纵膈淋巴瘤累及处放疗时前后对穿适形放疗及调强放疗的剂量学比较

目的比较前后对穿野放疗(POP)计划及调强放疗(IMRT)计划中在累及纵膈区恶性淋巴瘤行累及处放疗(ISRT)的中的靶区剂量分布及正常组织剂量对比。方法对均累及纵膈的20个淋巴瘤患者均分别按照ISRT的放疗照射野的概念勾画放疗靶区及危及器官,再用这两个不同照射概念的靶区分别按照常规前后对穿野及五野调强分别制作放疗计划。对比两种不同计划POP及IMRT中PTV的覆盖及肺、心脏、脊髓及乳腺的剂量的区别。结果在IMRT计划中,PTV的适形指数优于POP计划(P<0.05),但均匀性指数无明显差异。在IMRT计划中明显降低心脏、脊髓及肺的高剂量照射体积(P<0.05)。但乳腺低剂量V4、肺的低剂量V5在POP计划中明显更低(P<0.05)。结论在累及纵膈区恶性淋巴瘤ISRT设野放疗中,相对于POP计划,IMRT计划对靶区覆盖的适形性及心脏、脊髓保护有优势,但增加了肺及乳腺的低剂量体积,可能导致第二原位癌风险增加。可根据患者的不同情况选择放疗方式。     

Effect of composite biological preservative containing <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> on postharvest litchi quality

Biological preservatives containing live microorganisms are environmentally friendly and non-toxic substances used to preserve the quality of fresh fruits. This study investigated whether a composite biological preservative containing live Lactobacillus plantarum (designated as DN003) could preserve the quality of postharvest litchi fruits at high temperature and in humid environment. Postharvest litchi fruits were briefly soaked in DN003, then dried and stored at 29–33°C with 95–98% relative humidity; prochloraz treatment was included as positive control and non-treatment as negative control. In comparison with negative control group, litchi fruits in both DN003-treated and positive control groups better retained their appearance with lower polyphenol oxidase and peroxidase activities and showed higher concentrations of vitamin C, titratable acids, and total sugar content. These data demonstrated that the new composite biological preservative containing L. plantarum is promising to be used in the preservation of postharvest litchi fruit, particularly in high-temperature and humid environment.     

Comparison of bacterial community in matured and degenerated pit mud from Chinese Luzhou‐flavour liquor distillery in different regions

The bacterial community in the pit mud of a Luzhou‐flavour liquor distillery in different regions was analysed by combined polymerase chain reaction–denaturing gradient gel electrophoresis (PCR‐DGGE) and quantitative PCR (qPCR) in order to distinguish a matured and a degenerated pit mud, judged according to sensory and physicochemical characteristics. The phyla Firmicutes, Cloacimonetes, Actinobacteria, Proteobacteria, Synergistetes and Unclassified Bacteria were detected. Firmicutes predominated in the pit mud. The diversity and homogeneity of the bacterial community in the matured pit mud were superior to those in the degenerated pit mud in the same distillery. There were significant differences in the bacterial community structure between the matured and degenerated pit mud. Moreover, the bacterial community in the degenerated pit mud samples was similar, which indicated that the bacterial community in the degenerated pit mud did not change within the two different regions. However, the bacterial community in matured pit mud samples was different, demonstrating that there were visible differences in the bacterial community between the samples of matured pit mud collected from the Luzhou‐flavour liquor distilleries in the two different regions. Notably, the quantity of Actinobacteria in the matured and the degenerated pit mud was found to be different by quantitative analysis. Potentially, the Actinobacteria could serve as an indicator bacteria to distinguish between matured and degenerated pit muds. Copyright © 2016 The Institute of Brewing & Distilling     

Comparative studies of quality changes in white and dark muscles from common carp (Cyprinus carpio) during refrigerated (4 °C) storage

Differences between white and dark muscles from common carp (Cyprinus carpio) in sensory assessment, total viable counts (TVC), total volatile basic nitrogen (TVB‐N), pH, electrical conductivity (EC), biogenic amines (BAs), nucleotide degradation products and colours were investigated under air and vacuum conditions during refrigerated (4 °C) storage. Compared with white muscle, dark muscle had a higher lipid content, but lower crude protein and moisture content. TVC, TVB‐N, pH, and L* value were higher in white muscle, while K value and a* value were higher in dark muscle. Under both conditions, white and dark muscles had significant (P < 0.05) differences in tyramine and cadaverine content. Although dark muscle was significantly (P < 0.05) lower in ATP content, it had higher rate of IMP degradation and K value increase. Taking sensory and microbial indexes into consideration, dark muscle appeared to have a longer shelf life than white muscle under both conditions.     

2002年北京市市售鲜鸡蛋和生鸡肉的沙门菌污染情况调查

为了了解北京市市售鲜鸡蛋、生鸡肉的沙门菌污染情况,并为建立食物污染及中毒的预警系统提供数据基础,2002年7、8和9月从北京市四个区的集贸市场、超市、商场和街边小商店共采集鲜鸡蛋100件,生鸡肉100件,进行了沙门菌的定性、定量检测及血清分型。结果表明鲜鸡蛋蛋液中未检出沙门菌,生鸡肉的沙门菌阳性检出率为30%,沙门菌在生鸡肉中的污染情况与销售温度有关。因此,控制沙门菌的污染来源和生鸡肉销售的温度条件是控制沙门菌污染的手段之一。然而,还需要进一步研究的是鲜鸡蛋外源性污染情况的调查;销售温度与污染情况之间相关性的进一步证实。     

酒花油的HS-GC/MS分析研究

采用静态顶空 气相色谱 质谱法 (HS GC/MS)对酒花油的成分进行了分析研究 ,共分离和鉴定了 74种化合物 ,它们分别属于萜烯类碳氢化合物、含氧化合物和含硫化合物。用归一法对所测酒花油的成分进行定量分析发现 ,萜烯类碳氢化合物占酒花油的 5 0 %～ 80 %左右 ,含氧化合物占 1 0 %～ 2 5 %左右 ,含硫化合物占 2 %以下。以酒花挥发性成分为基础对酒花进行聚类分析 ,既能寻找酒花的替代品也能够进行酒花品种的鉴定。     

金属元素自动分析仪测定铬鞣剂中痕量Cr(Ⅵ)的研究

提出了自动参比流动注射法 ,对铬鞣剂中的痕量Cr(Ⅵ )的测定。采用ZJ- 1a金属元素自动分析仪的流动注射功能 ,以二苯碳酰二肼、丙酮、硫酸的混合溶液为显色剂 ,丙酮的硫酸溶液为参比溶液 ,对铬鞣剂中的痕量Cr(Ⅵ )进行了测定。考察了显色剂中二苯碳酰二肼浓度、显色剂中酸的种类及浓度、流速等因素的影响 ,优化了试验条件。在优化的试验条件下 ,测得Cr(Ⅵ )的检出限为 0 .2 8× 10 -9g/mL ,相对标准偏差为 1.2 4 % ,对铬鞣剂中的Cr(Ⅵ )进行分析 ,回收率在 96 .1%～ 10 3% ,结果令人满意     

超细纤维PU革缝合撕裂强度影响因素的研究(续)

采用正交试验法研究了超细纤维PU革 ,在不同缝合工艺条件下制成试样的撕裂强度 ,结果表明 :对缝合效果要求不同时 ,影响皮革缝合撕裂强度各因素的显著性排列的顺序也不同。     

瓦楞纸板用淀粉胶粘剂的作用机理和载糊改性淀粉的性质

本文叙述瓦楞纸板用淀粉胶粘剂在上浆过程,润湿、扩散、吸附过程,原淀粉糊化过程,初贴合形成过程和干燥过程中的作用机理及其性质变化,探讨改性淀粉在胶粘剂中的作用和性质.