Profiling the scent of weathered training aids for blood-detection dogs

At outdoor crime scenes, cadaver-detection and blood-detection dogs may be tasked with locating blood that is days, weeks or months old. Although it is known that the odour profile of blood will change during this time, it is currently unknown how the profile changes when exposed to the environment. Such variables must be studied in order to understand when the odour profile is no longer detectable by the scent-detection dogs and other crime scene tools should be implemented. In this study, blood was deposited onto concrete and varnished wood surfaces and weathered in an outdoor environment over a three-month period. Headspace samples were collected using solid phase microextraction (SPME) and analysed using comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC–TOFMS). The chemical odour profiles were compared with the behavioural responses of cadaver-detection and blood-detection dogs during training. Data interpretation using principal component analysis (PCA) and hierarchical cluster analysis (HCA) established that the blood odour could no longer be detected using SPME–GC×GC–TOFMS after two months of weathering on both surfaces. Conversely, the blood-detection dogs had difficulty locating the blood samples after one month of weathering on concrete and after one week of weathering on varnished wood. The scent-detection dogs evaluated herein had not been previously exposed to environmentally weathered blood samples during training. Given that this study was conducted to test the dogs' baseline abilities, it is expected that with repeated exposure, the dogs' capabilities would likely improve. The knowledge gained from this study can assist in providing law enforcement with more accurate training aids for blood-detection dogs and can improve their efficiency when deployed to outdoor crime scenes.     

亳菊总黄酮对大鼠急性心肌缺血的保护作用

目的 研究亳菊总黄酮对急性心肌缺血模型大鼠心脏的保护作用,为其进一步开发提供实验依据。方法 将SD大鼠随机分成假手术组,模型组,复方丹参滴丸组（140 mg/kg）,亳菊总黄酮小、中、大剂量组（分别为75、150、300 mg/kg）。采用冠状动脉结扎法复制大鼠急性心肌缺血模型。分别于手术前,手术后0、0.5、1.0、2.0 h测定各组大鼠心电图ST段变化;冠状动脉结扎后24 h测定血清天冬氨酸转移酶（aspartate aminotransferase, AST）、乳酸脱氢酶（lactate dehydrogenase, LDH）、肌酸激酶（creatine kinase, CK）含量;观察各组大鼠心肌梗死率及心肌组织形态学变化。结果 亳菊总黄酮可降低急性心肌缺血大鼠各时点心电图ST段抬高值,降低血清AST、LDH、CK含量,降低心肌梗死率,改善心肌组织形态学变化,呈现出一定的剂量效应。结论 亳菊总黄酮对急性心肌缺血模型大鼠心脏有一定的保护作用。     

宣木瓜总三萜、齐墩果酸和熊果酸含量测定

目的 测定宣木瓜总三萜、齐墩果酸和熊果酸含量,为宣木瓜质量控制和评价提供依据。方法 采用5%香草醛-冰醋酸-高氯酸显色,550 nm处测定总三萜含量;齐墩果酸、熊果酸用超高液相色谱法测定,色谱参数：BEH C18色谱柱(100 mm×2.1 mm,1.7 μm),流动相为甲醇-水-冰醋酸-三乙胺（255∶45∶0.1∶0.05）,紫外检测波长为210 nm,柱温为25 ℃。结果 不同农家品种的6批宣木瓜样品总三萜含量为2.46%~3.96%,齐墩果酸和熊果酸的总含量为0.449%~0.581%。结论 香草醛比色法和超高液相色谱法分别适合宣木瓜总三萜、齐墩果酸和熊果酸含量的测定,可同时用于宣木瓜药材质量控制。     

传统硫熏加工与现代微波加工滁菊质量比较

目的 通过对硫熏加工滁菊和微波加工滁菊中主要化学成分进行比较,为滁菊的合理加工方法提供依据.方法 以挥发油、总黄酮、绿原酸及二氧化硫残留量为检测指标,对两种方法加工的滁菊的主要化学成分进行比较分析.结果 硫熏滁菊中挥发油、绿原酸含量均高于微波滁菊;硫熏滁菊中总黄酮的含量略低于微波滁菊;硫熏滁菊的薄层色谱斑点数与微波滁菊...     

全人类共同价值国际传播：意义阐释、困境透视与优化路径

全人类共同价值站在世界发展与人类进步的道义制高点上，旨在打破不同国家和地域间的文化隔阂，赋能世界人民的美好生活追求，体现了新时代中国共产党人的全球视野和大国担当。全人类共同价值的国际传播对解构西方的“普世价值”话语霸权、夯实人类命运共同体构建的价值根基、提升中国的对外话语权和软实力等方面具有深层价值意蕴。当下全人类共同价值的国际传播仍面临传播环境阻滞、传播主体协同性不够、传播受众针对性不足、传播媒介影响力不强等多元困境。为此，应通过优化国际传播环境、整合国际传播主体、对国际传播受众进行细分和策略选择、打造国际传播媒介矩阵等多维路径协同推进，全面提升全人类共同价值国际传播效能。     

互联网国际规则建构:话语策略的公共安全视角

对当今世界各主要经济体而言,互联网安全已成为一个利益攸关的重要议题,但该领域国际共识和国际规则严重缺失,这与持续加剧的互联网安全威胁之间产生了尖锐的矛盾。在中国,互联网治理日益成为关乎国家安全的政策焦点,同时也是参与全球治理不可或缺的组成部分;建构互联网国际规则的话语能力直接影响着中国对外传播话语体系的建立和制度性话语权的提升,但目前中国对该领域话语策略的学术与政策研究仍严重缺失。当前,对互联网国际规则之制度理念的应然性研究仍显不足,关于中国在该领域对外传播话语策略的探讨更是近乎空白。互联网国际规则的缺失本质上源于互联网信息自由带来的收益与政府信息管控对此种收益的限制之间存在难以调和的矛盾。由于日益严峻的互联网安全形势正逐渐打破互联网信息自由与政府信息管控之间原有的平衡,加之全球化趋势将世界各国的命运更加紧密地联系在一起,该领域国际规则的建构开始具备现实的可能性。鉴于传播话语在规则建构的过程中占据着举足轻重的地位,以公共安全为切入点赢得国际共识、提升中国在互联网全球治理中的话语能力和制度性话语权就成为中国政策制定机构和宣传机构在通过对外传播推进互联网国际规则建构时应采取的话语策略。     

Personal attributes and (mis)perceptions of local environmental risk

Individuals' risk perceptions shape their attitudes and behaviors, and to the extent that governments respond to public demands, they also influence public policy priorities. Conversely, risk misperceptions—that is, when risk perceptions do not align with realities—may lead to suboptimal behaviors and inefficient public policy. This study investigates the phenomena of environmental risk misperceptions. Specifically, with an original survey that enables a direct comparison of perceived and actual environmental risks at the local level, it examines the relationships between personal attributes and risk misperceptions. The findings show that individuals exhibit optimism bias in assessing local environmental risk. On average, people rank their communities as experiencing less risk from toxic air pollution than objective measures suggest. Moreover, Whites, males, conservatives, and older people tend to have larger optimism bias and have lower chances of possessing correct risk perceptions than their counterparts, respectively, while respondents who are married, poor, who go to church regularly, and have strong pro-environmental orientation, tend to have smaller optimism bias and have higher chances of possessing correct risk perceptions than their respective counterparts. The systematic misperception of local environmental risk underscores the importance of information provision and risk communication, and the sociopolitical correlates of misperception suggest that targeted and more nuanced strategies are required to correct misperceptions.     

重楼总皂苷对人胃癌MNK-45和MGC80-3细胞增殖的影响

目的 观察重楼总皂苷(Rhizoma paridis total saponins，RPTS)对人胃癌MNK 45和MGC80 3细胞增殖的影响。方法 设定5个不同浓度（5、10、20、40、80 μg/ml）RPTS处理两种细胞24、48、72 h后，采用四甲基偶氮唑蓝(methyl thiazolyl tetrazolium，MTT)法测定MNK 45细胞和MGC80 3细胞增殖抑制率；设定浓度为10 μg/ml处理两种细胞24 h，采用吖啶橙/溴化乙锭（acridine orange/ethidium bromide, AO/EB）双染观察细胞形态学变化；设定浓度为10、20 μg/ml处理两种细胞6 h，用流式细胞仪测定细胞周期。结果 5～80 μg/ml RPTS对MNK 45和MGC80 3细胞增殖均具有显著的抑制作用(P<0.05，或P<0.01)，且药物剂量越大、作用时间越长，其抑制作用越强（P<0.01）；在相同药物浓度及相同作用时间下，RPTS对MNN 45细胞增殖的抑制作用较对MGC80 3作用显著增强（P<0.01）；RPTS作用于两种细胞后荧光显微镜下观察均显示细胞凋亡特征；RPTS使MNK 45细胞增殖被阻滞于G0/G1期，使MGC80 3细胞增殖被阻滞于S期。结论 RPTS能抑制人胃癌MNK 45和MGC80 3细胞增殖，诱导两种肿瘤细胞凋亡，影响两种肿瘤细胞周期时相的分布，但对两种肿瘤细胞株的抑制作用和对细胞周期时相的影响存在差异。     

黄蜀葵花总黄酮对大鼠湿热型慢性肾炎的作用及其对红细胞免疫黏附功能的影响

目的 观察黄蜀葵花总黄酮(total flavones of Abelmoschus manihot (L) Medic,TFA)对湿热型慢性肾炎的作用及其对红细胞免疫黏附功能的影响.方法 采用葡萄球菌肠毒素B分次由尾静脉注射、牛血清清蛋白隔日灌胃及完全弗氏佐剂和不完全弗氏佐剂分次皮下注射复制大鼠慢性肾炎湿热证模型.8...