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Metal impurities in carbon nanotubes (CNTs) are undesirable for their uses in diverse applications, for instance, they may potentially have a negative health impact when using in biomedical fields. However, so far there is a lack of analysis methods able to quantify metallic impurities in CNTs. In this paper, using the neutron activation analysis (NAA) technique as a nondestructive standard quantification method and inductively coupled plasma mass spectrometry (ICPMS) as a practical approach, we established an analytical method for quantitative determination of metallic impurities in CNTs. ICPMS, one of the most sensitive analytical techniques used for coincident multielement measurements, has become a common tool in many laboratory, and thus it is easily available and a good selection for determining the metal impurities in CNTs. However, because of their extremely stable structure and the encapsulated metals in the defect structure, CNTs must undergo special pretreatments before ICPMS. We investigated different sample pretreatment procedures for ICPMS analysis, including dry ashing coupled with acid extraction, wet digestion, and a combination of dry ashing with acid digestion. With the reference data from the nondestructive analytical method of NAA, we found that the quantitative determination of metal impurities in CNTs is highly dependent on the sample pretreatment in which the conditions are largely different from those used for conventional biological samples or environmental materials. This paper not only provides the practical method and analysis conditions for quantifying the metal impurities of CNTs but also the first protocol for pretreatment processes of CNT samples.

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Our study aimed to determine the effect of increasing dietary levels of turmeric rhizome extract (TRE) on performance, carcass characteristics, antioxidant capability and meat quality of Wenchang broiler chickens. Three hundred, 1-day-old Wenchang broiler chickens were brooded together for 2 weeks, then randomly allocated into four treatments with five replicates of 15 birds each. Birds were fed a corn-soybean basal diet supplemented with TRE at 0, 100, 200 and 300 mg/kg for 12 weeks. The results revealed that a TRE-supplemented diet had no significant effect (P>0.05) on the body weight, although birds fed a diet with TRE at 100 and 200 mg/kg had higher average daily weight gains and average daily feed as compared to controls from 9 to 12 week (P<0.05). Also, the addition of TRE at 100 to 300 mg/kg had a better feed conversion ratio compared to controls from week 9 to 12 (P<0.05). Dietary supplementation with TRE at 300 mg/kg increased the breast muscle weight ratio (P<0.05). Meanwhile, dietary supplementation with TRE at 100 to 300 mg/kg reduced the abdominal fat ratio (P<0.05), compared to that of the control group. TRE increased enzymatic activities of superoxide dismutase and glutathione peroxidase, and reduced malondiadehhyde concentrations, compared to the control group. Dietary TRE supplementation at 300 mg/kg decreased the drip loss in both breast muscle and thigh muscles, compared with the control group (P<0.05). In conclusion, dietary TRE supplementation enhanced antioxidant capability, growth performance, breast muscle weight ratio, and reduced the abdominal fat ratio of Wenchang broiler chickens.

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The global burden of bacterial disease remains high and is set against a backdrop of increasing antimicrobial resistance. There is a pressing need for highly effective and natural antibacterial agents. In this work, the anti-biofilm effect of cinnamon oil on methicillin-resistant Staphylococcus aureus was evaluated. Then, cinnamon oil was encapsulated in liposomes to enhance its chemical stability. The anti-biofilm activities of the liposome-encapsulated cinnamon oil against MRSA biofilms on stainless steel, gauze, nylon membrane and non-woven fabrics were evaluated by colony forming unit determination. Scanning electron microscopy and laser scanning confocal microscopy analyses were employed to observe the morphological changes in MRSA biofilms treated with the encapsulated cinnamon oil. As a natural and safe spice, the cinnamon oil exhibited a satisfactory antibacterial performance on MRSA and its biofilms. The application of liposomes further improves the stability of antimicrobial agents and extends the action time.