运用TTI法恢复地层原始沉积厚度——以华北晋西、中原地区为例

岩石中有机质的成熟度是它在埋藏史中热演化效应的累积,这种累积效应可用时间-温度指数(TTI值)或镜煤反射率(R°)表示。在取得某地区研究层的TTI(或R°)值及埋藏史后,就可反演出其最大埋深,恢复地层原始沉积厚度。此法的精度取决于地温、厚度及TTI或R°等参数,当研究区地质历史上发生多次降升和沉降时,必须进行深度校正和时间-温度的热校正。     

Mortality and some biochemical changes in mink (Mustela vison) given sublethal doses of aflatoxin each day

Two feeding trials were done to study the susceptibility of mink (Mustela vison) to multiple sublethal doses of aflatoxins. In the 1st trial, twenty 3-month-old male mink were divided equally among groups. Each mink in groups 1, 2, 3, and 4 was given a meatball daily that contained 15, 30, 45, or 0 mug of aflatoxins (B1:G1, 40:60), respectively. All mink in group 3 died between the 25th and the 30th days of the feeding trial. Each mink had ingested 1,035 to 1,480 mug of aflatoxins. Four of the mink in group 2 died almost as soon as did mink in group 3. Four mink in group 1 died between 40 and 59 days after the start of the feeding trial. Generally, a marked increase in plasma cholesterol and alkaline phosphatase activity appeared before mink died. The liver from animals that died of aflatoxicosis showed prominent pathologic changes which included hemorrhages and appearance of pink yellow spots. Histopathologic examination of liver from dead mink revealed fatty infiltration, bile duct proliferation, bile stasis, pseudotubular formation, congestion, and fibrosis. The feeding trial was repeated with 20 mink (8 males and 12 females) that were 1.5 to 2 years old. In this instance, 0, 20, 40, and 60 mug of aflatoxins were administered each day. All treated animals, except 1, were dead within 37 days after the experiment started. The survivor was given the lowest dosage of toxins and died after 52 days by which time 960 mug of aflatoxins were consumed. Plasma cholesterol content and alkaline phosphatase activity generally were similar to those observed in younger mink of the 1st feeding trial.     

Antrodia camphorata ameliorates high-fat-diet induced hepatic steatosis via improving lipid metabolism and antioxidative status

Nonalcoholic fatty liver disease (NAFLD) commonly results from excessive dietary fat intake which characterized by obesity and insulin resistance. Wild fruiting body of Antrodia camphorata (AC) was assayed for alleviative effects on NAFLD. An NAFLD animal model was successfully established in male 7-week-old C57BL/6 mice fed with high-fat diet (HFD) for 36 weeks. The HFD mice exhibited obese and impaired glucose metabolism. After an induction of NAFLD syndrome, AC was given for one week via gavage. Mice with AC treatment showed lowered (p < 0.05) serum TG and TC, lowered (p < 0.05) liver TG content, improved (p < 0.05) oxidative status (TBARS values and GSH levels), and ameliorated (p < 0.05) liver damage (AST, ALT, and LDH values). In addition, AC activated (p < 0.05) gene expressions of PPAR-α with its downstream genes in the liver and caused higher (p < 0.05) rectal temperature, which showed AC attenuates hepatic lipid accumulation by promoting lipid oxidation and further suggests the role of AC in energy expenditure. Overall, our findings revealed that AC possesses alleviative effect on NAFLD.     

Volatile components of the enzyme-ripened sufu, a Chinese traditional fermented product of soy bean

In the present study, sufu, a soft cheese-like oriental fermented food, was prepared by ripening the salted-tofu cubes in Aspergillus oryzae-fermented soybean-rice koji at 37°C for 16 days (16-day sufu). Sufu was further held at room temperature for another 30 days (46-day sufu). The volatile components of the non-fermented tofu cubes and the sufu products were identified and quantified by GC and GC-MS. A total of 70 volatile compounds including 20 aldehydes, 18 alcohols, 16 esters, 5 ketones, 5 acids and 6 other compounds were identified. Sufu products contained more volatile compounds than non-fermented tofu cubes qualitatively and quantitatively. After 16-days of ripening, fatty acid, aldehyde and ester were noted to be the dominant volatile fractions. In contrast, the 46-day sufu contained ester, and alcohol as the major volatile fractions. They comprise approximately 63.9% of the total volatile components.     

Transformation of bisphenol A and alkylphenols by ammonia-oxidizing bacteria through nitration

Transformation of bisphenol A (BPA) by ammonia-oxidizing bacteria (AOB) Nitrosomonas europaea ATCC 19718 was investigated. On the basis of the ultraperformance liquid chromatography (UPLC) coupled to quadrupole time-of-flight mass spectrometry (Q-TOF MS) and nuclear magnetic resonance analysis, we found N. europaea could transform BPA into nitro- and dinitro-BPA, suggesting that abiotic nitration between the biogenic nitrite and BPA played a major role in the transformation of BPA in the batch AOB system. Nitrite concentrations, temperature, and pH values were the major factors to influence the reaction rate. Furthermore, the yeast estrogenic screening assay showed that the formed nitro- and dinitro-BPA had much less estrogenic activity as compared with its parent compound BPA. Similar reactions of abiotic nitration were considered for 4-n-nonylphenol (nNP) and 4-n-octylphenol (nOP) since nitro-nNP and nitro-nOP were detected by UPLC-Q-TOF MS. In addition, results from the local wastewater treatment plant (WWTP) showed the occurrence of nitro-BPA and dinitro-BPA during the biological treatment process and in the effluent, indicating that nitration of BPA is also a pathway for removal of BPA. Results of this study provided implication that AOB in the WWTPs might contribute to removal of selected endocrine-disrupting compounds (EDCs) through abiotic nitritation.     

Survival of bifidobacteria after spray-drying

To investigate the survival of bifidobacteria after spray-drying, Bifidobacterium infantis CCRC 14633, B. infantis CCRC 14661, B. longum ATCC 15708, B. longum CCRC 14634 and B. longum B6 were first spray-dried with different carrier media including 10% (w/w) gelatin, gum arabic and soluble starch. B. infantis CCRC 14633 and B. longum were also determined in skim milk. It was found that survival of bifidobacteria after spray-drying varied with strains and is highly dependent on the carriers used. Among the test organisms, B. longum B6 exhibited the least sensitivity to spray-drying and showed the highest survival of ca. 82.6% after drying with skim milk. Comparisons of the effect of carrier concentrations revealed that spray-drying at 10% (w/w) gelatin, gum arabic or soluble starch resulted in the highest survival of bifidobacteria. In addition, among the various outlet-air temperatures tested, bifidobacteria showed the highest survival after drying at 50 degrees C. Elevation of outlet-air temperature caused increased inactivation of bifidobacteria. However, the inactivation caused by increased outlet-air temperature varied with the carrier used, with the greatest reduction observed using soluble starch and the least with skim milk.     

Antioxidant activities of chicken liver hydrolysates by pepsin treatment

This study was divided into two parts: (i) an optimal hydrolysing procedure of chicken liver hydrolysates (CLHs) and (ii) the in vivo antioxidant properties of CLHs via a D‐galactose‐induced mouse model. A pepsin‐to‐raw chicken liver mass ratio (1:400, w:w) and 2‐h hydrolysing period were chosen to manufacture CLHs based on yield, peptide level and antioxidant effect. Molecular masses of CLHs were lower than 10 kDa. CLH was rich in aspartic acid and glutamic acid, and also contained both manganese and selenium, which are essential cofactors of superoxide dismutase and glutathione peroxidase, respectively. The contents of cadmium, mercury, tin, and arsenic in CLHs were very low and even no detectible. Regarding the in vivo antioxidant activity of CLHs, a dosage of 1.2 g D‐galactose kg^?1 body weight increased (P < 0.05) 2‐thiobarbituric acid reactive substances values and decreased (P < 0.05) glutathione and Trolox equivalent antioxidant capacity values, as well as superoxide dismutase, catalase, and glutathione peroxidase activities in serum and organs of mice. However, the in vivo antioxidant capacities were improved (P < 0.05) by supplementing CLHs.