ABSTRACT The spoilage of beer by bacteria is of great concern to the brewer as this can lead to turbidity and abnormal flavors. The polymerase chain reaction (PCR) method for detection of beer-spoilage bacteria is highly specific and provides results much faster than traditional microbiology techniques. However, one of the drawbacks is the inability to differentiate between live and dead cells. In this paper, the combination of propidium monoazide (PMA) pretreatment and conventional PCR had been described. The established PMA-PCR identified beer spoilage Lactobacillus brevis based not on their identity, but on the presence of horA gene which we show to be highly correlated with the ability of beer spoilage LAB to grow in beer. The results suggested that the use of 30 µg/mL or less of PMA did not inhibit the PCR amplification of DNA derived from viable L. brevis cells. The minimum amount of PMA to completely inhibit the PCR amplification of DNA derived from dead L. brevis cells was 2.0 µg/mL. The detection limit of PMA-PCR assay described here was found to be 10 colony forming units (CFU)/reaction for the horA gene. Moreover, the horA-specific PMA-PCR assays were subjected to 18 reference isolates, representing 100% specificity with no false positive amplification observed. Overall the use of horA-specific PMA-PCR allows for a substantial reduction in the time required for detection of potential beer spoilage L. brevis and efficiently differentiates between viable and nonviable cells.

The superlarge Dongfeng gold deposit is located in the Potouqing faults-alteration belt of the eastern part of the 'Zhao-Lai-gold ore belt', which belongs to the northwestern part of the Jiaodong area. Tectonically, ore bodies are controlled by faults and gold mainly occurs in the pyrite and polymetallic sulfide-bearing quartz vein. In this paper, Rb-Sr isotopic analysis is carried out with the beresite, which formed by hydrothermal metasomatism, and the Rb-Sr isochron age is 125.5±6.7Ma, indicating this deposit set up in the early Cretaceous of the late Yanshanian. Based on the relationship between the Dongfeng gold deposit and the Mesozoic granite, it is suggested that the formation of the gold deposit is a complex geological process of gradual enrichment and precipitation of the ore-forming elements. The initial 87Sr/86Sr ratio of the beresite is 0.711502±0.000069, which indicates the ore-forming materials mainly come from the crust. Combined with the complex mineralization process of the Dongfeng gold deposit and the reported H-O isotopic data, it is suggested that the ore-forming materials are mainly derived from the crust with some mantle materials, while the ore-forming fluids are originated primarily from magmatic hydrothermal and mantle with some precipitate water.

OBJECTIVE: Little is known about metabolic factors in cirrhotic patients in China. Therefore, we aimed to quantify the prevalence of both metabolic factors and non-alcoholic steatohepatitis-related liver cirrhosis in China. METHODS: The medical records of 1,582 patients diagnosed with liver cirrhosis from June 2003 to July 2013 at Daping Hospital (Chongqing, China) were retrospectively reviewed through a computer-generated search. RESULTS: Serum hepatitis B virus surface antigen was present in 1,083 (68.5%) patients, and hepatitis B was found to be the only etiological factor in 938 (59.3%) of all patients. Obesity, diabetes mellitus, and arterial hypertension were observed in 229 (14.5%), 159 (10.1%), and 129 (8.2%) patients, respectively. From 2012-2013, the proportion of non-alcoholic steatohepatitis-related liver cirrhosis increased to 3.2%, whereas the average proportion of non-alcoholic steatohepatitis-related liver cirrhosis in the previous ten years was 1.9%. The incidence of hepatocellular carcinoma was much higher in males than in females (6.3% vs. 3.7%, respectively, p=0.036). Obesity and diabetes mellitus did not significantly increase the incidence of hepatocellular carcinoma in the whole cirrhotic group. The presence of hepatitis B virus was the only risk factor for hepatocellular carcinoma in cirrhotic patients (p<0.001). CONCLUSIONS: Although hepatitis B virus remains the main etiology of liver cirrhosis in China, steatohepatitis-related liver cirrhosis is increasing in frequency. Hepatitis B virus was the sole significant risk factor for hepatocellular carcinoma in the whole cirrhotic group in the present study, in contrast to obesity and diabetes mellitus, for which only a trend of increased hepatocellular carcinoma was found.