兔病毒性出血症弥漫性血管内凝血动态研究

对兔出血症的凝血象和组织病理学变化进行了动态研究。结果表明：兔出血症伴有弥漫性血管内凝血（ＤＩＣ）病理过程，并呈动态发展规律。凝血象检测发现：感染后６ｈ凝血酶原时间（ＰＴ）、白陶土部分凝血活酶时间（ＫＰＴＴ）缩短或正常，为高凝期，该期短，很快进入低凝期。感染后１８ｈＰＴ、ＫＰＴＴ显著延长，死前更明显。血小板数（ＰＣ）呈渐进性降低，纤维蛋白（原）降解产物（ＦＤＰ）在感染后６ｈ显著增加（Ｐ＜０．０１），感染后１８ｈ达高峰值。组织病理学观察表明：肺的病变严重而且有规律，感染后１２ｈ肺的微血栓检出率最高，同时在心、肝、肾、脑等器官也见微血栓。感染后２４ｈ或死兔的肺出血严重，血栓少见，表现为纤溶亢进的特征性变化。此外，患出血症的兔血管壁早期损伤明显，先于高凝期，可能是ＤＩＣ的启动因素之一。     

维生素K3对14日龄北京鸭凝血时间和维生素K依赖蛋白的影响

旨在研究维生素K₃对1~14日龄北京鸭凝血时间和维生素K依赖蛋白的影响,筛选评价肉鸭维生素K营养状况的敏感指标,并得到育雏期北京鸭饲粮维生素K₃适宜添加量。试验采用单因子完全随机试验设计,设6个维生素K₃添加水平（0、0.5、1、2、3和4 mg·kg^-1）,通过在玉米-大豆分离蛋白型基础饲粮中添加6个不同添加水平亚硫酸氢钠甲萘醌配制试验饲粮。将180只1日龄健康雄性北京鸭随机分为6个处理组,每处理组5个重复,每重复6只鸭。试验期14 d。结果表明：不同添加水平维生素K₃对1~14日龄北京鸭平均日增重、平均日采食量和料重比等生长性能指标未产生显著影响（P>0.05）。0和0.5 mg·kg^-1维生素K₃添加组凝血酶原时间显著高于2、3、4 mg·kg^-1维生素K₃添加组（P<0.05）。0 mg·kg^-1维生素K₃添加组血清凝血酶原前体蛋白水平显著高于0.5、1、2、3、4 mg·kg^-1维生素K₃添加组（P<0.05）;0 mg·kg^-1维生素K₃添加组血清羧化不全骨钙素水平显著高于2、3、4 mg·kg^-1维生素K₃添加组（P<0.05）。以凝血酶原时间、血清凝血酶原前体蛋白和羧化不全骨钙素为评价指标,采用折线模型估算1~14日龄北京鸭维生素K₃需要量分别为2.00、0.56和1.27 mg·kg^-1。综上,饲粮中添加维生素K₃可增强肉鸭凝血功能,降低血清凝血酶原前体蛋白和羧化不全骨钙素水平。在本试验基础饲粮条件下,以凝血酶原时间为评价指标,采用折线模型估测1~14日龄北京鸭维生素K₃需要量为2.00 mg·kg^-1。     

Fe2O3-TiO2/UV/O3+PSAF协同处理猪场废水效果及其除碳脱氮机制

为实现低碳高氨氮猪场废水深度除碳脱氮,该研究提出了 Fe_2O_3-TiO_2/UV/O_3+PSAF组合处理工艺技术。应用响应面法确立了组合工艺的最优工况条件,采用三维荧光和紫外-可见吸收光谱分析了有机物的荧光和分子结构变化特征,并结合碳、氮形态变化探明了其协同处理特性及除碳脱氮机制。结果表明,Fe_2O_3-TiO_2投加量为1.06 g/L、O_3流量为3.02 g/h、曝气时间为90.75 min、聚硅酸铝铁(PSAF)用量为833.29 mg/L,COD及NH_(3-)N去除效果最好,试验值与预测值偏差0.75%和0.56%,拟合性良好;组合工艺对猪场废水中的溶解性微生物代谢产物和类腐殖质处理效果显著,溶解性有机碳和总溶解性氮去除率分别达77.7%和82.6%,协同因子分别为1.11和1.50。其中,Fe_2O_(3-)TiO_2/UV/O_3对类腐殖质削减效果显著,O_3和·OH协同氧化类腐殖质、NH_3-N为小分子物质、NO_3~--N和N_2 (N_2转化率达39.71%),提高了富氧官能团的数量,促进了氮素的转化和矿化,利于PSAF对小分子物质和NO_3~--N等污染物的去除,组合工艺协同互补作用明显。研究结果为深度处理低碳高氨氮有机废水提供一种新思路。     

Effect of Two Pretreatment Techniques on Preventing Membrane Fouling

Ultrafiltration membrane was used to filter the Yangtze River water by powder activated carbon (PAC) pretreated, such as Tai Lake water by coagulation-sedimentation pretreatment. The changes of organic polar content were compared in each process. Combined with the scanning electron microscope(SEM) photographs of the membrane, the mechanism of slowing down membrane fouling by PAC and coagulation-sedimentation pretreatment was studied. The results showed that hydrophobic organic compounds were the main factors of membrane fouling, while hydrophilic organics had less impact. When the dosing quantity of PAC filtered by ultrafiltration membrane was 20 mg/L to pre-treat the water samples of Yangtze River, and that of polyaluminium chloride was 25 mg/L for the pretreatment of Tai Lake water samples, the flux could be recovered effectively after backwashing compared with filtering the two raw water directly. The cake layer formed on the surface of the membrane was looser after pretreatment, and could be discharged easily by periodic backwashing, The cake layer could prevent hydrophobic organic matters deposit on the surface of membrane directly, which will slow down the membrane fouling and improve the chemical safety of the membrane effluent.     

用超声谐振法确定牛奶凝固时间的试验研究

在奶酪的生产过程中,确定牛奶的凝固时间是极为关键的一步,它直接关系到奶酪的品质和产量。文中提出一种非破坏性测定凝固时间的新方法一超声谐振检测法。即利用超声的衰减特性测定牛奶在凝固过程中的物理性能变化,以确定牛奶凝固点和凝块切割的最佳时间。试验研究结果表明:超声信号的衰减与牛奶在凝固过程中的物理性能变化密切相关。超声谐振法可显著地提高检测的精确度。     

典型白炭黑工业园区废水的混凝沉淀试验研究

针对白炭黑产业园区废水污染成分较复杂的特性,选用氧化钙、氢氧化钙及聚合氯化铝作为混凝药剂,开展了不同加药量(0.1‰、0.2‰、0.4‰、0.6‰、0.8‰、1‰、2‰)的混凝试验,对废水中关键水质指标变化进行了重点分析,藉此全面展现此种废水混凝处理效果并获取最优适用药剂。试验结果表明:三种混凝药剂对于白炭黑废水混凝处理效果差异较大;总体上,混凝工艺对溶液COD、SO₄^2-处理效果较差,而对于表观浊度、活性硅、悬浮物SS及总磷TP有较好的去除效果;针对活性硅、SS及TP三项指标综合考量,可选取氢氧化钙为混凝药剂,药剂添加量为1‰,此条件下混凝试验后,活性硅、SS及TP的浓度分别为:10mg/L、30mg/L及0.12mg/L;氢氧化钙添加后将对溶液的pH产生影响,反应后需增加酸碱回调工序。此研究结果对于白炭黑废水混凝处理,尤其是活性硅的去除具有较好的生产实践指导意义。     

Incidence of prolonged prothrombin time in dogs following gastrointestinal decontamination for acute anticoagulant rodenticide ingestion

Objective: To determine the effect of gastrointestinal (GI) decontamination on the incidence of prolonged prothrombin time (PT) in dogs after anticoagulant rodenticide ingestion. Design: Retrospective study. Setting: Urban emergency room. Animals: One hundred and fifty‐one client‐owned dogs. Measurements: Dogs presented to the emergency room within 6 hours of ingestion of an anticoagulant rodenticide and had a PT measured within 2–6 days of toxicant ingestion before initiating vitamin K therapy were included. Dogs were categorized as treated or untreated based on the institution of vitamin K therapy following PT testing. The signalment, body weight, type of rodenticide ingested, time elapsed between ingestion and initial presentation, method(s) of GI decontamination, and the times elapsed between both toxicant ingestion and initial hospital presentation until determination of PT were recorded. The PT results were recorded as well as any treatment received following the recheck examination. Any reported incidents of bleeding or untoward effects between exposure and reexamination were recorded. Main results: Of 151 dogs, only 11 dogs (8.3%) developed prolonged PT requiring vitamin K supplementation. None of the 11 dogs with prolonged PTs exhibited signs of bleeding or required transfusion therapy. No differences in age, weight, or time elapsed between treated and untreated patients were found. Conclusions: The incidence of prolonged PT is low in dogs receiving GI decontamination within 6 hours of anticoagulant rodenticide ingestion. Delaying vitamin K therapy until a PT has been assessed 48–72 hours after initial exposure appears to be safe and sensitive in dogs following anticoagulant rodenticide ingestion.