2017-2018年吉林部分地区规模化猪场猪细环病毒的遗传变异分析

为了解猪细环病毒（Torque teno sus virus, TTSuVs）在吉林部分规模化猪场的流行及其遗传变异情况。本研究对2017-2018年间,来自吉林地区10家规模化猪场的574份血清样本进行TTSuVs流行情况调查。并根据收地点,对20株TTSuVs进行ORF1全基因序列扩增及遗传变异性分析。结果显示：TTSuV1感染率为35.0%;TTSuV2感染率为63.2%;TTSuV1与TTSuV2混合感染率为30.3％;10株TTSuV1测序株之间的核苷酸同源性为75.7%-94.7%,氨基酸同源性为48.1%-88.2%;10株TTSuV2测序株之间的核苷酸同源性为77.5%-93.7%,氨基酸同源性为70.6%-87.4%;且吉林地区流行的TTSuV1均属于TTSuV1-lb型,而TTSuV2流行情况较为复杂,各种亚型均有涉及。     

基于线粒体基因的新疆托氏兔遗传多样性和种群遗传结构评价

旨在利用线粒体基因测序方法评价新疆托氏兔的遗传多样性水平,并探究亚种间的遗传结构.本研究通过PCR扩增及测序技术,获得来自新疆北部、西北部以及中东部地区的共计78例新疆托氏兔线粒体DNA的CO1和D-LOOP基因序列,并采用生物信息学的方法进行数据分析.结果 表明,78个新疆托氏兔样本的合并序列共定义了68种单倍型,新...     

纳米纤维素水凝胶的制备与表征及其对猪肉的保鲜作用

水凝胶因具有低毒性、高生物相容性和可降解性而常用于食品保鲜,但其机械性能和抗疲劳性有待提高。为了探究大豆种皮纳米纤维素对水凝胶机械性能和抗疲劳性的影响,并提高水凝胶的综合机械性能。因此,本研究通过-20 ℃低温循环冷冻-解冻法制备具有可拉伸、强韧、抗疲劳的聚乙烯醇/海藻酸钠/纳米纤维素水凝胶,探究水凝胶对猪肉货架期的影响。通过扫描电子显微镜、傅里叶红外变换光谱仪、X-射线衍射仪、热重仪和质构仪测定了水凝胶的理化性质和机械性能。研究结果表明,水凝胶内部单体之间以氢键和酯键交联,内部呈现多孔结构,断裂伸长率为230%、压缩强度为70 kPa、拉伸强度为17 kPa,经过多次循环拉伸仍具有良好的机械性能和较高的抗疲劳性。猪肉保鲜试验表明,水凝胶维持了猪肉色泽的稳定性,防止内部水分流失,并且将猪肉的保质期延长至10 d。因此,该水凝胶可用于食品包装以延长冷藏肉制品的保质期。同时,本研究为构建一种可拉伸、强韧、抗疲劳的多功能水凝胶提供了一种新的视角。     

耐热黄瓜新品种'津优4号'

‘津优４号’为耐热型黄瓜杂交种,夏季在３４～３６℃高温下可正常发育。对枯萎病、霜毒病、白粉病的抗性强,适合华北地区春露地及秋露地和越夏栽培。植株生长势强,春露地栽培产量可达７５ｔ／ｈｍ＾２。果实棒状,长３０ｃｍ左右,单瓜量１５０ｇ左右。商品性好,瓜色深绿,有光泽;瘤显著,密生白刺;果肉浅绿色,质脆,味甜,品质优。     

Effect of poly(ADP-ribose) polymerase on the response of guinea pig tracheas induced by peroxynitrite in vitro

AIM and METHODS: to elucidater the effect of poly(ADP-ribose) polymerase(PARP) on tracheal hyperreactivity of guinea - pig induced by peroxynitrite, the responses of guinea pig tracheas to histamine af- ter incubation with peroxynitrite in the absence and presence of 3 - aminobenzamide(3 - AB), a highly selective inhibitor for PARP, were observed in vitro. RESULTS: The exposure of tracheal strips to peroxynitrite led to epithelial damage and hyperreacitivity to histamine, both of which were reversed by 3 - AB(lmmol/L or 5mmol/L), whereas incubation of tracheal strips with 3 - AB(5mmol/L) had no effect on the reponses. CONCLUSION: PARP is involved in the epithelial damage and hyperreactivity of guinea - pig tracheas induced by peroxynitrite. The results suggested that inhibition of excessive activation of PARP may represent a novel strategy for the prevention and therapy of airway hyperreactivity in asthma.     

CYP450 epoxygenase/EET pathway attenuates adipose inflammation of obese mice through HIF-1α

AIM To investigate the effects of cytochrome P450 （CYP450） epoxygenase/epoxyeicosatrienoic acid （EET） pathway on insulin resistance in obese mice, and to explore the possible mechanisms. METHODS High-fat diet-induced obesity model was established in C57BL/6Cnc mice, and the obese mice were randomly divided into 3 groups, including obesity group （treated with saline; n=10）, EET group （treated with 11,12-EET; n=10） and EET inhibitor 14,15-epoxyeicosa-5（Z）-enoic acid （EEZE） group （n=10）. Normal C57BL/6Cnc mice （n=10） treated with saline served as control. Protein expression of CYP2J2 （one of CYP450 epoxygenases） and hypoxia-inducible factor-1α （HIF-1α） was measured by Western blot. Vessel-like structure was detected by immunofluorescence staining. The serum levels of insulin, tumor necrosis factor-α （TNF-α）, interleukin （IL）-1β, IL-6 and monocyte chemoattractant protein-1 （MCP-1） were measured by ELISA. RESULTS In obese mice, homeostasis model assessment of insulin resistance （HOMA-IR） values were increased, the protein level of CYP2J2 was reduced, and the protein level of HIF-1α was increased in adipose tissues as compared with the controls （P<0.05）. The serum levels of MCP-1, IL-1β, IL-6 and TNF-α were also significantly increased in obese mice （P<0.05）. After treatment with 11, 12-EET, the HOMA-IR values were decreased compared with vehicle-treated obese mice, HIF-1α expression levels were decreased in the adipose tissue, and the serum levels of MCP-1, IL-1β, IL-6 and TNF-α were reduced （P<0.05）. Immunohistochemical results of adipose tissue from vehicle-treated obese mice showed a marked decrease in vessel-like structures （CD31-positive） compared with normal control mice （P<0.05）. EET treatment significantly increased the newly formed vessel-like structures in the visceral adipose tissues of obese mice as compared with vehicle-treated obese mice （P<0.05）. CONCLUSION High-fat diet-induced obesity and insulin resistance are closely related to the CYP450 pathway. Exogenous EETs effectively decrease obesity-induced insulin resistance possibly through pro-angiogenesis and attenuation of hypoxia and inflammation.     

玉米小斑病抗性种质鉴定及生理生化分析

以200份玉米优良自交系为材料,2022-2023年夏分别进行小斑病菌的田间接种,综合两年数据共鉴定出高抗小斑病的玉米自交系3份,分别为K22、CML50和齐319;筛选到包括Mo17在内的抗性玉米自交系24份。选取K22和B73两个具有不同抗性水平的玉米自交系进行小斑病菌的室内接种。结果表明,48 h和72 h时,自交系K22叶片的病斑数、病斑面积和病斑面积比等各项指标均显著优于自交系B73,进一步验证田间鉴定的准确性。48 h或72 h时,高抗小斑病自交系K22与感病对照B73相比,5种防御酶活性增加14.32%～70.45%。     

凹坑形表面土壤减阻率试验及界面动态观察

利用切向粘附动态试验台,测试并研究了土壤含水率为35．1％条件下,玻璃和有机玻璃凹坑形仿生非光滑表面和光滑表面与土壤相互作用的摩擦阻力。采用二元二次回归正交组合设计试验方案,探讨当凹坑形非光滑表面和光滑表面在正压力和速度变化时,土壤摩擦阻力的变化规律,观察两种材料表面与土壤界面的动态变化,讨论试样表面形态与界面水膜及土壤摩擦阻力的关系。试验结果表明,在试验条件下,与光滑试样相比凹坑形非光滑表面玻璃试样减阻率为8．29％～24．65％,有机玻璃试样的减阻率为1．29％～8．18％。     

板翅换热器平直翅片的传热与阻力性能试验

对11种不同结构参数的紧凑式板翅换热器平直翅片的传热和流动阻力进行了试验研究,分析比较平直翅片间距、翅片高度、翅片长度对其传热和流动阻力的影响。结果表明,翅片间距对传热和流动阻力影响较小,而翅片长度和高度对其传热和流动阻力有重要影响。同时对11种翅片的220个试验数据点进行了j因子和f因子的试验关联式拟合,拟合关联式的误差范围为±10%。     

棉蚜对吡虫啉抗性的初步研究

用吡虫啉对棉蚜进行室内抗性筛选,用药处理25次后抗性是筛选前的20.03倍;2007年对田间棉蚜进行抗性调查,发现不同地区种群对吡虫啉的抗性差异显著,江苏南京种群最为敏感,河南安阳、山东泰安和北京地区棉蚜与之相比,抗性分别为2.21、7.63和9.53倍;抗、感品系解毒酶活力分析发现,抗性品系的谷胱甘肽S-转移酶活性增加很少(比活力1.12倍),但酯酶活力显著高于敏感品系(比活力1.71倍);增效试验结果表明,顺丁烯二酸二乙酯(DEM)在抗、感品系中对吡虫啉均没有明显的增效作用,而磷酸三苯酯(TPP)和增效醚(PBO)虽然在敏感品系中对吡虫啉的增效作用较小(SR 1.24和1.29),但在抗性品系中的增效作用显著增高(SR 2.13和1.74);此外还发现,吡虫啉处理可提高棉蚜群体的酯酶活力。由此认为,棉蚜至少具有对吡虫啉产生中等水平抗性的风险,其抗性可能是由于棉蚜的酯酶和P450单加氧酶的解毒能力提高所致。