Isolation and characterization of cellulose from date palm tree spathe sheath

This study deals with a series of operations to isolate the micro-cellulose from the palm tree spathe sheath by using a modified chemical method to take into account the low cost and the completion speed and its characterization using X-ray diffraction technique (XRD), infrared spectroscopy (FTIR) and scanning electron microscope coupled with element analyzer (SEM/EDX). The results showed that the extraction method succeeded in obtaining very pure microscopic fibers with a width of 2–10 μm with a crystallinity index equal to 79.21%, containing the two cellulose features Iβ and II, that, the conversion ratio of the first to the second was estimated at 32, 87%.     

Microstructural characterization and fracture behavior of a microhybrid and a nanofill composite

OBJECTIVES: To characterize the microstructure and composition of two different composites, and to determine their influence on the physical properties and fracture behavior. METHODS: The microstructure and composition of a microhybrid (Filtek Z250-Z2) and a nanofill (Filtek Supreme-SU) composite were analyzed using scanning electron microscopy (SEM) and electron dispersive spectroscopy (EDS). Filler wt% was determined by thermogravimetric analysis. Hardness (H) and degree of conversion (DC) were evaluated at top and bottom surfaces of 2-mm thick specimens, and the dynamic elastic modulus (E) was determined with ultrasonic waves. Bar specimens (n=30) were subjected to flexure loading and flexural strength (sigmaf) was calculated (MPa). Fractographic analysis (FA) was performed to determine the fracture origin (c) for calculation of fracture toughness (KIc), and these results were compared to those from the single edge notch beam (SENB) method. Results were statistically analyzed using two-way ANOVA, Student's t-test and Weibull analysis (alpha=0.05). RESULTS: Z2 had higher filler wt%, H, E and DC at 2-mm depth as compared with SU. The fracture behavior (sigmaf and KIc) and the structural reliability (m) of the composites were similar. Results of KIc tested by SENB or calculated from fracture surfaces from flexure testing were similar. SIGNIFICANCE: The microstructural organization of the composites determines their physical properties, in spite of the similar filler content. In contrast, the microstructure did not influence the fracture behavior and the structural reliability of these highly filled composites. FA was shown to be a reliable method for determining the KIc of composites.     

促结缔组织增生型成釉细胞瘤细胞的体外培养与鉴定

目的：观察体外培养的促结缔组织增生型成釉细胞瘤细胞的生长特点。方法：对促结缔组织增生型成釉细胞瘤细胞用酶消化法进行体外培养，免疫组化证实其细胞来源，以倒置显微镜观察细胞形态及生长情况．并用流式细胞仪分析细胞周期，MTT法绘制细胞生长曲线。结果：促结缔组织增生型成釉细胞瘤为上皮来源，细胞在体外培养过程中包含2种形态的细胞，与实性成釉细胞瘤细胞在体外培养相比，存在较多梭形细胞，细胞生长缓慢，培养的各代细胞未见异倍体。结论：促结缔组织增生型成釉细胞瘤细胞在体外培养过程中包含较多的梭形细胞．可能与其较多的细胞间质有关。     

阿霉素载药栓塞微球的制备和性能表征

目的：研究离子交换型阿霉素载药透明质酸栓塞微球（DHAMs）的制备方法及性能表征。方法：采用油包水（W/O）乳化交联法,以改性透明质酸（HA）为载药基质,通过离子交换原理制备载阿霉素的透明质酸栓塞微球。采用光学显微镜、扫描电子显微镜观察表面形态,考察粒径和溶胀率;采用恒温摇床模拟体内环境初步测定透明质酸微球降解率;采用紫外分光光度法测定DHAMs载药量、包封率和体外释放率;采用傅里叶变换红外光谱（FT-IR）和粉末X射线衍射法（PXRD）对DHAMs进行表征。结果：透明质酸微球形态圆整、表面光滑,平均粒径为（111.83 ± 12.21）μm,溶胀率为201.81%;微球56 d体外降解率为34.31%;微球载药量和包封率分别为（22.09% ± 0.05%）和（99.41% ± 0.21%）,且72 h累计释放量可达50%;FT-IR和PXRD分析显示,阿霉素在微球中以无定形形式存在。结论：阿霉素透明质酸微球有较好的载药性能,理化性能良好,具有动脉化疗栓塞的应用前景。     

Synthesis and Characterization of Impurities in the Production Process of Lopinavir

Lopinavir is an antiretroviral drug used for the inhibition of HIV protease. Four related substances of lopinavir were observed during the manufacturing process of lopinavir in the laboratory and they were identified. The present work describes the origin, synthesis, characterization, and control of these related substances.     

Taguchi L16 orthogonal array approach for optimization of fluoride removal from aqueous solution using Saccharum spontaneum weed grass novel biosorbent

Optimization of operating and design parameters is needed for the greater application to achieve higher quality, performance, and minimum cost. The paper mainly concentrates on, the optimization of process parameters influencing the deflouridation of water by Analysis of mean (ANOM) approach. The current work mainly aims at the utilization of the Taguchi approach to optimize influencing operating parameters for maximizing the removal of fluoride under batch experimental studies by using biosorbent developed from Saccharum spontaneum, weed plant. The optimum conditions were found at pH 7, sorbate content 5 mg/L, period of contact 120 min, sorbent dosage 10 g/L, and temperature 30 °C. The percent part of various process parameters is obtained in the successive sequence pH 56.21% > initial concentration of adsorbate 33.94% > biosorbent dose 5.49% > contact time 3.35% > temperature 1.01%. The equilibrium study indicates fluoride sorption on Saccharum spontaneum adsorbent fulfill the Langmuir model with parameters ‘a' and ‘b' determined as 1.617 mg/g and 0.473 L/mg. The kinetic study with sorption data suggested the Pseudo-second order kinetic model as best fitting with kinetic rate k₂ 0.218 g/mg min. The thermodynamic analysis suggested a spontaneous and endothermic nature (ΔH = 16.268 kJ/mol). Characterization of adsorbent was done using BET, SEM, and also by the determination of textual properties. Regeneration of the biosorbent is done for three cycles and is used for fluoride removal.