The application of epoxidized rapeseed oil as a biodegradable lubricant is described. The epoxidation treatment has no adverse effect on the biodegradability of the base stock. Epoxidized rapeseed oil has superior oxidative stability compared to rapeseed oil based on the results of both oven tests and rotary oxygen bomb tests. Moreover, the oxidative stability can be dramatically promoted by the addition of a package of antioxidants. The epoxidized rapeseed oil has better friction-reducing and extreme pressure abilities according to tribological investigations. Formation of a tribopolymerization film is proposed as explanation of the tribological performance of epoxidized rapeseed oil.

BACKGROUND.Methylation‐mediated suppression of detoxification, DNA repair, and tumor suppressor genes has been implicated in cancer development and progression. Studies also have indicated that concordant methylation of multiple genes (methylator phenotypes), rather than a single gene, may predict cancer prognosis. The current study was designed to determine whether a methylator phenotype exists in ovarian cancer, whether methylation frequencies differ between malignant ovarian tumors and ovarian tumors with low malignant potential (LMP or borderline), and whether methylation of multiple genes affects patient survival.METHODS.The current study included 234 consecutively diagnosed patients with either LMP (n = 19 patients) or malignant (n = 215 patients) ovarian tumors. DNA samples were extracted from fresh frozen tissues and were analyzed for methylation in the promoter region of 6 genes (p16, breast cancer 1 [BRCA1], insulin‐like growth factor‐binding protein 3 [IGFBP‐3], glutathione S‐transferase π 1 [GSTP1], estrogen receptor‐α [ER‐α], and human MutL homologue 1 [hMLH1]) by using methylation‐specific polymerase chain reaction analysis.RESULTS.The frequencies of methylation in malignant tumors and LMP tumors were 0% and 0% for GSTP1, respectively; 9% and 0% for hMLH1, respectively; 21% and 5% for BRCA1, respectively; 42% and 21% for p16, respectively; 44% and 26% for IGFBP‐3, respectively; and 57% and 42% for ER‐α, respectively. A methylator phenotype was not detected, but a calculated methylation index (MI) that was based on the total number of genes methylated in each tumor was associated with ovarian cancer risk and progression. A higher MI was associated with malignant tumors (odds ratio, 10.11; 95% confidence interval [95% CI], 1.19–85.75) and disease progression (hazards ratio, 6.53; 95% CI, 1.39–30.65).CONCLUSIONS.Although a methylator phenotype was not identified, the current results suggested that methylation of multiple genes may play an important role in ovarian cancer development and progression and may have clinical implications in prognosis. Cancer 2006. © 2006 American Cancer Society.

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Two cleavable cationic lipids were designed to trigger the fusogenicity and membrane permeation of their lipoplexes in endosomes via the formation of inverted hexagonal phases (HII). Both lipids contain a cationic head group and an unsaturated hydrophobic dioleylglycerol moiety joined together by a linear or a cyclic ortho ester linker. At pH 7.4, the lipids formed stable complexes with plasmid DNA together with the conelike helper lipid 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE). The decrease of pH enhanced the hydrolysis of the ortho ester linkers, which removed the cationic head groups and caused the aggregation of the lipoplexes. At pH 5.5, the cationic lipid N-[2-methyl-2-(1',2'-dioleylglyceroxy)dioxolan-4-yl]methyl-N,N,N-trimethylammonium iodide (2) with a cyclic ortho ester linker showed exceptional pH-sensitivity and triggered its lipoplex to permeate model biomembranes within the time span of endosome processing prior to lysosomal degradation. Lipid 2 significantly improved gene transfection in cultured cells compared to the pH-insensitive control lipid 1,2-dioleoyl-3-trimethylammoniopropane (DOTAP).

In this paper, we have investigated the surface energy and adhesion of one functional PFPE (Zdol) and two series of nonfunctional PFPEs (Z and D) on carbon-overcoated disk surfaces. The effects of end group functionality, backbone chain flexibility, molecular weight, and film thickness were systematically examined. Our results indicated that nonfunctional PFPEs have weak attraction with carbon overcoat. However, due to backbone chain effect, Z has slightly stronger attraction than D. Based on the surface energy analyses and bonded thickness results, schematic bonding models were proposed, which indicate strong hydrogen bonding∕ordered packing structure∕low mobility for functional PFPE films and weak attraction∕less-ordered packing structure∕high mobility for nonfunctional PFPE films.

In an effort to develop pH-sensitive lipoplexes for efficient gene delivery, we report three novel cationic lipids containing a linear ortho ester linker that conjugates either the headgroup (Type I) or one hydrocarbon chain (Type II) with the rest of the lipid molecule. The cationic lipids carry either an iodide or a chloride counterion. Compared to our previously reported cyclic ortho ester linker, the linear ortho ester linker facilitated the construction of cationic liposomes and lipoplexes with different helper lipids. The chloride counterion not only facilitated the hydration of the lipid films during liposome construction, but also enhanced the hydrolysis of the ortho ester linker in the lipoplexes. After incubation at endosomal pH 5.5, the Type I lipoplexes aggregated and destabilized the endosome-mimicking model liposomes, but not the Type II lipoplexes. The helper lipids (DOPE or cholesterol) of the lipoplexes enhanced the pH-sensitivity of the Type I lipoplexes. In CV-1 cells (monkey kidney fibroblast), the Type I ortho ester-based lipoplexes, especially those with the chloride counterion, significantly improved the gene transfection efficiency, in some cases by more than 100 fold, compared to their pH-insensitive counterparts consisting of DOTAP. The gene transfection efficiency of the ortho ester-based lipoplexes was well correlated with their rate of aggregation and membrane destabilization in response to the endosomal pH 5.5.

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ObjectiveThe purpose of this investigation was to monitor the contamination characters and spatial and temporal distributions of 23 Per uorinated alkyl substances (PFASs) in seafood along South China Coastal Regions. The exposure risks of PFOA and PFOS to human health in marine aquatic products were also evaluated. MethodsA total of 844 samples including 359 shes, 391 shell shes and 94 crustaceans were collected from Guangdong, Guangxi and Hainan provinces. The samples were extracted and puri ed using a modi ed QuEChERS procedure and analyzed by UPLC-MS / MS. The statistical analysis was performed in view of the detection of different PFAS components in variety of shes, shell shes and crustaceans, respectively. ResultsSixteen PFASs were detected in the survived samples and the total detection rates reached to 99.21 %. The highest ∑PFASs in each sample was 28.27 μg/kg, and the average and medium values of ∑PFAS were 1.83 μg/kg and 1.18 μg/kg, respectively. PFOS and PFBA have been considered as predominant PFAS components with corresponding pollution contribution rates of 29.14% and 24.71%, respectively. However, it is noted that PFNA and PFBS were primarily enriched in the oyster and mussel. During the period of this investigation (2014-2016), ∑PFAS average concentrations turned out constantly rising trend and new pollution component PFHxS detected in 2016. ∑PFAS concentrations of Guangdong, Guangxi and Hainan provinces were approximately at similar level. ConclusionThe contamination status of PFASs were getting worse in South China Coastal Regions. Safety and risk exposure assessments of PFOA and PFOS via daily diet intakes showed relatively low to local residents.