LIPSS Applied to Wide Bandgap Semiconductors and Dielectrics: Assessment and Future Perspectives

With the aim of presenting the processes governing the Laser-Induced Periodic Surface Structures (LIPSS), its main theoretical models have been reported. More emphasis is given to those suitable for clarifying the experimental structures observed on the surface of wide bandgap semiconductors (WBS) and dielectric materials. The role played by radiation surface electromagnetic waves as well as Surface Plasmon Polaritons in determining both Low and High Spatial Frequency LIPSS is briefly discussed, together with some experimental evidence. Non-conventional techniques for LIPSS formation are concisely introduced to point out the high technical possibility of enhancing the homogeneity of surface structures as well as tuning the electronic properties driven by point defects induced in WBS. Among these, double- or multiple-fs-pulse irradiations are shown to be suitable for providing further insight into the LIPSS process together with fine control on the formed surface structures. Modifications occurring by LIPSS on surfaces of WBS and dielectrics display high potentialities for their cross-cutting technological features and wide applications in which the main surface and electronic properties can be engineered. By these assessments, the employment of such nanostructured materials in innovative devices could be envisaged.     

Synthesis and Characterization of Imidazolium-Based Ionic Liquids and Evaluating Their Performance as Asphaltene Dispersants

With the projected increase in the production of heavy oil due to the energy crisis, asphaltene-related issues are likely to come to the forefront. This leads to operational problems, safety hazards, and oil production deficiencies, resulting in huge economic losses for the petroleum industry. Therefore, in this work, we aimed to inhibit asphaltene precipitation using ionic liquid (IL) compounds. ILs with long alkyl chains can inhibit the precipitation of asphaltene molecules due to the π–π* interactions between them and the formation of hydrogen bonds. A series of imidazolium-based ionic liquids, IL-0, IL-4, IL-10, and IL-16, were synthesized with yield percents of 79, 81, 80, and 83%, respectively. The prepared materials were characterized well using FTIR, ¹H-NMR, and Elemental Analysis. The surface tension, interfacial tension (IFT), and different surface parameters were investigated at different temperatures to simulate the reservoir temperature. IL-0, IL-4, IL-10, and IL-16 displayed their γ_cmc values at 35, 34, 31, and 32 mN/m at 303 °K, respectively. It was found that the prepared ILs are good surfactants with low values of interfacial tension. Quantum structure–activity relationships using Density Functional Theory (DFT) were used to investigate the geometry optimization electronic structures, the energy gap (ΔE), and the reactivity of the cations of the prepared ILs. The synthesized ILs were evaluated as asphaltene dispersants using two different techniques. The viscometric technique showed that the asphaltene onset precipitation was 28.5 vol.%. This percent was postponed to 42.8, 50, 78.5, and 64.3 vol.%, after adding IL-0, IL-4, IL-10, and IL-16, respectively, and the spectroscopic technique confirmed the results.     

Dimensional study of prostate cancer using stereological tools

This study analyzes the dimensional changes of the glands from prostate cancer by applying stereology to estimate the variations in volume, length, surface, and cellular densities of tumor acini. Normal and tumor acini were visualized using immunohistochemistry for cytokeratin18. On immunostained sections, parameters related to the dimensions and cell population of prostate acini were measured. The immunohistochemical expression of proliferative cell nuclear antigen was also measured to correlate the quantitative changes estimated with the proliferative activity of the epithelium. The average cell volume in normal and tumor epithelium was estimated using the method of the nucleator. The relative size of the acini was similar in the carcinoma compared with the normal prostate. Within the acini, the fraction of acinar volume occupied by the epithelium was significantly higher in cancer than in the nontumor prostate. Conversely, the glandular lumen of the cancer acini is lower than in the normal acini. The significant increase of acinar length density in the carcinoma indicates that the glandular tree's growth in the carcinoma is higher and with more branches than in the case of nonneoplastic glands. The basal surface density is higher in the carcinoma than in the controls. The number of epithelial cells per unit length of acini was significantly decreased in the neoplastic glands. This "dilution" of the cell population along the cancer acinus can be explained by the significant increase in the tumor cell's mean cell volume.     

突触小泡膜表面突起的研究

本文首次报道了用透射电镜观察大白鼠的大脑皮质和海马内的突触小泡膜表面突起的超微结构，发现神经终末内的突触小泡膜表面有短突起的微细结构，借此使小泡与小泡、小泡与突触前膜、小泡与骨架发生联系，为突触小泡的转运、入坞和释放的分子神经生物学研究提供了超微形态学的证据     

听骨链螺旋CT三维表面遮盖显示技术的临床应用

目的 探讨听小骨螺旋CT三维表面遮盖显示技术(SSD)的临床应用价值及相关的技术要点。资料与方法 对43例患者进行螺旋高分辨率CT扫描，利用密集放大的重建图像，采用手动编辑，先移去听小骨周围的骨质，仅保留听小骨，用经编辑的轴位图像进行SSD三维成像。结果 40侧正常耳的听小骨三维SSD显示了听小骨的细微结构，还反映了听小骨之间的关系。病变听小骨的三维SSD重建图像与轴位图像的表现基本相符；慢性中耳炎25耳中，22耳进行了听小骨SSD成像，10耳见有骨质破坏；先天性外、中耳畸形16耳均见有听小骨发育不良；外伤后听力下降5耳中，1耳锤砧关节脱位和1耳并有移位的锤骨骨折在听小骨三维SSD成像直观地显示。结论 螺旋CT扫描和三维SSD有利于听小骨的显示和病变的诊断。     

骨髓间充质干细胞成骨定向分化的研究进展

就骨髓间充质干细胞的形态和表面分子特征、体外成骨定向分化的特性及影响因素等方面的研究进展作一综述 ,并初步探讨了骨髓间充质干细胞在骨组织工程中的应用前景。     

非竞争性ELISA法测定人源抗HBsAg Fab功能性亲和常数

目的　测定完全人源化基因工程抗体HBsAgFab的亲和常数。方法　采用非竞争性ELISA固相法 ,经确定最佳抗原包板浓度、最佳抗原包板时间及最佳抗原与抗体结合反应时间后 ,得到了HBsAg与抗体片段抗HBsAgFab及完整抗体抗HBsAgIgG的抗原抗体结合反应曲线 ,计算出抗HBsAgFab及抗HBsAgIgG的亲和常数。结果　人源基因工程抗体抗HBsAgFab的功能性亲和常数在 10 7～10 8M 1水平 ,比完整抗HBsAgIgG仅仅小约 1个数量级 (10 8～ 10 9M 1)。结论　该基因工程抗体与抗原结合能力较强 ,为今后开发应用Fab进行生物导向治疗提供了理论基础。     

星点设计-效应面法优化淫羊藿苷固体脂质纳米粒制备工艺

目的采用星点设计-效应面法优化淫羊藿苷固体脂质纳米粒制备工艺。方法采用高压乳匀法制备淫羊藿苷固体脂质纳米粒,考察卵磷脂,F68,投药量对包封率,载药量以及药物利用率的影响,应用星点设计-效应面法优化处方工艺。结果采用二项式方程拟合实验结果,相关性较好(r>0.9),采用优化后处方条件对预测值进行验证,包封率为(93.09±0.13)%,载药量为(6.34±0.18)%,药物利用率为(84.53±2.45)%,与预测值偏差较小。结论采用星点设计-效应面法优化淫羊藿苷固体脂质纳米粒处方工艺,快速简单,预测准确度高,是较为理想的处方设计及优化方法。     

程序性细胞死亡分子10调控EphB4信号通路促进胶质母细胞瘤迁移和侵袭的作用及其机制

目的:探讨程序性细胞死亡分子10(PDCD10)调控胶质母细胞瘤(GBM)迁移和侵袭的作用与机制。方法:采用慢病毒转染GBM细胞系(U251和U373)构建稳定转染的PDCD10过表达(oxPDCD10)或沉默(shPDCD10)的GBM细胞系。分别采用划痕实验和Transwell实验检测细胞迁移和侵袭。蛋白质印迹法(...