Remarkably enhanced stereocomplex crystallization of high-molar-mass enantiomeric polylactide blends by adding double-grafted copolymers.

Stereocomplex (SC) crystallization can prominently improve the physico-chemical properties of poly(l-lactide)/poly(d-lactide) (PLLA/PDLA) blends, yielding a novel polylactide (PLA) material. However, the predominant formation of SC crystals in the melt-processing of high-molar-mass (high-MW, >100 kg/mol) enantiomeric PLA blends remains a huge challenge due to the competition between SC crystallization and homocrystallization. Herein, double-grafted copolymer having both PLLA and PDLA side chain has been designed and synthesized as an efficient crystallization promoter for the harvest of SC crystals in the high-MW PLLA/PDLA blends. The results show that, with the addition of such a copolymer, the blends can preferentially crystallize into SC crystals in both isothermal and non-isothermal conditions. Promisingly, the SC crystals can be exclusively formed by adding only small amounts (e.g., 0.5 wt%) of the copolymer, without the formation of any homocrystals. This interesting observation can be interpreted by the crucial role of the unique copolymer in suppressing the phase separation of the opposite PLA enantiomers upon melting as an efficient compatibilizer and then encouraging the generation of alternatingly arranged PLLA/PDLA chain clusters favored for SC nucleation and crystal growth. These findings provide new inspiration for the development of high-performance PLA with desirable SC crystallizability.

A "copolymer-co-morphology" conception for shape-controlled synthesis of Prussian blue analogues and as-derived spinel oxides.

The morphologically and compositionally controlled synthesis of coordination polymers and spinel oxides is highly desirable for realizing new advanced nanomaterial functionalities. Here we develop a novel and scalable strategy, containing a "copolymer-co-morphology" conception, to shape-controlled synthesis of various types of Prussian blue analogues (PBAs). Three series of PBAs MyFe1-y[Co(CN)6]0.67·nH2O (MyFe1-y-Co, M = Co, Mn and Zn) with well-controlled morphology have been successfully prepared through this strategy. Using MnyFe1-y-Co PBAs as the model, by increasing the relative content of Mn, flexible modulation of the morphology could be easily realized. In addition, a series of porous MnxFe1.8-xCo1.2O4 nano-dices with well-inherited morphologies and defined cation distribution could be obtained through a simple thermal treatment of the PBAs. All these results demonstrate the good universality of this novel strategy. When evaluated as an electrocatalyst, the octahedral-site Mn(III)/Mn(IV) content in MnxFe1.8-xCo1.2O4, mainly determined by sensitive (57)Fe Mössbauer in combination with X-ray photoelectron spectroscopic techniques, was discovered to be directly correlated with the oxygen reduction/evolution reaction (ORR/OER) activity.

Meta-analysis of the associations between TNF-α or IL-6 gene polymorphisms and susceptibility to lung cancer.

BACKGROUND: Several studies have indicated an association between tumor necrosis factor-alpha (TNF-α) or interleukin (IL)-6 gene polymorphisms and lung cancer risk. However, the conclusions remain controversial. METHODS: An English literature screening about case-control trials with regard to TNF-α (-308G/A) or IL-6 (174G/C) polymorphisms and lung cancer susceptibility was performed on PubMed, EMBASE, and EBSCO until November 2012. The pooled odds ratio (OR) and 95% confidence intervals (CI) were calculated using STATA 11.0. Sensitivity analysis was performed by sequential omission of individual studies. Publication bias was evaluated by Egger's linear regression test and funnel plots. RESULTS: Eight eligible studies, including 1,690 patients and 1,974 controls, were identified in this meta-analysis. Compared with the control, no significant association was revealed between TNF-α-308G/A (GG + GC vs. CC: OR = 1.10, 95% CI: 0.73 to 1.64; GG vs. GC + CC: OR = 1.02, 95% CI: 0.81 to 1.27; GC vs. CC: OR = 1.13, 95% CI: 0.73 to 1.77; GG vs. CC: OR = 1.04, 95% CI: 0.80 to 1.36; G vs. C: OR = 1.03, 95% CI: 0.90 to 1.18) or IL-6 174G/C (GG + GC vs. CC: OR = 1.10, 95% CI: 0.73 to 1.64; GG vs. GC + CC: OR = 1.02, 95% CI: 0.81 to 1.27; GC vs. CC: OR = 1.13, 95% CI: 0.73 to 1.77; GG vs. CC: OR = 1.04, 95% CI: 0.80 to 1.36; G vs. C: OR = 1.03, 95% CI: 0.90 to 1.18) and lung cancer risk. The pooled OR remained unchanged after removing the maximum-weight study and no publication bias was observed. CONCLUSIONS: The study raises the possibility of no correlation between the polymorphisms of the two genes and lung cancer susceptibility. However, further researches with large-sample or subgroup analyses are necessary to validate the conclusions.

SPARC is over-expressed in adipose tissues of diet-induced obese rats and causes insulin resistance in 3T3-L1 adipocytes.

Secreted protein acidic and rich in cysteine (SPARC) is a secretory multifunctional matricellular glycoprotein. High circulating levels of SPARC have been reported to be associated with obesity and insulin resistance. The aim of the present study was to investigate whether SPARC induces insulin resistance and mitochondrial dysfunction in adipocytes. Our results showed that feeding high fat diet to rats for 12 weeks significantly increased SPARC expression in adipose tissues at both mRNA and protein levels. Moreover, SPARC overexpression in stably transfected 3T3-L1 cells induced insulin resistance and mitochondrial dysfunction, as evidenced by inhibition of insulin-stimulated glucose transport, lower ATP synthesis and mitochondrial membrane potential, reduced expression of glucose transporter 4 (GLUT4), and increased levels of reactive oxygen species (ROS) in mature adipocytes. Finally, overexpression of SPARC also modulated the expression levels of several inflammatory cytokines, which play important roles in insulin resistance, glucose and lipid metabolism during adipogenesis. In conclusion, our data suggest that SPARC is involved in obesity-induced adipose insulin resistance and may serve as a potential target in the treatment of obesity and obesity-related insulin resistance.