Binding characteristics of plasma protein in active parts of Daidai lipid-lowering flavonoid extract / 中国中药杂志

To study the binding capacity of active ingredients of Daidai lipid-lowering flavonoid extract and plasma protein,investigate the ways to improve the traditional formula for calculating protein binding rates based on ultrafiltration,and increase the stability and reliability of the experimental results. UPLC-MS/MS was used to establish a quantitative analysis method for simultaneous determination of active ingredients( neohesperidin and narngin) in ultrafiltrate. The protein binding rates were calculated by the traditional ultrafiltration formula. The correction factors( F) were introduced later,and the binding rates calculated with the correction factors were compared with those without the correction factors. The binding capacity of the extract and plasma protein was evaluated. The quantitative analysis method established by UPLC-MS/MS had a good specificity. The standard curve and linear range,method accuracy,precision and lower limit of quantitation all met the requirements. The method met the requirement for quantitative detection of the active ingredients in ultrafiltrate after the rat plasma was filtrated in the ultrafiltration tube. Under the experimental conditions,the binding rates of both active ingredients( neohesperidin and narngin) were higher than 90%. The active ingredients and rat plasma protein were bound in a concentration-dependent manner,with statistically significant differences( P<0. 01). There was no statistically significant difference between the protein binding abilities of the two active ingredients with rat plasma protein. Therefore,the active ingredients of Daidai lipid-lowering flavonoid extract had a relatively strong binding strength with rat plasma protein,and they were bound in a concentration-dependent manner. Additionally,when calculating protein binding rates by the traditional ultrafiltration formula,the correction factors could be introduced to effectively reflect the errors of multiple ingredient groups in traditional Chinese medicine extracts.This correction method could provide a reference thinking and practical reference for the improvement of the determination method of the traditional Chinese medicine plasma protein binding ability based on ultrafiltration.

Metabolic characteristics of active parts of lipid-lowering flavonoid extract of Daidai in liver and intestinal microsomes of rats / 中国中药杂志

The paper studies and compares the metabolic difference of active ingredients of lipid-lowering flavonoid extract of Daidai in rat livers and intestinal microsomes,in order to explore the phase Ⅰ metabolism characteristics of active ingredients in livers and intestines. UPLC-MS/MS was used to establish a quantitative analysis method for active ingredients,neohesperidin and narngin,in a phase Ⅰ metabolism incubation system of liver and intestinal microsomes. Differential centrifugation was used to make liver and intestinal microsomes of rats. A phase Ⅰ metabolism incubation system was established,and the concentrations of the residual at different incubation time points were analyzed. Graphs were plotted to calculate the metabolic elimination half-life of the main active parts,with the natural logarithm residual percentage values ln( X) at different time points as the y axis,and time t as the x axis. The metabolism characteristics of the active ingredients were compared. The established UPLC-MS/MS quantitative analysis method has a good specialization,standard curve and linear range,accuracy and precision,with a satisfactory lower quantitative limit. The method allows quantitative detection of the active ingredients in a phase Ⅰ metabolism incubation system of liver and intestinal microsomes of rats. In the rats liver microsomes incubation system,the metabolic elimination half-life of neohesperidin and narngin were( 2. 20 ± 0. 28) h and( 1. 97±0. 28) h respectively. The elimination half-life of neohesperidin was larger than that of narngin,but with no statistically significant difference. In the rats intestinal microsomes incubation system,the metabolic elimination half-lives of neohesperidin and narngin were( 3. 68±0. 54) h and( 2. 26±0. 13) h respectively. The elimination half-life of neohesperidin was larger than that of narngin,with statistically significant differences( P<0. 05). The elimination half-lives of the active ingredients in liver microsomes were smaller than those in intestinal microsomes. The experiment results showed that the active ingredients of lipid-lowering flavonoid extract of Daidai had different elimination half-lives in phase Ⅰ rats liver and intestinal microsomes incubation system. This implied that they had different metabolic characteristics in rats liver and intestine,and liver may be the main metabolism site of the active ingredients. The phaseⅠ metabolism of narngin was stronger than that of neohesperidin. The differences between their metabolic characteristics may be related to the binding sites of B-ring hydroxyl in flavonoid glycosides and the number of methoxyl group. The results provided an important experimental basis for further development and clinical application of lipid-lowering flavonoid extract preparation of Daidai.

Rosa26-targeted sheep gene knock-in via CRISPR-Cas9 system.

Recent advances in our ability to design DNA binding factors with specificity for desired sequences have resulted in a revolution in genetic engineering, enabling directed changes to the genome to be made relatively easily. Technologies that facilitate specific and precise genome editing, such as knock-in, are critical for determining the functions of genes and for understanding fundamental biological processes. The CRISPR/Cas9 system has recently emerged as a powerful tool for functional genomic studies in mammals. Rosa26 gene can encode a non-essential nuclear RNA in almost all organizations, and become a hot point of exogenous gene insertion. Here, we describe efficient, precise CRISPR/Cas9-mediated Integration using a donor vector with tGFP sequence targeted in the sheep genomic Rosa26 locus. We succeeded in integrating with high efficiency an exogenous tGFP (turboGFP) gene into targeted genes in frame. Due to its simplicity, design flexibility, and high efficiency, we propose that CRISPR/Cas9-mediated knock-in will become a standard method for the generation transgenic sheep.

Microwave sintering of nanometer powder of alumina and zirconia-based dental ceramics / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The objective of the present study was to investigate the feasibility and reliability of sintering alumina and zirconia-based all-ceramic materials through a recently introduced microwave heating technique. The variation of crystal phases, the growth of grain sizes and microstructural features of these materials were evaluated after sintering.</p><p><b>METHODS</b>Four different groups of powder (l00%Al2O3, 60%Al2O3+40%ZrO2, 40% Al2O3+60%ZrO2, 100% ZrO2) were respectively press-compacted to fabricate green disk samples, 5 specimen of each group were prepared. All the samples were surrounded by refractory materials for heat containment and processed at 1 600 degrees C in a domestic microwave oven (850 W, 2 450 MHz), 1 600 degrees C/5 min for heating rate, 10 min for holding time. After sintering, the phase composition and average grain size of these ceramics were examined using X-ray diffraction (XRD). Their microstructure characteristics were studied by scanning electron microscopy (SEM).</p><p><b>RESULTS</b>All the specimens were successfully sintered with the application of microwave heating system in combination with a suitable thermal insulator. No phase change was found in alumina while monoclinic-zirconia was found to be transformed to tetragonal-zirconia. A little grain size growth of Al2O3 and ZrO2 has been observed with Al2O3 24.1 nm/before and 51.8 nm/after; ZrO2 25.3 nm/before and 29.7 nm/after. The SEM photos indicated that the microwave-sintered Al2O3-ZrO2 ceramics had a uniform crystal distribution and their crystal sizes could be maintained within the range of nanometers.</p><p><b>CONCLUSION</b>It is expected that in the near future microwave heating system could be a promising substitute for conventional processing methods due to its unparalled advantages, including more rapid heating rate, shortened sintering time, superfine grain size, improved microstructure and much less expensive equipment.</p>