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1.
目的:鉴定在实验过程中分离到的一株生长快速,并且可以将L-山梨糖转化为2-酮基-L-古龙酸的菌株。方法:将快生小菌传代,并进行产酸、抗菌谱、山梨糖脱氢酶活性等分析,通过PCR方法扩增并分析16S rDNA。结果:在传代过程中还分离得到了不产酸菌株;从快生小菌中扩增得到了普通酮古龙酸菌16S rDNA;从产酸菌中能够扩增得到包含酮古龙酸菌和乙酸钙不动杆菌的16S rDNA序列;在不产酸菌中只检测到乙酸钙不动杆菌的16S rDNA序列。结论:产酸的快生小菌可能是普通酮古龙酸菌和乙酸钙不动杆菌形成的融合细胞,这种融合细胞基因组表现为很不稳定,普通酮古龙酸菌基因组容易丢失,且丢失后也失去了产酸能力。  相似文献   
2.
Series of nanoporous carbons are prepared from sunflower seed shell (SSS) by two different strategies and used as electrode material for electrochemical double-layer capacitor (EDLC). The surface area and pore-structure of the nanoporous carbons are characterized intensively using N2 adsorption technique. The results show that the pore-structure of the carbons is closely related to activation temperature and dosage of KOH. Electrochemical measurements show that the carbons made by impregnation-activation process have better capacitive behavior and higher capacitance retention ratio at high drain current than the carbons made by carbonization-activation process, which is due to that there are abundant macroscopic pores and less interior micropore surface in the texture of the former. More importantly, the capacitive performances of these carbons are much better than ordered mesoporous carbons and commercial wood-based active carbon, thus highlighting the success of preparing high performance electrode material for EDLC from SSS.  相似文献   
3.
In this study, trichostatin A (TSA), a histone deacetylase inhibitor, increased the Bone morphogenetic protein-2 (BMP-2) mRNA level in a human osteoblasts line. Deletion analysis of the promoter region revealed that TSA-induced luciferase was regulated by the BMP-2 promoter spanning from −320 to −310. Electrophoresis mobility shift assay (EMSA) and Chromatin immunoprecipitation (CHIP) assay proved that this position was a nuclear factor (NF)-κB responsive element. The results above demonstrated that acetylation plays a crucial role in BMP-2 expression, and acetylation of NF-κB p65 and p50 subunits by TSA treatment may activate the BMP-2 promoter. Published in Russian in Molekulyarnaya Biologiya, 2008, Vol. 42, No. 6, pp. 984–989. The text was submitted by the authors in English.  相似文献   
4.
In order to regulate the skin permeation rate (flux) of escitalopram (ESP), ion-pair strategy was used in our work. Five organic acids with different physicochemical properties, benzoic acid (BA), ibuprofen (IB), salicylic acid (SA), benzenesulfonic acid (BSA), and p-aminobenzoic acid (PABA), were employed as counter-ions to regulate the permeation rate of ESP across the rabbit abdominal skin in vitro. The interaction between ESP and organic acids was characterized by FTIR and 13C NMR spectroscopy. Results showed that all organic acids investigated in this study performed a controlling effect on ESP flux. To further analyze the factors concerned with the permeation capability of ESP-acid complex, a multiple linear regression model was used. It is concluded that the steady-state flux (J) of ESP-acid complexes had a positive correlation with log K o/w (the n-octanol/water partition coefficient of ion-pair complex) and pK a (the acidity of organic acid counter-ion), but a negative correlation with MW (the molecular weight of ion-pair complex). The logK o/w of ion-pair complex is the primary one in all the factors that influence the skin permeation rate of ESP. The results demonstrated that organic acid with appropriate physicochemical properties can be considered as suitable candidate for the transdermal drug delivery of escitalopram.  相似文献   
5.
Peganum harmala L. is a traditional Chinese and Uygur medicine used to treat cancer. Bioactivity‐guided fractionation was applied to determine the cytotoxic constituents from P. harmala. A novel triterpenoid and a phenolic glycoside were isolated and identified, as well as seven known compounds. The novel metabolites were elucidated to be 3α‐acetoxy‐27‐hydroxyolean‐12‐en‐28‐oic acid methyl ester ( 1 , OA) and N‐acetyl‐9‐syringinoside ( 9 ). Some compounds exhibited potent cytotoxicity against human tumor cells. Among them, OA showed the highest cytotoxicity against human lung cancer cells A549 with an IC50 value of 8.03 ± 0.81 μm . OA had a potent anti‐NSCLC cell activity by interfering with the epidermal growth factor receptor (EGFR) activation and its downstream signaling, and could exert an antiproliferative effect by inactivation of EGFR‐driven antiapoptotic pathway followed by the release of mitochondrial cytochrome c, which might prove to be a promising leading compound for the development of an anti‐lung cancer drug.  相似文献   
6.
The optical response of lanthanum hexaboride (LaB6) nanoparticles has been investigated by both theoretically and experimentally. The LaB6 nanoparticles obtained by solid-state reaction could avoid serious surface oxidization and exhibit excellent optical performance. The discrete dipole approximation (DDA) has been used to investigate the optical response of LaB6 nanoparticles with different sizes and different shapes. The calculation results coincide with the experimental results and reveal that the largest extinction peak value appears at 60 nm for cubic particles and 40 nm for spherical particles, respectively. Our calculation results show that the existence of the largest extinction peak value is not only due to the surface oxides but also relate to the particle shape of LaB6 compound. In addition, the LaB6 nanoparticles with cubic and spherical shapes exhibit different optical responses, and the cubic particles exhibit stronger near infrared (NIR) extinction than spherical particles. With increasing particle size, the extinction peak value of spherical particle decreases more rapidly than that of cubic ones.  相似文献   
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工业生产排放和土壤氟高背景值导致我国部分地区氟污染严重,给生态安全和人类健康造成严重威胁.本文基于我国氟排放重点行业的生产产能,估算重点行业生产过程中氟排放量,构建我国重点行业氟排放清单,基于数据集成和融合,分析我国土壤氟背景值、氟地球化学分布和土壤氟浓度分布,并对氟污染典型区域氟污染成因及控制进行系统分析.分析发现,我国氟排放的重点行业有钢铁、磷肥和电解铝.磷肥施用的氟排放量最大,但施用面积大,浓度贡献小;电解铝行业的氟排放强度大;钢铁行业的氟排放总量大,但排放强度较小.我国大部分地区土壤氟背景值不高,环境容量大.但部分地区氟污染严重,主要是由工业氟排放和土壤氟高背景值造成,这些地区应采取相应的防控措施.  相似文献   
9.
城市建设中的矿物质材料开发利用活动不仅导致大量碳排放,也产生了碳吸收.以往建筑矿物质材料的碳吸收过程一直没有得到重视和科学量化.本研究采用遥感影像阴影高度反演技术,提取地块的建筑容量,识别建筑类型,以此为依据确定矿物材料用量及碳含量参数,采用热重分析法测定碳化率,基于以上步骤构建城市建筑碳汇量的核算方法,并选取沈阳市蒲河新来测试这一核算方法,同时进行不确定性分析.结果表明: 1996—2016年,沈阳市蒲河新城各类型建筑产生的碳汇总量依次为:居住建筑>公共服务建筑>其他类建筑>商业金融建筑>工业建筑;各类建筑用地的碳汇容积率依次为:商业金融建筑>居住建筑>公共服务建筑>其他类建筑>工业建筑.本研究构建的基于建筑容量提取的城市尺度的建筑碳汇量核算方法,可以快速准确地估算不同类型城市建设用地无机材料产生的碳汇量.在城市自然碳汇有限条件下,利用建筑碳汇增加城市碳汇量,能够为我国城市低碳发展提供新的思路.  相似文献   
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