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31.
There are many different types of cardiovascular diseases, which impose a huge economic burden due to their extremely high mortality rates, so it is necessary to explore the underlying mechanisms to achieve better supportive and curative care outcomes. Sphingosine 1‐phosphate (S1P) is a bioactive lipid mediator with paracrine and autocrine activities that acts through its cell surface S1P receptors (S1PRs) and intracellular signals. In the circulatory system, S1P is indispensable for both normal and disease conditions; however, there are very different views on its diverse roles, and its specific relevance to cardiovascular pathogenesis remains elusive. Here, we review the synthesis, release and functions of S1P, specifically detail the roles of S1P and S1PRs in some common cardiovascular diseases, and then address several controversial points, finally, we focus on the development of S1P‐based therapeutic approaches in cardiovascular diseases, such as the selective S1PR1 modulator amiselimod (MT‐1303) and the non‐selective S1PR1 and S1PR3 agonist fingolimod, which may provide valuable insights into potential therapeutic strategies for cardiovascular diseases.  相似文献   
32.
肺癌是当今世界最常见的恶性肿瘤之一,其新发率和死亡率多年来都居于各类癌症之首,其中85%的肺癌都是非小细胞癌,而腺癌又是最常见的非小细胞癌。肺癌的高隐匿性是造成其高死亡率的最主要原因,因此为肺癌的早期诊断和病理分期寻求高效可靠的方法是十分必要的。代谢组学揭示了小分子代谢物的一系列变化,反映了生命活动的最终状态,因此也能直接反映疾病不同发展阶段的病理生理变化。本研究利用核磁共振氢谱(1H-NMR),对在我院就诊的27例不同病理分期的肺腺癌患者和13例健康志愿者进行了血清代谢物分析,运用正交偏最小二乘判别分析(OPLS-DA)对1H-NMR数据进行建模,单变量统计分析对模型进行评价。结果表明肺腺癌患者组的血清中有14种代谢物出现明显差异,其中丙酮酸、丙氨酸、NAC1、乳酸、GPC和甘氨酸比起对照组来有显著上升,而葡萄糖、谷氨酰胺、亮氨酸、异亮氨酸、缬氨酸、丙酮、乙酰乙酸和苏氨酸则显著下降。而在不同分期肺腺癌患者间进行比较后发现,异亮氨酸、乙酰乙酸、NAC1和乳酸的变化与肺腺癌的发展有相关性,可能是肺腺癌早期诊断和分期的潜在生物标志物。  相似文献   
33.
Prostate cancer is the most common cancer among men beyond 50 years old, and ranked the second in mortality. The level of Prostate-specific antigen (PSA) in serum has been a routine biomarker for clinical assessment of the cancer development, which is detected mostly by antibody-based immunoassays. The proteolytic activity of PSA also has important functions. Here a genetically encoded biosensor based on fluorescence resonance energy transfer (FRET) technology was developed to measure PSA activity. In vitro assay showed that the biosensor containing a substrate peptide ‘RLSSYYSGAG’ had 400% FRET change in response to 1 µg/ml PSA within 90 min, and could detect PSA activity at 25 ng/ml. PSA didn’t show enzymatic activity toward the biosensor in serum solution, likely reflecting the existence of other inhibitory factors besides Zn2+. By expressing the biosensor on cell plasma membrane, the FRET responses were significant, but couldn’t distinguish well the cultured prostate cancer cells from non-prostate cancer cells under microscopy imaging, indicating insufficient speci- ficity to PSA. The biosensor with the previously known ‘HSSKLQ’ substrate showed little response to PSA in solution. In summary, we developed a genetically encoded FRET biosensor to detect PSA activity, which may serve as a useful tool for relevant applications, such as screening PSA activation substrates or inhibitors; the purified biosensor protein can also be an alternative choice for measuring PSA activity besides currently commercialized Mu-HSSKLQ-AMC substrate from chemical synthesis.  相似文献   
34.

This study was to evaluate the effect of Streptococcus salivarius K12 on tongue coating–associated halitosis. Twenty-eight subjects having tongue coating–associated halitosis were randomly divided into either a test or control group. For each of the 30 days, the test subjects sucked S. salivarius K12 tablet while the control subjects sucked placebo tablets. All the subjects did not take physical (tongue scraping) and chemical (antiseptic mouth-rinse) oral cavity pretreatment prior to use of the tablets. At baseline, and on the 1st, 7th, and 14th day after completing the course of tablets, the subjects were assessed for their organoleptic test (OLT) scores, volatile sulfur compound (VSC) levels, and tongue coating scores (TCS). During the course, all subjects kept their routine oral care habits without scraping their tongue coating. Plaque index, probing depth, and bleeding index were recorded at baseline and at the completion of the trial. On the 1st day following the end of tablet use, the OLT scores and VSC levels had significantly decreased in the test group when compared with the baseline values (P = 0.001 and P = 0.012). The TCS in the test group were also significantly decreased (P = 0.05). At days 7 and 14, the OLT scores in the test group were still significantly lower than the baseline levels (P = 0.006 and P = 0.039 respectively). However, there were no statistical differences with OLT, VSC, and TCS between the test group and the placebo group by analysis of multi-level regression model. The use of S. salivarius K12 did not have significant effect on halitosis with tongue coating cause when the tongue coating was not physically or chemically pre-treated, which implies removing tongue coating is required before Streptococcus salivarius K12 use.

  相似文献   
35.
邱胜荣 《生态学报》2020,40(3):1015-1020
中国自然保护区建设已由数量扩张型进入质量效益型的新阶段,运用自然保护区统计年鉴数据,基于logistic模型,借助R语言,对自然保护区发展上限进行了估算。同时,运用高等数据曲线曲率求导方法,对发展阶段进行划分,对持续时长和增长速度进行了测算。结果表明:①面积理论饱和值为15470.00万hm~2;②将自然保护区发展历程分为缓慢起步期(1956—1989年)、快速发展期(1990—2008年)和稳定完善期(2009—至今);③目前则处于稳定完善期,面积已渐近饱和值,数量仍在小幅度增加。希望本研究结果能为自然保护区主管部门制定管理政策、规划以及整合组建以国家公园为主体的自然保护地体系提供参考。  相似文献   
36.
Zhang  Heng-Sheng  Ouyang  Bo  Ji  Xiong-Ying  Liu  Mei-Fang 《Neurochemical research》2021,46(7):1747-1758

Cerebral ischaemia/reperfusion (I/R) injury-induced irreversible brain injury is a major cause of mortality and functional impairment in ageing people. Gastrodin (GAS), derived from the traditional Chinese herbal medicine Tianma, has been reported to inhibit the progression of stroke, but the mechanism whereby GAS modulates the progression of cerebral I/R remains unclear. The middle cerebral artery occlusion method was used as a model of I/R in vivo. Rats were pretreated with GAS by intraperitoneal injection 7 days before I/R surgery and were then treated with GAS for 7 days after I/R surgery. Additionally, an oxygen–glucose deprivation/reoxygenation model using neuronal cells was established in vitro to simulate I/R injury. 2,3,5-Triphenyltetrazolium chloride and Nissl staining were used to evaluate infarct size and neuronal damage, respectively. Lactate dehydrogenase release and cell counting kit-8 assays were used to assess neuronal cell viability. Enzyme-linked immunosorbent assay, qPCR, flow cytometry and western blotting were performed to analyse the expression levels of inflammatory factors (IL-1β, IL-18), lncRNA NEAT1, miR-22-3p, NLRP3 and cleaved caspase-1. Luciferase reporter experiments were performed to verify the association between lncRNA NEAT1 and miR-22-3p. The results indicated that GAS could significantly improve the neurological scores of rats and reduce the area of cerebral infarction. Meanwhile, GAS inhibited pyroptosis by downregulating NLRP3, inflammatory factors (IL-1β, IL-18) and cleaved caspase-1. In addition, GAS attenuated I/R-induced inflammation in neuronal cells through the modulation of the lncRNA NEAT1/miR-22-3p axis. GAS significantly attenuated cerebral I/R injury via modulation of the lncRNA NEAT1/miR-22-3p axis. Thus, GAS might serve as a new agent for the treatment of cerebral I/R injury.

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37.
北京市湿地生态补偿标准研究   总被引:3,自引:3,他引:0  
确定合理的湿地生态补偿标准是构建有效湿地生态补偿机制的关键。以北京市境内的湿地为研究对象,利用DPSIR模型明晰北京市湿地生态补偿的机理;基于问卷调查数据,分别利用二元Logistic模型和Tobit模型对影响受调查者受偿态度和受偿意愿的相关因素进行分析;运用条件价值法以及考虑时间价值和经济社会发展阶段的修正湿地生态系统服务价值确定最终的生态补偿标准,并对北京市制定湿地生态补偿机制提出了政策建议。研究结果表明:(1)北京市合理的湿地生态补偿标准为2.728×104-4.84×104元hm-2a-1;(2)地区差异、受调查者对湿地保护政策的了解程度以及湿地与社区之间的关系显著影响其受偿态度;(3)地区差异、年龄、受教育程度、家庭收入情况、对生态补偿的了解程度显著影响其受偿意愿;(4)为减少将来推进湿地生态补偿过程中可能遭遇的潜在阻碍,北京市应该加强湿地保护相关政策的宣传普及工作,注重对基层政策落实情况的监督,协调湿地政策与社区的关系;(5)有必要结合地区特征制定差异化的湿地生态补偿标准。研究结果可为今后北京市探索建立湿地生态补偿机制、提升湿地保护效率提供科学数据和理论参考。  相似文献   
38.
探究植物功能性状的种内和种间变异不仅有助于揭示植物对环境的适应, 也能够反映植物的生态策略, 但不同菌根类型树木生长过程中根叶形态学功能性状的适应策略仍有待探究。本研究依托中国亚热带森林生物多样性与生态系统功能实验研究平台(BEF-China)选取7种丛枝菌根(AM)树木和7种外生菌根(EM)树木的纯林, 测定各个树种的比叶面积、叶干物质含量、比根长、根系直径、树高生长速率、地径生长速率及细根生物量等根叶形态学功能性状和生长指标, 探讨了两种菌根类型树种间的根叶形态学特征的差异。结果表明: 与AM树种相比, EM树种具有较小的比叶面积、吸收根平均直径和生长速率, 但具有更大的叶干物质含量; 两种菌根树种之间的比根长和细根生物量无显著差异。比叶面积、叶干物质含量、树高生长速率、地径生长速率和细根生物量等功能性状及生长指标在不同菌根类型、树种及二者的交互作用中均存在显著差异; 且树种、根功能型、菌根类型及三者之间的交互作用均对根功能性状有显著影响。EM树种地上指标的种内变异均大于种间变异, 而AM树种地上指标的种内和种间变异程度类似; 但两种菌根树种细根生物量的种间变异均大于种内变异。尽管两种菌根树种地上部分生长速率较快通常表现为较低的叶干物质含量, 但AM树种通常拥有较高的吸收根比根长, 而EM树种拥有较粗的运输根平均直径。吸收根比根长越低, 两类菌根树种的细根生物量就越多。由此可见, 根叶功能性状对植物地上部分的生长具有一定的协同效应, 其中运输根主要在EM树种地上生长过程中发挥重要作用, 吸收根主要与AM树种的地上部分生长有关; 但两类菌根树种的地下细根生物量均与吸收根有关。  相似文献   
39.
ObjectiveMounting evidence demonstrates that long non-coding RNA (lncRNA) is dysregulated in breast cancers. This study was designed to detect the influences and regulatory mechanism of lncRNA PDCD4-AS1 in triple-negative breast cancer (TNBC).MethodsqRT-PCR and Western blot were utilized to investigate the expression levels of PDCD4-AS1, miR-10b-5p and IQGAP2 in TNBC tissues and cells. Online software and luciferase reporter gene system were employed to testify the interactions among these molecules. Loss and gain of function of PDCD4-AS1, miR-10b-5p or IQGAP2 were performed before MTT and colony formation assay, TUNEL staining in addition to Transwell and scratch assays were applied to measure the cell biological functions.ResultsIn this work, PDCD4-AS1 and IQGAP2 were lowly expressed while miR-10b-5p was strongly expressed in TNBC tissues and cells. PDCD4-AS1 or IQGAP2 overexpression effectively attenuated TNBC cell proliferation, migration and invasion, and increased the apoptosis rate, while this effect was abandoned in response to miR-10b-5p mimics transfection. miR-10b-5p bound to IQGAP2 and acted as a downstream target of PDCD4-AS1.ConclusionOur findings identified lncRNA PDCD4-AS1 as a tumor suppressor in TNBC by regulating IQGAP2 expression via miR-10b-5p, giving a novel insight into the regulatory mechanism of PDCD4-AS1 in the pathogenesis of TNBC.  相似文献   
40.
沿长江中下游(宜昌-铜陵段)13座城市共37个位点,分别于丰水期和枯水期对岸带的湿生植物进行调查,从物种和系统发育2个维度研究群落的构建机制,并结合环境和空间因子探讨其驱动因素。结果显示:(1)丰水期湿生植物群落的α多样性高于枯水期,且丰水期α多样性主要与水分条件呈正相关,而枯水期则主要与温度和土壤总氮含量有关。(2)丰水期的系统发育结构指数呈聚集趋势,暗示生境过滤起着主导作用,而枯水期的NRI(net relatedness index)和NTI(nearest taxon index)呈不同趋势,暗示存在近期的群落分化。(3)群落的α多样性在物种层面和系统发育层面存在显著关联性,其多样性水平可在一定程度上互为表征。(4)长江中下游沿岸湿生植物群落的构建机制在不同时期存在差异,丰水期的群落构建是环境筛选和扩散限制共同作用的结果,且以环境筛选作用占主导,而枯水期的群落构建仅在物种层面受一定程度环境筛选作用的影响。(5)大生境的温度变化、微生境的土壤水分和养分条件是影响长江中下游岸带湿生植物群落差异的主要驱动因素。该研究结果可为长江中下游岸带湿地生态系统的管理和保护提供科学支持。  相似文献   
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