Bone quality characteristics obtained by Fourier transform infrared and Raman spectroscopic imaging

Background

Bone strength, which is an indicator of the risk of fracture, is determined by bone mass (bone mineral density, 70%) and bone quality (30%). Bone quality results from a combination of various material and structural properties, making it difficult to determine a suitable method for the evaluation of bone quality based on clinical measurements. Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy are powerful techniques for the assessment of bone quality and reveal similar information on molecular structures; however, this molecular information is based on different physical phenomena. Therefore, a comparison of FTIR and Raman spectra is required for an accurate assessment of bone quality.

指纹图谱技术评价不同干燥方式对地龙氨基酸组分提取物的影响

目的 对不同干燥方式所得地龙氨基酸组分提取物进行指纹图谱测定方法的研究, 比较不同干燥方式对地龙氨基酸组分提取物品质的影响。方法 采用异硫氰酸苯酯柱前衍生化反相高效液相色谱法, 测定并比较真空冷冻干燥、真空减压干燥和微波干燥3种方式所得地龙干燥样品以及未经干燥样品的指纹图谱, 以中药色谱指纹图谱相似度评价系统计算相似度, 并进行图谱比较和指认分析。结果 建立了不同干燥技术处理的地龙氨基酸组分提取物高效液相指纹图谱, 确定了17个共有峰, 同一干燥方法不同批次干燥产品的镜像度较高, 具有良好的相似性(>0.9), 不同干燥方法所得提取物之间有较大的质量差异。结论 HPLC指纹图谱分析法可较全面的反映不同干燥技术处理的地龙氨基酸组分提取物间的差异, 可用于同类提取物干燥工艺的质量控制和工艺评价。冷冻干燥法是地龙氨基酸组分提取物最适宜的干燥方法。     

蓝萼香茶菜高效液相指纹图谱研究

目的:采用RP-HPLC法建立蓝萼香茶菜药材的指纹图谱。方法:采用Diamonsil钻石C18色谱柱(250 mm×4.6 mm,5μm);流动相为甲醇-水(体积比70∶30),流速为1.0 m L/min,柱温为20℃,检测波长为231 nm。结果:建立了蓝萼香茶菜药材的RP-HPLC指纹图谱,5批蓝萼香茶菜药材指纹图谱R≥0.962 7。结论:采用RP-HPLC指纹图谱检测技术可以有效控制蓝萼香茶菜药材的内在质量。     

用超高效液相色谱蒸发光散射检测桔梗流浸膏指纹图谱的研究

目的建立桔梗流浸膏的指纹图谱检测方法,以达到质量的均一和稳定。方法采用UPLC-ELSD法,乙腈-水梯度洗脱,色谱柱:ACQUITY UPLC BEH C18(2.1mm×100mm,1.7μm),柱温:30℃,流速:0.2ml/min,在20min内,得到11个分离度良好的色谱峰。结果采用中药色谱指纹图谱相似度软件计算,桔梗流浸膏样品相似度均大于0.90,符合指纹图谱要求。结论该方法经稳定性、重复性、精密度考察,是一种快速、准确的中药质量评价方法。     

Analytical Study of Porous Organosilicate Glass Films Prepared from Mixtures of 1,3,5- and 1,3-Alkoxysilylbenzenes

Organosilicate glass (OSG)-based porous low dielectric constant (low-k) films with different molar ratios of 1,3,5-tris(triethoxysilyl)benzene to 1,3-bis(triethoxysilyl)benzene bridging organic groups (1:3 and 1:7) were spin-on deposited, followed by a soft bake in air and N₂ at 150 °C and hard bake in air and N₂ at 400 °C. Non-ionic template (Brij^®30) concentrations were varied from 0 to 41 wt% to control the porosity of the films. The chemical composition of the matrix of the films was evaluated and discussed with the shrinkage of the film during the curing, refractive indices, mechanical properties, k-values, porosity and pore structure. The chemical composition of the film cured in both air and N₂-containing ambient were evaluated and compared. The benzene bridging groups containing films change their porosity (0 to 43%) but keep the pore size constant and equal to 0.81 nm when porosity is lower than 30%. The k-value decreases with increasing porosity, as expected. The films containing benzene bridge have higher a Young’s modulus than plasma-enhanced chemical vapor deposition (PECVD) methyl-terminated low-k films with the same porosity and show good hydrophobic properties after a hard bake and close to the values reported for 1,4-benzene-bridged films. The fabricated films show good stability after a long time of storage. However, the improvement of mechanical properties was lower than the values predicted by the published literature data. It was concluded that the concentration of 1,3,5-benzene bridges was below the stiffness threshold required for significant improvement of the mechanical properties. The films show UV-induced luminescence with a photon energy of 3.6 to 4.3 eV. The luminescence is related to the presence of oxygen-deficient-type defects or their combination with organic residues. The most intensive luminescence is observed in as-deposited and soft bake samples, then the intensity is reduced after a hard bake. It is assumed that the oxygen-deficient centers form because of the presence of Si–OC₂H₅ groups in the films and the concentration of these centers reduces when all these groups completely transformed into siloxane (Si–O–Si).     

Characterization and Evaluation of Hydrothermal Liquefaction Char from Alkali Lignin in Subcritical Temperatures

An evaluation of hydrothermal liquefaction (HTL) char is investigated in this work. Morphological studies, N₂ adsorption behavior, FTIR analysis, thermal behavior, and elemental composition are studied. The HTL char yield showed an increase with higher operating temperatures. It increased from 11.02% to 33% when the temperature increased from 573 K to 623 K. At lower temperatures, the residence time showed an impact on the yield, while close to the critical point, residence time became less impactful. Elemental analysis showed that both higher operating temperatures and longer residence times increased the nitrogen content of the chars from 0.32% to 0.51%. FTIR analysis suggested the char became more aromatic with the higher temperatures. The aliphatic groups present diminished drastically with the increasing temperature. Residence time did not show a significant impact as much as the temperature when considering the functional group elimination. An increase in operating temperatures and residence times produced thermally stable chars. HTL char produced at the lowest operating temperature and showed both the highest surface area and pore volume. When temperature and residence time increase, more polyaromatic char is produced due to carbonization.     

Phase Composition of Silica Fume—Portland Cement Systems Formed under Hydrothermal Curing Evaluated by FTIR,XRD, and TGA

Two substitution levels of Portland cement by silica fume (SF; 30 and 50 mass%) and three hydrothermal treatment regimes (0.5, 1.2, and 2 MPa and 165, 195, and 220 °C for 7 days, respectively) were selected for the investigation of high-temperature phase formation. A combination of thermogravimetric, X-ray diffraction, and Fourier transform infrared analyses in the mid-IR region was used to overcome the shortcomings of individual techniques for the identification of these complex systems. Changes in molecular water amounts, the polymerization degree of silicate chains, or their decomposition due to transformations and crystallization of phases at hydrothermal conditions were observed and discussed concerning composition. Contrary to the calciochondrite, hydrogrossular phases, α-C₂SH, and jaffeite detected in the systems without SF, a decrease in CaO/SiO₂ ratio resulted in the formation of stable tobermorite in the case of 30 mass% SF, whilst calcium hydrogen silicate, gyrolite, and cowlesite were identified as more thermally stable phases in the samples with 50 mass% SF.     

UPLC结合化学计量学方法的肿节风指纹图谱研究

目的建立不同产地肿节风药材超高效液相色谱指纹图谱,为建立快速而高效的肿节风药材整体质量控制方法提供实验依据。方法采用UPLC法,色谱柱为Acquity HSS T3柱(50 mm×2.1 mm,1.8μm),采用乙腈(D)-水(C)(各含0.1%甲酸)为流动相进行梯度洗脱,体积流量0.5 m L/min,检测波长330 nm,柱温35℃,建立肿节风药材指纹图谱;通过相似度评价,结合聚类分析和主成分分析(PCA),对不同批次的肿节风药材进行质量评价。结果建立的肿节风药材UPLC指纹图谱方法确证16个共有峰,并对9个共有峰进行了明确化学成分指认;18批肿节风药材的相似度为0.869~0.979;通过聚类分析可大致聚成2类;PCA结果支持了聚类分析结果,并发现指纹图谱中迷迭香酸、新绿原酸、隐绿原酸等5个差异性较大的化合物。结论肿节风的UPLC指纹图谱的构建和化学模式的识别为药材质量控制提供更全面的参考。     

指纹图谱结合化学计量学用于香橼品种鉴别的可行性分析

该文拟探讨利用指纹图谱结合化学计量学手段进行香橼品种鉴别的可行性.共有23批香橼样本,涵盖《中国药典》收载的香圆和枸橼品种,采用高效液相色谱法采集色谱图.对部分特征峰进行初步鉴别,建立共有模式,用相似度评价、二维聚类分析、主成分分析(PCA)和偏最小二乘判别分析(PLS-DA)进行考察.结果表明由25个特征峰组成的共有模式可以有效将香圆和枸橼区分,稳定性好,并且模式识别也初步验证了结果的可靠性.进一步利用绝对峰面积(APA)进行相对定量,体现出品种之间的量化差异,对今后质控所选择合适的指标提供了一定基础.     

双标线性校正结合PDA辅助色谱峰定性用于印度獐牙菜指纹图谱分析

 目的 建立印度獐牙菜指纹图谱,探讨和验证双标线性校正法结合PDA辅助法用于色谱峰定性的可行性。方法 采用HPLC建立印度獐牙菜指纹图谱,使用相似度分析和二维聚类分析进行质量评价,并使用双标线性校正结合PDA辅助法进行色谱峰定性。结果 10批次印度獐牙菜药材选定10个色谱峰作为指纹图谱的共有峰,经化学计量学评价,可对其质量进行初步评价;双标线性校正法预测保留时间的精度优于相对保留时间法;双标线性校正法结合PDA辅助法可更好的对色谱峰进行定性。结论 与相对保留时间法相比,双标线性校正法预测保留时间的准确度更高,色谱柱的适用范围更广。双标线性校正结合PDA对色谱法进行辅助定性可扩大双标线性校正的使用范围。