Recently, some attempts have been made to enhance the gas barrier properties of semicrystalline polymers by precisely controlling the arrangement of their impermeable crystalline lamellae. However, it is still a great challenge to achieve regular arrangement of the lamellae along the direction perpendicular to the gas diffusion path, especially using conventional polymer processing technologies. This work presents a novel and simple strategy to dramatically improve oxygen barrier performance of biobased and biodegradable polylactide (PLA) through constructing parallel-aligned shish-kebab-like crystals with well-interlocked boundaries with the aid of a highly active nucleating agent. The nucleating agent was introduced into PLA by melting compounding and the sheet-like specimens were fabricated by compression molding. We demonstrate that the fibrillar nucleating agent dispersed in PLA melt can serve as shish to induce the change of crystallization habit of PLA from isotopic spherulitic crystals to unique shish-kebab-like crystals and the shear flow in the compression molding can induce the highly ordered alignment of the nucleating agent fibrils as well as the subsequent shish-kebab-like crystals along the direction parallel to the sheet surface. More importantly, the growing lamellae are found to interpenetrate and tightly interlock with each other at the boundary regions of the shish-kebab-like crystals in the later stage of the crystallization, forming a densely packed nanobrick wall structure to prevent gas molecules from permeating through the crystals and thus imparting the PLA sheets with unprecedentedly low oxygen permeability. This work provides not only a successful example of preparing semicrystalline polymer with super gas barrier properties by tailoring crystal superstructure but also a promising route to rapidly fabricate high-performance food packaging materials via industrially meaningful melt processing.

Tumor immunosuppression is commonly braided with chronic inflammation during tumor development. However, the relationship between immunosuppression and inflammation in tumor microenvironment is still unclear. We have demonstrated that mast cells are accumulated and exacerbate the inflammation and immunosuppression in tumor microenvironment via SCF/c-kit signaling pathway. Here, we further elucidate the underlying mechanism, which involves both myeloid-derived suppressor cells (MDSCs) and regulatory T (Treg) cells. Our data showed that mast cells mobilized the infiltration of MDSCs to tumor and induced the production of IL-17 by MDSCs; MDSCs-derived IL-17 indirectly attracted Treg cells, enhanced their suppressor function, and induced the IL-9 production by Treg cells; in turn, IL-9 strengthened the survival and protumor effect of mast cells in tumor microenvironment. Our findings disclose a closed loop among mast cells, MDSCs and Treg cells in tumor microenvironment, which provides a new insight into the paralleled developments of inflammation and immunosuppression in tumor microenvironment. Based on these findings, we propose that targeting tumor inflammation might be a potential strategy to reverse the immunosuppression of tumor microenvironment, thus facilitating cancer immunotherapy.

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Inorganic nanofillers are often added into polymer/elastomer blends as a third component to modify their performance. This work aims to clarify the role of interface-localized spherical nanoparticles in determining the impact toughness of polymer blends. The selective distribution of titanium dioxide (TiO2) nanoparticles in poly(L-lactide)/poly(ether) urethane (PLLA/PU) blends was investigated by using scanning electron microscope. It is interesting to find that, regardless of the method of TiO2 introduction, nano-TiO2 particles are always selectively localized at the phase interface between PLLA and PU, leading to a significant improvement in notched Izod impact toughness. The moderately weakened interfacial adhesion induced by the interfacially-localized nano-TiO2 particles is believed to be the main reason for the largely enhanced impact toughness

BackgroundThis study was designed to measure changes in anterior chamber depth (ACD), central cornea thickness (CCT), and axial length (AL) after scleral buckle (SB) surgery or pars plana vitrectomy (PPV) for the repair of rhegmatogenous retinal detachment (RD).MethodsWe prospectively reviewed the records of 245 eyes of 245 patients scheduled to undergo SB surgery and 238 eyes of 238 patients scheduled to undergo PPV. ACD, CCT, and AL were measured by spectral-domain optical coherence tomography (SD-OCT) and biometry, before surgery as well as 6 and 12 months postoperatively.ResultsFor both SB and PPV surgeries, ACD was observed to decrease significantly postoperatively, with this trend continuing throughout the follow-up period (p < 0.005). CCT showed no significant difference after PPV or SB surgery. AL increased significantly after SB surgery but not PPV.ConclusionOur results show that SB surgery altered the shape of the eye by changing both ACD and AL. PPV resulted in altered ACD. These findings should elucidate the changes to be expected after SB and PPV surgeries.

Baseline blood concentrations of metals are important references for monitoring metal exposure in environmental and occupational settings. The purpose of this study was to determine the blood levels of manganese (Mn), copper (Cu), zinc (Zn), lead (Pb), and cadmium (Cd) among the residents (aged 12–60 years old) living in the suburb southwest of Beijing in China and to compare the outcomes with reported values in various developed countries. Blood samples were collected from 648 subjects from March 2009 to February 2010. Metal concentrations in the whole blood were determined by ICP-MS. The geometric means of blood levels of Mn, Cu, Zn, Pb and Cd were 11.4, 802.4, 4665, 42.6, and 0.68 μg/L, respectively. Male subjects had higher blood Pb than the females, while the females had higher blood Mn and Cu than the males. There was no gender difference for blood Cd and Zn. Smokers had higher blood Cu, Zn, and Cd than nonsmokers. There were significant age-related differences in blood levels of all metals studied; subjects in the 17–30 age group had higher blood levels of Mn, Pb, Cu, and Zn, while those in the 46–60 age group had higher Cd than the other age groups. A remarkably lower blood level of Cu and Zn in this population as compared with residents of other developed countries was noticed. Based on the current study, the normal reference ranges for the blood Mn were estimated to be 5.80–25.2 μ/L; for blood Cu, 541–1475 μ/L; for blood Zn, 2349–9492 μ/L; for blood Pb, <100 μ/L; and for blood Cd, <5.30 μ/L in the general population living in Beijing suburbs.