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排序方式: 共有9314条查询结果,搜索用时 15 毫秒
1.
Jianhua Zhang Mei Liu Hongjian Jin Liandong Deng Jinfeng Xing Anjie Dong 《AAPS PharmSciTech》2010,11(2):894-903
Lactate esters are widely used as food additives, perfume materials, medicine additives, and personal care products. The objective
of this work was to investigate the effect of a series of lactate esters as penetration enhancers on the in vitro skin permeation of four drugs with different physicochemical properties, including ibuprofen, salicylic acid, dexamethasone
and 5-fluorouracil. The saturated donor solutions of the evaluated drugs in propylene glycol were used in order to keep a
constant driving force with maximum thermodynamic activity. The permeability coefficient (K
p), skin concentration of drugs (SC), and lag time (T), as well as the enhancement ratios for K
p and SC were recorded. All results indicated that lactate esters can exert a significant influence on the transdermal delivery
of the model drugs and there is a structure-activity relationship between the tested lactate esters and their enhancement
effects. The results also suggested that the lactate esters with the chain length of fatty alcohol moieties of 10–12 are more
effective enhancers. Furthermore, the enhancement effect of lactate esters increases with a decrease of the drug lipophilicity,
which suggests that they may be more efficient at enhancing the penetration of hydrophilic drugs than lipophilic drugs. The
influence of the concentration of lactate esters was evaluated and the optimal concentration is in the range of 5∼10 wt.%.
In sum, lactate esters as a penetration enhancer for some drugs are of interest for transdermal administration when the safety
of penetration enhancers is a prime consideration. 相似文献
2.
Noni (Morinda citrifolia) is increasing in worldwide popularity as a food or dietary supplement with versatile health benefits. The aim of this study was to investigate the effects of Noni fruit on anxiety symptoms in vitro. To this end, a competitive GABAa receptor-binding assay was developed. Our preliminary study indicates that the methanol crude extract of Noni fruit showed significant affinity to the gamma-aminobutyric acid A (GABAa) inhibitory neurotransmitter receptors, and displayed 75% binding inhibition of the agonist radioligand [3H] muscimol at a concentration of 100 microg/ml. Further experiments demonstrated that the MeOH extract, and its BuOH and H2O partitions, exhibited IC50 values of 22.8, 27.2, and 17.1 microg/ml, respectively, in the GABAa-binding assay. Experimental results with Noni fruit indicate the presence of competitive ligand(s), which may bind to the GABAa receptor as an agonist, and thus induce its anxiolytic and sedative effects. The study provides an in vitro rationale for one of Noni's versatile and traditional uses. In addition, an HPLC fingerprint profile of the methanolic extract of Noni fruit has been established for quality control purpose. 相似文献
3.
我们分子鉴别了一个缺失型中国(A_γδβ)°-地贫家系。先证者为这一缺失的纯合子,具有中度贫血症状。家系的另五个成员均为这一缺失的杂合子,其胎儿血红蛋白(HbF)为16—21%,接近或达到HPFH杂合子的HbF水平,并且几乎不表现贫血症状。限制性内切酶图谱分析证明了β-珠蛋白基因簇内的DNA顺序缺失,缺失的5′端点位于Aγ基因IVSⅡ内,3′端点在β-珠蛋白基因下游区远端,距HPFH-2的3′缺失端点上游区约11kb。缺失的总长度约为80kb。本文讨论了这一缺失导致胎儿血红蛋白在成人中持续活跃表达的可能机制。 相似文献
4.
Lei Deng Yunyun Zeng Hui Liu Zixuan Liu Xuejun Liu 《Current issues in molecular biology》2022,44(5):2287
Drug-target interactions provide insight into the drug-side effects and drug repositioning. However, wet-lab biochemical experiments are time-consuming and labor-intensive, and are insufficient to meet the pressing demand for drug research and development. With the rapid advancement of deep learning, computational methods are increasingly applied to screen drug-target interactions. Many methods consider this problem as a binary classification task (binding or not), but ignore the quantitative binding affinity. In this paper, we propose a new end-to-end deep learning method called DeepMHADTA, which uses the multi-head self-attention mechanism in a deep residual network to predict drug-target binding affinity. On two benchmark datasets, our method outperformed several current state-of-the-art methods in terms of multiple performance measures, including mean square error (MSE), consistency index (CI), , and PR curve area (AUPR). The results demonstrated that our method achieved better performance in predicting the drug–target binding affinity. 相似文献
5.
Harshad S. Ugamraj Kevin Dang Laure-Hlne Ouisse Benjamin Buelow Eduardo N. Chini Giulia Castello James Allison Starlynn C Clarke Laura M. Davison Roland Buelow Rong Deng Suhasini Iyer Ute Schellenberger Sankar N. Manika Shipra Bijpuria Astrid Musnier Anne Poupon Maria Cristina Cuturi Wim van Schooten Pranjali Dalvi 《MABS-AUSTIN》2022,14(1)
6.
7.
Electron acceptors for anaerobic oxidation of methane drive microbial community structure and diversity in mud volcanoes 下载免费PDF全文
Ge Ren Anzhou Ma Yanfen Zhang Ye Deng Guodong Zheng Xuliang Zhuang Guoqiang Zhuang Danielle Fortin 《Environmental microbiology》2018,20(7):2370-2385
Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high‐throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate‐ and iron‐reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM). The impacts of sulfate/iron/nitrate on AOM in the MVs were verified by microcosm experiments. Further, two representative MVs were selected to explore the microbial interactions based on phylogenetic molecular ecological networks. The sites showed distinct network structures, key species and microbial interactions, with more complex and numerous linkages between methane‐cycling microbes and their partners being observed in the iron/sulfate‐rich MV. These findings suggest that electron acceptors are important factors driving the structure of microbial communities in these methane‐rich environments. 相似文献
8.
Noggin and bFGF cooperate to maintain the pluripotency of human embryonic stem cells in the absence of feeder layers 总被引:20,自引:0,他引:20
Wang G Zhang H Zhao Y Li J Cai J Wang P Meng S Feng J Miao C Ding M Li D Deng H 《Biochemical and biophysical research communications》2005,330(3):934-942
Human embryonic stem (hES) cells are typically maintained on mouse embryonic fibroblast (MEF) feeders or with MEF-conditioned medium. However, these xenosupport systems greatly limit the therapeutic applications of hES cells because of the risk of cross-transfer of animal pathogens. Here we showed that the bone morphogenetic protein antagonist noggin is critical in preventing differentiation of hES cells in culture. Furthermore, we found that the combination of noggin and basic fibroblast growth factor (bFGF) was sufficient to maintain the prolonged growth of hES cells while retaining all hES cell features. Since both noggin and bFGF are expressed in MEF, our findings suggest that they may be important factors secreted by MEF for maintaining undifferentiated pluripotent hES cells. Our data provide new insight into the mechanism how hES cell self-renewal is regulated. The newly developed feeder-free culture system will provide a more reliable alternative for future therapeutic applications of hES cells. 相似文献
9.
Michael D. Weiser Sean T. Michaletz Vanessa Buzzard Ye Deng Zhili He Lina Shen Brian J. Enquist Robert B. Waide Jizhong Zhou Michael Kaspari 《Ecography》2018,41(2):255-264
The abundance–adaptation hypothesis argues that taxa with more individuals and faster generation times will have more evolutionary ‘experiments’ allowing expansion into, and diversification within, novel habitats. Thus, as older taxa have produced more individuals over time, and smaller taxa have higher population sizes and faster generation times, the Latitudinal Diversity Gradients (LDGs) of these clades should show shallower slopes. We describe the LDGs for archaea, bacteria, fungi, invertebrates and trees from six North American forests. For three focal groups – bacteria, ants, and trees – older taxa had shallower LDG slopes than the more recent, terminal taxa. Across 12 orders of magnitude of body mass, LDG slopes were steeper in larger taxa. The slopes of LDGs vary systematically with body size and clade age, underscoring the non‐canonical nature of LDGs. The steepest LDG slopes were found for the largest organisms while the smallest, from bacteria to small litter‐soil invertebrates, have shallower‐ to zero‐slope LDGs. If tropical niche conservatism is the failure of clades to adapt to, and diversify in temperate habitats, then the steep LDGs of chordates and plants likely arise from the decreased ability of clades with large individuals to adapt to the multiple challenges of extra‐tropical life. 相似文献
10.
为了探讨CO2浓度升高下不同水稻品种荣优398 (RY)和粤杂889(YZ)吸收重金属Cd差异性的原因,利用水培试验研究了不同浓度Cd处理下两种水稻吸收Cd的差异及根形态的变化特征.结果表明:低Cd处理(5、10、20 μmol·L-1)显著增加水稻生物量;当Cd浓度高于50 μmol·L-1时,Cd胁迫效果开始显现,水稻生物量减少.CO2浓度升高显著增加了水稻的生物量,增加了YZ茎Cd含量而降低了RY茎Cd含量.在5~200 μmol·L-1的Cd浓度下,CO2浓度升高增加了YZ活性根在总根长中的比例,降低了RY活性根的比例.CO2浓度升高下不同水稻品种根形态的变化是导致其对Cd吸收差异性的原因之一. 相似文献