电炉渣场烟尘及其捕集方式探讨

针对电炉渣场烟尘无组织排放和烟尘性质较为特殊的特点,探讨了两种渣场烟尘捕集方式.     

Root GS and NADH-GDH Play Important Roles in Enhancing the Ammonium Tolerance in Three Bedding Plants

Ammonium is a paradoxical nutrient because it is more metabolically efficient than nitrate, but also causes plant stresses in excess, i.e., ammonium toxicity. Current knowledge indicates that ammonium tolerance is species-specific and related to the ammonium assimilation enzyme activities. However, the mechanisms underlying the ammonium tolerance in bedding plants remain to be elucidated. The study described herein explores the primary traits contributing to the ammonium tolerance in three bedding plants. Three NH₄⁺:NO₃⁻ ratios (0:100, 50:50, 100:0) were supplied to salvia, petunia, and ageratum. We determined that they possessed distinct ammonium tolerances: salvia and petunia were, respectively, extremely sensitive and moderately sensitive to high NH₄⁺ concentrations, whereas ageratum was tolerant to NH₄⁺, as characterized by the responses of the shoot and root growth, photosynthetic capacity, and nitrogen (amino acid and soluble protein)-carbohydrate (starch) distributions. An analysis of the major nitrogen assimilation enzymes showed that the root GS (glutamine synthetase) and NADH-GDH (glutamate dehydrogenase) activities in ageratum exhibited a dose-response relationship (reinforced by 25.24% and 6.64%, respectively) as the NH₄⁺ level was raised from 50% to 100%; but both enzyme activities were significantly diminished in salvia. Besides, negligible changes of GS activities monitored in leaves revealed that only the root GS and NADH-GDH underpin the ammonium tolerances of the three bedding plants.     

室内火灾烟气流动随机性研究述评

评述了目前国内外室内火灾烟气流动随机性研究的现状、室内空间火灾烟气流动随机性的基本原因、影响烟气流动随机性的因素以及这些因素的影响机理等.     

2019—2022年聊城市食品和病例分离单增李斯特菌基于全基因组测序的分子特征及耐药性分析

目的 基于全基因组测序（WGS）比较分析2019—2022年聊城市单核细胞增生李斯特菌（Lm）食品和病例分离株基因组特征、毒力性、耐药性以及遗传多样性。方法 对聊城市33株市售食品和临床病例中Lm分离株开展抗生素敏感性试验和WGS。利用MGAP对WGS数据进行拼接组装,对组装基因组进行基因预测和功能注释、MLST,制作cg MLST最小生成树图,并与美国国家生物信息中心（NCBI）上获取的18株国内外Lm构建wg-SNP进化树。结果 33株Lm分离株的基因组大小为2.89～3.41 Mb,CG含量为37.81%～37.97%,可分为6个ST型（ST9、ST121、ST8、ST87、ST155、ST101）,分别属于6个克隆复合群（CC9、CC121、CC8、CC87、CC155、CC101）;分离株均携带fosX和mprF耐药基因,此外还携带lplA1、prsA2等其他18个毒力基因,有不同程度的毒力基因缺失情况。2株菌对四环素耐药,1株菌对林可霉素耐药。均携带毒力岛LIPI-1和LIPI-2,未检测到毒力岛LIPI-3和LIPI-4。wg-SNPs、cgMLST和基于单拷贝核心蛋白序列的系统发育树遗传进化分析显示,33株Lm分子分型呈现高度多样性,病例来源菌株与食品分离株亲缘关系密切,食品分离株与国外暴发分离株在进化关系上密切相关。结论 山东省聊城市食品和病例中分离的单增李斯特菌均携带毒力基因,具有一定的潜在致病能力,耐药情况尚不严重。分子型别呈现出多样性,食品来源菌株和病例分离株具有较近的亲缘关系,提示市售食品有食源性感染的潜在风险。     

黄连花茶加工工艺及其抗氧化作用研究

以黄连的花薹为原料,研究了黄连花茶的加工工艺及其抗氧化活性。结果表明,黄连花薹经杀青、冷却后,干燥,包装制得的黄连花茶风味清香、复水性好。采用霍恩氏法,对花茶的急性毒性(LD50)进行测定,21.5g/kg·BW剂量下,实验动物未发现死亡及异常;大于15g/kg·BW剂量,属无毒。水浸出物对羟自由基(·OH)和过氧化氢(H2O2)均具有清除作用。     

红外烟幕干扰效果的测试与评估

介绍了国内外烟幕发展状况,对红外烟幕干扰效果的理论计算方法进行了研究。针对海上战场环境研究提出海上试验测试方法,并详细分析了干扰效果的评估方法。     

新疆蔷薇红景天总黄酮抗炎作用及急性毒性研究

目的研究新疆蔷薇红景天总黄酮的抗炎作用及其急性毒性。方法昆明种小鼠60只,随机分为模型组、阿司匹林组(0.2 g/kg)、总黄酮低、中、高剂量组(1.0、2.0、4.0 g/kg),建立二甲苯致小鼠耳肿胀急性炎症模型,考察蔷薇红景天总黄酮对二甲苯致小鼠耳肿胀的影响; SD大鼠50只,随机分为模型组、阿司匹林组(0.14 g/kg),总黄酮低、中、高剂量组(0.7、1.4、2.8 g/kg),建立棉球诱发大鼠肉芽肿慢性炎症模型,考察蔷薇红景天总黄酮对大鼠棉球肉芽肿形成的抑制作用;酶联免疫检测试剂盒测定慢性炎症大鼠血清中肿瘤坏死因子(tumor necrosis factor-α, TNF-α)、环氧化酶-2(cyclooxygenase-2, COX-2)、白介素(interleukin-6, IL-6)、丝裂原激活蛋白激酶(mitogen-activated protein kinase, MAPK)4种炎症因子的含量,考察蔷薇红景天总黄酮的抗炎作用;选取20只昆明种小鼠,随机分为实验组(160 g/kg)和空白组(蒸馏水),灌胃连续给药2 w,观察蔷薇红景天总黄酮的急性毒性。结果与模型组比较,蔷薇红景天总黄酮低、中、高剂量组对二甲苯致小鼠耳肿胀均有显著抑制作用(P0.05, P0.01, P0.01),其抑制率分别为25.75%、38.87%和61.13%;蔷薇红景天总黄酮低、中、高剂量组对大鼠棉球肉芽肿的形成均有明显抑制作用(P0.05, P0.01, P0.01),其抑制率分别为42.06%、53.89%、54.15%;蔷薇红景天总黄酮低、中、高各剂量组均能显著降低大鼠血清COX-2(P0.01)和MAPK的含量(P0.05, P0.01, P0.01);其中、高剂量组能显著降低大鼠血清TNF-α和IL-6的含量(P0.05, P0.01)。结论蔷薇红景天总黄酮具有一定抗急、慢性炎症作用,并且安全无毒。     

七类食品单核细胞增生性增李斯特菌污染状况调查

利用李斯特显色培养基对食品中单增李斯特菌进行分离纯化后,提取基因组DNA,用PCR技术扩增hlyA基因特异性350bp的片段和iap基因特异性1500bp的片段,用此方法对七类食品进行检测。结果表明,冬春夏三季采集的62、60、62份样品中,分别检出单增李斯特菌3株、3株、10株,污染率分别为4.84%、5%、16.13%。夏季单增李斯特菌的污染情况比冬季和春季严重,其中蔬菜和牛奶中未检出单增李斯特菌;PCR检测可用于单增李斯特菌快速、特异、敏感检测。     

细胞技术在食品毒理学毒性快速细胞技术在食品毒理学毒性快速筛选方面的应用研究

对食品中外源化合物毒性的考察是一项繁重而艰巨的工作,传统食品毒理学方法效率低、耗资较大,不能满足实际工作的需要,因此,建立简单、快速、可靠的快速筛选替代模型,一直是国际上讨论的课题。近年来,应用细胞技术对食品中的外源性化合物的毒性进行筛选和安全评价进展迅速,现就细胞技术在食品毒理学毒性快速筛选方面的应用做一总结。     

Plant products as fumigants for stored-product insect control

Research studies on plant essential oils and their constituents as fumigants, i.e., compounds acting on target insects in the vapour or gaseous phase, against stored-product insects have been reviewed. Fumigant toxicity tests conducted with essential oils of plants (mainly belonging to Apiaceae, Lamiaceae, Lauraceae and Myrtaceae) and their components (cyanohydrins, monoterpenoids, sulphur compounds, thiocyanates and others) have largely focused on beetle pests such as Tribolium castaneum, Rhyzopertha dominica, Sitophilus oryzae and Sitophilus zeamais but little or no attention has been paid towards moths such as Corcyra cephalonica and Sitotroga cerealella. Adults were generally susceptible, whereas, eggs were either tolerant or highly susceptible depending on insect species and the type of essential oil or component. The essential oils proved effective in mixture with CO₂ or ethyl formate. Mode of action studies on monoterpenoids indicate inhibition of acetylcholinesterase enzyme activity as the major site of action. Although, in laboratory tests with adult insects, some of the plant compounds have shown insect toxicity comparable to methyl bromide or chloropicrin, their physical properties such as high molecular weight as well as high boiling point and very low vapour pressure are barriers for application in large-scale fumigations. Plant products, therefore, have the potential for small-scale treatments, space fumigations and as adjuvants for conventional fumigants. The constraints including lack of data for single or multiple components of essential oils on sorption, tainting and residues in food commodities, and registration protocols have been highlighted. The use of egg and pupal stages or preferably mixed-age cultures of target insects in screening tests with any new plant essential oil/compound has also been stressed.