Nanoparticle Production of Terminalia Chebula Extracts by Expansion of Supercritical Solution (ESS)

2021 ◽  
pp. 2150037
Author(s):  
Zahra Rezvanjoo ◽  
Farhad Raofie
Keyword(s):  
Extraction Procedure ◽  
Fluid Pressure ◽  
Rapid Expansion ◽  
Terminalia Chebula ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Dynamic Extraction ◽  
Microscopy Analysis ◽  
Supercritical Solution ◽  
Average Size

Terminalia chebula pharmaceuticals were extracted by using the supercritical fluid extraction (SFE) technique. Under the optimal conditions of 184 [Formula: see text]L modifier volume, 46 min dynamic extraction time, and 316 atm fluid pressure, the extraction procedure was optimized by central composite design. A modified rapid expansion of supercritical solution (RESS) technique, named expansion of the supercritical solution (ESS) was used to create the extracted pharmaceutical nanoparticles (NPs). In ESS, supercritical carbon dioxide (SC-CO[Formula: see text] was saturated with the extracts at high-pressure. Next, a pressure drop reduced the SC-CO2 solubility power in a way the extracts started to precipitate. In contrast to RESS, the pressure was permanently conserved above the critical pressure before and after depressurization. Therefore, the expansion process was gentle, which led to obtaining small and uniform particles. In the NP production process, the most adequate parameters were 360[Formula: see text]atm premier pressure, 120[Formula: see text]atm subsequent pressure, 25[Formula: see text]min equilibrium time, 30[Formula: see text]min sedimentation time, and [Formula: see text]C temperature. The average size of precipitated NPs was 41[Formula: see text]nm according to the results of field emission scanning electron microscopy analysis. The liquid chromatography-mass spectrometry evaluation demonstrated the presence of chebulinic and chebulagic acids in the extracted sample.

scholarly journals Three-Dimensional Nano-Morphology of Carbon Nanotube/Epoxy Filled Poly(methyl methacrylate) Microcapsules

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1387 ◽  
Author(s):  
M. Galip Icduygu ◽  
Meltem Asilturk ◽  
M. Akif Yalcinkaya ◽  
Youssef K. Hamidi ◽  
M. Cengiz Altan
Keyword(s):  
Confocal Microscopy ◽  
Methyl Methacrylate ◽  
Laser Scanning ◽  
Three Dimensional ◽  
Laser Scanning Confocal Microscopy ◽  
Poly Methyl Methacrylate ◽  
Scanning Confocal Microscopy ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Average Size

The three-dimensional nano-morphology of poly(methyl methacrylate; PMMA) microcapsules filled with carbon nanotubes (CNTs) and epoxy resin were investigated by various microscopy methods, including a novel, laser scanning confocal microscopy (LSCM) method. Initially, PMMA microcapsules containing various amounts of CNTs were synthesized by a solvent evaporation method. Scanning electron microscopy analysis showed that pore-free, smooth-surface microcapsules formed with various types of core-shell morphologies. The average size of CNT/epoxy/PMMA microcapsules was shown to decrease from ~52 μm to ~15 μm when mixing speed during synthesis increased from 300 rpm to 1000 rpm. In general, the presence of CNTs resulted in slightly larger microcapsules and higher variations in size. Moreover, three-dimensional scans obtained from confocal microscopy revealed that higher CNT content increased the occurrence and size of CNT aggregates inside the microcapsules. Entrapped submicron air bubbles were also observed inside most microcapsules, particularly within those with higher CNT content.

scholarly journals Electron microscopy analysis of femtosecond laser-assisted capsulotomy before and after lens fragmentation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wolfgang J. Mayer ◽  
Andreas Ohlmann ◽  
Anna Schuh ◽  
Siegfried Priglinger ◽  
Thomas Kohnen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Femtosecond Laser ◽  
Sem Analysis ◽  
Cutting Edge ◽  
Age Related ◽  
Anterior Lens Capsule ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Lens Fragmentation

AbstractStudying anterior lens capsule cutting edge profiles from femtosecond laser-assisted capsulotomy procedures performed before and after lens fragmentation. Twenty eyes (10 patients) with age-related cataract underwent femtosecond laser-assisted surgery (FLACS) using the Ziemer Z8 platform. First step of laser surgery was either capsulotomy (group first) or fragmentation (group second). One eye of each patient was assigned randomly, the second eye treated with the different sequence of procedures. After anterior capsule removal, tissue was fixed in cacodylate-buffered solution and cutting-edge profiles were analysed using scanning electron microscopy (SEM). All cases had cataract grade 2 and 3 based on LOCS III grading. SEM analysis showed more smooth edges in the first group, especially in cases with pseudoexfoliation (P = 0.037); more tags and bridges and a significant number of staggered cutting patterns (7 out of 10 cases) in the second group. All cases evolved the same microgroves with “valleys and mountains “ as signs of the photodisruption process. Femtosecond laser capsulotomy should be performed before lens fragmentation minimizing the rate of cutting errors. Especially in eyes with advanced cataract, as intracapsular pressure may increase due to lens fragmentation without anterior capsular opening.

Low Angle Annular Dark Field Scanning Transmission Electron Microscopy Analysis of Phase Change Material

2021 ◽  
Author(s):  
J. Li ◽  
K. Brew ◽  
K. Cheng ◽  
V. Chan ◽  
N. Arnold ◽  
...  
Keyword(s):  
Rapid Development ◽  
Dark Field ◽  
Transmission Electron Microscopy Analysis ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Before And After ◽  
Annular Dark Field ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Change Material

Abstract The continuously growing demands in high-density memories drive the rapid development of advanced memory technologies. In this work, we investigate the mushroom type PCM cells based on Ge2Sb2Te5 at nanoscale by low angle annular dark field (LAADF) STEM imaging technique as well as energy dispersive X-ray spectroscopy (EDX) to study the changes in microstructure and elemental distributions in PCM mushroom cells before and after SET and RESET conditions. We describe the microscope settings used for LAADF image formation to reveal the amorphous dome in RESET device and discuss the application example in failure analysis of PCM test device.

scholarly journals Recrystallization and Micronization of p-Toluenesulfonamide Using the Rapid Expansion of Supercritical Solution (RESS) Process

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 449 ◽  
Author(s):  
Tsung-Mao Yang ◽  
Chie-Shaan Su ◽  
Jin-Shuh Li ◽  
Kai-Tai Lu ◽  
Tsao-Fa Yeh
Keyword(s):  
Operating Conditions ◽  
Rapid Expansion ◽  
Optimum Operating ◽  
Control Factor ◽  
Process Conditions ◽  
Extraction Temperature ◽  
Control Factors ◽  
Supercritical Solution ◽  
Average Size ◽  
Expansion Temperature

This study is focused on the micronization of p-toluenesulfonamide (p-TSA) using the rapid expansion of supercritical solution (RESS) process. Taguchi’s experimental design method was applied to determine the optimum operating conditions. L9(34) orthogonal array with four control factors and three levels of each control factor was used to design nine experimental conditions. Four control factors were selected, including extraction temperature, extraction pressure, pre-expansion temperature, and post-expansion temperature. The particle size and morphology of the prepared samples were observed by scanning electron microscopy (SEM). In addition, Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were employed to compare the differences between the raw and micronized p-TSA particles. The experimental and analytical results indicated that the extraction temperature was the most significant factor for the micronization of p-TSA in the RESS process, and the optimal operating conditions were at an extraction temperature of 50 °C, an extraction pressure of 220 MPa, a pre-expansion temperature of 220 °C, and a post-expansion temperature of 30 °C. The p-TSA particles were micronized from the original average size of 294.8 μm to the smallest average size of 1.1 μm at the optimal RESS process conditions. Furthermore, the physicochemical characteristics of p-TSA did not differ significantly before and after recrystallization.

Material analysis techniques using the ion mill

1996 ◽  
Vol 54 ◽  
pp. 1034-1035
Author(s):  
J. P. Benedict ◽  
R. M. Anderson ◽  
S. J. Klepeis
Keyword(s):  
Polished Surface ◽  
Surface Material ◽  
Analysis Techniques ◽  
Material Analysis ◽  
Optical Inspection ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis ◽  
Argon Ions ◽  
The Impact ◽  
Scanning Electron

Ion mills equipped with flood guns can perform two important functions in material analysis; they can either remove material or deposit material. The ion mill holder shown in Fig. 1 is used to remove material from the polished surface of a sample for further optical inspection or SEM ( Scanning Electron Microscopy ) analysis. The sample is attached to a pohshing stud type SEM mount and placed in the ion mill holder with the polished surface of the sample pointing straight up, as shown in Fig 2. As the holder is rotating in the ion mill, Argon ions from the flood gun are directed down at the top of the sample. The impact of Argon ions against the surface of the sample causes some of the surface material to leave the sample at a material dependent, nonuniform rate. As a result, the polished surface will begin to develop topography during milling as fast sputtering materials leave behind depressions in the polished surface.

A pilot study on the effect of ulipristal acetate on myoma angiogenesis, measured by 2D ultrasound and VEGF serum levels

2020 ◽  
pp. 19-29
Author(s):  
Patricia Diaz Ortega ◽  
Manuel García Manero
Keyword(s):  
Pilot Study ◽  
Power Doppler ◽  
Uterine Fibroids ◽  
Premenopausal Women ◽  
Serum Levels ◽  
Ulipristal Acetate ◽  
Before And After ◽  
Angiogenesis Process ◽  
2D Ultrasound ◽  
Average Size

Introduction: Symptomatic uterine fibroids can cause symptoms that can be disabling. There are many treatments, including ulipristal acetate, whose role in reducing symptoms and decreasing the size of the fibroid is well known. With this preliminary study, we also try to evaluate the correlation between myoma vascularization measured by ultrasound (Power Doppler 2D) and serum VEGF levels, before and after treatment with ulipristal acetate; in patients diagnosed with symptomatic uterine fibroids. Materials and Methods: A preliminary, prospective observational pilot study was designed. Twenty-four premenopausal women, diagnosed with symptomatic uterine fibroids, were included and all of them completed the study. Four cycles of ulipristal acetate were administered according to the dose and indications specified in the data sheet. In order to assess the influence of this treatment on the angiogenesis process of the fibroids, measurements of VEGF serum levels were made and their vascularization was assessed by means of 2D power doppler ultrasound; at the beginning and the end of treatment. In addition, several determinations of the same parameters were made throughout the successive visits. Endpoints were defined as the decrease in VEGF levels from previous levels, the decrease in myoma vascularization on ultrasound, and the reduction in myoma size. Result: 24 patients who met the inclusion criteria were enrolled (n=24). The average size of myomas was reduced from 45,08 ? 24,02mm to 29?16,96mm after treatment. The average VEGF serum level significantly decreased after the first treatment cycle (from 147,17 ? 153,51 pg/ml to 102,04 ? 186,08pg/ml). Vascularization of myomas after treatment with ulipristal acetate was analyzed, and a significantly decrease was achieved in 83,3% of cases. Conclusion: There is a correlation between myoma vascularization and treatment with Ulipristal acetate. SPRMs may provide effective treatment for women with symptomatic fibroids by two ways: supports selective progesterone receptor modulators and reduced angiogenesis. Keywords: Angiogenesis; Ulipristal Acetate; Uterine fibroids; VEGF

Sign in / Sign up

Export Citation Format

Share Document