首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   15篇
  免费   2篇
  国内免费   1篇
化学   16篇
物理学   2篇
  2022年   2篇
  2021年   3篇
  2020年   1篇
  2018年   1篇
  2015年   2篇
  2014年   1篇
  2012年   1篇
  2010年   1篇
  2007年   1篇
  2006年   2篇
  2001年   1篇
  1996年   1篇
  1994年   1篇
排序方式: 共有18条查询结果,搜索用时 0 毫秒
1.
In Asia, Amomum tsao-ko has long been used as a spice or seasoning in food to stimulate digestion. In the present study, we evaluated the effects of ethanol extract of Amomum tsao-ko (EEAT) on menopausal osteoporosis and obesity. After the administration of EEAT in ovariectomy (OVX) mice models for five weeks, microcomputed tomography and a histological analysis were performed to assess, respectively, the trabecular structure and the fat accumulation in adipose, liver, and bone tissues. We also examined the effects of EEAT on a bone marrow macrophage model of osteoclastogenesis by in vitro stimulation from the receptor activator of nuclear factor-kappa Β ligand (RANKL) through real-time PCR and Western blot analysis. In addition, ultrahigh performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS) with authentic standards was applied to characterize the phytochemical profiling of EEAT. We found that EEAT significantly decreased OVX-induced body weight gain and fat accumulation, significantly prevented OVX-induced deterioration of bone mineral density and microstructure of trabecular tissues, and significantly inhibited osteoclast differentiation by downregulating NF-κB/Fos/NFATc1 signaling in osteoclasts. Furthermore, UHPLC–MS/MS identified eight beneficial phytochemicals in EEAT. Collectively, these results suggest that EEAT might be an effective nutraceutical candidate to attenuate menopausal osteoporosis by inhibiting osteoclastogenesis and to prevent obesity by suppressing fat accumulation.  相似文献   
2.
春砂仁无机成分与药效的研究   总被引:3,自引:0,他引:3  
采集了阳春县三个产地有代表性的春砂仁.用原子吸收光谱、控制气忿和罩帽电极发射光谱等法,测定其无机成分。结果表明,春砂仁对Zn、Mn有较大富集作用.其含量与春砂仁质量正相关;不同产地春砂仁的挥发油、无机成分与药效成分之间存在差别,证实以金花坑的春砂仁质量最优。  相似文献   
3.
The clinical application of gentamicin may lead to acute kidney injury (AKI), and the nephrotoxicity of gentamicin is related to the pathological mechanism of several oxidative and inflammatory cytokines. Plant-derived essential oils have good anti-inflammatory and antioxidant properties. This study aimed to clarify the protective effect of Amomum tsao-ko essential oils (AOs) on gentamicin-induced AKI in rats and its possible mechanism. The rat AKI model was induced by intraperitoneal injection of gentamicin. After 14 days of oral AO treatment, the renal function and pathological changes of the kidney tissues were evaluated, and the level of kidney tissue oxidative stress was detected. The content of inflammatory cytokines was measured by ELISA. The expression of ERK1/2, JNK1/2, p38, NF-κB, caspase-3, and Bax/Bcl-2 proteins were estimated by Western blot analysis. The results showed that taking AO reduced the contents of serum urea and creatinine in AKI rats and improve the pathological changes and oxidative stress of the kidney tissue in rats. At the same time, AO reduced inflammation and apoptosis during AKI by regulating the MAPK pathway. The data show that AO has a protective effect on the kidneys and may be a potential drug for treating kidney injury.  相似文献   
4.
从毛姜花(Hedychium villosum Wall.)中分离得到1个新二萜(1)和1个已知二萜(3). 新二萜命名为Villosumcoronarin, 该化合物在氯仿或甲醇溶液中发生异构化, 部分转化为其差向异构体1'; 其平面结构经质谱、红外光谱、氢谱、碳谱及无畸变极化转移增强技术(DEPT)、氢氢相关谱(1H-1H COSY)和异核多键相关谱(HMBC)等方法确证; 其相对构型由氢谱、ROESY及量化计算确证. 化合物3用琼斯试剂氧化后得到化合物4. 生物活性筛选结果表明, 化合物1对人白血病细胞株(HL-60)和肝癌细胞株(SMMC-7721)具有强的细胞毒活性, 其活性超过阳性对照顺铂(DDP). 化合物4对HL-60和SMMC-7721细胞具有显著的细胞毒活性.  相似文献   
5.
建立了同步测定砂仁中28种有机磷类农药残留的QuEChERS结合气相色谱-三重四极杆串联质谱分析方法。砂仁样品先用1%(体积分数)乙酸乙腈提取,再经900 mg MgSO4、150 mg PSA、100 mg C18和25 mg GCB组合吸附剂净化后,将提取液浓缩过滤,采用气相色谱-三重四极杆串联质谱在多反应监测(MRM)模式下检测,基质匹配标准曲线外标法定量。结果表明,28种有机磷农药在0.05~1.00 mg/L范围内线性良好,相关系数(r2)均大于0.99;在0.2、0.4、1.0 mg/kg 3个加标水平下的平均回收率为82.1%~104%,相对标准偏差(RSD)不大于15%。28种有机磷农药残留的检出限(LODs)为0.005~0.010 mg/kg,定量下限(LQDs)为0.010~0.033 mg/kg。该方法简便、快速、灵敏,具有良好的灵敏度、准确度和精密度,为提高砂仁的质量和安全性提供了一种快速、高效、可靠的分析方法。  相似文献   
6.
产地对爪哇白豆蔻无机元素含量的影响   总被引:4,自引:0,他引:4  
研究表明:不同产地引种的爪哇白豆蔻在无机元素含量方面与进口的相比,发生了明显的变化,为建立引种爪哇白豆蔻的质量标准提供了依据。  相似文献   
7.
The chemical composition of essential oils obtained from the hydrodistillation of different parts of Amomum maximum Roxb and Amomum muricarpum C. F. Liang & D. Fang (Zingiberaceae) grown in Vietnam are reported. The analysis was performed by means of gas chromatography–flame ionisation detectoorand gas chromatography coupled with mass spectrometry. The major compounds identified in the oils of A. maximum were β-pinene (20.4–40.8%), α-pinene (6.8–15.0%), β-elemene (2.5–12.8%) and β-caryophyllene (2.3–10.3%). Moreover, β-phellandrene (11.6%) was present in the root oil. The main compound identified in all the oil samples of A. muricarpum was α-pinene (24.1–54.7%) and β-pinene (9.2–25.9%). In addition, limonene (7.4%) and δ-3-carene (9.4%) were present in the leaves and stem oils, respectively. However, while β-phellandrene (8.3%) could be seen prominent in the root oil, the fruits contained significant amount of zingiberene (6.3%). The largest amount of τ-muurolol (13.0%) was found in the flower oil.  相似文献   
8.
郭亚东 《光谱实验室》2006,23(3):461-462
样品经灰化处理后,用火焰原子吸收光谱法测定样品中铜、锌、锰和铁的含量,平均加标回收率为85.5%-99.4%,相对标准偏差(RSD)为1.70%-2.70%.在给定范围内呈现良好的线性关系,相关系数大于0.998,方法简便,快速,结果可靠.  相似文献   
9.
Four new compounds having an unusual 1,7-dioxadispiro[5.1.5.2]-12-ene-11-one tricyclic ring system (1-4), their potential precursor, 5R-hydroxy-1-(4-hydroxyphenyl)-eicosan-3-one (5), and two known compounds, aculeatins A (6) and B (7), have been isolated from Amomum aculeatum. All compounds were characterized by spectroscopic methods and the configurations were established by 2D NOE correlations. Compounds 1-4, 6, and 7 showed cytotoxic activity against several human cancer cell lines.  相似文献   
10.
In this study, a novel solidification of floating organic drop liquid‐phase microextraction cell fishing with gas chromatography–mass spectrometry (SFOD‐LPME‐CF‐GC‐MS) method was established and used to screen, isolate and analyze bioactive components from Amomum villosum Lour. extract. Through comparision of its effect on the models of normal cell and inflammatory cells, anti‐inflammatory active components of essential oil from A. villosum Lour. were readily screened, and the components obtained are in agreement with related pharmacological articles. SFOD‐LPME‐CF‐GC‐MS was used to analyze the interaction of A. villosum Lour. extracts with normal and lipopolysaccharide‐stimulated RAW264.7 macrophage cells. The effect of A. villosum Lour. essential oil extracts in the LPS‐stimulated RAW264.7 model were also assessed in terms of cytotoxicity and nitric oxide production as an indication of bioactivity. Three potentially bioactive components were identified, demonstrating that SFOD‐LPME‐CF‐GC‐MS can be used successfully in the drug‐screening process. This approach avoids the requirement for protein precipitation, but more importantly, generates a high concentration ratio, allowing analysis of trace components in traditional Chinese medicines. SFOD‐LPME‐CF‐GC‐MS is a simple, fast, effective and reliable method for the screening and analysis of bioactive components, and it can be extended to screen other bioactive components from TCMs. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号