"Green" route to 6-hydroxy-3-succinoyl-pyridine from (S)-nicotine of tobacco waste by whole cells of a Pseudomonas sp

A new technology for 6-hydroxy-3-succinoyl-pyridine (HSP) production from (S)-nicotine in tobacco waste by whole cells of a Pseudomonas sp. has been developed. When deionized water was used in the transformation reaction as a medium and the initial pH value of reaction mixture was adjusted to 7.0, 1.45 g/L HSP was produced from 3 g/L of nicotine in 5 h with 3.4 g/L of cells in a 5-L flask at 30 degrees C. HSP could be easily purified from the reaction without perplexing separation steps. A quantity of 1.3 g of HSP was recovered without impurity, and the overall yield of HSP was 43.8% (w/w), based on an initial concentration of 3.0 g/L of nicotine in reaction. This biotransformation made it possible to convert nicotine in tobacco wastes with high nicotine content into valuable compounds.     

家具设计研究定位于青少年健康的课外学习

本文从青少年的课外学习与行为方式的特点入手,结合中国国情以及社会现实,提出了青少年健康课外学习家具设计的课题,并以基本数据和相关案例为论据,论证和剖析了这一研究课题的必要性、可行性及其基本思路。     

米通织物用纱的生产实践

为提高CJ 14.6 tex米通织物用纱的成纱质量,从原料的选配、纺纱工艺流程着手,采取相应的工艺技术措施:梳棉和精梳以减少棉结为主要目的;并粗工序采用重定量;细纱工序要控制毛羽产生;络筒着重控制毛羽的增长,同时控制好温湿度,从而提高了米通织物用纱的成纱质量.     

氮素与氨基酸微肥混施在设施早黑宝葡萄上的应用初探

以设施早黑宝葡萄为试材,在生长季节喷施不同浓度氮素和氨基酸微肥混合液,研究了不同浓度氮素和氨基酸微肥混合喷施对设施早黑宝葡萄叶绿素含量、叶片电导率、可溶性固形物含量以及果穗质量的影响。结果表明:6种不同浓度氮素和氨基酸微肥混合喷施后,均可明显提高设施早黑宝葡萄叶片叶绿素含量、果实可溶性固形物含量和果穗质量,显著降低叶片电导率,其中尤以1‰尿素+600倍氨基酸微肥效果最好。     

棉纺细纱大牵伸工艺的演变与发展(上)

系统阐述了棉纺细纱大牵伸工艺的演变历程.棉纺细纱牵伸工艺是随着总牵伸倍数的增大和成纱质量要求不断提高而发展的,形成了"重加压、强控制"细纱大牵伸基本工艺路线.介绍了细纱大牵伸发展过程中后区出现的两类工艺,实践验证,实现细纱大牵伸后区应采用小牵伸工艺.分析了细纱前区工艺配置对牵伸质量的影响,指出机织纱工艺配置前区"小浮游区长度、小钳口隔距、小罗拉中心距"是可行的,而针织纱工艺要适可而止.介绍了机织纱工艺、针织纱工艺和V形牵伸工艺的机理及细纱大牵伸的发展,探讨了重定量大牵伸高效工艺的应用效果,R2V型牵伸及V形牵伸后区附加压力棒牵伸形式的发展潜力.     

碳纤维纸与燃料电池的发展现状

阐述了国内外燃料电池及其多孔扩散层电极材料——碳纤维纸的发展概况,介绍了碳纤维纸的作用、性能要求与应用前景。     

Co-contamination of aflatoxin B1 and fumonisin B1 in food and human dietary exposure in three areas of China

Aflatoxins and fumonisins are ubiquitous foodborne toxicants and the co-occurrence of these mycotoxins in human foods represents a significant public health concern, which has been strongly associated with human aflatoxicosis, neural tube defects, as well as many types of primary cancers. In this study the co-contamination of aflatoxin B(1) (AFB(1)) and fumonisin B(1) (FB(1)) in food and human dietary exposure was investigated in residents of three different areas of China. A total of 209 food samples were measured for AFB(1) and FB(1). The median AFB(1) levels were 13.5, 2.3 and 1.3 μg kg(-1) and the median FB(1) levels were 2.6, 0.4 and 0.3 mg kg(-1) in corn samples collected from Huaian (a high-risk area for oesophageal cancer), Fusui (a high-risk area for liver cancer) and Huantai (a low-risk area for both oesophageal and liver cancers), respectively. The median level of AFB(1) in plant oil of Fusui was the highest (52.3 μg kg(-1)) among all food samples analysed. Co-contamination of these two mycotoxins was found in corn, rice and wheat flour. Based on measured food consumption data, the averaged daily dietary intake of AFB(1) was 0.397 μg (range = 0.269-1.218 μg) in residents of Huantai, 1.723 μg (0.224-49.772 μg) in Huaian, and 2.685 μg (1.006-14.534 μg) in Fusui. The averaged FB(1) daily dietary intake was 92.4 μg (range = 55.0-362.1 μg) for residents of Huantai, 460.0 μg (83.2-2894.5 μg) in Huaian, and 138.6 μg (30.0-10,541.6 μg) in Fusui. These data suggest that the co-exposure to AFB(1) and FB(1) in residents of rural China may contribute to the aetiology of human chronic diseases in high-risk areas.     

居室装饰风格浅析

本文阐述了居室的审美形式及与现实生活的关系,介绍了中国传统装饰风格与民族风格、国外现代风格等的主要装饰特点和内容。     

Resveratrol inhibits migration and invasion of human breast‐cancer cells

Metastasis is the primary cause of death from breast cancer. Cell migration and invasion play important roles in neoplastic metastasis. The insulin‐like growth factor (IGF‐1) stimulates cell migration through activation of PI‐3K/Akt signaling pathway. IGF‐1 induces the tumorigenicity of many types of cancer cells and is critical for metastatic cell spread in estrogen receptor (ER)‐negative breast‐cancer cells. Matrix metalloproteinase‐2 (MMP‐2) is a key enzyme in the degradation of extracellular matrices and its expression has been dysregulated in breast cancer invasion and metastasis. Resveratrol exhibited potential anticarcinogenic activities in several studies. However, the inhibitory effects of resveratrol on the expression of MMP‐2, migration and invasion of breast‐cancer cell have not been demonstrated yet. In the present study, we investigated the anti‐invasive mechanism of resveratrol in human breast cancer MDA‐MB 435cells. Here, we showed that IGF‐1 is a potent stimulant of the migration of ER‐negative human breast‐cancer cells. Resveratrol could inhibit IGF‐1‐mediated cell migration of MDA‐MB 435 in vitro. The inhibitory effect of resveratrol was mediated in part through the suppression of the activation of PI‐3K/Akt signaling pathway. Furthermore, IGF‐1‐mediated expression of MMP‐2 was significantly inhibited by resveratrol in concomitance with alteration of cell invasion.     

Proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera)

The proximate composition of seagrape (Caulerpa lentillifera) from culture ponds in Penghu, Taiwan was analyzed. The phenolic content and the antioxidant activities including the 1,1-diphenyl-2-picryl-hydrazil (DPPH) radical scavenging activity, ferric ion-reducing activity, hydrogen peroxide scavenging activity, and ferrous ion chelating (FIC) activity of the ethanolic extracts of dry seagrape samples using 2 drying methods of freeze drying and thermal drying were compared with the ethanolic extract of Oolong tea as a reference. The contents (dry weight basis) of carbohydrate, crude protein, crude lipid, crude fiber, and ash of seagrape obtained from culture ponds in Taiwan were 64.00%, 9.26%, 1.57%, 2.97%, and 22.20%, respectively. The total phenolic content (1.30 mg gallic acid equivalent [GAE]/g dry weight) of the ethanolic extract of thermally dried seagrape was significantly lower (P < 0.05) than that (2.04 mg GAE/g dry weight) of freeze-dried seagrape, and both were significantly lower than that (13.58 mg GAE/g dry weight) of Oolong tea. At the same phenolic content, the antioxidant activities of freeze-dried seagrape were significantly higher (P < 0.05) than those of thermally dried seagrape. Compared with Oolong tea, seagrape, irrespective of drying method used, generally had strong hydrogen peroxide scavenging activity; but it was weak in DPPH radical scavenging activity, ferric ion-reducing activity, and FIC activity. The antioxidant activity of seagrape and Oolong tea was significantly influenced by their phenolic contents. PRACTICAL APPLICATION: The proximate composition, total phenolic content, and antioxidant activity of seagrape (Caulerpa lentillifera) in Taiwan were determined in this research to indicate nutritionally of this edible seaweed to human health, and compared these results to previous studies.