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A brainstem slice preparation was used to investigate GABA-inducedresponses in the gustatory region of the nucleus of the solitarytract (NST) of the hamster. The baseline activities of 91 cellsin the rostral NST were examined extracellularly; 59 cells werelocated in the rostral central (RC), 21 in the rostral lateral(RL), six in the ventral (V) and five in the medial (M) subdivisionof the NST. Of the 80 cells in the gustatory region of the NST(RC and RL subdivisions), application of GABA produced dose-dependentinhibition in 55 (69%), excitation in 9 (11%) and no effectin 16 cells (22%). In contrast, only nine cells were responsiveto baclofen, a GABAB agonist. In all subdivision of the rostralNST, 57 cells were inhibited by GABA and the responses of 48of these were blocked by the specific GABAA antagonist, bicucullinemethiodide (BICM). Application of BICM alone often yielded anexcitatory burst of impulses; this effect was eliminated whensynaptic release was blocked by perfusion with a high magnesiumphysiological saline solution (PSS/Mg++). The GABAA-responsivecells were distributed predominantly within the RC subdivision,whereas the GABAB-responsive neurons were mostly in the RL subdivisionof the NST. The influences of GABA on the membrane properties of cells withinthe gustatory region (RC and RL subdivisions) of the NST wererecorded using conventional intracellular (16 cells) or whole-cellpatch (17 cells) recording methods. Intracellular recordingrevealed that GABA produced hyperpolarisation of the membrane,decreased the firing frequency, and increased the membrane conductance.In the patch-clamp experiments, the application of GABA evokedboth inward and outward currents, and an increase in membraneconductance. The reversal potential produced by GABA was closeto the Cl– equilibrium potential. The effects of GABAwere blocked by BICM. These results suggest that (i) GABA hasa strong inhibitory influence on rostral NST neurons, whichin the majority of cells is mediated through GABAA, receptors;and (ii) the gustatory region of the NST may contain a tonicallyactive GABAergic netw  相似文献   
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Brassica napus (AACC) is a recent allotetraploid species evolved through hybridization between two diploids, B. rapa (AA) and B. oleracea (CC). Due to extensive genome duplication and homoeology within and between the A and C genomes of B. napus, most SSR markers display multiple fragments or loci, which limit their application in genetics and breeding studies of this economically important crop. In this study, we collected 3,890 SSR markers from previous studies and also developed 5,968 SSR markers from genomic sequences of B. rapa, B. oleracea and B. napus. Of these, 2,701 markers that produced single amplicons were putative single-locus markers in the B. napus genome. Finally, a set of 230 high-quality single-locus SSR markers were established and assigned to the 19 linkage groups of B. napus using a segregating population with 154 DH individuals. A subset of 78 selected single-locus SSR markers was proved to be highly stable and could successfully discriminate each of the 45 inbred lines and hybrids. In addition, most of the 230 SSR markers showed the single-locus nature in at least one of the Brassica species of the U’s triangle besides B. napus. These results indicated that this set of single-locus SSR markers has a wide range of coverage with excellent stability and would be useful for gene tagging, sequence scaffold assignment, comparative mapping, diversity analysis, variety identification and association mapping in Brassica species.  相似文献   
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2000年来吕梁连片贫困区植被净初级生产力时空变化特征   总被引:1,自引:0,他引:1  
多年来吕梁连片贫困区实施的生态恢复措施对其生态环境产生了较大影响,为掌握该区域在生态恢复措施实施(2000年)以来植被净初级生产力的变化状况,利用2000—2018年时序的遥感数据和基于光能利用率的CASA模型对其进行了模拟,并分析了导致其变化的主要控制因素,结果显示:(1)2000年以来吕梁连片贫困区NPP整体上升,其中93.46%的区域NPP呈增长状态,6.54%的区域呈减少状态,2010—2015年区域NPP出现下降。(2)受人类活动影响,过去18年来区域土地利用类型变化较为显著,耕地面积缩减,草地面积基本保持稳定,林地与城镇面积增加且城镇面积扩张迅速,不同土地利用下的NPP特征差异显著,耕地NPP年均值增长最为迅速,为5.9 gC m-2 a-1,林地最为平稳,为1.32 gC m-2 a-1。(3)研究区降水量波动对区域NPP的变化影响显著,未来气候变化中降水量的变化可能对区域NPP产生直接影响。研究结果将为区域生态恢复、精准扶贫及黄河中游地区的经济发展提供重要的理论支撑。  相似文献   
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黄土丘陵区坡耕地与撂荒地土壤水分对降雨的响应特征   总被引:3,自引:0,他引:3  
为了揭示黄土丘陵区不同土地覆被方式下土壤含水量对不同强度降雨的响应过程,选取山西省冯家沟小流域农耕地和撂荒地为研究对象,基于2019年4—10月降雨和土壤含水量以小时为单位的观测数据,分析了土壤含水量对不同强度降雨的响应规律。结果表明:(1)小雨、中雨、大雨和暴雨对土层的影响深度分别为20、20、60 cm和60 cm,研究区降雨最主要的形式—小雨对土壤水分的补给作用较小。(2)各强度降雨过程中,除0—10 cm土层外,农耕地土壤含水量均大于撂荒地,且大雨条件下农耕地各土层土壤含水量变化较显著,而撂荒地仅0—10 cm和10—20 cm土层土壤含水量有所增加。(3)不同土层土壤含水量对降雨的响应不同,表层响应相对明显而深层相对减弱;农耕地土壤平均含水量最大值出现在50—60 cm土层,而撂荒地出现在30—40 cm土层。(4)本地区农耕地土壤含水量高于撂荒地,表明在该地区适当的作物种植有较好的储存土壤水分的作用。本研究的结果对地区水资源的高效利用和水土流失防控提供了一定的科学依据。  相似文献   
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Cardiovascular diseases (CVDs) are still a major cause of people deaths worldwide, and mesenchymal stem cells (MSCs) transplantation holds great promise due to its capacity to differentiate into cardiovascular cells and secrete protective cytokines, which presents an important mechanism of MSCs therapy for CVDs. Although the capability of MSCs to differentiate into cardiomyocytes (CMCs), endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) has been well recognized in massive previous experiments both in vitro and in vivo, low survival rate of transplanted MSCs in recipient hearts suggests that therapeutic effects of MSCs transplantation might be also correlated with other underlying mechanisms. Notably, recent studies uncovered that MSCs were able to secret cholesterol-rich, phospholipid exosomes which were enriched with microRNAs (miRNAs). The released exosomes from MSCs acted on hearts and vessels, and then exerted anti-apoptosis, cardiac regeneration, anti-cardiac remodeling, anti-inflammatory effects, neovascularization and anti-vascular remodeling, which are considered as novel molecular mechanisms of therapeutic potential of MSCs transplantation. Here we summarized recent advances about the role of exosomes in MSCs therapy for CVDs, and discussed exosomes as a novel approach in the treatment of CVDs in the future.  相似文献   
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污水资源化、二氧化碳减排及微藻生物柴油是当前能源与环境领域的前沿课题。以下围绕污水及烟道气资源化培养产油微藻的培养体系,就藻种、营养条件、培养方式、培养环境及微藻生物反应器等影响产油微藻培养的因素研究进展进行了综述。在综述的基础上提出:由于微藻具有特殊营养方式,通过藻种筛选、微藻营养条件和培养环境的优化以及高效光生物反应器和生产工艺等的创新,可利用污水进行产油微藻生产,以获得生物柴油等高附加值产品,实现微藻生物能源、污水资源化处理和CO2减排三者高度耦合的产油微藻生产体系,从而减少微藻培养费用及污水处理费用,因此,该体系具有重要的环境、社会、经济价值和商业化应用前景。  相似文献   
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A UPLC/TOF-MS-based metabonomic study was conducted to assess the holistic efficacy of Traditional Chinese Medicine Shuanglong Formula (SLF) for myocardial infarction in rats. Thirty male Sprague-Dawley rats were randomly divided into five groups after surgery. The Panax ginseng group, Salvia miltiorrhiza group, and SLF group were treated with water extractions of Panax ginseng (PG), Salvia miltiorrhiza (SM), and SLF (the ratio of SM to PG was 3:7) at a dose of 5 g/kg·w·d for 21 consecutive days, respectively; the model group and sham surgery group were both treated with 0.9% saline solution. Urinary samples for metabonomic study, serum samples for biochemical measurement, and heart samples for histopathology were collected. As a result, metabonomics-based findings such as the PCA and PLS-DA plotting of metabolic state and analysis of potential biomarkers in urine correlated well to the assessment of serum biochemistry and histopathological assay, confirming that SLF exerted synergistic therapeutic efficacies to exhibit better effect on MI compared to PG or SM. The shifts in urinary TCA cycle as well as pentose phosphate pathway suggested that SLF may diminish cardiac injury of MI with its potential pharmacological effect in the regulation of myocardial energy metabolism.  相似文献   
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