共查询到20条相似文献，搜索用时 0 毫秒
1.
2.
侧穗姜Zingiber ellipticum曾因其花序自茎侧穿叶鞘而出而被童绍全等(1987)置于偏穗姜属作为新种椭圆偏穗姜发表,但侧穗姜的侧生退化雄蕊与唇瓣连合,使唇瓣具3裂片,其药隔附属体发达,延长弯曲成喙状,包囊花柱,具有典型的姜属花的特征;由于姜属侧穗姜组Sect. Pleuranthesis Benth. 的花序亦为侧生,因此,该植物应置于姜属而不应置于偏穗姜属。侧穗姜的花粉表面具脑皱状纹饰,与姜属姜组的花粉纹饰相同,形态亦相似,而与表面具长刺的偏穗姜属花粉迥异。侧穗姜种子内种皮由砖形薄壁细胞构成,与姜属的薄壁细胞型内种皮相同,而与偏穗姜属的石细胞型内种皮明显区别。本文综合花的形态学、孢粉学和种子解剖学特征,将侧穗姜转移至姜属并建立新组合〖WTBX〗Zingiber ellipticum[WTBZ] (S. Q. Tong et Y. M. Xia) Q. G.Wu et T. L. Wu. 相似文献
3.
Alkystis Phinikaridou Kevin J. Hallock Ye Qiao James A. Hamilton 《Journal of lipid research》2009,50(5):787-797
4.
Flexistyly in Plagiostachys was first reported by Takano et al., while they provided no detailed study on pollination biology and breeding system. In this study, we tested this suspicion in one species of Plagiostachys (Plagiostachys austrosinensis). Field observations suggested that flexistyly was present in this species, and stigmatic behavior was similar to that reported for Alpinia and Amomum species. Two phenotypes (anaflexistylous and cataflexistylous) occurred in a ratio of 1:1 in natural populations. Anthesis began around 1530–1600 h and lasted for about 24 h. Pollen viability and stigma receptivity remained high throughout the flowering process. Mean nectar volume (4.15–11.30 μL) and mean sugar concentration (>32%) also remained at a high level during the flowering process. No fruit set occurred in unpollinated bagged plants. Two pollinators (Bombus pyrosoma and Vespidae spp.) and one pollen robber (Mutillidae spp.) were found as flower visitors. Fruit set following self‐pollination and cross‐pollination did not differ significantly in the cataflexistylous morph. Partial self‐incompatibility was apparent in the anaflexistylous morph. These results provide the concrete evidence of flexistyly in Plagiostachys and a more thorough understanding of its evolutionary origin in gingers. 相似文献
5.
保持生态环境与经济建设的协调发展是新阶段国家扶贫开发的重要策略之一。以甘肃省为例,运用系统耦合协调度理论,构建双系统发展多指标综合评价体系,对研究区2000—2014年脆弱生态环境与贫困评价得分、两者耦合协调度及时空分异进行测度和分析。结果表明:从时序角度看,甘肃省脆弱生态环境和贫困耦合协调度整体呈上升状态,受政策调整等因素的影响呈现低水平耦合协调、耦合协调度增长、高水平耦合协调生态环境滞后3个不同阶段;从空间分异角度看,甘肃省脆弱生态环境和贫困耦合协调度由东南向西北递增,耦合协调度空间分布不均衡,脆弱生态环境与贫困共生共存,需充分重视和保护贫困地区生态环境。 相似文献
6.
The Institute of Medicine (IOM) Committee on Ethical Considerations for Revisions to DHHS Regulations for Protection of Prisoners Involved in Research published its report in 2006. It was charged with developing an ethical framework for the conduct of research with prisoners and identifying the safeguards and conditions necessary to ensure that research with prisoners is conducted ethically. The recommendations contained in the IOM report differ from current European regulations in several ways, some being more restrictive and some less so. For example, the IOM report suggests limiting the percentage of prisoners that should be involved in a biomedical study to 50%, a limit that does not exist in Europe. However, the report does not specifically advise against research without a direct benefit to an individual prisoner: the European regulations are more restrictive than the IOM committee recommendations in this respect. The definition of minimal risk varies, as well as the proposed role of the minimal risk requirement and of the principle of subsidiarity (research that can only be done effectively in prisons). The IOM report proposes a number of thoughtful suggestions, which it would be beneficial to implement everywhere, such as registers of research on prisoners. The European regulations offer pragmatic solutions to several thorny issues. In summary, the IOM committee report represents an admirable effort to tackle the present inconsistencies and deficiencies of federal regulations in the US on research on prisoners (45 CFR 46 Subpart C). Nonetheless, before acting on the recommendations, US regulators might consider revisiting international guidelines such as those published by the Council for International Organizations of Medical Science (CIOMS) and the Declaration of Helsinki. 相似文献
7.
8.
9.
10.
11.
Qingqing Xiao Xinyu Che Bin Cai Zhenyu Tao Hengyuan Zhang Qin Shao Jun Pu 《Journal of cellular and molecular medicine》2020,24(1):260-275
The vulnerable plaque is a key distinguishing feature of atherosclerotic lesions that can cause acute atherothrombotic vascular disease. This study was designed to explore the effect of autophagy on mitochondria‐mediated macrophage apoptosis and vulnerable plaques. Here, we generated the mouse model of vulnerable carotid plaque in ApoE?/? mice. Application of ApoE?/? mice with rapamycin (an autophagy inducer) inhibited necrotic core formation in vulnerable plaques by decreasing macrophage apoptosis. However, 3‐methyladenine (an autophagy inhibitor) promoted plaque vulnerability through deteriorating these indexes. To further explore the mechanism of autophagy on macrophage apoptosis, we used macrophage apoptosis model in vitro and found that 7‐ketocholesterol (7‐KC, one of the primary oxysterols in oxLDL) caused macrophage apoptosis with concomitant impairment of mitochondria, characterized by the impairment of mitochondrial ultrastructure, cytochrome c release, mitochondrial potential dissipation, mitochondrial fragmentation, excessive ROS generation and both caspase‐9 and caspase‐3 activation. Interestingly, such mitochondrial apoptotic responses were ameliorated by autophagy activator, but exacerbated by autophagy inhibitor. Finally, we found that MAPK‐NF‐κB signalling pathway was involved in autophagy modulation of 7‐KC–induced macrophage apoptosis. So, we provide strong evidence for the potential therapeutic benefit of macrophage autophagy in regulating mitochondria‐mediated apoptosis and inhibiting necrotic core formation in vulnerable plaques. 相似文献
12.
Fei Gao Shi Fang Ding Mei Ni Chun Xi Liu Cheng Zhang Yun Zhang 《Journal of cellular and molecular medicine》2011,15(3):602-611
To test the hypothesis that combinatorial interference of toll-like receptor 2 (TLR2) and TLR4 is superior to isolated interference of TLR2 or TLR4 in stabilizing atherosclerotic plaques, lentiviruses carrying small interfering RNA of TLR2 or TLR4 were constructed and proved efficacious for knocking down mRNA and protein expression of TLR2 or TLR4 significantly in vitro. One hundred and fifty apolipoprotein E−/− mice fed a high-fat diet were divided into the control, mock, TLR2i, TLR4i and TLR2 + 4i subgroups and a constrictive collar was placed around carotid artery of these mice to induce plaque formation. TLR2i and TLR4i viral suspension was transfected into carotid plaques, respectively, in TLR2i and TLR4i subgroups, or in combination in TLR2 + 4i subgroup. Four weeks after lentivirus transfection, mRNA and protein expression of TLR2 or TLR4 was attenuated markedly in carotid plaques, leading to reduced local inflammatory cytokine expression and plaque content of lipid and macrophages, increased plaque content of collagen and lowered plaque vulnerability index. Factorial ANOVA analysis revealed that there was a synergistic effect between TLR4i and TLR2i in stabilizing plaques. In conclusion, combinatorial interference of TLR2 and TLR4 reduces local inflammation and stabilizes plaques more effectively than interference of TLR2 or TLR4 alone. 相似文献
13.
STEFAN ERIKSSON 《Bioethics》2012,26(1):15-21
In this article, it is claimed that the protective provisions for adults with impaired decision‐making capacity are misguided, insofar as they do not conclusively state whether research on this group should be permitted only as an exception, and as they arbitrarily allow for some groups to benefit from such research while others will not. Moreover, the presumed or former will of the subject is given insufficient weight, and the minimal risk standard does not make sense in this context. Because of these problems, the present guidelines allow for the possibility of vulnerable people being exploited, something that is hidden behind a guise of solidarity. Instead we need to address the real issues at stake by rewriting the present statutes. It is suggested that new guidelines should be in some continuity with earlier efforts. However, in order to protect these subjects there is additional need for appointed representatives who monitor research and for legal obligations to compensate for any injuries suffered. Without these or similar measures we won't have an adequate system in place for the protection of non‐benefiting persons who are unable to consent to research. 相似文献
14.
生态系统受威胁等级的评估标准和方法 总被引：2，自引：0，他引：2
生态系统受威胁等级评估是认识生物多样性丧失的重要手段.在2008年的第四次世界自然保护大会上,国际自然保护联盟(IUCN)成立专门工作组,着手建立类似于物种灭绝风险的定量评估方法,对生态系统受威胁等级进行评估.最终的目标是在局地、区域和全球尺度上确定生态系统的受威胁等级,建立生态系统红色名录.在制定生物多样性保护策略时,生态系统红色名录与物种红色名录可作为互补.目前,生态系统受威胁等级评估方案的评估依据包括4类:生态系统分布或生态系统功能短期衰退;生态系统分布或生态系统功能长期衰退;生态系统当前的分布狭窄、同时生态系统分布或生态系统功能衰退;生态系统当前的分布极狭窄.应用Rodríguez等(2011)建立的评估标准,基于文献记载的中国辽河三角洲4个生态系统1988年和2006年的面积,我们详细介绍了生态系统受威胁等级的评估过程.目前的评估方法面临挑战,生态系统分布范围和占有面积的估计应基于合理的空间尺度,同时还需建立合理的方法定量描述生态系统功能的变化.生态系统受威胁等级评估方案将提交2012年召开的世界自然保护大会讨论. 相似文献
15.
为研究湖北十堰地区急性冠脉综合征(ACS)患者PAPP-A基因IVS6 +95(C/G)多态性与血浆PAPP-A水平和斑块性质的相关性,随机选择215例ACS患者(包括58例急性心肌梗死(AMI)患者、73例不稳定型心绞痛(UAP)患者和84例稳定型心绞痛(SAP)患者)及142例健康对照者作为研究对象,检测PAPP-A基因IVS6+ 95 (C/G)多态性和血浆PAPP-A浓度,并进行统计学分析.结果显示,AMI组、UAP组和SAP组的PAPP-A浓度具有极显著差异(p＜0.01),在稳定性斑块和易损性斑块组间的PAPP-A浓度亦具有极显著差异(p＜0.01);AMI组、UAP组和SAP组与对照组间的基因型频率和等位基因频率具有显著差异(p＜0.05);在ACS组和对照组中,组内各类基因型人群的血浆PAPP-A浓度的差异不显著(p＞0.05).结果表明,PAPP-A基因IVS6+ 95多态性与急性冠脉综合征患者密切相关,血浆PAPP-A浓度与斑块性质相关,能够反映ACS患者斑块的易损性,是ACS患者危险分层的标志物. 相似文献
16.
Genetic diversity and differentiation were analyzed in 11 populations of Magnolia stellata (Sieb. and Zucc.) Maxim. (Magnoliaceae) in the Tokai district, Japan. Variation at four nuclear microsatellite (nSSR) loci
was examined, three chloroplast microsatellite (cpSSR) markers were developed and 13 haplotypes identified. The 11 populations
were divided into three groups (A, B and C). Each population within the group was separated less than 40 km. Group B harbored
the highest gene diversity (H) and allelic richness (Ar) for nSSR (H=0.74 and Ar=8.02). Group C had the highest diversity of chloroplast haplotypes (H=0.79 and Ar=6.8): 2.5 times more haplotypes than the other groups. Each population contributed differently to the total diversity, with
respect to nSSR and cpSSR. AMOVA revealed that 58% of haplotypic and 15% of nSSR variation was partitioned among populations
within groups. A Mantel test revealed significant correlations between population pairwise geographic ln(distance) and FST/(1−FST) for both nSSR (r=0.479; P=0.001) and cpSSR (r=0.230; P=0.040). Dendrograms of populations for nSSR, based on Nei’s genetic distance, were constructed using UPGMA and the neighbor-joining
method. These results suggest that populations in group C have diverged from the other populations, while those in group B
are similar to each other. For group B, fragmentation between populations should be avoided in order to maintain gene flow.
For group C, the uniqueness of each population should be given the highest priority when planning genetic conservation measures
for the species. 相似文献
17.
Ruberg FL Viereck J Phinikaridou A Qiao Y Loscalzo J Hamilton JA 《Journal of lipid research》2006,47(2):310-317
Vulnerable atherosclerotic plaques may be identified by their large lipid component, particularly liquid cholesteryl ester (CE), covered by a fibrous cap. We hypothesized that image-guided 1H proton magnetic resonance spectroscopy (MRS) would identify mobile CE in discrete, preselected regions of atherosclerotic plaque. Human carotid endarterectomy specimens (n = 10) were imaged ex vivo by magnetic resonance imaging (MRI) at high field (11.7 T) utilizing standard T1- and T2-weighted spin echo protocols. MRS spectra were acquired from 1 mm3 voxels, localized to plaque regions that we judged by MRI to be lipid rich or lipid poor. The spectra revealed methyl and methylene resonances of fatty acyl chains with relative intensities and linewidths characteristic of pure CE, by comparison with lipid standards. Regions judged to be lipid rich by MRI showed much more intense CE resonances than did lipid-poor regions. The integrated intensities of lipid peaks were 5.5 +/- 2.0% (lipid-rich regions) versus 0.9 +/- 0.6% (lipid-poor regions) of the unsuppressed water peak (P < 0.0001). Lipid distribution by histology, MRS, and MRI showed strong correlation. Image-guided proton MRS accurately identified CE in selected regions of atherosclerotic plaque as small as 1 mm3 in an ex vivo setting. This procedure may permit the noninvasive detection and quantification of CE in atherosclerotic plaque in vivo. 相似文献
18.
This paper reports the first population ecology study of the endangered Magnolia sargentiana Rehder ＆ Wilson （Magnoliaceae）. Magnolia sargentiana is a protected species in China, but little is known about its present status in the field. In 2007 and 2008, we surveyed the population and conservation status ofM. sargentiana in the Provincial Mamize Nature Reserve and the National Meigu Dafengding Nature Reserve, Sichuan Province, southwestern China. Natural regeneration is poor because of unfavorable environmental conditions and anthropogenic disturbances. Flower buds and bark ofM. sargentiana are used in traditional Chinese medicine and their collection by local people over the period 1983-1994 has led to marked population declines. The collection of flower buds and bark is now banned, but hewing branches for firewood and grazing continues to have a negative impact on the recovery of M. sargentiana populations. To protect the species, we require a ban on hewing branches, closure of primary forests to reduce the impact of humans and ungulates, better education of local people, and increased awareness of wildlife conservation. 相似文献
19.
Hurst SA 《Bioethics》2008,22(4):191-202
Despite broad agreement that the vulnerable have a claim to special protection, defining vulnerable persons or populations has proved more difficult than we would like. This is a theoretical as well as a practical problem, as it hinders both convincing justifications for this claim and the practical application of required protections. In this paper, I review consent-based, harm-based, and comprehensive definitions of vulnerability in healthcare and research with human subjects. Although current definitions are subject to critique, their underlying assumptions may be complementary. I propose that we should define vulnerability in research and healthcare as an identifiably increased likelihood of incurring additional or greater wrong. In order to identify the vulnerable, as well as the type of protection that they need, this definition requires that we start from the sorts of wrongs likely to occur and from identifiable increments in the likelihood, or to the likely degree, that these wrongs will occur. It is limited but appropriately so, as it only applies to special protection, not to any protection to which we have a valid claim. Using this definition would clarify that the normative force of claims for special protection does not rest with vulnerability itself, but with pre-existing claims when these are more likely to be denied. Such a clarification could help those who carry responsibility for the protection of vulnerable populations, such as Institutional Review Boards, to define the sort of protection required in a more targeted and effective manner. 相似文献
20.
冠状动脉易损斑块破裂或腐蚀继发血栓形成是急性冠脉事件发生的病理基础,寻找易损斑块新血清标记物对于早期识别和干预高危患者至关重要。新近发现妊娠相关蛋白A(PAPP-A)参与动脉粥样硬化的发生发展,并且与斑块的不稳定性关系密切,是冠心病患者不良事件的预测因子。本综述主要介绍妊娠相关蛋白-A的生物学特性及其与心血管疾病以及易损斑块关系的研究进展,为临床诊断和治疗带来新的思路。 相似文献