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Transition from a maternal to external nitrogen source in maize seedlings

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Journal of Integrative Plant Biology 2017年第4期59卷 261-274页

作者： Kasra Sabermanesh luke R. Holtham Jessey George Ute Roessner Berin A. Boughton sigrid Heuer Mark Tester Darren C. Plett Trevor P. Garnett Australian Centre for Plant Functional Genomics Waite Research Institute University of Adelaide Adelaide SA 5064 Australia School of Agriculture Food and Wine Waite Research Institute University of Adelaide Adelaide SA 5064 Australia Australian Centre for Plant Functional Genomics School of BioSciences University of Melbourne Parkville Vic. 3010 Australia Metabolomics Australia School of BioSciences University of Melbourne Vic. 3010 Australia King Abdullah University of Science and Technology Center for Desert Agriculture Thuwal 23955-6900 Kingdom of Saudi Arabia6. The Australian Plant Phenomics Facility The Plant Accelerator Waite Campus The University of Adelaide Adelaide SA 5064 Australia The Australian Plant Phenomics Facility The Plant Accelerator Waite Campus The University of Adelaide Adelaide SA 5064 Australia

Maximizing NO3 uptake during seedling development is important as it has a major influence on plant growth and yield. However, little is known about the processes leading to, and involved in, the initiation of root NO3 uptake capacity in developing seedlings. This study examines the physiological processes involved in root NO3 uptake and metabolism, to gain an understanding of how the NO3 uptake system responds to meet demand as maize seedlings transition from seed N use to external N capture. The concentrations of seedderived free amino acids within root and shoot tissues are initially high, but decrease rapidly until stabilizing eight days after imbibition （DAI）. Similarly, shoot N% decreases, but does not stabilize until 12-13 DAI. Following the decrease in free amino acid concentrations, root NO3- uptake capacity increases until shoot N% stabilizes. The increase in root NO3 uptake capacity corresponds with a rapid rise in transcript levels of putative NO3 transporters, ZmNRT2.1 and ZmNRT2.2. The processes underlying the increase in root NO3- uptake capacity to meet N demand provide an insight into the processes controlling N uptake.

关键词： NRT Transition from a maternal to external nitrogen source in maize seedlings NO

土地海外出让：中国粮食安全的可行的策略？机遇与莫桑比克中国农业投资的风险

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土地海外出让：中国粮食安全的可行的策略？机遇与莫桑比克中国农...

作者： sigrid-Marianella Stensrud Ekman 复旦大学

学位级别：硕士

中国作为一个拥有世界20%人口的国家,却只拥有世界可耕用地的7%。据一些西方媒体报导,在2008年中国食品危机发生之后,中国为了保证其食品供应免受国际市场不稳定因素所造成的负面冲击,开始采取纵向一体化的战略,向海外租用农业用地;进一... 详细信息

中国作为一个拥有世界20%人口的国家,却只拥有世界可耕用地的7%。据一些西方媒体报导,在2008年中国食品危机发生之后,中国为了保证其食品供应免受国际市场不稳定因素所造成的负面冲击,开始采取纵向一体化的战略,向海外租用农业用地;进一步,有些西方媒体又将中国的这种行为贴上了新殖民主义的标签。为了研究中国在莫桑比克从事的农业活动,本人在莫桑比克进行了实地调查,获得了大量的第一手或第二手材料。本文以这些材料为基础,探讨了中国在海外租用农业用地战略的可行性。研究表明,即便向海外寻求土地资源可以起到适当分散粮食安全风险的作用,但它并不是中国本土粮食生产和供应的完美替代。一个更加有趣的发现是,目前莫桑比克并不存在旨在将农业产品出口到中国的中国投资项目。这个研究结果与许多大型非政府组织和国际机构目前所相信的媒体说法正好相反。本文研究并不支持中国在非洲奉行“新殖民主义”的论点。站在非洲国家的角度看,中国的角色并不是所谓的“殖民者”,而是他们的战略合作伙伴。与发达国家相比,中国对非洲实施援助的一大特点是将援助与商业运营和技术转移密切结合在一起,能够更加有力地促进非洲本身的发展;当然,在此过程中,中国也会获得很大的好处。简言之,对中非而言,这是一个双赢博弈。关于中国在非洲租用土地的动机,西方媒体认为主要是因为中国的农业耕地非常有限,进而需要拓展“生存空间”。但需要注意的是,尽管其农业耕地非常有限,现在中国95%的食品需求仍是由国内生产而供应的。本文分析表明,中国企业之所以海外租用农业用地的动力,主要还不是因为中国国内土地资源的稀缺,而是因为中国拥有适合于非洲当地情况的农业技术。正因如此,通过援助和开发非洲,中国企业(包括国有的和私营的)不但有利于非洲本身的繁荣,也能够在此过程中获得自身发展的机会。

关键词：中国粮食安全 investments overseas 农业投资 agricultural farming 媒体报导粮食生产 viable 食品供应

Strictures, diaphragms, erosions or ulcerations of ischemic type in the colon should always prompt consideration of nonsteroidal anti-inflammatory drug-induced lesions

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World Journal of Gastroenterology 2005年第37期11卷 5828-5833页

作者： Manfred Stolte Diana Karimi Michael Vieth Hildegard Volkholz Klaus Dirschmid sigrid Rappel Birgit Bethke Institute of Pathology Klinikum Bayreuth GmbH Bayreuth 95445 Germany

AIM： To investigate whether NSAIDs/ASA lesions in the colon can histologically be diagnosed on the basis of ischemic necrosis similar to biopsy-based diagnosis of NSAIDs/ASA- induced erosions and ulcers of the stomach. METHODS： In the period between 1997 and 2002, we investigated biopsy materials obtained from 611 patients （415 women, 196 men, average age 60.5 years） with endoscopic focal erosions, ulcerations, strictures or diaphragms in the colon. In the biopsies obtained from these lesions, we always established the suspected diagnosis of NSA/D-inducecl lesions whenever necroses of the ischemic type were found. Together with the histological report, we enclosed a questionnaire to investigate the use of medication. The data provided by the questionnaire were then correlated with the endoscopic findings, the location, number and nature of the lesions, and the histological findings. RESUlTS： At the time of their colonoscopy, 86.1% of the patients had indeed been taking NSAID/ASA medication for years （43.9%） or months （29.5%）. The most common indication for the use of these drugs was pain （64.3%）, and the most common indication for colonoscopy was bleeding （55.5%）. Endoscopic inspection revealed multiple erosions and/or ulcers in 60.6%, strictures in 15.8%, and diaphragms in 3.0% of the patients. The lesions were located mainly in the right colon including the transverse colon （79.9%）. A separate analysis of age and sex distribution, endoscopic and histological findings for NSAIDs alone, ASA alone, combined NSAID/ASA, and for patients denying the use of such drugs, revealed no significant differences among the groups. CONClUSION： This uncontrolled retrospective study based on the histological finding of an ischemic necrosis shows that the histologically suspected diagnosis of NSAID-induced lesions in the colon is often correct. The true diagnostic validity of this finding and the differentiation from ischemic colitis should, however, be investigated in a prospective

关键词： Erosion Ulceration Stricture Diaphragm Ischemic necrose NSAIDs ASA

G-CSF/SCF通过诱导心肌肥厚而改善小鼠心肌梗死后心功能(英文)

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中国现代医学杂志 2007年第19期17卷 2305-2309,2317页

作者：田文曾定尹 Michael Kuhlmann sigrid Nikol 中国医科大学附属第一医院循环内科辽宁沈阳110001 德国明斯特大学医院心血管内科

目的了解粒细胞集落刺激因子(G-CSF)和干细胞因子(SCF)对小鼠心肌梗死后的心脏结构、功能以及缺血区炎症反应的影响。方法90只CD1小鼠随机分组后,分别连续给予6天的G-CSF/SCF(n=50)或生理盐水(n=40)。在干预的第三天制作小鼠的心肌梗死... 详细信息

目的了解粒细胞集落刺激因子(G-CSF)和干细胞因子(SCF)对小鼠心肌梗死后的心脏结构、功能以及缺血区炎症反应的影响。方法90只CD1小鼠随机分组后,分别连续给予6天的G-CSF/SCF(n=50)或生理盐水(n=40)。在干预的第三天制作小鼠的心肌梗死模型。术后3周利用心脏超声检测心功能,应用组织学技术检测心肌细胞结构改变以及判断组织的炎症程度。结果细胞因子干预可以增加心肌梗死后心输出量,但不缩小心肌梗死的面积;同时可以诱导缺血区心肌细胞肥大以及促进白细胞在缺血区域的浸润。结论G-CSF/SCF干预可以改善心肌梗死后小鼠的心功能,但与心肌再生无明显相关。骨髓动员可以加重缺血局部心肌组织的炎症反应。

关键词：粒细胞集落刺激因子心肌梗死再生炎症

Blockade of Na^+/H^+ exchanger type 3 causes intracellular acidification and hyperexcitability via inhibition of pH-sensitive K^+ channels in chemosensitive respiratory neurons of the dorsal vagal nucleus in rats

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Neuroscience Bulletin 2014年第1期30卷 43-52页

作者： Jing Zhang Hui Peng sigrid C.Veasey Jing Ma Guang-Fa Wang Ke-Wei Wang Department of Respiratory and Critical Care Medicine Peking University First Hospital Departments of Neurobiology and Molecular and Cellular Pharmacology Peking University Health Science Center Center for Sleep and Circadian Neurobiology University of Pennsylvania School of Medicine Department of Medicine University of Pennsylvania School of Medicine

Extracellular pH （pHe） and intracellular pH （pHi） are important factors for the excitability of chemosensitive central respiratory neurons that play an important role in respiration and obstructive sleep apnea. It has been proposed that inhibition of central Na^＋/ H^＋ exchanger 3 （NHE-3）, a key pHi regulator in the brainstem, decreases the pH, leading to membrane depolarization for the maintenance of respiration. However, how intracellular pH affects the neuronal excitability of respiratory neurons remains largely unknown. In this study, we showed that NHE-3 mRNA is widely distributed in respiration-related neurons of the rat brainstem, including the dorsal vagal nucleus （DVN）. Whole-cell patch clamp recordings from DVN neurons in brain slices revealed that the standing outward current （Iso） through pH-sensitive K^＋ channels was inhibited in the presence of the specific NHE-3 inhibitor AVE0657 that decreased the pHi. Exposure of DVN neurons to an acidified PIle and AVE0657 （5 μmol/l） resulted in a stronger effect on firing rate and Iso than acidified pHe alone. Taken together, our results showed that intracellular acidification by blocking NHE-3 results in inhibition of a pH- sensitive K^＋ current, leading to synergistic excitation of chemosensitive DVN neurons for the regulation of respiration.

关键词： Na^+/H^+ exchange potassium channel dorsal vagal nucleus in situ hybridization respiration

骨髓动员对骨髓造血干细胞在心肌梗死后心脏中定植及分化的影响

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中国组织化学与细胞化学杂志 2009年第3期18卷 304-310页

作者：田文曾定尹 Michael Kuhl mann sigrid Nikol 中国医科大学附属第一医院心内科沈阳110001 德国明斯特大学医院心血管内科 d48149

目的观察小鼠心肌梗死后骨髓造血干细胞在心脏内的分化及细胞因子的影响。方法C57/Bl6小鼠60只分为骨髓动员组和对照组,先后行脾切除、骨髓移植(骨髓供体为增强绿色荧光蛋白转基因小鼠)、骨髓动员及建立心肌梗死模型。心肌梗死后3周将... 详细信息

目的观察小鼠心肌梗死后骨髓造血干细胞在心脏内的分化及细胞因子的影响。方法C57/Bl6小鼠60只分为骨髓动员组和对照组,先后行脾切除、骨髓移植(骨髓供体为增强绿色荧光蛋白转基因小鼠)、骨髓动员及建立心肌梗死模型。心肌梗死后3周将小鼠心脏取出并切片行组织学及激光共聚焦显微镜免疫荧光检查。结果骨髓动员可以增加EGFP阳性细胞在心脏中梗死区和边缘区的定植,但绝大多数EGFP阳性细胞都同时表达CD45。仅发现有极少数骨髓来源的心肌细胞、成纤维细胞及血管内皮细胞,且与骨髓动员无相关性。结论骨髓动员能够明显促进骨髓来源细胞定植入小鼠心脏的梗死区;极少数骨髓造血干细胞可以分化为心肌细胞,其数量远不足以修复梗死心肌及改善心功能;骨髓造血干细胞不参与梗死区疤痕形成的病理过程。

关键词：骨髓造血干细胞骨髓动员增强绿色荧光蛋白共聚焦激光扫描心肌梗死

Burden, Health and Sense of Coherence among Relatives of Depressed Inpatients

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Open Journal of Nursing 2015年第3期5卷 163-172页

作者： Hege Skundberg-Kletthagen Birgitta Hedelin sigrid Wangensteen Marie louise Hall-lord Department of Health Sciences Faculty of Health Science and Technology Karlstad University Karlstad Sweden Department of Nursing Faculty of Health Care and Nursing Gj&oslashvik University College Gj&oslashvik Norway

In Europe, there are an increasing number of persons suffering from depression, which also affects many relatives. The burden and health when being the relative of an inpatient suffering from severe depression has been less examined. The aim of the study was to describe burden, health and sense of coherence among relatives of inpatients with severe depression. Furthermore, the aim was to investigate relatives’ burden in relation to their health and sense of coherence. A cross-sectional design was performed, with a questionnaire consisting of background questions and three instruments;Burden Assessment Scale, General Health Questionnaire and Sense of Coherence scale. The participants consisted of 68 relatives recruited from a sample of inpatients diagnosed with depression in the psychiatric specialist health services in one hospital trust in Norway. The Regional Committee for Medical and Health Research Ethics, Norway South East, gave approval to the study. The relatives reported burden to a various degree, with some reporting a significantly greater burden, poorer health and a weaker sense of coherence than others. With regard to subjective burden eight out of ten relatives reported “Worry about future”, and almost six out of ten were “Upset by change in patient”. Regarding objective burden, more than half the relatives reported having “less time for friends” and “Reduced leisure time”. In conclusion the relatives with a high level of burden reported more mental distress, poorer health and weaker sense of coherence than those with lower level of burden. Further research should focus on identification of factors predicting burden and health of relatives of inpatients with severe depression.

关键词： Burden Depression Health Inpatients Relatives

又红又专、土洋结合——从蒲蛰龙生物害虫防治的科研活动看20世纪50—70年代中国的“科学”观

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中国科技史杂志 2018年第2期39卷 153-168页

作者：舒喜乐田田 History Department University of Massachusetts 中国科学院大学人文学院

本文通过昆虫学家蒲蛰龙及其生物害虫防治研究工作的个案,探讨20世纪50—70年代中国的主流科学观。本文首先指出,(激进的)"革命主义"不能简单地等同于"反科学",或仅注重科学的技术应用方面。革命主义的科学观与其他科学观的不同之处在于... 详细信息

本文通过昆虫学家蒲蛰龙及其生物害虫防治研究工作的个案,探讨20世纪50—70年代中国的主流科学观。本文首先指出,(激进的)"革命主义"不能简单地等同于"反科学",或仅注重科学的技术应用方面。革命主义的科学观与其他科学观的不同之处在于,它主张一种"群众性科学",要求技术性的、专业的"专"知识和来自外国的、学院式的"洋"知识与政治的、革命性的"红"知识和"土"知识结合起来,实际上更多的是服从于"红"知识和"土"知识。通过蒲蛰龙的个案,我们可以看到一个科学家如何在自相矛盾的科学观中求得平衡。这一个案清楚地展示了,为取得符合国家政治目标的科学成就,蒲蛰龙是怎样设法在红与专、土与洋之间取得平衡的。此外,这一个案还提供了一种讨论的角度:不同的时代如何衡量科学成就。就蒲蛰龙的工作而言,20世纪50—70年代的叙事所强调的那些方面,与改革开放后的叙事截然不同。本文指出,为了全面地理解20世纪50—70年代中国的科学事业,历史学者必须综合三种叙事:其一是强调专业性和跨国科学的叙事,其二是强调扎根农民和自力更生的叙事,其三是强调个人经历和人际关系的叙事。

关键词：中国现代科技史群众性科学蒲蛰龙生物害虫防治

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