Increased catabolism and decreased unsaturation of ganglioside in patients with inflammatory bowel disease

AIM: To investigate whether accelerated catabolism of ganglioside and decreased ganglioside content contribute to the etiology of pro-inflammatory intestinal disease. METHODS: Intestinal mucosa from terminal ileum or colon was obtained from patients with ulcerative colitis or inflammatory Crohn's disease(n = 11) undergoing bowel resection and compared to control samples of normal intestine from patients with benign colon polyps(n = 6) and colorectal cancer(n = 12) in this observational case-control study. Gangliosides and phospholipids of intestinal mucosa were characterized by class and ceramide or fatty acid composition using liquid chromatography triple-quad mass spectrometry. Content and composition of ganglioside classes GM1, GM3, GD3, GD1 a, GT1 and GT3 were compared among subject groups. Content and composition of phospholipid classes phosphatidylcholine(PC) and phosphatidylethanolamine were compared among subject groups. Unsaturation index of individual ganglioside and phospholipid classes was computed and compared among subject groups. Ganglioside catabolism enzymes beta-hexosaminidase A(HEXA) and sialidase-3(NEU3) were measured in intestinal mucosa using western blot and compared among subject groups. RESULTS: Relative GM3 ganglioside content was 2-fold higher(P < 0.05) in intestine from patients with inflammatory bowel disease(IBD) compared to control intestine. The quantity of GM3 and ratio of GM3/GD3 was also higher in IBD intestine than control tissue(P < 0.05). Control intestine exhibited 3-fold higher(P < 0.01) relative GD1 a ganglioside content than IBD intestine. GD3 and GD1 a species of ganglioside containing three unsaturated bonds were present in control intestine, but were not detected in IBD intestine. The relative content of PC containing more than two unsaturated bonds was 30% lower in IBD intestine than control intestine(P < 0.05). The relative content of HEXA in IBD intestine was increased 1.7-fold(P < 0.05) and NEU3 was increased 8.3-fold(P < 0.01) compared to normal intestine. Intestinal mucosa in IBD is characterized by increased GM3 content, decreased GD1 a, and a reduction in polyunsaturated fatty acid constituents in GD3, GD1 a and PC.CONCLUSION: This study suggests a new paradigm by proposing that IBD occurs as a consequence of increased metabolism of specific gangliosides.

Modulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver by probiotics

The potential for the positive manipulation of the gut microbiome through the introduction of beneficial microbes, as also known as probiotics, is currently an active area of investigation. The FAO/WHO define probiotics as live microorganisms that confer a health benefit to the host when administered in adequate amounts. However, dead bacteria and bacterial molecular components may also exhibit probiotic properties. The results of clinical studies have demonstrated the clinical potential of probiotics in many pathologies, such as allergic diseases, diarrhea, inflammatory bowel disease and viral infection. Several mechanisms have been proposed to explain the beneficial effects of probiotics, most of which involve gene expression regulation in specific tissues, particularly the intestine and liver. Therefore, the modulation of gene expression mediated by probiotics is an important issue that warrants further investigation. In the present paper, we performed a systematic review of the probiotic-mediated modulation of gene expression that is associated with the immune system and inflammation. Between January 1990 to February 2014, PubMed was searched for articles that were published in English using the MeSH terms &#x0201c;probiotics' and 'gene expression' combined with &#x0201c;intestines', 'liver', 'enterocytes', 'antigen-presenting cells', 'dendritic cells', 'immune system', and 'inflammation'. Two hundred and five original articles matching these criteria were initially selected, although only those articles that included specific gene expression results (77) were later considered for this review and separated into three major topics: the regulation of immunity and inflammatory gene expression in the gut, in inflammatory diseases of the gut and in the liver. Particular strains of Bifidobacteria, Lactobacilli, Escherichia coli, Propionibacterium, Bacillus and Saccharomyces influence the gene expression of mucins, Toll-like receptors, caspases, nuclear factor-&#x003ba;B, and interleukins and lead mainly to an anti-inflammatory response in cultured enterocytes. In addition, the interaction of commensal bacteria and probiotics with the surface of antigen-presenting cells in vitro results in the downregulation of pro-inflammatory genes that are linked to inflammatory signaling pathways, whereas other anti-inflammatory genes are upregulated. The effects of probiotics have been extensively investigated in animal models ranging from fish to mice, rats and piglets. These bacteria induce a tolerogenic and hyporesponsive immune response in which many genes that are related to the immune system, in particular those genes expressing anti-inflammatory cytokines, are upregulated. By contrast, information related to gene expression in human intestinal cells mediated by the action of probiotics is scarce. There is a need for further clinical studies that evaluate the mechanism of action of probiotics both in healthy humans and in patients with chronic diseases. These types of clinical studies are necessary for addressing the influence of these microorganisms in gene expression for different pathways, particularly those that are associated with the immune response, and to better understand the role that probiotics might have in the prevention and treatment of disease.

Inflammatory bowel disease: An increased risk factor for neurologic complications

Only a very few systematic studies have investigated the frequency of neurologic disorders in patients with Crohn&#x02019;s disease (CD) and ulcerative colitis (UC), which are the two main types of inflammatory bowel disease (IBD). Results have been inconsistent and variable, owing to differences in case-finding methods and evaluated outcomes in different studies. The most frequent neurologic manifestations reported in CD and UC populations are cerebrovascular disease (with either arterial or venous events), demyelinating central nervous system disease, and peripheral neuropathy (whether axonal or demyelinating); however, the literature describes numerous nervous system disorders as being associated with IBD. The pathogenesis of nervous system tissue involvement in IBD has yet to be elucidated, although it seems to be related to immune mechanisms or prothrombotic states. The recently-introduced tumor necrosis factor (TNF) inhibitors have proven successful in controlling moderate to severe IBD activity. However, severe neurologic disorders associated with TNF inhibitors have been reported, which therefore raises concerns regarding the effect of anti-TNF-&#x003b1; antibodies on the nervous system. Although neurological involvement associated with IBD is rarely reported, gastroenterologists should be aware of the neurologic manifestations of IBD in order to provide early treatment, which is crucial for preventing major neurologic morbidity.

Can Na+/K+ATPase be a novel target to treat anxiety?A hint from its regulatory effect on neuroinflammation

OBJECTIVE Na+/K+-ATPase(NKA)is large membrane protein expressed uni⁃versally which is indispensable for the mainte⁃nance of ionic gradient as well as neuronal excit⁃ability.The role of NKA in inflammatory regula⁃tion is still unclear.Inflammatory responses are initiated upon the activation of inflammasomes.In order to investigate the crosslink between NKA and inflammasome,NKAα1 knockout(KO)N2a cells were generated using CRISPR/Cas9 system.METHODS AND RESULTS qPCR results showed that NLRP1 and NLRP3 were upregulated in response to NKAα1 loss while both NLRC4 and AIM2 remained unaffected.Meanwhile,consistent with the change in NLRP1 and NLRP3,both the mRNA level of ASC and IL-1βwere significantly increased in NKAα1 KO cells.These data indicated that NKAα1 interfer⁃ence might influence the level of NLRP1 and NLRP3 inflammasomes in neuronal cells.Further evidence indicating the potential link between NKA and inflammasome pathway were provided using cytokine array assay where all the differen⁃tiated protein detected were closely linked to NLRP1 and NLRP3.To confirm this effect,we also observed the transcriptional levels of inflam⁃masome proteins in the brain cortex from both NKAα1+/+and NKAα1+/-mice.In line with the observation gained in NKAα1 KO cells,the mRNA level of NLRP1,NLRP3 and IL-1βwere significantly upregulated in NKAα1+/-mice brain.Interestingly,in the primary cultured astrocytes,treatment with LPS/ATP significantly reduced the mRNA and protein levels of NKAα1 expression.These data imply that a negative regulation loop between NKAα1 and inflammation may exist in the central nervous system.Since neuroinflam⁃matory mechanism is currently considered the most potential of interventions to target anxiety,we therefore perform behavioural experiments to investigate the role of NKAα1 in anxiety.Chronic restraint stress(CRS)for 10 d significantly reduced the time and frequency of entering the open arm and prolonged the retention time in the closed arm in the elevated plus-maze test.In the open field test,CRS also reduced both duration and frequency of entering into the central region.Although NKAα1 loss itself did not alter the behaviour performance in the normal condition,it exacerbated CRS-induced above behaviour abnormalities.CONCLUSION NKAα1 is regulat⁃ed upon inflammatory challenger and may be a novel target to treat anxiety.

紫外可见光谱结合化学模式识别对紫苏油的真伪鉴别

作为高经济价值且昂贵的非常规植物油,紫苏油易被低价食用油掺假。由于食用油的匀质性及其组成的复杂性,传统鉴别方法难以快速准确地鉴别紫苏油的真伪。该文探索了紫外可见光谱结合化学模式识别对紫苏油真伪鉴别的可行性。首先购买了40个纯紫苏油样品,并将大豆油、棕榈油分别按一定的比例加入到纯紫苏油中配制了51个二元掺伪和63个三元掺伪紫苏油样品。根据鉴别目的,从154个总样品中获得两个数据集,一个是由40个纯紫苏油和114个掺伪紫苏油构成的真伪紫苏油二分类数据集;另一个是由40个纯紫苏油、51个二元掺伪和63个三元掺伪紫苏油构成的真伪紫苏油三分类数据集。然后采用主成分分析(PCA)、簇类独立软模式(SIMCA)、偏最小二乘-判别分析(PLS-DA)和极限学习机(ELM)4种方法,依次对以上两个数据集进行分类。使用混淆矩阵可视化分类结果,并用准确率、精确率、召回率、F1分数对模型性能进行评价。结果表明,对于真伪紫苏油二分类和三分类数据集,PLS-DA均为最佳模型,预测准确率分别为98.04%和100%。因此,紫外可见光谱结合化学模式识别可以实现真伪紫苏油的快速准确鉴别。

深部强矿压工作面水力压裂裂纹扩展规律研究

目的为了研究深部强矿压工作面水力压裂裂纹扩展规律,方法以余吾煤矿的3号煤层S5207回风巷为工程背景,首先建立水力压裂力学模型,分析最大周向拉应变准则和裂纹扩展准则,其次通过三维数值模拟,分析水力压裂裂纹扩展影响因子D和地应力对水力压裂裂纹扩展规律的影响,并根据现场情况设计水力压裂试验方案,实施水力压裂增透技术,分析现场施工效果。结果结果表明:预制裂纹沿着与原裂纹呈一定角度开裂并向外延伸,其扩展方向最终与最小主应力方向垂直;随着D增大,裂纹与原裂纹的夹角越来越小,当D较大时,裂纹呈现自相似的扩展状态;不同应力场下,裂纹扩展轨迹主要取决于主应力方向,最终与最小主应力方向垂直,水力裂缝为垂直缝,且在裂纹尖端有应力集中现象;现场监测发现,裂纹扩展符合最大周向拉应变准则,裂纹尖端沿着环向拉应变最大的地方扩展,环向拉应变达到最大时裂纹开始扩展,压裂过程中出现了较大环向裂隙,裂纹沿垂直于最小主应力方向延伸,与S5207回风巷的最大水平主应力方向大致相同,与数值模拟结果接近。结论研究结果可为深部强矿压工作面水力压裂提供参考和依据。

不平衡电压下励磁绕组匝间短路对同步调相机磁场及转子振动特性的影响

随着新一代同步调相机的大量使用,调相机的安全性问题日益突出。励磁绕组匝间短路是一种常见的故障,直接影响到调相机的正常工作。本文以电网电压不平衡状态下调相机发生励磁绕组匝间短路的故障特征分析为目标,建立了电网电压平衡状态下调相机正常运行与发生励磁绕组匝间短路故障、不平衡电压下调相机未发生故障以及发生励磁绕组匝间短路故障四种工况下气隙磁通密度、转子不平衡磁拉力的统一数学表征,分析了不同工况下调相机的转子振动特性,并从谐波含量、谐波幅值等多方面进行了对比分析,揭示了调相机故障机理。基于某场站TTS-300-2型新型同步调相机建立了四种工况下的有限元仿真模型,并在动态模拟实验室中,以MJF-30-6型故障模拟同步电机模拟调相机运行进行了实验验证。结果表明,在不平衡电压下发生故障时气隙磁通密度产生衰减,转子不平衡磁拉力出现三次谐波分量。通过仿真分析与实验验证,理论研究成果的准确性得到了充分证实,为调相机故障诊断工作奠定了坚实的理论基础。

北秦岭南召盆地太山庙组下部凝灰岩锆石U-Pb年龄及其地质意义

晚三叠世卡尼期全球古气候发生明显转变,全球降水量增加,海水温度上升了6~8℃,大量陆源碎屑物质输入海洋,导致海洋中出现碳酸盐生产危机。北秦岭南召盆地太山庙组可能记录了卡尼期洪水事件。目的为精确限定太山庙组沉积时代,凸显其地质意义,方法采用激光剥蚀电感耦合等离子体质谱法(LA-ICP-MS)对太山庙组下部凝灰岩进行锆石U-Pb同位素定年分析。结果结果表明:凝灰岩锆石颗粒呈粒状、短柱状,无磨圆;阴极发光图像显示振荡环带结构明显;根据阴极发光图像和Th/U,认为太山庙组下部凝灰岩中18颗锆石均为火山来源,剔除轻稀土富集的锆石后,选择其中15颗锆石进行计算,得到其加权平均年龄为(241.4±1.3)Ma(1σ;MSWD=0.27),代表凝灰岩中锆石的结晶年龄;结合前人研究成果,计算出太山庙组下部平均沉积速率为20.6 m/Ma,太山庙组底界年龄约246 Ma,因此,太山庙组至少自中三叠世安尼期就开始沉积,至晚三叠世卡尼期末结束;根据南召盆地遗迹化石组合演化规律和植物孢粉变化,认为太山庙组沉积时期古气候发生了明显转变,由干旱炎热气候转变为温暖、湿润气候。结论研究结果对北秦岭南召盆地三叠纪地层划分产生了新认识,有助于研究探讨南召盆地对卡尼期洪水事件的沉积响应。

压水堆国产SA-508-Ⅲ-1钢环境影响疲劳试验研究和预测模型开发

对压水堆核电厂一回路设备用国产SA-508 Gr.3 Cl.1低合金钢(简称SA-508-Ⅲ-1钢)进行室温和320℃空气环境,以及模拟压水堆一回路水环境下的疲劳性能试验研究,获得国产SA-508-Ⅲ-1钢在空气环境下的疲劳寿命最佳拟合曲线(平均曲线)。在此基础上,对影响国产SA-508-Ⅲ-1钢在压水堆核电厂一回路水环境下疲劳性能的应变速率、温度和溶解氧含量等参数的影响规律进行研究,获得各影响参数的影响函数方程。基于获得的各影响参数的函数方程,建立国产SA-508-Ⅲ-1钢的环境影响疲劳修正因子F_(en)预测模型。本文获得的压水堆核电厂一回路水环境下国产SA-508-Ⅲ-1钢的疲劳寿命都位于95%置信度限值(10^(±2σ))范围内,验证了本文预测模型的有效性。同时,本文获得的压水堆核电厂一回路水环境下国产SA-508-Ⅲ-1钢的疲劳寿命与美国阿贡国家实验室(ANL)模型所预测的寿命相比,也都位于95%置信度限值(10^(±2σ))范围内,说明ANL模型可用于国产SA-508-Ⅲ-1钢的疲劳寿命预测。本文获得的国产SA-508-Ⅲ-1钢的环境影响疲劳预测模型与ANL模型相比,更适用于国产SA-508-Ⅲ-1钢的寿命预测,为国内第3代核电厂一回路设备考虑压水堆一回路水环境影响的疲劳设计提供参考。

西部大开发背景下职普融通教材建设:价值诉求、逻辑遵循与路径选择

西部地区高质量教育体系建设的关键在职普融通,职普融通的关键在课程,而课程的关键在教材建设。在西部大开发形成新格局的背景下,职普融通教材承载了更多的价值诉求,加快职普融通教材建设是促进西部地区产业转型升级的重要方式,是西部地区教育改革发展的关键一环,更是西部地区人力资源开发的有效途径。西部大开发背景下职普融通教材建设作为一项综合性的教育工程,要遵循“区域适配”的社会逻辑、“多元一体”的文化逻辑,以及“知行合一”的教育逻辑,进而以教材为载体打破职普分离的壁垒,精准满足西部大开发战略对西部地区经济社会、文化政治与人才培养的需求。未来,西部地区职普融通教材建设要以“素质提升”为目标,以“理实共融”为重点,以“区域特色”为资源,为推进西部大开发形成新格局提供持久的教育活力。

深部煤层钻孔保压取心流程分析及含气量测定方法

含气量是煤层气储量计算和勘探开发的重要参数。针对深煤层,由于提心时间长,损失气量计算失准,导致绳索取心含气量测试方法准确性降低。为了准确获取深煤层的真实含气量,确定气体的赋存状态,能够保留样品原位压力和原位含气量的保压取心技术被认为是最有效的方法。然而,由于非常规储层保压取心的特殊性(含吸附气),目前还没有统一的取心流程和标准的含气量测定方法。为此,通过分析保压取心各阶段的环境特点和含气量损失特征,针对深煤层存在吸附气和游离气的特点,提出了基于保压取心的吸附气和游离气的测定方法。分析表明,保压取心含气量计算具有“四阶段、两损失、两收集”的特点;合理设计保压取心降压集气阶段的压力点,能够有效区分吸附气和游离气。此外,分析保压取心和常规绳索取心的差异和联系,认为通过同井台保压取心含气量可校正绳索取心损失气量,进而建立基于绳索取心的深煤层含气量计算方法。保压取心技术的成功应用对深煤层勘探意义重大,建议在深煤层勘探区适当增加保压取心井测试,以明确储层的真实含气性。

健全人民当家作主制度体系:中国式现代化的政治基础

人民当家作主制度体系是全过程人民民主的制度支撑,发展全过程人民民主是中国式现代化的本质要求,因而健全人民当家作主制度体系成为中国式现代化的政治基础。人民当家作主制度体系是在马克思主义指导下内生演化于我国基本国情的制度体系。健全人民当家作主制度体系的首要前提是在马克思主义指导下,立足于中国社会文化传统的基本特征以及世界范围内民主实践的优秀成果,不断疏通人民当家作主制度体系中的结构性梗阻,拓展制度体系的应用范围和价值功用,回应中国式现代化道路中的新问题。健全人民当家作主制度体系是一项系统工程,要全面把握党的全面领导制度、人民代表大会制度、中国共产党领导的多党合作和政治协商制度、民族区域自治制度、基层群众自治制度等构成要素。需要统筹推进根本制度、基本制度和重要制度的协同衔接,科学构建系统性、整体性、协同性的结构关系,整体推进民主制度与社会发展相适应、政治民主与社会民主相结合的人民当家作主制度体系。在遵循全过程人民民主逻辑的前提下,健全“全链条、全方位、全覆盖”的人民当家作主制度体系,同时以问题为导向选择重点推进路径,既要面向国家发展中的重要问题,也要回应人民群众急难愁盼的问题,在“大问题”和“小问题”的共同解决中提升人民当家作主制度体系的制度效能。

热输入对高锰钢模拟焊接热影响区显微组织和低温韧性的影响

作为一种新型低温用材料,高锰钢具有低成本及优异的低温力学性能等优势,在液化天然气(LNG)储罐等领域具有广阔的应用前景.然而在实际焊接过程中,高锰钢焊接热影响区中距熔合线3 mm处的特定亚区(FL+3亚区)会出现低温韧性恶化的问题.针对这一问题,采用焊接热模拟技术再现了不同热输入下的FL+3亚区,通过扫描电子显微镜、电子探针X射线显微分析仪和透射电子显微镜观察晶界比例、偏析及析出相.结果表明,模拟FL+3亚区具有较好的低温韧性,其冲击断口形貌均为大量的韧窝.然而随着热输入增加,其冲击吸收功降低,10 kJ/cm、15 kJ/cm、30 kJ/cm和45 kJ/cm不同热输入下的-196℃冲击吸收功分别为177 J、172 J、138 J和112J.FL+3亚区的显微组织为单相奥氏体组织,随着热输入增加,晶粒尺寸无明显变化,而小角度晶界比例升高.热输入增加会加剧FL+3亚区的C、Cu晶界偏析和Mn带状偏析,提高偏析区域的层错能以及临界剪切孪晶应力,使得孪生机制难以激活,进而减弱了形变孪晶的韧化作用,降低低温韧性.当热输入增大到15 kJ/cm时,FL+3亚区开始析出尺寸约为200 nm的颗粒状和块状Cr_(23)C_(6)碳化物,且析出相的尺寸和数量随着热输入增加而进一步增加.碳化物析出易引起应力集中而产生裂纹萌生,降低了FL+3亚区的低温韧性.

Aerodynamic, Kinematic and Control Coupling Simulation of Aircraft Maneuvering Flight

Aiming at the high angle of attack pull-up and multi-channel roll pull-up coupling problems of high maneuvering aircraft, this paper establishes the flight attitude control rate by means of unsteady flow numerical solution, dynamic unstructured nested mesh assembly method and numerical solution method of flight mechanics equation. On this basis, a virtual flight simulation platform integrating pneumatics, motion and control is established. Based on this virtual flight simulation platform, F-16 aircraft is simulated by high angle of attack pull-up flight mode and multi-channel roll pull-up coupling flight mode. Finally, the influence of rudder on the yaw control channel is investigated. The results show that the numerical virtual flight simulation platform established in this paper has the ability to simulate maneuvering flight of aircraft.

出生体质量、妊娠日龄和世代间隔对奶牛泌乳性能的影响

[目的]为充分发挥青年牛产犊后的产奶潜力,研究出生、配种及妊娠等不同阶段对其产后泌乳性能的影响。[方法]2021年1月—2023年12月收集新疆石河子2个规模化奶牛场中青年牛出生日期、配种日期、妊娠日期、产犊和所产犊牛体质量以及产后产奶量等信息,分析青年牛出生体质量、妊娠日期、世代间隔等因素与其产后泌乳性能的相关性。[结果]青年牛的出生体质量、配种体质量及妊娠日龄和世代间隔等因素均对其产后泌乳性能均产生显著影响,呈正相关(P<0.05)。出生体质量在37 kg以上、配种体质量达到410 kg,妊娠日龄超过438 d以及世代间隔711.16 d以上的青年母牛产后头胎次泌乳量相对较高。[结论]应加强青年母牛妊娠期的营养管理,同时合理控制配种体质量和妊娠时间,并优化世代间隔。

颈动脉钙化模式与急性脑梗死患者短期预后的相关研究

目的 探讨颈动脉的钙化模式与急性脑梗死患者治疗3个月的预后相关性。方法 纳入2021年3月—2022年9月就诊于浙江大学医学院附属金华医院的急性缺血性脑卒中(AIS)患者112例为研究对象,入院24h完成头部CT血管成像,评估颈动脉的钙化模式(无钙化、内膜钙化和中膜钙化)以及钙化负荷(低和高钙化)。治疗7 d复查头部CT评估出血转化和梗死体积,随访3个月根据改良Rankin评分(mRS)分为预后良好组82例(<3分)和不良组30例(≥3分)。结果 不良组年龄≥70岁、平均收缩压≥165 mmHg、空腹血糖≥7.5 mmol/L、入院NIHSS评分≥12分、内膜钙化和中膜钙化、高钙化、出血转化以及梗死体积≥50 mm3显著高于良好组(P<0.05)。多因素Logistic回归显示,入院NIHSS评分≥12分、内膜钙化、出血转化以及梗死体积≥50 mm3是预后不良的危险因素(P<0.05)。结论 AIS患者颈动脉的内膜钙化可能与短期预后不良有关,可作为预后评估的新型无创性指标。

Fixation and Creep of Compressed Wood of Chinese Fir Irradiated with Gamma Rays

In order to discuss the mechanisms of permanent fixation of wood compression set , compressed wood of Chinese fir (Cunninghamia lanceolata) was irradiated by gamma rays from 60 Co. The irradiation doses were 0 (for match specim ens), 10 3, 5×10 3, 10 4, 5×10 4, 10 5, 5×10 5, 10 6, 5×10 6 Gy, res pectively. Then the weight loss, the equilibrium moisture content (EMC), the rec overy of wood compression set after adsorption (RSA) and the recovery after imme rsion in water (RSW), as well as the creep behaviour under a dry specimen condit ion and under an adsorption and subsequent desorption condition were measured an d discussed. This research proves that the doses of gamma irradiation have great effect on weight loss, EMC, RSA, RSW of irradiated compressed wood of Chinese f ir. The weight loss and the EMC increase, the RSA and the RSW fall drastically w hen the irradiation doses exceed 10 6 Gy. Both the instantaneous compliance and the creep compliance of the irradiated specimens under the two measurement cond itions show the general trend of increase with the increase of gamma irradiation doses. It can be deduced that decomposition or decrystallization reactions happ en in the wood cell wall at high gamma irradiation doses, especially at doses of around 5×10 6 Gy. In addition, this research proves that decomposition of mai n components of cell wall of compressed wood will lead to fixation of compressio n set of wood to a certain degree.

Determination of Heavy Metals in Dendrobium candidium Wall.ex Lindl.by ICP-MS

[Objective] This research aimed to establish an inductively coupled plasma mass spectrometry （ICP-MS） method for determination of five kinds of heavy metals （Pb, Cd, Cu, As and Hg） in Dendrobium candidium Wall. ex Lindl. [Method] The samples were digested in HNO3-H202 acids system by closed vessel microwave di- gestion. At the same time, internal standard was added to avoid the matrix effect. [Result] The five kinds of heavy meals all showed good linear relationships, and the correlation coefficients ranged from 0.998 2 to 0.999 9. The detection limits of the five kinds of heavy metals were in the range of 0.008-0.750 μg/L, while the stan- dard recovery rates were in the range of 90.4%-96.9%. The relative standard devi- ations ranged from 1.6% to 8.2%. The heavy metals in the Ginseng and Astragalus national standard samples were determined by the established ICP-MS method, and the results were in conformity with the standard values. [Conclusion] The established method has simple and convenient operation and accurate and reliable results, and it meets the requirements by determination of heavy metals in Dendrobium candididium Wall. ex Lindl.

基于论元结构和论元角色的英语-(a)tion型后缀动词名物词具体义研究

英语双音节和多音节及物动词大多可以通过添加-(a)tion或同类后缀的形式构成相应的动词名物词。宏观上讲,这类词有具体和抽象两种意义,抽象义往往和原动词的意义十分接近,表示动作或行为本身,而具体义则可从相应动词的论元结构和论元角色来找到语义依据。具体来说,具体义往往可以通过原动词论元结构中的某一论元或其上位词来表达。英语这类名物词的具体义与相应动词论元的这种内在关系的形成,与动词词义本身以及人类的认知规律均有重要联系。

Standard Operating Procedure of Houttuynia cordata Thunb.Plastic Greenhouse Cultivation

This standard operating procedure stipulated the natural condition of pro- ducing area, cultivation technique, disease and pest control, harvest, quality stan- dard, packaging, transportation and storage of H. cordata, in order to provide a ba- sis for the standard cultivation of H. cordata.