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Wh-question":A Useful Method in Language Teaching
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作者 夏立珍 《天津农学院学报》 CAS 2002年第B06期81-85,共5页
为了活跃英语课堂教学气氛,提出了一种实用性的教学方法———Wh question。该方法容易使用,有助于培养学生的听、说、写的技能。英语教学中教师较为棘手的问题是学生多且英语水平不一,教师在语言训练过程中就很难调动每一个学生的思维... 为了活跃英语课堂教学气氛,提出了一种实用性的教学方法———Wh question。该方法容易使用,有助于培养学生的听、说、写的技能。英语教学中教师较为棘手的问题是学生多且英语水平不一,教师在语言训练过程中就很难调动每一个学生的思维注意力。很难使每个学生都得到充分的展示。简单易行的Wh question方法得到了全体同学,特别是基础差的同学的喜欢。此方法不仅可用于英语听说技能的教学,也可用于英语词汇、课文讲解。 展开更多
关键词 英语教学 课堂教学 教学方法 wh-question方法
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Iage a Comparative Study of Wh-questions in English and Chinese
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作者 何莉 《海外英语》 2013年第4X期226-227,共2页
This paper presents a comparative study of English and Chinese wh-questions and aims at providing explanations of distinctions between English and Chinese wh-questions.The different feature strength of the position C ... This paper presents a comparative study of English and Chinese wh-questions and aims at providing explanations of distinctions between English and Chinese wh-questions.The different feature strength of the position C causes the different sentence pattern of Chinese and English wh-questions and the aim is to meet the requirement of feature-checking.The overt whmovement is constrained by some principles.Then Do Chinese learners of English also have this principle in their mind? Through the experiment,the study compared the rates of accuracy of the Chinese group and the native controls. 展开更多
关键词 wh-question wh-MOVEMENT GENERATIVE MECHANISM Subja
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Fatigue sensation following peripheral viral infection is triggered by neuroinflammation: who will answer these questions? 被引量:1
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作者 Masanori Yamato Yosky Kataoka 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第2期203-204,共2页
Fatigue is best defined as difficulty in initiating or sustaining voluntary activities, and is thought to be accompanied by deterioration of performance. Fatigue can be caused by many factors such as physical and ment... Fatigue is best defined as difficulty in initiating or sustaining voluntary activities, and is thought to be accompanied by deterioration of performance. Fatigue can be caused by many factors such as physical and mental stress, disturbance in the circadian rhythm, and various diseases. For example, following the flu or other types of infections, everyone has experienced a sense of fatigue that can last for days or weeks. The fatigue sensation is thought to be one of the signals for the body to suppress physical activity in order to regain health. The mechanism of induction of the fatigue sensation following viral infection has not been well understood. Although fatigue was once thought to be caused by fever, our recent study with an animal model of viral infection demonstrated that the fatigue sensation is caused not by fever, but rather, 展开更多
关键词 who will answer these questions WILL
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The Land Question and Catholic-Anglican Relations in Buha, Western Tanzania: The White Fathers and C.M.S. Experience, 1934-1959
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作者 Salvatory Stephen Nyanto 《History Research》 2016年第1期10-22,共13页
Land was important--in the course of spreading and seeking new converts--for both Missionaries of Africa (White Fathers) and Church Missionary Society (C.M.S.) in Buha, Western Tanzania. This paper examines the la... Land was important--in the course of spreading and seeking new converts--for both Missionaries of Africa (White Fathers) and Church Missionary Society (C.M.S.) in Buha, Western Tanzania. This paper examines the land question as one of the challenges that the White Fathers encountered in their attempt to evangelize communities in Western Tanzania. I argue that the land question remained throughout the late-colonial period one of the unresolved issues, and at some mission stations, impeded the activities of the White Fathers and C.M.S. missionaries. This paper relies on archival documents first, to examine the land question and White Fathers-C.M.S. relations in Buha from 1934 to 1959. Second, I intend to demonstrate the fact that land issues remained at the heart of the missionary enterprise in Buha. Both Catholic and Anglican missionaries were determined to have more mission plots for medical, education and religious purposes. 展开更多
关键词 land question white Fathers C.M.S. Buha
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Special Issue:Questions&Data for Better Science and Innovation Call for submissions
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《Journal of Data and Information Science》 CSCD 2024年第3期I0002-I0002,共1页
Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CAS Topic of the Special Issue What are the top questions to... Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CAS Topic of the Special Issue What are the top questions towards better science and innovation and the required data to answer these questions? 展开更多
关键词 COLLEGE questionS ISSUE
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空间关键字top-k查询的why问题
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作者 黄金亮 李艳红 卢航 《中南民族大学学报(自然科学版)》 CAS 2024年第1期61-68,共8页
为提高空间关键字top-k查询的why问题处理效率,设计了一种名为WIR-tree的索引结构,以在访问非叶子结点下的子树之前,先估算其索引的所有对象与查询之间的空间距离和文本相似性的上限值,进而进行剪枝操作.此外,基于所构建的WIR-tree,提... 为提高空间关键字top-k查询的why问题处理效率,设计了一种名为WIR-tree的索引结构,以在访问非叶子结点下的子树之前,先估算其索引的所有对象与查询之间的空间距离和文本相似性的上限值,进而进行剪枝操作.此外,基于所构建的WIR-tree,提出了一种WSKQK算法,通过编辑距离递增方式枚举关键字集,并结合查询处理提早结束策略,加速空间关键字top-k查询why问题的整个处理过程.最后,通过与现有的基于setR-tree索引的BS算法进行对比实验,验证了所提方法的高效性和可扩展性. 展开更多
关键词 查询 why问题 WIR-tree树索引结构 WSKQK算法
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MKEAH:Multimodal knowledge extraction and accumulation based on hyperplane embedding for knowledge-based visual question answering
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作者 Heng ZHANG Zhihua WEI +6 位作者 Guanming LIU Rui WANG Ruibin MU Chuanbao LIU Aiquan YUAN Guodong CAO Ning HU 《虚拟现实与智能硬件(中英文)》 EI 2024年第4期280-291,共12页
Background External knowledge representations play an essential role in knowledge-based visual question and answering to better understand complex scenarios in the open world.Recent entity-relationship embedding appro... Background External knowledge representations play an essential role in knowledge-based visual question and answering to better understand complex scenarios in the open world.Recent entity-relationship embedding approaches are deficient in representing some complex relations,resulting in a lack of topic-related knowledge and redundancy in topic-irrelevant information.Methods To this end,we propose MKEAH:Multimodal Knowledge Extraction and Accumulation on Hyperplanes.To ensure that the lengths of the feature vectors projected onto the hyperplane compare equally and to filter out sufficient topic-irrelevant information,two losses are proposed to learn the triplet representations from the complementary views:range loss and orthogonal loss.To interpret the capability of extracting topic-related knowledge,we present the Topic Similarity(TS)between topic and entity-relations.Results Experimental results demonstrate the effectiveness of hyperplane embedding for knowledge representation in knowledge-based visual question answering.Our model outperformed state-of-the-art methods by 2.12%and 3.24%on two challenging knowledge-request datasets:OK-VQA and KRVQA,respectively.Conclusions The obvious advantages of our model in TS show that using hyperplane embedding to represent multimodal knowledge can improve its ability to extract topic-related knowledge. 展开更多
关键词 Knowledge-based visual question answering HYPERPLANE Topic-related
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PAL-BERT:An Improved Question Answering Model
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作者 Wenfeng Zheng Siyu Lu +3 位作者 Zhuohang Cai Ruiyang Wang Lei Wang Lirong Yin 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第6期2729-2745,共17页
In the field of natural language processing(NLP),there have been various pre-training language models in recent years,with question answering systems gaining significant attention.However,as algorithms,data,and comput... In the field of natural language processing(NLP),there have been various pre-training language models in recent years,with question answering systems gaining significant attention.However,as algorithms,data,and computing power advance,the issue of increasingly larger models and a growing number of parameters has surfaced.Consequently,model training has become more costly and less efficient.To enhance the efficiency and accuracy of the training process while reducing themodel volume,this paper proposes a first-order pruningmodel PAL-BERT based on the ALBERT model according to the characteristics of question-answering(QA)system and language model.Firstly,a first-order network pruning method based on the ALBERT model is designed,and the PAL-BERT model is formed.Then,the parameter optimization strategy of the PAL-BERT model is formulated,and the Mish function was used as an activation function instead of ReLU to improve the performance.Finally,after comparison experiments with traditional deep learning models TextCNN and BiLSTM,it is confirmed that PALBERT is a pruning model compression method that can significantly reduce training time and optimize training efficiency.Compared with traditional models,PAL-BERT significantly improves the NLP task’s performance. 展开更多
关键词 PAL-BERT question answering model pretraining language models ALBERT pruning model network pruning TextCNN BiLSTM
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Operational requirements analysis method based on question answering of WEKG
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作者 ZHANG Zhiwei DOU Yajie +3 位作者 XU Xiangqian MA Yufeng JIANG Jiang TAN Yuejin 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期386-395,共10页
The weapon and equipment operational requirement analysis(WEORA) is a necessary condition to win a future war,among which the acquisition of knowledge about weapons and equipment is a great challenge. The main challen... The weapon and equipment operational requirement analysis(WEORA) is a necessary condition to win a future war,among which the acquisition of knowledge about weapons and equipment is a great challenge. The main challenge is that the existing weapons and equipment data fails to carry out structured knowledge representation, and knowledge navigation based on natural language cannot efficiently support the WEORA. To solve above problem, this research proposes a method based on question answering(QA) of weapons and equipment knowledge graph(WEKG) to construct and navigate the knowledge related to weapons and equipment in the WEORA. This method firstly constructs the WEKG, and builds a neutral network-based QA system over the WEKG by means of semantic parsing for knowledge navigation. Finally, the method is evaluated and a chatbot on the QA system is developed for the WEORA. Our proposed method has good performance in the accuracy and efficiency of searching target knowledge, and can well assist the WEORA. 展开更多
关键词 operational requirement analysis weapons and equipment knowledge graph(WEKG) question answering(QA) neutral network
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汉语儿童wh-词“谁”的习得规律研究
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作者 何洪霞 《重庆交通大学学报(社会科学版)》 2024年第4期111-120,共10页
使用个案追踪法调查汉语儿童wh-词“谁”的历时习得情况。汉语儿童wh-词“谁”疑问用法习得时间早于非疑问用法,“谁”习得顺序为疑问(1;04)→虚指(2;04)→全指(2;06)→反问(3;01)。汉语儿童wh-词“谁”疑问用法使用频次高于非疑问用法... 使用个案追踪法调查汉语儿童wh-词“谁”的历时习得情况。汉语儿童wh-词“谁”疑问用法习得时间早于非疑问用法,“谁”习得顺序为疑问(1;04)→虚指(2;04)→全指(2;06)→反问(3;01)。汉语儿童wh-词“谁”疑问用法使用频次高于非疑问用法,使用频次由高到低为疑问>全指>反问>虚指。“谁-虚指”习得时间与使用频次并不匹配,其特点为“习得早,使用少”;“谁-全指”内部分项中的“多项wh-词”习得时间与使用频次同样存在不匹配现象,具体表现为“习得晚,使用多”。无论是疑问用法还是非疑问用法,“谁”所占句法位置的习得时间与使用频次均表现为主语位→宾语位→定语位的扩散特征。语言标记性、可及性等级、任务复杂度及学习者个体差异等因素是造成上述习得表现的主要原因。 展开更多
关键词 汉语儿童 wh-词 疑问 非疑问 纵向研究
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DPAL-BERT:A Faster and Lighter Question Answering Model
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作者 Lirong Yin Lei Wang +8 位作者 Zhuohang Cai Siyu Lu Ruiyang Wang Ahmed AlSanad Salman A.AlQahtani Xiaobing Chen Zhengtong Yin Xiaolu Li Wenfeng Zheng 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第10期771-786,共16页
Recent advancements in natural language processing have given rise to numerous pre-training language models in question-answering systems.However,with the constant evolution of algorithms,data,and computing power,the ... Recent advancements in natural language processing have given rise to numerous pre-training language models in question-answering systems.However,with the constant evolution of algorithms,data,and computing power,the increasing size and complexity of these models have led to increased training costs and reduced efficiency.This study aims to minimize the inference time of such models while maintaining computational performance.It also proposes a novel Distillation model for PAL-BERT(DPAL-BERT),specifically,employs knowledge distillation,using the PAL-BERT model as the teacher model to train two student models:DPAL-BERT-Bi and DPAL-BERTC.This research enhances the dataset through techniques such as masking,replacement,and n-gram sampling to optimize knowledge transfer.The experimental results showed that the distilled models greatly outperform models trained from scratch.In addition,although the distilled models exhibit a slight decrease in performance compared to PAL-BERT,they significantly reduce inference time to just 0.25%of the original.This demonstrates the effectiveness of the proposed approach in balancing model performance and efficiency. 展开更多
关键词 DPAL-BERT question answering systems knowledge distillation model compression BERT Bi-directional long short-term memory(BiLSTM) knowledge information transfer PAL-BERT training efficiency natural language processing
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环保无镀铜实心焊丝WH50-6N的研制
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作者 周海龙 吴光辉 +3 位作者 韩海峰 张翔 许鑫宇 熊刚 《焊接技术》 2024年第7期101-105,共5页
文中通过对焊丝生产工艺改进和表面功能化处理技术,研制出一种50 kg级无镀铜气体保护实心焊丝。经过与同类镀铜焊丝的焊接工艺对比试验,发现该焊丝具有电弧稳定、飞溅率低、成形美观、环保低尘、防锈性能优良等特点,避免了传统镀铜焊丝... 文中通过对焊丝生产工艺改进和表面功能化处理技术,研制出一种50 kg级无镀铜气体保护实心焊丝。经过与同类镀铜焊丝的焊接工艺对比试验,发现该焊丝具有电弧稳定、飞溅率低、成形美观、环保低尘、防锈性能优良等特点,避免了传统镀铜焊丝铜烟污染、铜屑脱落等问题,是一种工艺优良、环境友好型焊接材料,具有广阔应用前景。 展开更多
关键词 气体保护焊丝 无镀铜焊丝 焊材 wh50-6N ER50-6
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WHS_3菌株产几丁质酶对棉铃虫HaSNPV的增效作用 被引量:19
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作者 徐红革 彭辉银 +2 位作者 刘家欣 白志强 谢薇 《中国病毒学》 CSCD 2002年第3期239-242,共4页
WHS3 (Serratiamarcescens)菌是一株几丁质酶的高产菌株 ,在诱导培养基中几丁质酶的产量可达84 .4 μg/mL。通过对中国棉铃虫进行的生物测定表明 :WHS3 菌所产的几丁质酶 (A3 )能有效地提高HaSNPV的毒力 2 0 %~ 70 % ,LT50 、LT90 比... WHS3 (Serratiamarcescens)菌是一株几丁质酶的高产菌株 ,在诱导培养基中几丁质酶的产量可达84 .4 μg/mL。通过对中国棉铃虫进行的生物测定表明 :WHS3 菌所产的几丁质酶 (A3 )能有效地提高HaSNPV的毒力 2 0 %~ 70 % ,LT50 、LT90 比对照组缩短天数最高可达 1.1d、1.3d。 展开更多
关键词 whS3菌株 几丁质酶 棉铃虫HaSNPV 增效作用 棉铃虫核型多角体病毒
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多项WH-问句中WH-词的功能解释 被引量:5
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作者 伍雅清 《现代外语》 CSSCI 北大核心 2002年第1期14-24,共11页
本文分析了汉语WH-问句中一直不被语言学界重视的问题即多项WH-问句中WH-词的解释问题。文章首先对英语多项WH-问句中的WH-词的解释进行了较全面的概括,如成对的答案,第一个WH-词的语义特征,多项WH-问句和WH-词与全称量词结合的句子的... 本文分析了汉语WH-问句中一直不被语言学界重视的问题即多项WH-问句中WH-词的解释问题。文章首先对英语多项WH-问句中的WH-词的解释进行了较全面的概括,如成对的答案,第一个WH-词的语义特征,多项WH-问句和WH-词与全称量词结合的句子的相似性等。在此基础上我们用汉语进行了验证,结果表明,汉语的典型多项WH-问句的解释和英语中的结论相同,但由于汉语多项WH-问句中的一些特殊性,如存在句、“都”字句以及汉语WH-词与英语WH-词的性质上的区别,对英语中多项WH-词的解释并不完全适用于汉语。多项WH-问句的语义表征也可以印证这一点。 展开更多
关键词 汉语 问句 英语 解释 存在句 语义特征 语言学 句子 相同 语义表征
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WH-m/M相乘复合码扩频系统的互扰统计特性 被引量:4
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作者 任勇 魏双庆 山秀明 《电子学报》 EI CAS CSCD 北大核心 1999年第7期5-8,共4页
本文建立了复合码DSCDMA扩频系统的数学模型,推导了多址干扰的数学表示,定义了用户之间的互扰因子,并进行了计算.研究发现:在扩频比相同的条件下,若PN序列周期大于扩频比,且序列的伪随机性较好,则采用WHm/M复... 本文建立了复合码DSCDMA扩频系统的数学模型,推导了多址干扰的数学表示,定义了用户之间的互扰因子,并进行了计算.研究发现:在扩频比相同的条件下,若PN序列周期大于扩频比,且序列的伪随机性较好,则采用WHm/M复合序列与采用m、M序列的扩频系统,其互扰因子均呈高斯分布,且数字特征相同;当PN序列周期等于扩频比时,互扰因子不具有高斯分布特性.该结论不要求扩频比足够大,而且对同步和异步DSCDMA通信系统都适用. 展开更多
关键词 DS-CDMA wh序列 M序列 M序列 扩频通信系统
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二语熟练度对汉-英二语者英语wh疑问句加工策略的影响 被引量:1
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作者 常欣 何晶 王沛 《心理与行为研究》 CSSCI 北大核心 2017年第5期599-605,共7页
选取大学英语专业的高熟练度双语者与非英语专业的低熟练度双语者作为被试,利用自控速度阅读与生成意义即止任务,探讨了母语为汉语的高熟练度双语者和低熟练度双语者对英语wh疑问句的加工策略。通过分析反应时和不合理判断率,发现高熟... 选取大学英语专业的高熟练度双语者与非英语专业的低熟练度双语者作为被试,利用自控速度阅读与生成意义即止任务,探讨了母语为汉语的高熟练度双语者和低熟练度双语者对英语wh疑问句的加工策略。通过分析反应时和不合理判断率,发现高熟练度双语者采用了填充驱动策略,对句子的加工易受句子合理性的影响。低熟练度双语者则采用了最后间隙策略,同时对句子合理性限制完全免疫,这可能与其工作记忆容量较小或者是二语的熟练程度偏低有关,说明二语熟练度在一定程度上会对双语者加工wh-疑问句产生影响。 展开更多
关键词 wh疑问句 双语者 二语熟练度 填充驱动策略 最后间隙策略
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汽车罐车罐体用WH590(17MnNiVNbR)钢板的开发和试验研究 被引量:15
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作者 许强 王利 +2 位作者 徐亮 李书瑞 丁庆丰 《压力容器》 北大核心 2010年第3期7-12,共6页
系统地研究了WH590(17MnNiVNbR)钢的各项力学性能,结果表明:WH590(17MnNiVNbR)钢具有优良的综合力学性能,可以作为我国汽车罐车罐体更新换代材料。
关键词 wh590(17MnNiVNbR)钢 力学性能 汽车罐车
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PCV2 WH株人工感染断奶仔猪复制多系统衰竭综合征 被引量:1
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作者 吴胜昔 梁望旺 +4 位作者 徐斌 曾政 蔺露 董春霞 熊仲良 《南方农业学报》 CAS CSCD 北大核心 2014年第5期864-869,共6页
【目的】建立猪圆环病毒2型(PCV2)WH株人工感染断奶仔猪多系统衰竭综合征(PMWS)的动物模型,为探讨PCV2的致病机理及疫苗免疫效果评价奠定基础。【方法】将PCV2WH株通过颈部肌注和滴鼻感染PCV2抗体阴性的7周龄仔猪,攻毒后第4、7 d用钥孔... 【目的】建立猪圆环病毒2型(PCV2)WH株人工感染断奶仔猪多系统衰竭综合征(PMWS)的动物模型,为探讨PCV2的致病机理及疫苗免疫效果评价奠定基础。【方法】将PCV2WH株通过颈部肌注和滴鼻感染PCV2抗体阴性的7周龄仔猪,攻毒后第4、7 d用钥孔血蓝蛋白(KLH)进行刺激,第7、11 d再腹腔注射巯基乙酸,同时设阴性对照组(单独KLH刺激)。攻毒后第35 d扑杀所有试验猪,观察其组织病变,并取肺脏、淋巴结组织提取病毒DNA,用PCR检测PCV2;取试验猪的肺脏、肝脏、脾脏、肾脏、淋巴结、心脏、膀胱等组织制作石蜡切片,进行HE染色和免疫组化分析。【结果】攻毒组仔猪的临床症状主要表现为发热、消瘦、被毛粗乱、皮肤苍白;攻毒后第35 d扑杀所有试验猪,剖检发现阴性对照组未出现病理变化,而攻毒组仔猪有明显病理变化,从其病变的肺脏、淋巴结、肾脏、脾脏、肝脏、心脏组织中均能检测到PCV2。HE染色结果显示,组织病理学变化主要为间质性肺炎、淋巴细胞缺失、间质性肾炎、肝脏肝窦单核巨噬细胞增生。免疫组化分析结果显示,肺脏支气管上皮细胞呈明显阳性,部分肺泡巨噬细胞可见阳性信号,主要位于胞浆内;肠系膜淋巴结均出现较强阳性信号,主要位于淋巴细胞的胞浆内;肾间质细胞呈明显阳性。【结论】用PCV2 WH株攻毒联合KLH和巯基乙酸反复刺激断奶仔猪能成功复制出PMWS,为后续PCV2疫苗的免疫效果评价及PMWS发病机理研究提供了理想的动物模型。 展开更多
关键词 猪圆环病毒 PCV2 wh 断奶仔猪多系统衰竭综合征 钥孔血蓝蛋白 HE染色 免疫组化分析
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戊糖乳杆菌WH12-2-1产细菌素条件的优化 被引量:6
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作者 苏芳 李莉 +1 位作者 罗斌 孟和毕力格 《中国乳品工业》 CAS 北大核心 2010年第3期10-15,共6页
以分离自内蒙古传统乳制品中的戊糖乳杆菌(Lactobacillus pentosus)WH12-2-1为试验菌株,研究其产细菌素的最佳条件,以提高该菌产细菌素的能力。对碳源、氮源等培养基成分及培养条件进行优化,并采用响应平面法确定其最佳的碳源、氮源和... 以分离自内蒙古传统乳制品中的戊糖乳杆菌(Lactobacillus pentosus)WH12-2-1为试验菌株,研究其产细菌素的最佳条件,以提高该菌产细菌素的能力。对碳源、氮源等培养基成分及培养条件进行优化,并采用响应平面法确定其最佳的碳源、氮源和缓冲盐的质量浓度。结果表明,L.pentosus WH12-2-1在37℃(pH值为7.0),抑菌活性最佳,培养基成分为:大豆蛋白胨10g/L,牛肉膏5g/L,酵母粉5g/L,葡萄糖30g/L,柠檬酸钠6g/L,磷酸氢二钾6g/L,乙酸钠15g/L,Tween-802g/L,硫酸镁1g/L,硫酸锰50mg/L,硫酸亚铁50mg/L。此条件下,细菌素的产量是原来的3.38倍。 展开更多
关键词 糖乳杆菌wh12—2—1 细菌素 优化
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WH505对实验性血栓形成的影响及其作用机制 被引量:18
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作者 姜开余 顾振纶 阮长耿 《中成药》 CAS CSCD 2000年第11期782-785,共4页
目的 :探讨WH5 0 5 (丹参和山楂提取物 )对实验性血栓形成的影响及其作用机制。方法 :用电刺激大鼠颈总动脉和结扎大鼠下腔静脉造成血栓形成模型 ;用放免法和聚合酶链反应方法检测体外培养血管内皮细胞缺氧后ET 1的表达。结果 :WH5 0 5... 目的 :探讨WH5 0 5 (丹参和山楂提取物 )对实验性血栓形成的影响及其作用机制。方法 :用电刺激大鼠颈总动脉和结扎大鼠下腔静脉造成血栓形成模型 ;用放免法和聚合酶链反应方法检测体外培养血管内皮细胞缺氧后ET 1的表达。结果 :WH5 0 5剂量依赖性地延长电刺激大鼠颈总动脉后血栓形成时间 ,与对照组比较有显著差异。WH5 0 5明显抑制静脉血栓的形成 ,抑制率分别为 12 .6 4%、19.30 %和 5 7.32 %。体外培养人血管内皮细胞经缺氧后 ,细胞内ET 1mRNA表达增加 ,培养液中ET 1浓度升高。在缺氧前 ,用不同浓度WH5 0 5与血管内皮细胞共孵育 ,则可明显抑制细胞内ET 1mRNA表达 ,减少内皮细胞分泌ET 1。结论 :WH5 0 5具有抗大鼠体内血栓形成的作用 ,其作用机制可能与保护血管内皮细胞损伤有关。 展开更多
关键词 丹参 山楂 血栓形成 大鼠 中医药治疗 wh505
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