前列地尔静注乳剂的制备及其物理性质的测定

用自制原料制备了前列地尔静注乳剂,并对其一些物理性质进行了测定,结果表明该制剂的粒度分布、pH值、渗透压等项均符合静脉注射制剂的要求.     

石菖蒲α-细辛醚抗癫痫作用的实验研究

目的探讨石菖蒲成分α-细辛醚的抗癫痫作用。方法采用MES、MST及Lithium-pilocarpine模型;预先给予不同剂量的α-细辛醚,2次/d,连续28d,记录发作潜伏期、发作级别及惊厥动物数,对比观察α-细辛醚在控制3种模型癫痫发作中的疗效。结果石菖蒲α-细辛醚能对抗MES、MST模型小鼠及Lithium-pilocarpine模型大鼠的惊厥发作,抗惊厥率分别为40%～100%、50%～90%、40%～80%;能明显延长MST模型小鼠及Lithium-pilocarpine模型大鼠惊厥发作潜伏期,分别为70～180s和4～15min;并能降低Lithi-um-pilocarpine模型大鼠惊厥发作级别达1.96。结论石菖蒲α-细辛醚具有确切的抗癫痫作用,是一种广谱抗癫痫药。     

龙胆苦苷药学研究进展及其临床配伍应用

目的综述龙胆苦苷的药学进展及临床配伍应用。方法查阅近20年的文献资料,总结龙胆苦苷的成分、结构、理化性质、药理作用、药代动力学研究及其临床应用情况。结果龙胆苦苷具有良好的抗炎、镇痛,保肝利胆和健胃养胃等作用;在体内分布较快,消除、排泄也较快。结论龙胆苦苷在临床上具有较高的应用价值,为开发新药及临床应用提供一定的参考。     

Increasing nodal vulnerability and nodal efficiency implied recovery time prolonging in patients with supplementary motor area syndrome

Supplementary motor area (SMA) syndrome is a surgery‐related complication that commonly occurs after removing SMA glioma, and needs weeks to recover. However, susceptible factors of patients suffering from SMA syndrome remain unknown. Graphic theory was applied to reveal topological properties of sensorimotor network (SMN) by processing resting‐state functional magnetic resonance images in 66 patients with SMA gliomas. Patients were classified into SMA and non‐SMA groups based on whether they suffered from SMA syndrome. We collected recovery time and used causal mediation analysis to find association between topological properties and recovery time. Compared with the non‐SMA group, higher vulnerability (left: p = .0018; right: p = .0033) and lower fault tolerance (left: p = .0022; right: p = .0248) of the whole SMN were found in the SMA group. Moreover, higher nodal properties of lesional‐hemispheric cingulate cortex (nodal efficiency: left, p = .0389; right, p = .0169; nodal vulnerability: left, p = .0185; right, p = .0085) and upper limb region of primary motor cortex (PMC; nodal efficiency: left, p = .0132; right, p = .0001; nodal vulnerability: left, p = .0091; right, p = .0209) were found in the SMA group. Nodal efficiency and nodal vulnerability of cingulate cortex and upper limb region of PMC were important predictors for SMA syndrome occurring and recovery time prolonging. Neurosurgeons should carefully deal with upper limb region of PMC and cingulate cortex, and protect them if these two region were unnecessary to damage during SMA glioma resection.     

乙基纤维素水性包衣技术I.水分散体与有机溶液包衣方法的比较

考察了乙基纤维素水分散体的基础性质,测定ＰＨ值、粘度、最低成膜温度、玻璃化转变温度,进行了处方相容性试验。以盐酸苯丙酸胺为模型工物,在流化床中蛊缓释微丸,考察在纤维素水分菜体的包衣应用特点,并与有机溶液包衣方法在缓释效果,增塑剂用量、包衣喷液方式的影响三方面进行比较。考察了水分菜体包衣微丸的稳定性,采用相似因子法评价微丸的体外释放度变化。     

麦角甾苷固体脂质纳米粒处方筛选和理化性质研究

目的 研究不同种类药用辅料成分对麦角甾苷固体脂质纳米粒（SLN）理化性质的影响,为研究SLN的处方筛选提供依据。方法 采用乳化-固化法制备麦角甾苷-SLN,单一变量法考察山嵛酸甘油酯（Compritol ATO 888）、单硬脂酸甘油酯、大豆卵磷脂、Myrj52等辅料对麦角甾苷-SLN粒径、包封率、表征分散度（PDI）等理化性质的影响,采用透射电镜法观察麦角甾苷-SLN的形态,X-射线衍射（XRD）分析其药物晶体结构。结果 随Compritol ATO 888用量增加,麦角甾苷-SLN粒径不断减小,包封率逐渐减小,PDI逐渐增加;随单硬脂酸甘油酯的用量增加,粒径明显增大,包封率略有降低,PDI减小;随卵磷脂用量增加,粒径明显增大,包封率降低,PDI减小;随Myrj52用量明显增加,粒径减小,包封率增加,PDI增大;麦角甾苷-SLN外观圆整,呈球形;麦角甾苷以分子分散状态被包裹在SLN中。结论 不同辅料对麦角甾苷-SLN的理化性质均产生一定影响趋势,为制备SLN的处方筛选研究提供启示与思路。     

Microstructure and Mechanical Properties of Metal Foams Fabricated via Melt Foaming and Powder Metallurgy Technique: A Review

Metal foams possess remarkable properties, such as lightweight, high compressive strength, lower specific weight, high stiffness, and high energy absorption. These properties make them highly desirable for many engineering applications, including lightweight materials, energy-absorption devices for aerospace and automotive industries, etc. For such potential applications, it is essential to understand the mechanical behaviour of these foams. Producing metal foams is a highly challenging task due to the coexistence of solid, liquid, and gaseous phases at different temperatures. Although numerous techniques are available for producing metal foams, fabricating foamed metal still suffers from imperfections and inconsistencies. Thus, a good understanding of various processing techniques and properties of the resulting foams is essential to improve the foam quality. This review discussed the types of metal foams available in the market and their properties, providing an overview of the production techniques involved and the contribution of metal foams to various applications. This review also discussed the challenges in foam fabrications and proposed several solutions to address these problems.     

Numerical Analysis of Microcrack Propagation Characteristics and Influencing Factors of Serrated Structural Plane

The serrated structural plane is the basic unit of structural plane morphology. However, the understanding of its internal stress distribution, failure mode and crack evolution law was not clear enough in previous studies. In this paper, the shear mechanical properties of the serrated structural planes were studied by numerical simulation, and the crack evolution law of the serrated structural planes and the effects of four microscopic parameters on the shear properties were analyzed. The results show that: (1) the number of microcracks increases with the increase in normal stress; the crack expansion rate is slow before the shear stress reaches the peak. After the shear stress reaches the peak, the crack expansion rate continues to increase, and the microcracks keep sprouting and expanding, and the number of microcracks tends to stabilize when the shear stress reaches the residual shear strength. (2) The particle contact stiffness ratio kn∗/ks∗ and parallel bond stiffness ratio kn/ks were negatively correlated with the shear strength; and the particle contact modulus E and parallel bond modulus E∗ were positively correlated with the shear strength. As the particle contact modulus E and parallel bond modulus E∗ increase, the peak shear displacement gradually decreases. The parallel bond stiffness ratio kn/ks has a negative correlation with the peak shear displacement. This study is expected to provide theoretical guidance for the microscopic parameter calibration and shear mechanical analysis of serrated structural planes. (3) Several XGBoost, WOA-XGBoost, and PSO-XGBoost algorithms are introduced to construct the quantitative prediction model, and the comparative analysis found that WOA-XGBoost has the best fitting effect and can be used for the prediction of shear strength. When using this model to calculate the weight shares of micro-parameters, it was found that kn∗/ks∗ has the greatest influence on shear strength, followed by E∗; E and kn/ks had the least influence.     

Correlation of Bone Material Model Using Voxel Mesh and Parametric Optimization

The authors present an algorithm for determining the stiffness of the bone tissue for individual ranges of bone density. The paper begins with the preparation and appropriate mechanical processing of samples from the bovine femur and their imaging using computed tomography and then processing DICOM files in the MIMICS system. During the processing of DICOM files, particular emphasis was placed on defining basic planes along the sides of the samples, which improved the representation of sample geometry in the models. The MIMICS system transformed DICOM images into voxel models from which the whole bone FE model was built in the next step. A single voxel represents the averaged density of the real sample in a very small finite volume. In the numerical model, it is represented by the HEX8 element, which is a cube. All voxels were divided into groups that were assigned average equivalent densities. Then, the previously prepared samples were loaded to failure in a three-point bending test. The force waveforms as a function of the deflection of samples were obtained, based on which the global stiffness of the entire sample was determined. To determine the stiffness of each averaged voxel density value, the authors used advanced optimization analyses, during which numerical analyses were carried out simultaneously, independently mapping six experimental tests. Ultimately, the use of genetic algorithms made it possible to select a set of stiffness parameters for which the error of mapping the global stiffness for all samples was the smallest. The discrepancies obtained were less than 5%, which the authors considered satisfactory by the authors for such a heterogeneous medium and for samples collected from different parts of the bone. Finally, the determined data were validated for the sample that was not involved in the correlation of material parameters. The stiffness was 7% lower than in the experimental test.     

A Three-Dimensional Equivalent Stiffness Model of Composite Laminates with Wrinkle Defects

The stiffness of composite laminates is easily affected by wrinkle defects. In this paper, a new effective analytical model was proposed to predict the three-dimensional equivalent elastic properties of multidirectional composite laminates with wrinkle defects. Firstly, a geometric model was established according to the microscopic characteristics of wrinkle defects. Then, based on the classical laminate theory and homogenization method, the constitutive equation and flexibility matrix of the wrinkle region were established. Finally, the equivalent stiffness parameters of unidirectional and multidirectional laminates were derived, and the effects of different wrinkle parameters and ply-stacking sequences on the stiffness of unidirectional and multidirectional laminates were studied by using the analytical model. The results show that the mechanical properties of the lamina and laminates are affected by the out-of-plane angle and in-plane angle of the wrinkle defects. The accuracy of the analytical model has been verified by the numerical model and other theoretical models, and it has the characteristics of few parameters and a high efficiency. The analytical model can be used to predict the stiffness of composite structures with wrinkle defects simply, effectively, and quantitatively. It can also be used as a tool to provide the mechanical response information of laminates with wrinkle defects.