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A new series of cellulose-graft-poly( N-isopropylacrylamide) (cellulose- g-PNIPAM) copolymers were prepared by atom transfer radical polymerization (ATRP) of N-isopropylacrylamide monomers from a cellulose-based macro-initiator, which was homogeneously synthesized in an ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl). The composition of cellulose- g-PNIPAM copolymers could be adjusted by altering the feeding ratio and reaction time. The resultant copolymers with relatively high content of PNIPAM segments (molar substitution of PNIPAM ≥ 18.3) were soluble in water at room temperature. Aqueous solutions of cellulose- g-PNIPAM copolymers exhibited clear temperature-sensitive behavior, and their sol-to-gel phase transition properties were investigated by dynamic light scattering (DLS) and UV measurements. Compared with pure PNIPAM, the cellulose- g-PNIPAM copolymers possessed higher lower critical solution temperatures (LCST) in a range from 36.9 °C to 40.8 °C, which are close to normal human body temperature, and could be tuned by adjusting the content of PNIPAM segments in copolymers. Spherical structure of cellulose- g-PNIPAM copolymers formed at temperatures above LCST and its morphology was observed by TEM and SEM. These novel cellulose- g-PNIPAM copolymers may be attractive substrates for some biomedical applications, such as drug release and tissue engineering. [ABSTRACT FROM AUTHOR]

Microspheres with thermo-responsible surface were fabricated by PCL- b-PEO- b-PNIPAM triblock copolymers. Thermo-responsible morphological changes of PCL- b-PEO- b-PNIPAM microspheres immersed in aqueous solution at temperatures above the LCST ( e.g. 37 °C) were observed from porous surface structure to compact surface layer. Enzymatic degradation and in vitro drug release results showed that the thermo-responsible surface layer greatly influenced the degradation of microspheres as well as the drug release behavior from microspheres. With the copolymerization of PNIPAM block into PCL- b-PEO copolymers, the drug release could be well regulated by changing temperatures and microspheres composition, which revealed the great potentials of microspheres with thermo-responsible surface for controlled drug release. [ABSTRACT FROM AUTHOR]

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Background: Recent studies have shown that the forkhead box P3 (FOXP3) protein has a prognostic role in breast cancer. However, these results are controversial. Therefore, the aim of this meta-analysis was to clarify the prognostic role of FOXP3 expression in operable breast cancer cases. Methods: Eligible studies describing the use of FOXP3 as a prognostic factor for operable breast cancer cases were identified. Clinicopathological features, disease-free survival (DFS), and overall survival (OS) data were collected from these studies and were analyzed using Stata software. Results: A total of 16 articles containing data from 13,217 breast cancer patients met the inclusion criteria established for this study. The subsequent meta-analysis that was performed showed that high levels of FOXP3 are not significantly associated with DFS and OS with significant heterogeneity. An additional subgroup analysis demonstrated that intratumoral FOXP3+ regulatory T cells (Tregs) were positively correlated with adverse clinicopathological parameters, yet they did not show an association with DFS or OS. For tumor cells, the pooled results revealed that FOXP3 is significantly associated with DFS (HR: 2.55, 95% CI: 1.23–5.30) but is not associated with clinicopathological parameters or OS. We also observed a significant correlation between FOXP3 expression and survival in the estrogen receptor-positive (ER)+ subgroup (HR: 1.83, 95% CI: 1.36–2.47 for DFS, HR: 1.87, 95% CI 1.28–2.73 for OS), in the Asian region (HR: 1.98, 95% CI: 1.56–2.50 for DFS, HR: 1.93, 95% CI: 1.12–3.35 for OS) and using the median as the FOXP3-positive cut-off value (HR: 1.94, 95% CI: 1.57–2.39 for DFS, HR: 2.06; 95% CI: 1.36–3.11 for OS). Conclusion: This meta-analysis indicates that a prognostic role for FOXP3 expression in operable breast cancer cases depends on the FOXP3-positive region, ER status, geographic region and the FOXP3-positive cut-off value. [ABSTRACT FROM AUTHOR]

p21-activated kinase 7 (PAK7), also named as PAK5, is a member of Rac/Cdc42-associated Ser/Thr protein kinases. It is overexpressed in some types of cancer such as colorectal and pancreatic cancers. However, the expression status and biological function of PAK7 in osteosarcoma are still ambiguous. To evaluate the expression levels of PAK7 in osteosarcoma tissues and cell lines, immunohistochemistry was used. To investigate the role of PAK7 in cell proliferation, apoptosis and tumorigenicity in vitro and vivo, a recombinant lentivirus expressing PAK7 short hairpin RNA (Lv-shPAK7) was developed and transfected into Saos-2 cells. The silencing effect of PAK7 was confirmed by quantitative real-time PCR (qRT-PCR) and Western blot technique. PAK7 was overexpressed in osteosarcoma tissue and cell line. By knocking-down of PAK7, the proliferation and colony formation of Saos-2 cells were inhibited and apoptosis enhanced significantly. The in vivo tumorigenic ability in xenograft model of Saos-2 cells was also notably inhibited when PAK7 was knocked down. Our results imply that PAK7 promotes cell proliferation and tumorigenesis and may be an attractive candidate for the therapeutic target of osteosarcoma. [ABSTRACT FROM AUTHOR]

The conformational changes, crystal structure and melting behavior of poly(ethylene/trimethylene terephthalate) (ET) copolyesters were investigated using in situ Fourier transform infrared (FTIR) spectroscopy, wide-angle X-ray diffraction (WAXD), transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) under isothermal crystallization conditions. The results show that the minimum melting temperature was observed in ET53, in which the relative amount of ethylene glycol (EG) to 1,3-propanediol (PDO) was 52.68/47.32 and the PDO-dimethyl terephthalate (DMT)-PDO segments in the molecular chain dominated the crystal formation. The minimum crystallinity of ET copolyesters was found in ET66, in which the relative amount of EG/PDO was 65.91/34.09 and the EG-DMT-EG segments in the molecular chain dominated the crystal formation. A rapid and continuous conformational transition in ET copolyesters was observed using in situ FTIR in the first 10 min under isothermal crystallization conditions. The continuously adjusting conformation in the molecules reflects the crystallization of ET copolyesters. Based on the DSC and the X-ray analyses of the crystallization behavior in the ET copolyesters, crystalline conformation transitions of molecules in ET copolyesters take place rapidly and early. Copyright © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Gas-liquid two-phase flow and heat transfer can be encountered in numerous fields, such as chemical engineering, refrigeration, nuclear power reactor, metallurgical industry, spaceflight. Its critical heat flux (CHF) is one of the most important factors for the system security of engineering applications. Since annular flow is the most common flow pattern in gas-liquid two-phase flow, predicting CHF of annular two-phase flow is more significant. Many studies have shown that the liquid film dryout model is successful for that prediction, and determining the following parameters will exert predominant effects on the accuracy of this model: onset of annular flow, inception criterion for droplets entrainment, entrainment fraction, droplets deposition and entrainment rates. The main theoretical results achieved on the above five parameters are reviewed; also, limitations in the existing studies and problems for further research are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The crystallization morphology and the melting behavior of the phase-separating poly(ɛ-caprolactone) (PCL) and poly(ethylene oxide) (PEO) blends were studied using atomic force microscopy. Two blends consisting of PCL and PEO with weight ratios of 10/90 and 90/10 were prepared to form the isolated spherical domains by the phase-separating process. The results show that the melting temperatures of the PCL and PEO lamellae in the confined domains increased as the lamellar length increased, and the melting behavior of the PCL and PEO lamellae in the matrix and confined domains was also studied. [Copyright &y& Elsevier]