高校公寓文化建设的几点思考

从校园文化、学风建设、素质教育、思想教育等方面，阐述公寓文化的作用和意义，提出理顺管理机制、发挥学生主体作用、加强制度建设，开展公寓文化活动等几点建议。     

Seroprevalence of porcine and human influenza A virus antibodies in pigs between 1986 and 1988 in Hassia

1,268 sera collected from slaughtered pigs in Hassia (FRG) from 1986 to 1988 were tested for antibodies against porcine and human influenza A virus strains using the single radial haemolysis test (SRHT). Antibodies against the porcine strains (subtype H1N1) A/Swine/Arnsberg/1/81, A/Swine/Iowa/15/30 and A/New Jersey/7/76 were detected in 411 (32.4%), 318 (25.1%) and 304 (24.0%) of sera, respectively. Up to 1988 a slight increase (10%) in the seroprevalence to A/Swine/Arnsberg/1/81 was noticed, whereas the results obtained with the other strains showed little variation. Antibodies against the human H1N1 strain A/Singapore/6/86 were only found in sera collected 1987 and 1988 in rates of 1.6% and 3.0%. Serological indication of infections with the human H3N2 strains A/Victoria/1/75, A/Hong Kong/1/68 and A/Philippines/2/82 could be shown in 286 (22.6%), 178 (14.4%) and 135 (10.6%) of the serum samples. Within the three year period the rate of sera positive for antibodies against A/Philippines/2/82 increased from 6.5% to 23.0%, whereas no variation in the rates were found using the other H3N2 strains. Antibodies simultaneously against porcine (H1N1) and human (H3N2) virus strains were detected in 9.9% of all sera tested.     

Youssoufenes A2 and A3, Antibiotic Dimeric Cinnamoyl Lipids from the ΔdtlA Mutant of a Marine-Derived Streptomyces Strain

Two new dimeric cinnamoyl lipids (CL) featuring with an unusual dearomatic carbon-bridge, named youssoufenes A2 (1) and A3 (2), were isolated from the ΔdtlA mutant strain of marine-derived Streptomyces youssoufiensis OUC6819. Structures of the isolated compounds were elucidated based on extensive MS and NMR spectroscopic analyses, and their absolute configurations were determined by combination of the long-range NOE-based ¹H-¹H distance measurements and ECD calculations. Compounds 1 and 2 exhibited moderate growth inhibition against multi-drug-resistant Enterococcus faecalis CCARM 5172 with an MIC value of 22.2 μM.     

4个品种猕猴桃发酵酒品质评价

【目的】研究猕猴桃品种对猕猴桃果酒品质的影响,探索理化指标与感官评价的相关性,为通过原料筛选生产优质猕猴桃酒提供依据。【方法】以生理成熟期的金艳、翠香、翠玉和东红4个品种猕猴桃为原料,经过后熟软化、带皮破碎、添加果胶酶及ADT活性干酵母发酵等工序,酿制4个品种猕猴桃发酵酒,测定4种猕猴桃原料的理化指标（可溶性固形物（TSS）、总酸（TA）、固/酸比、pH值等）,分析4种发酵酒在理化参数（TSS、TA、酒精度、残糖、挥发酸、可溶性蛋白）、抗氧化物质（总酚、维生素C、黄酮）、香气物质（酯类、醇类、萜烯类等）和感官品质（外观、香气、口感、风格）等方面的差异,研究不同品种猕猴桃果酒间感官指标与理化指标的关系。【结果】4个品种猕猴桃酿酒原料的TSS、TA和pH,以及4种果酒的TSS、TA、酒精度、可溶性蛋白及总酚、Vc、黄酮等均表现出不同程度的差异,发酵酒的酒精度与后熟果实原料的pH值之间存在极显著负相关。在4种猕猴桃果酒中,共检测出7类83种挥发性化合物,其中共有类型6类,共有物质24种,以酯类化合物的种类最多、相对含量最大。4种猕猴桃酒香气成分总质量浓度由大到小分别为金艳（3 907.28 μg/L）＞东红（3 493.22 μg/L）＞翠玉（3 176.01 μg/L）＞翠香（2 768.17 μg/L）。4种猕猴桃酒的感官评分中,外观和总分存在一定差异,总分由高到低依次为东红＞金艳＞翠香＞翠玉。感官指标与理化指标的相关性分析表明,不同品种猕猴桃果酒的外观与其可溶性蛋白质量浓度呈显著负相关,香气与芳樟醇和萜烯类物质质量浓度呈显著正相关,口感与原料果实的固/酸比呈显著正相关,而与黄酮质量浓度呈显著负相关。【结论】4个猕猴桃品种中,东红猕猴桃果酒的外观、香气、口感及与感官测试相关的理化指标表现最优,最适于酿制猕猴桃酒。     

生物结皮生长发育对黄绵土抗侵蚀性能的影响

[目的] 黄土高原退耕还林(草)工程驱动的生物结皮发育可显著抑制土壤侵蚀,为探明土壤抗侵蚀性能随生物结皮生长发育的变化特征及其响应机制。[方法] 设置藻结皮、藓结皮和自然演替结皮3个处理,培育176天,系统研究生物结皮不同发育阶段及其类型差异对黄绵土抗侵蚀性能的影响。[结果] (1)生物结皮盖度、厚度、生物量、叶绿素和粗糙度随生长时间均显著增加,培育初期藓结皮较高,培育末期自然演替结皮反而最高。(2)随生物结皮发育,土壤黏结力呈幂函数增强,较初期增加39.8%~60.3%;质量损失率呈指数函数减小,较初期降低45.6%~57.3%;饱和导水率变化趋势较为复杂,但培育末期均最低(0.08~0.12 mm/min)。(3)土壤黏结力随生物结皮盖度、厚度、叶绿素、生物量和表面粗糙度的增加呈幂函数增长,质量损失率随生物结皮盖度、厚度、叶绿素、生物量和表面粗糙度的增加呈指数函数下降。(4)土壤抗侵蚀综合指数(C_ser)可表示为盖度(Cov)、厚度(T)和生物量(B)的幂函数(C_ser=0.279 Cov^0.194 T^0.188 B^0.119, R²=0.73, p＜0.05)。[结论] 黄土高原生物结皮发育可显著提高黄绵土抗侵蚀性能,藓结皮效果最强。     

代谢酶抑制剂PX对除草剂防除稗草的增效作用

为解决除草剂防除困难的问题,采用室内盆栽试验测定了PX、PM和Mn²⁺三种代谢酶抑制剂对精喹禾灵、莠去津、烟嘧磺隆、硝磺草酮和烯禾啶防除稗草Echinochloa crus-galli的增效作用,测定不同用量代谢酶抑制剂PX对这5种除草剂的增效作用及其与莠去津混用后稗草体内谷胱甘肽转移酶（glutathione S-transferase,GST）和细胞色素 P450（cytochrome P450,CYP450）活性的变化。结果显示,在3种代谢酶抑制剂中,代谢酶抑制剂PX对精喹禾灵、莠去津、烟嘧磺隆、硝磺草酮和烯禾啶5种除草剂的增效作用最显著。不同用量代谢酶抑制剂PX对不同除草剂的增效作用不同,其中75 g (a.i.)/hm²代谢酶抑制剂PX对莠去津的增效最佳,株防除效果和鲜重防除效果分别增加了35.33个百分点和37.33个百分点。莠去津与代谢酶抑制剂PX混用后,稗草体内GST和CYP450活性均较对照显著降低。表明除草剂与代谢酶抑制剂PX混用能增加除草剂对稗草的防除效果,可以达到减施除草剂的目的。     

Effects of exosomes derived from hypoxia-preconditioned umbilical cord mesenchymal stem cells on function of endothelial cells

AIM To investigate the effect of exosomes derived from hypoxia-preconditioned human umbilical cord mesenchymal stem cells (hUCMSCs) on proliferation, migration and tube formation of human umbilical vein endothelial cells (HUVECs). METHODS hUCMSCs and HUVECs were isolated, cultured and identified. Exosomes derived from hUCMSCs were extracted by ultracentrifugation. The morphological change of exosomes was observed under transmission electron microscope. The particle size and concentration of exosomes were detected by nanoparticle tracking analysis, and the surface specific marker proteins of exosomes were determined by Western blot. hUCMSCs were divided into normoxia group and hypoxia group. The viability of hUCMSCs was measured by CCK-8 assay. HUVECs were divided into control group, normoxic exosome group and hypoxic exosome group. The proliferation of HUVECs was detected by EdU assay. The migration ability was detected by cell scratch assay and Transwell experiment. Tube formation ability was evaluated by tube formation experiment. RESULTS Compared with normoxia group, hypoxia pretreatment enhanced the viability and exosome release of hUCMSCs. Compared with normoxic exosome group, hypoxic exosomes enhanced the proliferation, migration and tube formation of HUVECs. CONCLUSION Exosomes derived from hUCMSCs under hypoxia enhances the proliferation, migration and tube formation of HUVECs.     

基于LF-NMR及MRI 的2种速生材干燥过程中水分分布状态研究

为了解太阳能干燥过程中速生材内部水分状态及迁移规律,采用低场核磁共振及核磁共振成像检测桉、杨木干燥过程中水分分布、含量变化及迁移过程,借助扫描电镜在微观层面进行分析。结果表明：核磁共振信号强度与称重法所测含水率相关性系数高达0.99以上,因此低场核磁共振可准确测定木材中的水分含量;桉木和杨木饱水试样的核磁共振信号中均存在3种峰,桉木弛豫时间分别为1.32、32.75、403.70 ms,杨木为2.66、32.75、352.12 ms,对应着结合水及两种状态的自由水;随着干燥进行,不同状态水分的横向弛豫时间逐渐减小,木材对水分的束缚增加。当桉木含水率为27.28%,杨木含水率为35.71%左右时,水分散失转为以结合水为主。通过核磁共振成像中氢质子密度的不同可对水分含量进行区分,进而可观测干燥过程中木材内部水分移动状态。因此,通过低场核磁共振及核磁共振成像可研究速生材干燥过程中的内部水分状态及分布。     

Molecular cloning and functional analysis of duck Toll-like receptor 5

Toll-like receptor 5 (TLR5) is responsible for the recognition of bacterial flagellin in vertebrates. In this study, we cloned the single-exon TLR5 gene of the Maya breed of Common Shelduck (Tadorna tadorna). The TLR5 open reading frame is 2580 bp in length and encodes an 859-amino acid protein. The putative amino acid sequence of duck TLR5 consisted of a signal peptide sequence, 11 leucine-rich repeat domains, a leucine-rich repeat C-terminal domain, a transmembrane domain, and an intracellular Toll-interleukin-1 receptor domain. The duck TLR5 gene was highly expressed in the lung, bone marrow, spleen, and liver; moderately expressed in kidney, small intestine, large intestine, and brain. A plasmid expressing duck TLR5 was constructed and transfected into HEK293T cells, and expression was confirmed by indirect immunofluorescence assay. HEK293T cells transfected with duck TLR5- and NF-κB-luciferase-containing plasmids significantly responded to flagellin from Salmonella typhimurium, indicating that it is a functional TLR5 homolog.     

Effect of stachyose supplementation on growth performance, nutrient digestibility and caecal fermentation characteristics in broilers

1. The objective of this study was to evaluate whether the oligosaccharide stachyose enhances gastrointestinal tract health by fermentation and proliferation of desirable bacteria species and thus affects growth performance and nutrient digestibility in broilers. 2. A total of 432 1-d-old male Arbor Acres (AA) broilers were randomly allocated to one of 6 treatments, with 12 replicate pens per treatment and 6 birds per pen. Chicks were fed a maize-hamlet protein 300 (HP300) basal diet with 0, 4.0, 8.0, 12.0 or 16.0 g/kg stachyose. A sixth diet contained no HP300 but soybean meal (SBM) and provided 8.7 g/kg stachyose and 3.1 g/kg raffinose. The duration of the study was 42 d. 3. Stachyose contents above 12.0 g/kg depressed group body weights, average daily gain and feed/gain but not feed intake during the whole experimental period. Broiler growth decreased linearly and quadratically with increasing stachyose content. No differences were detected between diets supplemented with 12.0 g/kg stachyose and SBM. 4. Nutrient digestibility tended to decrease but not significantly with increasing stachyose. 5. Stachyose content had no significant positive effects on caecal pH, microflora population and the resulting short-chain fatty acid (SCFA) metabolites during the 42 d experiment, with only butyrate differing significantly in the initial period.