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1.
The absorption of phospholipid may improve the fluidity of membrane and enzyme activities. Phospholipids also play a role in promoting Caveolae formation and membrane synthesis. Caveolin-1 has a significant effect on signaling pathways involved in regulating cell proliferation and stress responsiveness. Thus, we can speculate that Caveolin-1 could affect the sense of environmental stress. We use Chang liver cell line to investigate the ability of Caveolin-1 to modulate the cellular response to ethanol injury. Caveolin-1 downregulate cells (Cav-1?/?) were established by stable transfecting with psiRNA-CAV1 plasmids, which were more sensitive to toxic effects of ethanol than the untransfected parental cells (WT). Releasing of ALT and electric conductivity were changed significantly in Cav-1?/? cells compared with WT. Caveolin-1 gene silencing could obviously down-regulate the activities of protein kinase C-α (PKC-α) and phospho-p42/44 MAP kinase, indicating cell proliferation and self-repairing abilities were inhibited. However, the levels of Caveolin-1 and PKC-α were increased by phosphatidylcholine administration. The results indicated that the inhibition of lipid peroxidation by phosphatidylcholine could lead to the prevention of membrane disruption, which closely correlated with the level of Caveolin-1. Since the protective effects of phosphatidylcholine against ethanol-induced lipid peroxidation might be regulated by phospholipid-PKC-α signaling pathway, related with Caveolin-1, the potential effects of phosphatidylcholine on membranes need to be verified.  相似文献   
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选取我国东北、西南、西北及中北部地区的10个典型湖泊,调查了表层沉积物生物硅含量变化情况,并通过区域对比分析了生物硅含量变化的原因,寻找我国湖泊生物硅变化的空间规律。结果表明,西北及中北部地区湖泊生物硅含量平均值整体低于东北和西南地区湖泊,可能是由于西北及中北部地区较低的温度和较少的降水量导致硅藻生长受限,从而造成生物硅含量偏低。东北湖泊与西南湖泊生物硅含量相对较高,但其形成原因不同。东北2个湖泊均靠近人类聚居区,属富营养型湖泊,虽然东北地区年均温较低,但充足的营养盐为硅藻生长提供了必要因素。而西南地区湖泊大多为中贫营养型湖泊,其生物硅含量整体较高可能主要归因于较高的温度和较多的降水。  相似文献   
4.
Drug safety has become a very important subject, and more countries have joined in the fight against counterfeit drugs. This study demonstrated a non-invasive Raman spectroscopy method that could be utilized for screening liquid injectable drugs for spurious/falsely-labeled/falsified/counterfeit medical products (SFFCs). Two problems were solved to remove the blocks in identification and quantitation: one problem was the weak API signal extraction from the non-invasive Raman spectra and the other was the problem of Raman absolute measurement. Principal component analysis (PCA) and classical least square (CLS) algorithms were performed to establish the models. Water was chosen as the “internal standard” to normalize the spectra to solve the problem of Raman absolute measurement. The results showed that the 11 positive samples and 66 negative samples were all well identified with a threshold of 0.95. One of the positive samples contained the excipient propylene glycol, which was identified successfully at the same time. The accuracy of quantitative results was approximately 5% for doxofylline liquid injectables and about 10% for the low-concentration and big glass bottle-containers of Levofloxacin Lactate and Sodium Chloride Injections as compared to the results using an HPLC method, this is satisfactory for fast screening of SFFCs. In conclusion, with the development of a database of identification and quantitation models, this method may determine liquid injectable drugs in a fast and non-invasive way and become one of the most powerful weapons against SFFCs.

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Electronic supplementary material

The online version of this article (doi:10.1208/s12249-015-0286-0) contains supplementary material, which is available to authorized users.KEY WORDS: CLS, liquid injectables, non-invasive Raman fast screening method, PCA, SFFCs (Spurious/falsely-labeled/falsified/counterfeit medical products)  相似文献   
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血管生成素是核糖核酸酶A超家族成员之一,具有较弱的核糖核酸酶活性.最新研究发现,血管生成素参与细胞内多种RNA的代谢过程.在生长条件下,血管生成素可以发生核转位聚集于细胞核中,促进rRNA转录,并可参与其剪切加工,同时它也调控一系列mRNA基因的转录,最终促进细胞的生长和增殖;在应激条件下,血管生成素能降解tRNA形成tiRNA,抑制细胞内整体蛋白质的翻译水平,并促进应激小体的形成,激活细胞内应激保护机制,从而促进细胞存活.此外,血管生成素还可参与非编码小RNA等RNA代谢过程.本文概述了血管生成素在RNA代谢中的作用与分子机制等方面的进展,并探讨了其在疾病发生和发展中的作用,以期开拓血管生成素的研究新思路.  相似文献   
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圈养林麝母幼关系的初步研究   总被引:8,自引:2,他引:6  
本文研究圈养林麝(Moschusmoshiferusberezovskii)的母幼关系。林麝的母幼关系属于典型的隐蔽者(hider)类型。母幼分开躺卧,相距20.37±11.06m。吮乳时间、母幼联系时间、母幼联系时间/幼麝活动总时间随周龄的增加均呈明显的下降。4周龄前,幼麝躺卧居多,母麝以叫声主动联系幼麝,5周龄开始幼麝独立程度逐渐提高。听觉和视觉通讯是母幼远距离通讯的主要方式。  相似文献   
7.
Ethylene is instrumental to climacteric fruit ripening and EIN3 BINDING F‐BOX (EBF) proteins have been assigned a central role in mediating ethylene responses by regulating EIN3/EIL degradation in Arabidopsis. However, the role and mode of action of tomato EBFs in ethylene‐dependent processes like fruit ripening remains unclear. Two novel EBF genes, SlEBF3 and SlEBF4, were identified in the tomato genome, and SlEBF3 displayed a ripening‐associated expression pattern suggesting its potential involvement in controlling ethylene response during fruit ripening. SlEBF3 downregulated tomato lines failed to show obvious ripening‐related phenotypes likely due to functional redundancy among SlEBF family members. By contrast, SlEBF3 overexpression lines exhibited pleiotropic ethylene‐related alterations, including inhibition of fruit ripening, attenuated triple‐response and delayed petal abscission. Yeast‐two‐hybrid system and bimolecular fluorescence complementation approaches indicated that SlEBF3 interacts with all known tomato SlEIL proteins and, consistently, total SlEIL protein levels were decreased in SlEBF3 overexpression fruits, supporting the idea that the reduced ethylene sensitivity and defects in fruit ripening are due to the SlEBF3‐mediated degradation of EIL proteins. Moreover, SlEBF3 expression is regulated by EIL1 via a feedback loop, which supposes its role in tuning ethylene signaling and responses. Overall, the study reveals the role of a novel EBF tomato gene in climacteric ripening, thus providing a new target for modulating fleshy fruit ripening.  相似文献   
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四种常见杂草根系及根边缘细胞对铝胁迫的响应   总被引:2,自引:0,他引:2  
周楠  刘鹏  徐根娣  汪晔  孙芳华  陈文荣 《生态学报》2009,29(12):6512-6518
以2种禾本科杂草(升马唐、稗草)和2种菊科杂草(旱莲草、野茼蒿)为实验材料,通过砂培法研究不同科属杂草根部对铝胁迫的响应.结果表明:4种杂草根边缘细胞活性均随着铝胁迫浓度和时间呈显著下降的趋势,但禾本科杂草根系边缘细胞的活性高于菊科杂草,且活性的降低幅度较小;4种杂草根相对伸长率均随铝浓度和处理时间的增加呈递减趋势,但铝对旱莲草和野茼蒿根生长的抑制程度要明显高于升马唐和稗草;根系的铝含量、游离脯氨酸含量、MDA 含量和质膜透性均随铝处理浓度和处理时间的增加而增大,且在高铝浓度(1000 mg · L~(-1))时达到最大值,但升马唐和稗草根系的铝含量、游离脯氨酸含量、MDA含量和质膜透性均显著低于旱莲草和野茼蒿,且随着铝浓度的增加,禾本科杂草根系的游离脯氨酸含量及MDA含量的变化没有达到显著水平(P>0.05).由此说明,铝毒对杂草造成的伤害随着浓度增加和时间延长而加重;升马唐和稗草的根系通过较高的根边缘细胞活性和根相对伸长率及较低的铝含量、游离脯氨酸含量、MDA含量和质膜透性来增加其对铝的耐性;2种禾本科杂草(升马唐、稗草)的耐铝性高于2种菊科杂草(旱莲草、野茼蒿).  相似文献   
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为探讨栽培环境对大仔买麻藤(Gnetum montanum Markgr.f.megalocarpa Markgr.)叶片营养成分的影响,将采自云南省景东县的大仔买麻藤分别在北京和昆明的温室内培养,对其1年生幼苗叶片的营养成分进行研究。结果表明,不同栽培环境对大仔买麻藤叶片的大部分营养成分无显著影响;叶片总淀粉、总糖、黄酮和生物碱含量无显著差异;但在二糖、莰菲醇、部分氨基酸和某些元素含量上有显著差异;并且大部分的元素含量受土壤的影响显著。因此,不同栽培环境对大仔买麻藤叶片营养成分的影响不大。  相似文献   
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