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Per and polyfluoroalkyl substances (PFASs) have attracted major global concerns because some of them are environmentally persistent, bioaccumulative, and toxic. Perfluoroalkyl acids (PFAAs) have been well-characterized in water, soil, and sediment; however, fluorotelomer alcohols and perfluoroalkane sulfonamido substances have been overlooked. In this study, concentrations of three fluorotelomer alcohols and four perfluoroalkane sulfonamido substances were determined in the air at nine locations representing urban, rural-urban transect, and urban areas in the Pearl River Delta region, China to investigate their seasonal and spatial distributions and potential sources. At least two of the targeted PFASs were detected in all air samples in the Pearl River Delta region, with concentrations ranging from 371 pg/sampler to 18700 pg/sampler. Fluorotelomer alcohols were dominant compounds (contributing 46% to the ∑7PFAS concentration on average) in the atmosphere in the Pearl River Delta region. The total concentrations of the seven targeted PFASs were significantly higher in summer than in other seasons in urban areas. PFAS concentrations were positively related to the population density in the Pearl River Delta region. Local diffusive emission and long range transport could be sources of the seven PFASs in the air in the Pearl River Delta region. [ABSTRACT FROM AUTHOR]

By the use of a high-speed collection drum, poly(vinylidene fluoride) (PVDF) was electrospun into aligned ultrafine fibrous membranes from its solutions in a mixture of N, N-dimethylformamide and acetone (9:1, v/v), and a continuous hot-press post-treatment was performed on the membranes to improve their mechanical properties. Anisotropic tensile results and rupture behaviors of the hot-pressed PVDF membranes with higher fiber alignments in both revolving direction (RD) and cross direction were obtained. It was found that, due to the true fracture of electrospun fibers and improvement of the interfiber compaction by hot-press, the tensile strength and modulus of the hot-pressed membranes in RD reached the highest values at 58.12 ± 4.46 MPa and 519.9 ± 34.1 MPa, respectively when the collection speed was 10.42 m/s. The decrease of porosity and liquid absorption also represented the compaction improvement of the electrospun fibrous membranes. The combination of fiber alignments and hot-press could provide a novel method to fabricate high strength of electrospun membranes which have highly potential applications in filtration or battery separators. POLYM. ENG. SCI., 49:1291-1298, 2009. [C]2009 Society of Plastics Engineers, INTRODUCTION The electrospinning process has been studied as a useful method to produce ultrafine fibrous membranes from polymer solutions or melts under a high electric voltage for several years (1-5). [...]

Per- and poly-fluoroalkyl substances (PFASs) are a class of synthetic organic chemicals that include thousands of compounds. Analytical methods for PFASs in vegetables are limited. In this study, a rapid and sensitive method using on-line solid phase extraction (SPE) coupled with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed and validated for the simultaneous determination of 21 PFASs in vegetables. The extraction solvent volume and procedure were optimized to achieve good efficiencies (>93%) using the lowest quantity of solvent. The injection volume, elution condition of the online SPE system, and the mobile phases of the UHPLC-MS/MS system were also optimized to improve the sensitivity, peak symmetry, and resolution. The method detection limits of the 21 targeted PFAS were from 0.001 to 0.008 ng/g and the linearity was from 0.1 to 1000 pg/mL using an injection volume of 5 mL. The validation results indicate that this method is precise, accurate, and robust. Moreover, this method is high throughput (∼15 min per sample); thus, suitable for analyzing a large number of vegetable samples in a short time interval. In addition, the developed method was successfully applied to analyze vegetables. The results show that the total PFAS concentrations were the highest in lettuce, followed by potatoes and tomatoes, and the lowest in broccoli. Different profiles of PFASs were observed among the vegetable species. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride) (PVDF) was electrospun into ultrafine fibrous membranes from its solutions in a mixture of N,N-dimethylformamide and acetone (9:1, v/v). The electrospun membranes were subsequently treated by continuous hot-press at elevated temperatures up to 155°C. Changes of morphology, crystallinity, porosity, liquid absorption, and mechanical properties of the membranes after hot-press were investigated. Results of scanning electron microscopy showed that there were no significant changes in fibrous membrane morphology when the hot-press temperature varied from room temperature to 130°C, but larger pores were formed because of fibers melting and bonding under higher temperatures. Analyses of X-ray diffraction and differential scanning calorimeter exhibited that the crystalline form of PVDF could transfer from β-type to α-type during hot-press at temperatures higher than 65°C. Tensile tests suggested that the mechanical properties of the electrospun PVDF membranes were remarkably enhanced from 25 to 130°C, whereas the porosity and the liquid absorption decreased. The hot-press at 130°C was optimal for the electrospun PVDF membranes. The continuous hot-press post-treatment could be a feasible method to produce electrospun membranes, not limited to PVDF, with suitable mechanical properties as well as good porosity and liquid absorption for their applications in high-quality filtrations or battery separators. POLYM. ENG. SCI., 48:934-940, 2008. © 2008 Society of Plastics Engineers, INTRODUCTION The electrospinning is a straightforward way to produce ultrafine fibrous membranes from polymer solutions or melts under a high electric voltage [1-5]. Because of the tiny diameter in several [...]

RNA-binding protein Lin28A is frequently over-expressed in human malignant tumors and is associated with tumor advance and poor prognosis. However, the expression pattern and functions of Lin28A in colon cancer are unknown. In this study, we detected the expression of Lin28A in colon cancer patients and tested the effect of Lin28A on the chemotherapeutic sensitivity of colon cancer cells to 5-fluorouracil (5-FU). As expected, we showed that Lin28A is up-regulated in 73.3 % of colon cancer patients. However, to our surprise, we found that oncogenic protein Lin28A-enforced expression in colon cancer cells enhanced the chemosensitivity of cancer cells to 5-FU via promoting the cell apoptosis. Further mechanisms study revealed that the effect of Lin28A increasing chemosensitivity of cancer cells is in a let-7 independent manner, but which is associated with decreasing the expression of DNA damage repair protein H2AX. Conclusively, here we reported an unexpected function of Lin28A, which may shed lights on fully understanding the physiological and pathological roles of this oncogene. [ABSTRACT FROM AUTHOR]

MicroRNAs encoded by the miR-15b/16-2 cluster act as tumor suppressors. Aberrant regulation of miR-15b in human malignant tumors is reportedly involved in cancer development, contributing to cell death, reduced proliferation, angiogenesis and metastasis resistance, metabolism reprogramming, genome instability, and tumor-associated inflammation. In this review, we summarize the mechanisms involved in regulating miR-15b expression in mammalian tumors and discuss the effects of miR-15b dysregulation on the hallmarks of cancer and highlight its role as a potentially valuable target for future cancer therapeutic strategies. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride) (PVDF)/polycarbonate (PC) dispersed solutions were electrospun into ultrafine core/shell fibers and modified by hot-press. Morphology, tensile properties, porosity, and liquid absorption of the electrospun membranes as well as the crystallinity of PVDF were examined before and after hot-press. Results showed that the tensile strength and tensile modulus of the electrospun membranes increased after hot-press, especially when poly(methyl methacrylate) (PMMA) or benzyl triethylammonium chloride (BTEAC) was introduced for the formation of distinct core/shell fiber structure. The elongation of the hot-pressed electrospun PVDF/PC membrane with addition of BTEAC was also significantly enhanced by reason of the clearest core/shell structure. The crystallinity of PVDF did not change too much before and after hot-press, however the porosity and liquid absorption of the hot-pressed electrospun membranes decreased to about 58% and around 75-90%, respectively, with no significant differences between PVDF/PC, PVDF/PC/PMMA, and PVDF/PC with BTEAC membranes. This study could be an example of electrospun membranes in multi-polymer components and it could be extended to other systems of electrospinning for applications in filtration and so on. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

The article focuses on a study on the modification of electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) membranes with poly(ethylene glycol) dimethacrylate (PEGDMA) introduction. The study also looks into the impact of solution parameters for electrospinning. Mechanical tests show that PVDF-HFP/PEGDMA membranes increased in terms of tensile modulus and strength. It mentions the potential of PVDF-HFP/PEGDMA membranes as an electrolyte or separator in lithium batteries.

The pandemic of COVID-19 is of international concern and poses great challenges for management of oncology services.[1] Recent studies showed that patients with cancer histories[2] and cancer patients being treated[3] had higher infection rates than individuals. Our analysis provided systematic analysis of risk factors and a risk nomogram for cancer patients. Graph: Fig Risk factors and a risk nomogram for COVID-19 infection in cancer patients. [Extracted from the article]

Arginase-1 (Arg-1) metabolizes l -arginine to l -ornithine and urea. It has been documented to have a role in various malignancies. However, the relationship between Arg-1 expression and clinicopathological characteristics of colorectal cancer (CRC) patients remains to be elucidated. The present study aimed to analyze the expression and prognostic value of Arg-1 in patients with CRC. The mRNA and protein expressions of Arg-1 in fresh colorectal cancer tissue specimens and the corresponding noncancerous tissue specimens were examined by RT-qPCR (n = 24) and western blot analysis (n = 17). Arg-1 expression levels were determined in paraffin-embedded CRC tissue specimens (n = 236) by immunohistochemistry. The associations of Arg-1 expression and clinicopathological features and clinical prognosis in 236 CRC patients were analyzed. The expression levels of Arg-1 were significantly higher in the CRC tissues compared with the matched noncancerous tissues, and elevated Arg-1 expression was remarkably associated with stage III-IV tumors (P = 0.007), lymph node metastasis (P = 0.019) and a plasma albumin concentration <35 g/l (P = 0.022). Kaplan-Meier analysis indicated that Arg-1 overexpression was associated with adverse prognoses for overall survival (OS) (P < 0.001) and disease-free survival (DFS) (P < 0.001) in all cases. Further analysis revealed that the patients with high Arg-1 expression had significantly shorter OS and DFS at the advanced stages (III + IV) (P = 0.032 for OS, and P = 0.012 for DFS) but not at the early stages (I + II) (P = 0.194 for OS, and P = 0.065 for DFS). Multivariate analysis revealed that Arg-1 overexpression was an independent prognostic factor for OS (P = 0.002) and DFS (P < 0.001) in patients with CRC. The data indicated that Arg-1 overexpression in CRC may be a marker that can discriminate subgroups of patients with a poor prognosis. [ABSTRACT FROM AUTHOR]