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排序方式: 共有67条查询结果,搜索用时 15 毫秒
1.
Andrey Vyacheslavovich Vasilyev Valeriya Sergeevna Kuznetsova Tatyana Borisovna Bukharova Timofei Evgenevich Grigoriev Yuriy Dmitrievich Zagoskin Irina Alekseevna Nedorubova Igor Ivanovich Babichenko Sergey Nicolaevich Chvalun Dmitry Vadimovich Goldstein Anatoliy Alekseevich Kulakov 《Molecules (Basel, Switzerland)》2021,26(2)
Compositions based on chitosan/β-glycerophosphate hydrogels with highly porous polylactide granules can be used to obtain moldable bone graft materials that have osteoinductive and osteoconductive properties. To eliminate the influence of such characteristics as chain length, degree of purification, and molecular weight on a designed material, the one-stock chitosan sample was reacetylated to degrees of deacetylation (DD%) of 19.5, 39, 49, 55, and 56. A study of the chitosan/β-glycerophosphate hydrogel with chitosan of a reduced DD% showed that a low degree of deacetylation increased the MSCs (multipotent stromal cells) viability rate in vitro and reduced the leukocyte infiltration in subcutaneous implantation to Wistar rats in vivo. The addition of 12 wt% polylactide granules resulted in optimal composite mechanical and moldable properties, and increased the modulus of elasticity of the hydrogel-based material by approximately 100 times. Excessive filling of the material with PLA (polylactide) granules (more than 20%) led to material destruction at a ~10% strain. Osteoinductive and osteoconductive properties of the chitosan hydrogel-based material with reacetylated chitosan (39 DD%) and highly porous polylactide granules impregnated with BMP-2 (bone morphogenetic protein-2) have been demonstrated in models of orthotopic and ectopic bone formation. When implanted into a critical-size calvarial defect in rats, the optimal concentration of BMP-2 was 10 μg/mL: bone tissue areas filled the entire material’s thickness. Implantation of the material with 50 μg/mL BMP-2 was accompanied with excessive growth of bone tissue and material displacement beyond the defect. Significant osteoinductive and osteoconductive properties of the material with 10 μg/mL of BMP-2 were also shown in subcutaneous implantation. 相似文献
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《Mendeleev Communications》2020,30(1):25-27
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《International Journal of Approximate Reasoning》2014,55(3):853-866
In this paper, a novel cognitive system model is established based on formal concept analysis to exactly describe human cognitive processes. Two new operators, extent–intent and intent–extent, are introduced between an object and its attributes. By analyzing the necessity and sufficient relations between the object and some of its attributes, the information granule concept is investigated in human cognitive processes. Furthermore, theories of transforming arbitrary information granule into necessary, sufficient, sufficient and necessary information granules are addressed carefully. Algorithm of the transformation is constructed, by which we can provide an efficient approach to the conversion among information granules. To interpret and help understand the theories and algorithm, an experimental computing program is designed and two cases is employed as case study. Results of the small scale case are calculated by the method presented in this paper. The large-scale case is calculated by the experimental computing program and validated by the proposed algorithm. The considered framework can provide a novel convenient tool for artificial intelligence researches. 相似文献
6.
Identification of chemical constituents in traditional Chinese medicine formula using HPLC coupled with linear ion trap‐Orbitrap MS from high doses of medicinal materials to equivalent doses of formula: Study on Xiang‐Sha‐Liu‐Jun‐Zi‐Jia‐Jian granules
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Zhiwei Lu Qing Wang Meiling Wang Yuehong Liu Shuang Fu Xiaoyan Gao Xudong Tang 《Journal of separation science》2016,39(9):1619-1627
High‐resolution mass spectrometry has been a powerful tool for the research of chemical constituents in traditional Chinese medicine (TCM) formulas. However, the chromatographic peaks were difficult to discriminate clearly in data collection or analysis because of the complexity and the greatly different content of the constituents in TCM formula, which increased the difficulty of identification. In this study, a high‐performance liquid chromatography coupled with linear ion trap‐Orbitrap mass spectrometry based strategy focused on the comprehensive identification of TCM formula constituents was developed. Identification was carried out from a high dose of medicinal materials to equivalent dose of formula. Meanwhile, combined with mass spectrometry data, chromatographic behaviors, reference standards and previous reports, the identification of constituents in Xiang‐Sha‐Liu‐Jun‐Zi‐Jia‐Jian granules was described. 169 compounds were unambiguously or tentatively characterized, mainly including flavonoids, alkaloids, triterpenic acids, triterpene saponins, lactones, sesquiterpenoids and some other compounds. Among them, 11 compounds were unambiguously confirmed by comparing with reference standards. These results demonstrated that the method was effective and reliable for comprehensive identification of constituents of Xiang‐Sha‐Liu‐Jun‐Zi‐Jia‐Jian granules extracts and reveal the material basis of its therapeutic effects. This strategy might propose a research idea for the characterization of multi‐constituents in TCM formula. 相似文献
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目的通过测定8批复方木鸡颗粒中无机元素的含量,拟从无机成分的角度探讨复方木鸡颗粒的特征元素。方法采用电感耦合等离子体质谱仪(ICP-MS),以半定量分析的方式测定8批次复方木鸡颗粒无机元素的含量,建立复方木鸡颗粒无机轮廓谱,并对其差异元素中的重金属元素和人体有益元素进行全定量测定,同时,采用聚类分析和主成分分析,对其特征元素进行评价。结果构建了复方木鸡颗粒无机元素的轮廓谱,通过聚类分析和主成分分析共找到6个特征元素,包括Ca、Mg、Mn、K、Cr、Ni。结论从无机成分的角度明确了复方木颗粒的特征元素,为进一步探究复方木鸡颗粒的药效研究提供理论依据。 相似文献
8.
A reversed-phase high-performance liquid chromatographic (RP-HPLC) method was described for the determination of chlorogenic acid (CGA) in rat plasma using protocatechuic acid as internal standard (IS). CGA in plasma was extracted with acetonitrile, which also acted as deproteinization agent. Chromatographic separation was performed on a Kromasil C18 column with methanol-0.2 m acetic acid (pH 3.0, 25:75, v/v) as mobile phase at a flow-rate of 1.0 mL/min with an operating temperature of 30 degrees C and UV detection at 300 nm. The standard curve was found to be linear over the concentration ranges of 0.4-2.5 microg/mL and 2.5-40 microg/mL, and the limit of quantification (LOQ) was 0.4 microg/mL. The analytical precision and accuracy were validated by relative standard deviation (RSD) and relative error, which were in ranges 3.14-10.78% and -2.20-5.00%, respectively. The average recovery of CGA was 87.59%. The method was successfully applied to the pharmacokinetic study of CGA in Yin-Huang granules. 相似文献
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建立一种新的溶剂/流速双梯度-整体柱高效液相色谱法快速测定三七中药配方颗粒中4种皂苷成分. 通过乙腈浓度、流速与被测物的lg k线性相关性, 预测被测组分三七皂苷R1, 人参皂苷Rg1与人参皂苷Re的适宜k值, 以测得的分离度为优化指标, 建立分离R1, Rg1, Re的最佳分离模式1和2|在此基础上, 通过考察乙腈浓度和流速随时间的变化率对分离人参皂苷Rb1的影响, 以Rb1与相邻杂质的分离度为优化指标, 得到分离R1, Rg1, Re, Rb1的两种最佳模式. 应用色谱优化函数(COF)作为综合指标评价, 结果显示模式2优化效果更好. 采用模式2的色谱条件, 20 min内完成对三七配方颗粒中4种皂苷成分的质量分析, 结果表明该方法准确可行、快速. 相似文献
10.
Hassan Jafari Mohd Hasbullah Idris Ali Ourdjini Saeed Farahany Mohammed Rafiq Abdul Kadir 《Particle & Particle Systems Characterization》2012,29(4):263-272
Oxidation and melting behaviors of AZ91D granules throughout the in‐situ melting process using flux were investigated. The granules were heated under unprotected environment at four different temperatures between 650 and 800 °C, for the durations of 30 and 60 min. The products of heating process were characterized macroscopically and the oxides formed on the granules were examined using field emission scanning electron microscope, energy dispersive X‐ray spectroscopy and X‐ray diffraction analysis. Thermal analysis was used to reveal the response of the granules to heating during the in‐situ melting. The results showed that the granules experienced severe oxidation even in the presence of the flux, and significant amount of them changed to a powdered state due to oxidation and combustion, especially at 800 °C. It was discovered that the granules melted during heating; however, oxides formed on their surface encapsulated the molten metal and prevented the liquids from merging. The results also revealed that increasing heating temperature and time enhanced mold‐magnesium reaction resulted in the entrance of mold materials into the oxidation residues. 相似文献