Preparation of Rhus chinensis total phenolic acid pellets by extrusion-spheronisation method / 中国中药杂志

Extrusion-spheronisation method was used to prepare Rhus chinensis total phenolic acid pellets. The formula and preparation of R. chinensis total phenolic acid pellets were optimized. The formulas( drug loading capacity,diluent,wetting agent and anti-sticking agent) were determined by the single factor test with yield,appearance and performance as the indexes. The preparation was optimized by Box-Behnken design and response surface method,with the rate of extrusion,rate of spheronization and time of spheronization as the independent variables and the overall desirability value of yield,friability and roundness as the dependent variables. The optimal formula of pellets was as follows: drug loading capacity 28. 7%,MCC-lactose 9 ∶1,silicon dioxide as anti-sticking agent,and 60% ethanol as wetting agent. The optimal preparation was determined as follows: the rate of extrusion was 43 r·min-1,the rate of spheronization was 1 800 r·min-1,and the time of spheronization was 4 min. The absolute deviation between predicted value and estimated value under the conditions was less than 5. 0%,with a high degree of model fit. The preparation parameters obtained were accurate,reliable and reproducible. Under scanning electron microscopy( SEM),R. chinensis total phenolic acid pellets were uniform in diameter,round and smooth. The optimal formulation and process are stable and feasible for preparing R. chinensis total phenolic acid pellets.

Noninvasive Dynamic Respiratory Mechanics Parameter Estimation for Chronic Obstructive Pulmonary Patients with Spontaneous Breathing / 医用生物力学

Objective To study the method of estimating noninvasive dynamic respiratory mechanics parameters for patients with chronic obstructive pulmonary disease (COPD). Methods By simplifying the human respiratory system into a first order single compartment model and setting constraints based on optimization method, the respiratory system resistance and compliance of COPD patients were estimated. Results By using the model and setting the constraint conditions in the simulation experiment, the respiratory system resistance and compliance of COPD patients with spontaneous breathing could be estimated, and the results were relatively accurate (within 5% error). The estimated result could be obtained by data of one respiratory cycle within three respiratory cycles, which could meet the requirements of dynamic monitoring data. Conclusions Based on optimization method, the noninvasive dynamic evaluation on respiratory resistance and compliance of COPD patients were carried out in simulation experiments and proved to be feasible for further clinical trials. The research findings could help doctors to monitor the resistance and compliance changes of COPD patients in real time after clinical trial, and provided references for diagnosis and treatment of COPD.

Noninvasive Dynamic Respiratory Mechanics Parameter Estimation for Chronic Obstructive Pulmonary Patients with Spontaneous Breathing / 医用生物力学

Objective To study the method of estimating noninvasive dynamic respiratory mechanics parameters for patients with chronic obstructive pulmonary disease (COPD). Methods By simplifying the human respiratory system into a first order single compartment model and setting constraints based on optimization method, the respiratory system resistance and compliance of COPD patients were estimated. Results By using the model and setting the constraint conditions in the simulation experiment, the respiratory system resistance and compliance of COPD patients with spontaneous breathing could be estimated, and the results were relatively accurate (within 5% error). The estimated result could be obtained by data of one respiratory cycle within three respiratory cycles, which could meet the requirements of dynamic monitoring data. Conclusions Based on optimization method, the noninvasive dynamic evaluation on respiratory resistance and compliance of COPD patients were carried out in simulation experiments and proved to be feasible for further clinical trials. The research findings could help doctors to monitor the resistance and compliance changes of COPD patients in real time after clinical trial, and provided references for diagnosis and treatment of COPD.

Preparation of Astragalus polysaccharide colon targeting pellets / 中国药学杂志

OBJECTIVE: To study the preparation process of pH-dependent delayed colon targeting pellets of astragalus polysaccharide. METHODS: Colon targeting agents of APS pellets were produced by extrusion-spheronization and fluid bed coating method and the best preparation technology was chosen by response surface optimization method. RESULTS: The ratio of pill core: APS powder-avicel-tannic acid-carboxymethylcellulose sodium was 25:15:8:2, the wetting agent was water, the rate of extrusion was 60 r·min-1, the rate of spheronization was 1 400 r·min-1, and the time of spheronization was 4 min. The best fluid bed coating condition was as follows the fan frequency was 29.50 Hz, the pressure of spray gun was 0.70 kg·cm-2, the rate of coating flow was 3 mL·min-1, and the colon coating weight was 15%. The release degree of pill for simulated gastric fluid in 2 h was 0%, The release degree of pill for artificial intestinal fluid in 3 h was less than 5%. The release degree of pill for artificial colon fluid in 2 h was release completely. CONCLUSION: The preparation method can be qpplied to the preparation of APS pellets, it's simplicity of operator and had good reproducibility, it can be applied to the industrial production.

Numeric reconstruction of 2D cellular actomyosin network from substrate displacement

Introduction: One of the fundamental structural elements of the cell is the cytoskeleton. Along with myosin, actin microfilaments are responsible for cellular contractions, and their organization may be related to pathological changes in myocardial tissue. Due to the complexity of factors involved, numerical modeling of the cytoskeleton has the potential to contribute to a better understanding of mechanical cues in cellular activities. In this work, a systematic method was developed for the reconstruction of an actomyosin topology based on the displacement exerted by the cell on a flexible substrate. It is an inverse problem which could be considered a phenomenological approach to traction force microscopy (TFM). Methods An actomyosin distribution was found with a topology optimization method (TOM), varying the material density and angle of contraction of each element of the actomyosin domain. The routine was implemented with a linear material model for the bidimensional actomyosin elements and tridimensional substrate. The topology generated minimizes the nodal displacement squared differences between the generated topology and experimental displacement fields obtained by TFM. The structure resulting from TOM was compared to the actin structures observed experimentally with a GFP-attached actin marker. Results The optimized topology reproduced the main features of the experimental actin and its squared displacement differences were 11.24 µm2, 27.5% of the sum of experimental squared nodal displacements (40.87 µm2). Conclusion This approach extends the literature with a model for the actomyosin structure capable of distributing anisotropic material freely, allowing heterogeneous contraction over the cell extension.

Optimization of Protein Extraction for Lichen Thalli

Lichen-forming fungal proteins have been seldom searched due to many difficulties in their extraction. Phenols, quinones, proteases, and other components released during cell disruption have been known to be the greatest challenges related to protein extraction from lichens. To overcome these problems and maintain good electrophoretic resolution and high protein concentration, an extraction buffer containing polyvinylpolypyrrolidone, ascorbic acid, Triton X-100, polyethylene glycol, proteinase, and oxidase inhibitors in sodium phosphate buffer was developed. This extraction buffer showed high efficiency for all lichen species tested in the study.

Overview of extracting technique of compound Chinese materia medica / 中草药

As the key operation step in the production of compound Chinese materia medica (CMM) or the natural products, extracting technique not only directly affects the quality of CMM preparations, medicinal resource utilization, and clinical efficacy, but also relates to the development of Chinese pharmaceutical industry. On the basis of consulting literatures, extracting techniques appearing in recent five years are particularly reviewed in the traditional extracting method, new extracting technique, evaluating indicator, and process variable optimization. Further research application and development prospects of these extracting techniques are also suggested.