Oriented Growth of Thin Films of Covalent Organic Frameworks with Large Single-Crystalline Domains on the Water Surface.

It has been a longstanding challenge to rationally synthesize thin films of organic two-dimensional (2D) crystals with large single-crystalline domains. Here, we present a general strategy for the creation of 2D crystals of covalent organic frameworks (COFs) on the water surface, assisted by a charged polymer. The morphology of the preorganized monomers underneath the charged polymer on the water surface and their diffusion were crucial for the formation of the organic 2D crystals. Thin films of 2D COFs with an average single-crystalline domain size of around 3.57 ± 2.57 µm2 have been achieved, and their lattice structure, molecular structure, and grain boundaries were identified with a resolution down to 3 Å. The swing of chain segments and lattice distortion were revealed as key factors in compensating for the misorientation between adjacent grains and facilitating error corrections at the grain boundaries, giving rise to larger single-crystalline domains. The generality of the synthesis method was further proved with three additional 2D COFs. The oriented single-crystalline domains and clear grain boundaries render the films as model materials to study the dependence of the vertical conductivity of organic 2D crystals on domain sizes and chemical structures, and significant grain boundary effects were illustrated. This study presents a breakthrough in the controlled synthesis of organic 2D crystals with structural control at the molecular level. We envisage that this work will inspire further investigation into the microstructure-intrinsic property correlation of 2D COFs and boost their application in electronics.

Triterpenoids from the bark of Dysoxylum hainanense and their anti-inflammatory and radical scavenging activity.

A phytochemical investigation on the 70% EtOH extract of the bark of Dysoxylum hainanense resulted in the isolation of four new triterpenoids, dysoxyhaines A-D (1-4). Structural elucidation of all the compounds were performed by spectral methods such as 1D and 2D (1H1H COSY, HMQC, and HMBC) NMR spectroscopy, in addition to high resolution mass spectrometry. The isolated components were evaluated in vitro for anti-inflammatory activities for Cox-1 and Cox-2, and radical scavenging potential using ABTS·+ and DPPH test. As a result, nor seco-olean type triterpenoid 1 exhibited significant anti-inflammatory potential, while tirucallane triterpenoids 3 and 4 showed radical scavenging activities.

miR-153 regulates apoptosis and autophagy of cardiomyocytes by targeting Mcl-1.

MicroRNAs (miRs) are a class of important regulators, which are involved in the regulation of apoptosis. Oxidative stress­induced apoptosis is the predominant factor accounting for cardiac ischemia­reperfusion injury. miR­153 has been previously shown to have an antitumor effect in cancer. However, whether miR­153 is involved in oxidative stress­induced apoptosis in the heart remains to be elucidated. To this end, the present study used reverse transcription­quantitative polymerase chain reaction to detect miR-153 levels upon oxidative stress, and evaluated apoptosis, autophagy and expression of critical genes by western blotting. A luciferase assay was also used to confirm the potential target gene. In the present study, it was found that the expression of miR­153 was significantly increased upon H2O2 stimulation, and the inhibition of endogenous miR­153 decreased apoptosis. To further identify the mechanism underlying the pro­apoptotic effect of miR­153, the present study analyzed the 3'untranslated region of myeloid cell leukemia­1 (Mcl­1), and found that Mcl­1 was potentially targeted by miR­153. The forced expression of miR­153 inhibited the expression of Mcl­1 and luciferase activity, which was reversed by its antisense inhibitor. Furthermore, it was shown that the inhibition of miR­153 induced autophagy during oxidative stress, and that its effects of autophagy induction and apoptosis inhibition were efficiently abrogated by Mcl­1 small interfering RNA. In conclusion, the results of the present study elucidated a novel mechanism by which miR­153 regulates the survival of cardimyocytes during oxidative stress through the modulation of apoptosis and autophagy. These effects may be mediated directly by targeting Mcl­1. These finding revealed the potential clinical value of miR­153 in the treatment of cardiovascular disease.

A Rare Case of Toxic Myocarditis Caused by Bacterial Liver Abscess Mimicking Acute Myocardial Infarction.

BACKGROUND: Chills, high fever, right upper abdomen pain, and increased white blood cell count are the main and common clinical features of bacterial liver abscess. It is rare to see bacterial liver abscess present symptoms of myocardial injury first, and this can lead to misdiagnosis. CASE REPORT: We report a case of toxic myocarditis caused by bacterial liver abscess. The patient first presented with chest pain, ST segment elevation, and elevated TNI, which misled us to diagnose myocardial infarction, but the coronary artery had no stenosis or obstructive lesions after emergency coronary angiography. Then we modified the diagnosis to toxic myocarditis. Bacterial liver abscess was the proposed etiology after a series of auxiliary examinations. Finally, antibiotics and percutaneous liver puncture catheter drainage were used to improve the clinical outcome. CONCLUSIONS: It is rare that patients with bacterial liver abscess first present symptoms of myocardial injury. Differential diagnosis between myocarditis and myocardial infarction should be careful, as myocarditis is a diagnosis of exclusion, and coronary angiography is necessary to confirm coronary disease. Percutaneous liver puncture catheter drainage can effectively cure bacterial liver abscess.