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1.
大黄蒽醌类化合物的组织化学定位研究   总被引:18,自引:5,他引:13  
刘文哲  张爱新 《西北植物学报》2000,20(6):1082-1085,T007
利用新鲜材料的秆手切片直接观察,5%NaOH水溶液显色、荧光显微镜观察和戊二醛及饿酸固定薄切片法对大黄根茎蒽醌类化合物进行了组织化学定位研究。结果发现大黄根茎内蒽醌类化合物主要积累在次生木质部的木射线和次生韧皮部的韧皮射线细胞中。根据显色程度的不同,可以判断早期形成的维管射线细胞蒽醌类化合物的含量较晚期形成的射线细胞的含量高,二年生根茎的含量高于一所生根茎的含量。  相似文献   

2.
虎杖(Polygonum cuspidatum Sidb.et Zucc.)为蓼科多年生灌木状草本。其根茎入药。主要化学成分有蒽醌、萘醌、酚类和多糖化合物;其中蒽醌类化合物是虎杖的主要药用有效成分,包括大黄素、大黄酚,大黄素甲醚和大黄酸等。虎杖的蒽醌类化合物具显著的抗病毒、抗菌和消炎作用;并可保护心肌,防止血栓形成,改善微循环,提高细胞免疫力,也是致癌基因转导信号的抑制因子。关于虎杖蒽醌类化合物细胞化学研究尚未见报道。刘文哲等曾对贯叶连翘分泌结构中金丝桃素和大黄中蒽醌类同化合物进行了组织化学研究。本文对不同生长期虎杖的根茎以及同  相似文献   

3.
中国区域植被地上与地下生物量模拟   总被引:26,自引:0,他引:26  
黄玫  季劲钧  曹明奎  李克让 《生态学报》2006,26(12):4156-4163
应用大气-植被相互作用模型AVIM2在0.1°×0.1°经纬度网格上估算了中国区域植被总生物量、地下和地上生物量以及根茎比的空间分布格局。研究了植被生物量和根茎比的空间分布与水热限制条件的关系。研究表明:中国植被总生物量、地下和地上生物量受水热条件影响明显,空间分布趋势基本相似,即在暖湿的东南和西南地区生物量大,而在干冷的西部地区生物量小。同类植被生物量的空间分布有显著区域差异,气温高、降水量大的区域植被生物量大;低温和干旱地区的植被生物量小。除灌木以外,植被生物量大小的空间分布受水分的影响大于温度。中国区域植被根茎比的空间分布存在明显区域差异,全国大致以大兴安岭、太行山、秦岭以及青藏高原东南侧一线为界线,界线东南植被根茎比较小;界线以西,植被根茎比较大。植被根茎比的空间分布与年平均气温、土壤湿度和年降水量显著反相关,水分因子对根茎比空间分布的影响大于温度。  相似文献   

4.
为寻找促进药用植物活性代谢产物合成的微生物,该文以黄精为研究对象,利用高通量测序技术和生态功能预测平台,测定根际土真菌、根茎和根内生真菌的ITS序列,分析其真菌多样性和群落组成,并预测根茎内生真菌的生态功能。结果表明:(1)测序得到1 023个可操作分类单元(OTUs),根际、根茎和根真菌OTU数分别为703、128和141,三种部位真菌群落组成差异显著,根际土存在特有的真菌类群,即壶菌门。(2)根际土、根茎及根共有OTU 41个,子囊菌门占共有真菌的58.15%,丰度最大。(3)根茎内生真菌被划分6个生态功能群,包括未定义腐生菌、菌寄生真菌、动物病原菌、植物病原菌、丛枝菌根真菌和地衣共生真菌,37个undefined种类(34.91%)在FUNGuild数据库中没有参考信息。研究认为根茎中优势菌属Setophoma、新赤壳属等内生真菌可能与活性代谢产物密切相关,可为黄精药用功能菌群的发掘提供数据参考。  相似文献   

5.
RP-HPLC法同时测定虎杖中白藜芦醇和白藜芦醇苷的含量   总被引:14,自引:0,他引:14  
建立了国内首次用RP-HPLC同时测定虎杖中白藜芦醇和白藜芦醇苷含量的方法,并详细考察了2个指标成分的稳定性。对不同产地的虎杖药材、不同采收期的虎杖根及根茎以及虎杖的不同部位共25个样品中的白藜芦醇和白藜芦醇苷进行了含量测定,考察了两种活性成分的含量与产地、采收期及部位的关系,为虎杖资源的合理采收利用及进一步的研究提供了理论依据。  相似文献   

6.
掌叶大黄根茎大黄多糖的贮藏和分布特征   总被引:3,自引:0,他引:3  
章英才  李瑞 《植物学报》2010,45(3):372-378
采用组织化学方法和苯酚硫酸比色法研究了大黄多糖在掌叶大黄(Rheum palmatum)根茎中的贮藏分布特征及其含量变化规律。结果表明:大黄多糖在根茎中呈多位点贮藏,在根茎的周皮、皮层、次生维管组织的薄壁细胞以及髓内不同程度地贮藏和积累了一定数量的大黄多糖,次生木质部的木薄壁细胞以及次生韧皮部的韧皮薄壁细胞是大黄多糖的主要贮藏和积累部位;不同发育时期根茎中大黄多糖含量的变化规律为:随着植物的生长,根茎及其各组织中大黄多糖的总含量表现为逐渐增高的趋势,但在发育的后期略有下降;与木薄壁细胞相比,韧皮薄壁细胞贮藏大黄多糖量相对较多,大黄多糖的贮藏和积累方式为逐渐累积。次生维管组织为大黄多糖贮藏和积累的主要组织。  相似文献   

7.
白术根茎腐烂与栽培措施的相关性   总被引:7,自引:0,他引:7  
白术的根茎腐烂是白术生产中存在的重要问题,其发生面广,危害严重。据调查,此类病害的发生与栽培措施有直接关系。土壤重茬和移栽时修剪造成的伤口感染是病害流行的主要菌源;田间积水是病害发生的主要环境条件。改进栽培技术可减少白术根茎腐烂的发生。  相似文献   

8.
鸟鲁木齐市野生甘草资源经过多年利用已濒临枯竭。研究并推广甘草的人工种植是解决甘草资源再生的重要途径之一。  相似文献   

9.
莲的根茎构造,伸长与增粗   总被引:8,自引:0,他引:8  
莲 (Nelumbo nucifera)种苗的茎短而直立,叶互生。幼苗期茎延伸成横卧根茎,其上生有营养芽及混合芽。腋生鳞片为叶的衍生部分,形如叶鞘状,包着预芽。年苗上的冬芽内全为混合芽。根茎内的维管束分散排列,无导管及形成层存在。节间延长通过肋状分生组织及节间内的薄壁组织细胞分裂与增长来完成。根茎可由初生加厚分生组织,维管束细胞,皮层薄壁细胞等的细胞分裂,使层次增加,但增粗主要是由皮层薄壁细胞体积显著增大而引起的。  相似文献   

10.
西辽河平原不同利用条件下羊草无性系种群结构的研究   总被引:8,自引:0,他引:8  
1 引  言羊草 (Leymuschinensis(Trin .)Tzvel.)是典型的无性系根茎禾草 ,营养繁殖力强 ,在我国内蒙古东部和东北西部以及黄土高原地区的天然草地有广泛分布 .羊草具有很高的营养价值 ,是我国优良的牧草之一 ,多年来一直是草地学和生态学工作者研究的热点 ,并已开展到生物学的各个层次水平[1~ 3 ,8] .但对羊草无性系种群的研究较少 ,主要集中在年龄结构及营养繁殖特性等方面[4~ 7] .本文以天然草地灰绿型和黄绿型羊草种群为研究对象 ,对种群在不同干扰地段的变化进行了现实种群与潜在种群年龄结构的分析 ,为羊…  相似文献   

11.
The aim of this systematic review was to evaluate qualitative studies of the lived experience of companion-animal loss and grief. Six electronic databases (PsycINFO, CINAHL Plus, Ovid MEDLINE, ProQuest, Scopus, and Web of Science) were searched for English language, peer-reviewed articles from 1970 to July 2015. Only primary empirical studies using a qualitative method with textual data describing a direct ongoing relationship with, and subsequent loss of, a companion animal were included. A narrative synthesis was conducted on 11 eligible studies using inductive open coding techniques. Analysis revealed that pets were often labeled as family, and strong emotional connections between animals and humans were reported in some studies, whereas in other studies findings were inconsistent. Loss experience was predominantly with prototypical animals (cats, dogs); two studies involved other animals (horse, fish). Grief was described in five studies, with participants’ experience ranging from low to overwhelming. Prolonged grief was associated with self-disenfranchisement, whereas subjective healing was associated with remembrance, in which the animal remained as a memory in a “new” normal. Clinical implications are discussed.  相似文献   

12.

Background

Considering the uncertainty of safety of anti-malarial drugs in pregnancy, efficacy studies are one of the few sources of clinical safety data. Complete safety evaluation is not usually incorporated in efficacy studies due to financial and human resource constraints. This review reports the methods used for the assessment of safety of artemisinin-based and quinine-based treatments in efficacy studies in pregnancy.

Methods

Methodology of assessment and reporting of safety in efficacy studies of artemisinin-based and quinine-based treatment in pregnancy was reviewed using seven databases and two clinical trial registries. The protocol was registered to PROSPERO (CRD42017054808).

Results

Of 48 eligible efficacy studies the method of estimation of gestational age was reported in only 32 studies (67%, 32/48) and ultrasound was used in 18 studies (38%, 18/48). Seventeen studies (35%, 17/48) reported parity, 9 (19%, 9/48) reported gravidity and 13 (27%, 13/48) reported both. Thirty-eight studies (79%, 38/48) followed participants through to pregnancy outcome. Fetal loss was assessed in 34 studies (89%, 34/38), but the definition of miscarriage and stillbirth were defined only in 11 (32%, 11/34) and 7 (21%, 7/34) studies, respectively. Preterm birth was assessed in 26 studies (68%, 26/38) but was defined in 16 studies (62%, 16/26). Newborn weight was assessed in 30 studies (79%, 30/38) and length in 10 studies (26%, 10/38). Assessment of birth weight took gestational age into account in four studies (13%, 4/30). Congenital abnormalities were reported in 32 studies (84%, 32/38). Other common risk factors for adverse pregnancy outcomes were not well-reported.

Conclusion

Incomplete reporting and varied methodological assessment of pregnancy outcomes in anti-malarial drug efficacy studies limits comparison across studies. A standard list of minimal necessary parameters to assess and report the safety component of efficacy studies of anti-malarials in pregnancy is proposed.
  相似文献   

13.
乙型肝炎病毒变异株功能基因组研究及其临床意义   总被引:4,自引:0,他引:4  
武力  闻玉梅 《生命科学》2001,13(3):110-112,99
综述了近年对乙型肝炎病毒(HBV)变异株的复制、免疫学特性、致病性、耐药性等功能基因组研究及其临床意义的研究进展,阐述基因组水平研究HBV变异株功能的重要性及有关结果,展望今后HBV变异株生物学特性研究的方向。  相似文献   

14.

Background

There are many recent observational studies on smoking and risk of erectile dysfunction (ED) and whether smoking increases the risk of ED is still inconclusive. The objective of this meta-analysis was to synthesize evidence from studies that evaluated the association between smoking and the risk of ED.

Methods

We searched PubMed, Embase, Web of Science, and Scopus in January 2013 to identify cohort and case-control studies that evaluated the association between smoking and ED. Study quality of included studies was assessed by the Newcastle-Ottawa scale. Random-effects meta-analyses were used to combine the results of included studies.

Results

Four prospective cohort studies and four case-control studies involving 28, 586 participants were included. Because of significant heterogeneity after including case-control studies in meta-analysis, the consistent results of prospective cohort studies were considered more accurate, Because of significant heterogeneity after including case-control studies in meta-analysis, the consistent results of prospective cohort studies were considered more accurate, Compared with non-smokers, the overall odd ratio of ED in prospective cohort studies was 1.51(95% CI: 1.34 to 1.71) for current smokers, and it was 1.29 (95% CI: 1.07 to 1.47) for former smokers. Evidence of publication bias was not found.

Conclusion

Evidence from epidemiological studies suggests that smoking, especially current smoking, may significantly increase the risk of ED  相似文献   

15.
Prior to cryopreservation, a tooth is transported from a contaminated oral environment to the tooth bank. Our objective was to identify all studies reporting or investigating a transport protocol prior to the cryopreservation of teeth, in terms of decontamination of the subjects. The systematic literature search (1970–2017) was based on MEDLINE via PubMed, Web of Science and the Cochrane Library. The reference lists of the included studies and the Science Citation Index were used for hand searching (snowballing). Only studies reporting the transport conditions of the transplant were included. Language restrictions for English, Dutch or French were applied. The search led to 14 eligible studies. Almost all studies were laboratory studies, so the methodological quality of evidence was low. The majority of the included studies was performed by only five different research groups and the number of subjects varied between 1 and 120 teeth. In general, the teeth were stored in a tissue culture medium supplemented with fetal calf serum and/or different combinations of antibiotics and/or antimycotics. The teeth were transported cooled (4 °C) or at room temperature, for a period of time not exceeding 24 h. Only three studies reported the irrigation of the teeth with phosphate buffered saline prior to the transport. The optimisation of the decontamination during transport was investigated in three studies (from 1971, 1980 and 1982). It was concluded that the literature on this topic is scarce, and the decontamination protocol for teeth, prior to cryopreservation has not been validated recently.  相似文献   

16.
The aim of this study was to review the cytokine profiles in the synovial fluid (SF) of patients with temporomandibular joint disorders (TMJD). Databases were searched from 1965 till September 2015 using different combinations of the following key words: “Temporomandibular joint”; “Cytokine”; “disorder”; and “synovial fluid” and “inflammation”. Titles and abstracts of studies identified using the above-described protocol were screened and checked for agreement. Full-texts of articles judged by title and abstract to be relevant were read and independently evaluated. Hand-searching of the reference lists of potentially relevant original and review articles was also performed. The pattern of the present systematic review was customized to mainly summarize the relevant data. Fifteen studies were included. In 12 studies, cytokine profile of patients with TMJD was assessed using enzyme linked immunosorbent assay; and in 2 studies, histological analysis was performed to assess the cytokine profile of patients with TMJD. Patients with TMJD presented raised levels of interleukin (IL)-6 in 8 studies, IL-1beta (1β) in 5 studies and tumor necrosis factor-alpha (TNF-α) in 5 studies. Two studies showed no significant difference in TNF-α levels in patients with and without TMJD; and IL-1β levels were comparable in patients with and without TMJD in 2 studies. Raised levels of IL-6, TNF-α, IL-1β, IL-8, and IFN-γ in the SF have been associated with inflammation in patients with TMJD. Cytokines IL-10, osteoclastogenesis inhibitory factor/osteoprotegerin (OCIF/OPG), and VEGF found in the SF of TMJs could have an anti-inflammatory effect.  相似文献   

17.
Three talks were presented in the session on “Epidemiology”. The first talk was a review of prenatal studies. The second talk presented epidemiological evidence from prenatal studies. The third talk presented general issues regarding the planning of an epidemiological study. It was noted that epidemiological studies of prenatal exposures use data from the early 1980s when ultrasound was first introduced for foetal scans. These studies did not show associations between prenatal ultrasound scanning and childhood cancer, reduced birth weight, impaired childhood growth or neurological development in childhood. However, there was a possible association between prenatal ultrasound scanning and left-handedness in boys. The aetiology of this association remains uncertain.  相似文献   

18.
Cui LL  Wang M  Huang QY 《遗传》2010,32(10):1031-1036
国内多个研究报道了脂蛋白酯酶基因(LPL)PvuⅡ多态(rs285)与中国人高脂血症和冠心病的关系,但单个研究的样本量都较小(119~647),结果不尽一致.为了全面客观评价LPL基因PvuⅡ多态在中国人高脂血症和冠心病发病中的作用,文章对所有中国人群的研究进行了Meta分析.共11篇文献纳入研究,其中关于高脂血症的研究6项,包括患者943例,正常对照1 093例,关于冠心病的研究5项,包括患者821例,正常对照727例.入选研究无明显的发表偏倚,但经同质性检验存在明显的异质性.Meta分析结果显示LPL PvuⅡ多态的P+等位基因增加高脂血症的患病风险(OR=1.36,95%CI1.07~1.73,P=0.011),但与冠心病相关不显著(P=0.755).因此,文章结果表明LPL£基因pvuⅡ多态与中国人高脂血症易感性相关联,与冠心病关联不显著.  相似文献   

19.
20.
BACKGROUND: Corticosteroids are first-line drugs for the treatment of a variety of conditions in women of childbearing age. Information regarding human pregnancy outcome with corticosteroids is limited. METHODS: We collected prospectively and followed up 184 women exposed to prednisone in pregnancy and 188 pregnant women who were counseled by Motherisk for nonteratogenic exposure. The primary outcome was the rate of major birth defects. A meta-analysis of all epidemiological studies was conducted. The Mantel-Haenszel summary odds ratio was calculated for the pooled studies with 95% confidence intervals. A cumulative summary odds ratio was also calculated by combining studies in chronological order. Chi-squared for homogeneity was determined to establish the comparability of the studies. RESULTS: In our prospective study, there was no statistical difference in the rate of major anomalies between the corticosteroid-exposed and control groups. In the meta-analysis, the Mantel-Haenszel summary odds ratio for major malformations with all cohort studies was 1.45 [95% CI 0.80, 2.60] and 3.03 [95% CI 1.08, 8. 54] when Heinonen et al. ('77) was removed. This suggests a marginally increased risk of major malformations after first-trimester exposure to corticosteroids. In addition, summary odds ratio for case-control studies examining oral clefts was significant (3.35 [95% CI 1.97, 5.69]). CONCLUSIONS: Although prednisone does not represent a major teratogenic risk in humans at therapeutic doses, it does increase by an order of 3.4-fold the risk of oral cleft, which is consistent with the existing animal studies.  相似文献   

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