A series of PIM-1/POSS microfibrous membranes were fabricated by electrospinning technology. The addition of POSS particles could greatly enhance the hydrophobicity, and a superhydrophobic−superoleophilic membrane was obtained as the POSS concentration increased to 40 wt %. The scanning electron microscopy images indicate that the incorporation of POSS particles results in formations of hierarchical structures on the surface of the PIM-1/POSS fibers. Both the intrinsic hydrophobic nature of POSS and the increase in the fiber surface roughness led to the superhydrophobicity and superoleophilicity. The 40 wt % PIM-1/POSS fibrous membrane could not only separate a wide range of immiscible oil−water mixtures with efficiencies higher than 99.95% but also separate water-in-oil emulsions with efficiencies higher than 99.97%. Furthermore, because of the ultrahigh intrinsic microporosity of the PIM-1 polymer, the PIM-1 fibrous membrane exhibited the ability to adsorb a large amount of contaminants such as oil red O and solvent blue 35 from oils. Therefore, these membranes are multifunctional and can be applied to treating immiscible water−oil mixtures, water-in-oil emulsions, and cleanup of oil soluble contaminants.
Adiponectin is an important adipokine exclusively secreted from adipose tissue. Growing evidence suggests that adiponectin inhibits the growth of cancer cells and reduces cancer risk. Many studies have examined the association between circulating adiponectin levels and the risk of breast cancer. However, the results of numerous epidemiological studies have been inconsistent. The aim of the present study was to conduct a systematic review and a meta-analysis on the association between circulating adiponectin levels and the risk of breast cancer. PubMed, MEDLINE, EMBASE, and ISI Web of Science were searched to identify all observational studies that examined the relationship between circulating adiponectin and breast cancer. Standard mean difference (SMD) values and 95% confidence intervals (CIs) were estimated and pooled using the meta-analysis methodology. Summary effect estimates were derived using a random effects meta-analysis model. The analysis included eight studies that met the study criteria and described the relationship between circulating adiponectin levels and breast cancer. A total of 1803 participants and 885 cases of breast cancer were included in this meta-analysis. Serum total adiponectin concentrations were lower in patients with breast cancer, with a pooled SMD of -0.39 μg/ml (95% CI -0.618 to -0.161, P=0.001). However, adiponectin levels were not associated with the risk of breast cancer in premenopausal women [four studies, random effects SMD=0.02 μg/ml (95% CI -0.164 to 0.204, P=0.829)]. These results collectively suggest that lower adiponectin levels are associated with a higher risk of breast cancer in postmenopausal women.
A borrowing-hydrogen reaction between amines and alcohols is an atom-economic way to prepare alkylamines, ideally with water as the sole byproduct. Herein, nickel catalysts are used for direct N-alkylation of hydrazides and arylamines using racemic alcohols. Moreover, a nickel catalyst of (S)-binapine was used for an asymmetric N-alkylation of benzohydrazide with racemic benzylic alcohols.
A high
gas barrier performance should be ensured in case of biodegradable
packing applications. However, the gas barrier properties of the biodegradable
poly(lactic acid) (PLA) are not much effective. Nanocomposites can
provide innovative solutions to enhance the barrier performance. In
this study, different weight percentages of organically modified montmorillonite
(OMMT) (0, 2, 4, 6, 8, and 10 wt %)-incorporated PLA/OMMT nanocomposites
were prepared by melt mixing. Ethylene glycol diglycidyl ether (EGDE)
was used to regulate the interlayer spacing of OMMT and increase the
PLA crystallinity to further improve the gas barrier performance of
the PLA/OMMT films. The crystallinity of PLA was significantly improved
because EGDE-modified OMMT served as an efficient nucleating agent.
The PLA/EGDE/OMMT films demonstrated a unique structure such that
the adjacent OMMT layers were linked through the PLA crystals that
serve as a bridge with respect to the spaces between the OMMT layers.
The O
2
permeability of the PLA/EGDE4/OMMT-6 film decreased
by approximately 79% when compared with that of the neat PLA film.
X-ray diffraction and differential scanning calorimetry analyses denoted
that the reduced oxygen permeability of the PLA/EGDE4/OMMT-6 film
can be primarily attributed to the high crystallinity of the PLA matrix
and the bridging effect of the PLA crystals between two adjacent layers.
Based on the experimental results, the relation between the relative
permeability and vol % OMMT is in good agreement with that of the
predicted values obtained using the Bharadwaj model when
S
= 0. The added EGDE weakened the thermal stability and tensile strength,
mainly because of degradation of the hydroxyl groups of EGDE formed
by epoxy ring opening, and these hydroxyl groups can promote PLA matrix
degradation. However, the practical application temperature of the
packaging film is considerably lower than the thermal decomposition
temperature; therefore, the reduction of the thermal decomposition
temperature does not affect the use of the packaging film.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.