omental pedicle flap around esophagogastric anastomosis after esophagectomy for esophageal cancer.

BACKGROUND: Esophagogastrectomy for esophageal cancer is the standard surgical treatment as a curative measure or for palliation. Esophagogastric anastomotic leakage and stricture are common life-threatening postoperative complications (more so if the leakage occurs in the chest), and the success of the anastomosis created in the reconstruction of the resected esophagus can highly influence morbidity and mortality. METHODS: A prospective, randomized study was undertaken on 291 patients treated for carcinoma of the esophagus between January 2004 and December 2008. The study excluded 36 patients (12%) who were inoperable. Patients were assigned to 2 treatment groups that consisted of 128 patients in group A and 127 patients in group B according to a restricted, permuted block randomization plan. Patients in group A underwent an esophagogastrectomy with wrapping of the pedicle omental flap around the esophagogastric anastomosis. Group B patients underwent an esophagogastrectomy with only a stapled technique. RESULTS: Of all 255 patients who received an esophagogastric anastomosis, 226 (89%) were discharged from the hospital within 15 days of operation. There was no significant difference between these 2 groups in regard to the incidence of pulmonary complications, abdominal or thoracic infections, and days of hospital stay. Anastomotic leaks occurred in a single patient from group A (1%) and in 7 patients from group B (6%). In group A, 33 patients underwent transhiatal esophagogastrectomy and 95 had thoracic esophagogastrectomy, which resulted in an anastomotic leakage in 1 (3%) and 0 (0%) patients, respectively. In group B, 42 patients had transhiatal esophagogastrectomy and 85 had thoracic esophagogastrectomy, which resulted in anastomotic leakage in 5 (12%) and 2 (2%) patients, respectively. The leakage ratio of group B was significant greater than that of group A (P < .05). Two patients were excluded during the evaluation of the benign stricture due to hospital mortality. Anastomotic strictures were noted in 8 patients from group A (6%) and 20 patients from group B (16%), and the difference in the incidence of anastomotic strictures between these 2 groups was statistically significant (P < .05). CONCLUSION: Wrapping of the pedicle omental flap around the esophagogastric stapled anastomosis site decreases the incidence of anastomotic leakage and stricture rate after esophagectomy for esophageal cancer, thereby decreasing the morbidity and mortality of the procedure.