Application of CoMn/CoFe layered double hydroxide based on metal-organic frameworks template to activate peroxymonosulfate for 2,4-dichlorophenol degradation.

Metal-organic frameworks (MOFs) have unique properties and stable structures, which have been widely used as templates/precursors to prepare well developed pore structure and high specific surface area materials. In this article, an innovative and facile method of crystal reorganization was designed by using MOFs as sacrificial templates to prepare a layered double hydroxide (LDH) nano-layer sheet structure through a pseudomorphic conversion process under alkaline conditions. The obtained CoMn-LDH and CoFe-LDH catalysts broke the ligand of MOFs and reorganized the structure on the basis of retaining a high specific surface area and a large number of pores, which had higher specific surface area and well developed pore structure compared with LDH catalysts prepared by traditional methods, and thus provide more active sites to activate peroxymonosulfate (PMS). Due to the unique framework structure of MOFs, the MOF-derived CoMn-LDH and CoFe-LDH catalysts could provide more active sites to activate PMS, and achieve a 2,4-dichlorophenol degradation of 99.3% and 99.2% within 20 minutes, respectively. In addition the two LDH catalysts displayed excellent degradation performance for bisphenol A, ciprofloxacin and 2,4-dichlorophenoxyacetic acid (2,4-D). X-ray photoelectron spectroscopy indicated that the valence state transformation of metal elements participated in PMS activation. Electron paramagnetic resonance manifested that sulfate radical (SO4•-) and singlet oxygen (1O2) were the main species for degrading pollutants. In addition, after the three-cycle experiment, the CoMn-LDH and CoFe-LDH catalysts also showed long-term stability with a slight activity decrease in the third cycle. The phytotoxicity assessment determined by the germination of mung beans proved that PMS activation by MOF-derived LDH catalysts can basically eliminate the phytotoxicity of a 2,4-D solution. This research not only developed high-activity LDH catalysts for PMS activation, but also expanded the environmental applications of MOF derivants.

Application of microprobe-based flank method analysis of Fe3+ in garnet of North Qilian eclogite and its geological implication.

A newly developed microprobe-based methodology (the Flank Method) for Fe3+/ΣFe quantification has been successfully applied to some natural garnets from the North Qilian eclogites by JEOL JXA-8100 microprobe at Peking University. The results demonstrated an obvious discrepancy in comparison with the outcomes by conventional stoichiometric calculations. This methodology allows to measure the Fe3+/ΣFe ratio and perform elemental analyses simultaneously in the same condition. Accurate in-situ measurement of Fe3+ content in garnet may bring certain impact on the garnet-based P-T estimation. According to the compositional zonation displayed in the studied eclogitic garnets from North Qilian, a prograde metamorphic PT path from 19.5 kbar, 520 °C to 22 kbar, 600 °C was reconstructed. More interestingly, the measured Fe3+/ΣFe ratios in garnets decreasing from core to rim may probably imply that the oxygen fugacity (fO2) declines with the depth of the subduction zone.

Long Noncoding RNA-Sox2OT Knockdown Alleviates Diabetes Mellitus-Induced Retinal Ganglion Cell (RGC) injury.

Retinal ganglion cell (RGC) injury is one of the important pathological features of diabetes-induced retinal neurodegeneration. Increasing attention has been paid to find strategies for protecting against RGC injury. Long noncoding RNAs (lncRNAs) have emerged as the key regulators of many cell functions. Here, we show that Sox2OT expression is significantly down-regulated in the retinas of STZ-induced diabetic mice and in the RGCs upon high glucose or oxidative stress. SOX2OT knockdown protects RGCs against high glucose-induced injury in vitro. Moreover, Sox2OT knockdown plays a neuroprotective role in diabetes-related retinal neurodegeneration in vivo. Sox2OT knockdown could regulate oxidative stress response in RGCs and diabetic mouse retinas. Sox2OT knockdown plays an anti-oxidative role via regulating NRF2/HO-1 signaling activity. Taken together, Sox2OT knockdown may be a therapeutic strategy for the prevention and treatment of diabetes-induced retinal neurodegeneration.

Lignans Extracted from Eucommia Ulmoides Oliv. Protects Against AGEs-Induced Retinal Endothelial Cell Injury.

BACKGROUND/AIMS: Advanced glycation end products (AGEs) could elicit oxidative stress, trigger and aggravate endothelium damage in several ischemic retinopathies including diabetic retinopathy (DR). The leaves of Eucommia ulmoides O., also referred to as Tu-chung or Du-zhong, have been used for the treatment of hypertension and diabetes, showing great antioxidant activity and anti-glycation activity. Lignans is one of the main bioactive components of Eucommia ulmoides. This study mainly investigated the effect of lignans treatment on AGEs-induced endothelium damage. METHODS: MTT assay, Hoechst staining, and calcein-AM/ propidium iodide (PI) staining was conducted to determine the effect of lignans treatment on endothelial cell function in vitro. Retinal trypsin digestion, Evans blue assay, isolectin staining, and western blots were conducted to determine the effect of lignans treatment on retinal microvascular function in vivo. Western blot, protein immunoprecipitation (IP), MTT assays, and enzyme activity assay was conducted to detect the effect of ligans treatment on oxidative stress response. RESULTS: Lignans protected retinal endothelial cell against AGEs-induced injury in vitro and diabetes-induced vascular dysfunction in vivo. Lignans treatment could regulate oxidative stress response in retinal endothelial cell line, retina, and liver. Moreover, we showed that NRF2/HO-1 signaling was critical for lignans-mediated oxidative stress regulation. CONCLUSION: Lignans treatment could protect against endothelial dysfunction in vivo and in vitro via regulating Nrf2/HO-1 signaling. Lignans might be developed as a promising drug for the treatment of diabetes-induced microvascular dysfunction.

Statistical analysis of bivariate failure time data with Marshall-Olkin Weibull models.

This paper discusses parametric analysis of bivariate failure time data, which often occur in medical studies among others. For this, as in the case of univariate failure time data, exponential and Weibull models are probably the most commonly used ones. However, it is surprising that there seem no general estimation procedures available for fitting the bivariate Weibull model to bivariate right-censored failure time data except some methods for special situations. We present and investigate two general but simple estimation procedures, one being a graphical approach and the other being a marginal approach, for the problem. An extensive simulation study is conducted to assess the performances of the proposed approaches and shows that they work well for practical situations. An illustrative example is provided.