肿瘤抑制因子-P53的翻译后水平修饰

肿瘤抑制因子-P53是与癌症相关性最大的基因,P53要发挥正常功能必须进行翻译后水平的修饰,而其整个过程的全面认识对肿瘤治疗的分子机理和肿瘤防治具有重要意义。作者针对P53的翻译后水平修饰,即磷酸化修饰、乙酰化修饰、SUMO化修饰和P53的泛素蛋白酶体降解途径等问题进行了概括性的论述,阐明了P53翻译后水平的调控网络,为进一步认识肿瘤治疗的分子机理及防治肿瘤等方面提供了理论依据。     

树木休眠越冬期间水分代谢与均衡研究

试验研究树木休眠越冬期间水分代谢与均衡结果表明,越冬初期(11月30日)供试各树种体内含水量为39.36%~49.86%,到翌年3月10日减至34.05%~41.03%,3月中旬开始回升。此期间适宜含水量为35%~50%,>55%则易产生冻裂,<25%繁衍困难,<20%树木死亡。测试树木越冬(11月30日~3月10日)的100d内,水分代谢均衡值为-53.1~-88.3kg,获得补给水量为139.5~211.4kg,消耗水量为192.6~299.7kg,树木体内水分代谢保持负均衡。     

苦豆子药渣中主要饲用成分的测定

对苦豆子(Sophora alopecuroides L.)制药生产后的下脚料——苦豆子药渣中主要饲用成分进行测定,并以紫花苜蓿作为对照,采用t检验对比两者之间的差异。结果表明,苦豆子药渣中的粗蛋白、粗脂肪、磷的含量都极显著高于紫花苜蓿(P<0.01);粗纤维的含量与紫花苜蓿的基本相同(P>0.05);水分及钙的含量都极显著低于紫花苜蓿(P<0.01)。试验结果说明苦豆子药渣是一种营养价值较高的蛋白质饲料。     

木质粉尘旋风静电除尘器的设计

随着我国木材工业的发展,木材工业粉尘污染问题在一定程度上已成为制约我国木材工业发展的重要因素,已引起人们的高度重视[1].因此,探索设计一种能对木材工业传统除尘器进行补充的高效除尘器具有重要的现实意义.     

不同样品保存液和保存条件对动物细胞体外培养的影响

本研究取矮脚油鸡7日龄胚胎作为试验材料,用MEM、全培养基和PBS 3种不同的液体对鸡胚组织进行保存,同时在不同保存温度条件下按不同保存时间梯度,采用组织块贴壁培养法进行体外细胞培养。对细胞的保存液变化,细胞形态、细胞生长等情况进行研究,分析样品保存条件对细胞体外培养和细胞系构建的影响。结果发现,4 ℃保存的组织块培养效果明显优于室温保存;无论在4 ℃或常温,基础培养基保存的组织块培养效果明显优于保存液,全培养基效果最好。常温保存48 h以内3种保存液培养效果差别甚微,48 h后培养效果均急剧下降,96 h后保存在PBS中的组织失活,未长出细胞。本研究结果为建立细胞系采集样品的保存提供了一定的参考。     

Insecticidal activity against Aedes aegypti of m-pentadecadienyl-phenol isolated from Myracrodruon urundeuva seeds

BACKGROUND: Myracrodruon urundeuva Fr. Allemao is a common tree in the Caatinga that has been widely used for various medical purposes. Previous studies showed that the ethanol seed extract of M. urundeuva has potent activity against the larval stage of the dengue vector Aedes aegypti. Given this potential insecticidal activity, bioguided separation steps were performed in order to isolate the active compound(s). RESULTS: The isolation process resulted in only one active chemical compound, identified by infrared spectroscopy and mass spectrometry as m-pentadecadienyl-phenol. This compound presented potent larvicidal and pupicidal activity (LC₅₀ 10.16 and 99.06 µg mL⁻¹ respectively) and great egg hatching inhibitory activity (IC₅₀ 49.79 µg mL⁻¹). The mode of action was investigated through observations of behavioural and morphological changes performed in third-instar larvae treated with m-pentadecadienyl-phenol solution after 1, 6, 12, 16 and 20 h of exposure. Some changes were observed as flooding of the tracheal system, alterations in siphonal valves and anal gills and lethargy, probably caused by the strong anticholinesterasic activity reported previously. CONCLUSION: The compound isolated from M. urundeuva seeds, m-pentadecadienyl-phenol, showed potent activity against immature stages of dengue vector, Ae. aegypti, being considered the main larvicidal principle. Copyright © 2012 Society of Chemical Industry     

酶法提高蓝莓果花色苷与总酚溶出率的工艺条件研究

比较了纤维素酶、果胶酶以及复合果汁酶对蓝莓果浆的酶解效果,确定果汁酶具有最佳的提高花色苷及总酚溶出率的能力。通过单因素试验及正交试验,确定最佳酶解条件为酶添加量0.2 g/L,酶解温度60℃,酶解时间60 min。经酶解后的蓝莓果清汁中花色苷质量浓度达到410 mg/L,花色苷的提取率达到14.1%,较未经酶处理蓝莓果清汁中花色苷的提取率提高了2.17倍;总酚质量分数达到175.1 mg/100 g,提取率达到21.8%,较未经酶处理蓝莓果清汁中总酚的提取率提高了1.95倍。     

单板条层积材(PSL)施胶方法与热压工艺的研究

以杨木碎单板切成的单板条制作PSL为研究对象,通过分析单板条的尺寸形态、施胶的胶液浓度与施胶时间对单板条吸胶量影响,考察了3种不同的施胶方法、热压时间与温度对PSL物理力学性能的影响,优化了热压工艺。结果表明,单板条的尺寸形态对其吸胶量没有显著的影响,它主要影响产品的均一性和外观质量;胶黏剂的浓度是影响单板条吸胶量的一个重要因素,选用胶液浓度为30%的酚醛树脂胶;施胶方法是影响PSL力学性能的重要因素;热压时间和热压温度对PSL的物理力学性能有显著的影响。综合考虑产品的物理力学性能和产品均一性,以单板条长度为100mm,采用喷胶方式,热压时间为35min、热压温度为150℃时制成的PSL的性能较好。     

表观遗传对植物开花相关基因表达的调控

综述表观遗传对植物开花过程中基因表达的调控。目前,对表观遗传的研究越来越深入,对植物开花过程中的基因调控过程也有很大程度上的把握,但二者的结合即表观遗传对植物开花过程中基因表达的调控还处于初级的探索阶段。因此,对这方面进行深入的研究有助于加深对植物生命周期调控机制的理解,并且对农业生产具有较大的指导意义。     

Isolation, identification and antimicrobial susceptibility of Bacteroides fragilis group strains recovered from broiler faeces

1. The objective was to evaluate the occurrence of cultivable components of the Bacteroides fragilis group in faeces of broiler chickens and their antimicrobial susceptibility patterns.

2. Faecal samples of 36?×?45-d-old Cobb broilers of both sexes from 15 different flocks on one farm were diluted 10-fold and plated on to Bacteroides-bile-esculin agar for colony count and isolation. Identification was by molecular methods and antimicrobial susceptibility in the agar dilution assay.

3. A total of 236 isolates was recovered from a mean population of 3·32?×?10⁷ colony-forming units/g of faeces. B. fragilis was shown to be the predominant Bacteroides species (45·3%), followed by B. distasonis (35·6%), B. vulgatus (8·9%), B. ovatus (2·5%) and B. stercoris (1·3%).

4. Among 204 bacterial isolates tested, high resistance to ampicillin (98·5%), norfloxacin (95·1%) and tetracycline (88·2%) were observed. High (89·7%) multi-drug resistance was observed to 3–7 of the tested drugs.

5. Components of the B. fragilis group were sub-dominant in broiler faecal microbiota, with a different species pattern compared with human and high antimicrobial multi-drug resistance.