A new FTIR method for estimating the firing temperature of ceramic bronze-casting moulds from early China.

Intricate ceramic bronze-casting moulds are among the most significant archaeological remains found at Bronze Age metallurgical workshops in China. Firing temperature was presumably one of the most important technical factors in mould making. However, it has proven difficult to determine the firing temperatures of excavated moulds using existing analytical methods. This study establishes an innovative new method for using Fourier-transform infrared spectroscopy (FTIR) to estimate the firing temperature of clay-containing remains. The method is based on the finding that the infrared absorptivity of fired clay minerals, measured at the Si-O-Si stretching resonance band, is negatively correlated with firing temperature. Moulds and mould cores dating to the Early Shang period (sixteenth to fourteenth century BCE) are found to have been fired at extremely low temperatures-as low as 200-300 °C in many instances. These results provide critical new data for understanding the metallurgical technology of ancient China.

[Determination of 27 fragrances in cosmetics and perfume raw materials by gas chromatography-mass spectrometry].

A chromatographic separation method for 27 fragrances in cosmetics and perfume raw materials was developed using gas chromatography-mass spectrometry (GC-MS). A weak polar capillary column and electron impact ion source were used in the GC-MS analysis, with methanol as the extraction solvent. The limits of detection were 1.2, 15, and 15 mg/kg for musk xylene, hydroxycitronellal, and hydroxyisohexyl-3-cyclohexene carboxaldehyde, respectively, and 3.0 mg/kg for the other 24 fragrances. The calibration line of the 27 fragrances presented a good relationship with correlation coefficients ≥ 0.996. At three spiked concentration levels, the relative standard deviations were <10% and the spiked recoveries were in the ranges of 73.3%-76.1% for musk xylene and 81.5%-118% for the other fragrances. Based on these determinations, one or more fragrance ingredients were detected in 69 perfume raw materials and cosmetics, the labels of which indicated that they contained fragrances. This method can be used to determine 27 fragrances in cosmetic and perfume raw materials.

Surface chromium on Terracotta Army bronze weapons is neither an ancient anti-rust treatment nor the reason for their good preservation.

For forty years, there has been a widely held belief that over 2,000 years ago the Chinese Qin developed an advanced chromate conversion coating technology (CCC) to prevent metal corrosion. This belief was based on the detection of chromium traces on the surface of bronze weapons buried with the Chinese Terracotta Army, and the same weapons' very good preservation. We analysed weapons, lacquer and soils from the site, and conducted experimental replications of CCC and accelerated ageing. Our results show that surface chromium presence is correlated with artefact typology and uncorrelated with bronze preservation. Furthermore we show that the lacquer used to cover warriors and certain parts of weapons is rich in chromium, and we demonstrate that chromium on the metals is contamination from nearby lacquer after burial. The chromium anti-rust treatment theory should therefore be abandoned. The good metal preservation probably results from the moderately alkaline pH and very small particle size of the burial soil, in addition to bronze composition.

Longitudinal Study of DNA Methylation of Inflammatory Genes and Cancer Risk.

BACKGROUND: Chronic inflammation plays a key role in cancer etiology. DNA methylation modification, one of the epigenetic mechanisms regulating gene expression, is considered a hallmark of cancer. Human and animal models have identified numerous links between DNA methylation and inflammatory biomarkers. Our objective was to prospectively and longitudinally examine associations between methylation of four inflammatory genes and cancer risk. METHODS: We included 795 Normative Aging Study participants with blood drawn one to four times from 1999 to 2012 (median follow-up, 10.6 years). Promoter DNA methylation of IL6, ICAM-1, IFN, and TLR2 in blood leukocytes was measured using pyrosequencing at multiple CpG sites and averaged by gene for data analysis. We used Cox regression models to examine prospective associations of baseline and time-dependent methylation with cancer risk and compared mean methylation differences over time between cancer cases and cancer-free participants. RESULTS: Baseline IFN hypermethylation was associated with all-cancer (HR, 1.49; P = 0.04) and prostate cancer incidence (HR, 1.69; P = 0.02). Baseline ICAM-1 and IL6 hypermethylation were associated with prostate cancer incidence (HR, 1.43; P = 0.02; HR, 0.70; P = 0.03, respectively). In our time-dependent analyses, IFN hypermethylation was associated with all-cancer (HR, 1.79; P = 0.007) and prostate cancer (HR, 1.57; P = 0.03) incidence; and ICAM-1 and IL6 hypermethylation were associated with prostate cancer incidence (HR, 1.39; P = 0.02; HR, 0.69; P = 0.03, respectively). We detected significant ICAM-1 hypermethylation in cancer cases (P = 0.0003) 10 to 13 years prediagnosis. CONCLUSION: Hypermethylation of IFN and ICAM-1 may play important roles in early carcinogenesis, particularly that of prostate cancer. IMPACT: These methylation changes could inform the development of early detection biomarkers and potential treatments of inflammation-related carcinogenesis.

Blood Telomere Length Attrition and Cancer Development in the Normative Aging Study Cohort.

BACKGROUND: Accelerated telomere shortening may cause cancer via chromosomal instability, making it a potentially useful biomarker. However, publications on blood telomere length (BTL) and cancer are inconsistent. We prospectively examined BTL measures over time and cancer incidence. METHODS: We included 792 Normative Aging Study participants with 1-4 BTL measurements from 1999 to 2012. We used linear mixed-effects models to examine BTL attrition by cancer status (relative to increasing age and decreasing years pre-diagnosis), Cox models for time-dependent associations, and logistic regression for cancer incidence stratified by years between BTL measurement and diagnosis. FINDINGS: Age-related BTL attrition was faster in cancer cases pre-diagnosis than in cancer-free participants (pdifference = 0.017); all participants had similar age-adjusted BTL 8-14 years pre-diagnosis, followed by decelerated attrition in cancer cases resulting in longer BTL three (p = 0.003) and four (p = 0.012) years pre-diagnosis. Longer time-dependent BTL was associated with prostate cancer (HR = 1.79, p = 0.03), and longer BTL measured ≤ 4 years pre-diagnosis with any (OR = 3.27, p < 0.001) and prostate cancers (OR = 6.87, p < 0.001). INTERPRETATION: Age-related BTL attrition was faster in cancer cases but their age-adjusted BTL attrition began decelerating as diagnosis approached. This may explain prior inconsistencies and help develop BTL as a cancer detection biomarker.

Association study of miR­149 rs2292832 and miR­608 rs4919510 and the risk of hepatocellular carcinoma in a large­scale population.

Polymorphisms in pre­microRNAs (miRNAs) or mature miRNAs may influence miRNA processing or target binding, thus contributing to tumorigenesis and cancer development. The present study aimed to evaluate whether miR­149 rs2292832 (C>T) and miR­608 rs4919510 (G>C) are associated with the risk and clinical characteristics of hepatocellular carcinoma (HCC) in a large­scale population. miR­149 rs2292832 and miR­608 rs4919510 were genotyped in a total of 993 patients with HCC and 992 unrelated healthy subjects by Sequenom MassARRAY. The results showed that, compared with the reference CC genotype, the TC+TT genotype of miR­149 was more highly associated with HCC [CC vs. TC+TT: Odds ratio (OR)=1.384, 95% confidence interval (CI)=1.013­1.892, P=0.041], and was also associated with an increased risk of hepatitis B virus (HBV)­associated HCC (CC vs. TC+TT: OR=1.453, 95% CI=1.034­2.042, P=0.031). However, no significant association between miRNA­608 rs4919510 and the risk of HCC/HBV­associated HCC was found. In addition, these two SNPs were shown not to be correlated with a range of clinical characteristics. The present study may provide an indicator for identification of the high risk of HCC in patients.

[Preparation of whole-kidney acellular matrix in rats by perfusion].

OBJECTIVE: To prepare rat whole-kidney acellular matrix (ACM) scaffolds using fluid perfusion method. METHODS: The kidneys with ureters and renal vessels were harvested from 12-week-old Wistar rats. Intravenous catheters were inserted through the renal arteries to establish channels for whole-kidney retrograde perfusion successively with heparinized PBS, 1% SDS, deionized water, 1% TritonX-100 and antibiotic-containing PBS under a pressure of 100 cmH2O. After decellularization, the scaffolds were observed under microscope with HE staining, scanning electron microscope, and fluorescence microscope with DAPI fluorescence staining. RESULTS: No cell residue was found in the scaffolds under microscope. Scanning electron microscope identified reticular structures consisting of basilar membrane and collagen without normal cellular structures in the scaffolds, and no strong fluorescence due to the binding of DAPI to the cell nuclei was observed under fluorescence microscope. CONCLUSION: Fluid perfusion is simple and reliable to prepare rat whole-kidney acellular matrix, which may serve as an ideal cell-free scaffold.