Solid State Testing of Inhaled Formulations
Anthony J. Hickey, Sandro R.P. da Rocha in Pharmaceutical Inhalation Aerosol Technology, 2019
Crystallinity is the degree of order in the molecular arrangement in the solid. All molecules are in the correct lattice position in a perfect crystal, while all long-range order is lost in an amorphous solid. No real solids belong to these two extremes. Even the most ordered crystals and the most disordered amorphous solids possess low levels of disordered and ordered domains, respectively. The crystallinity and polymorphic form of a drug can affect its particle shape, dissolution rate, stability, and aerosol performance (Zeng et al. 2000), so their characterization is needed in product development (Guidance for Industry: Metered Dose Inhaler (MDI) and Dry Powder Inhaler (DPI) Drug Products 1998, Guideline on the Pharmaceutical Quality of Inhalation and Nasal Products 2006). Many pharmacopoeial methods can be used to determine crystallinity, namely, X-ray powder diffraction, DSC, microcalorimetry, solution calorimetry, near-infrared spectroscopy, infrared absorption spectrophotometry, Raman spectrometry, solid-state nuclear magnetic resonance, and optical microscopy (British Pharmacopoeia 2017, European Pharmacopoeia 2017, United States Pharmacopeia 40-National Formulary 35 2017). Optical microscopy is a simple, qualitative method in which the particles are viewed using a polarizing microscope. Crystalline particles show birefringence interference colors when the polariser or sample is turned. The most common methods for crystallinity determination are X-ray powder diffraction, DSC, microcalorimetry, and dynamic gravimetric water sorption.
Telescopes for Inner Space: Fiber Optics and Endoscopes
Suzanne Amador Kane, Boris A. Gelman in Introduction to Physics in Modern Medicine, 2020
We can use optical microscopes to obtain magnified virtual images of microscopic objects. The main optical components of a compound microscope are an objective lens and an eyepiece lens. In Figure 2.9e, these parts are represented by two lenses. The objective lens, which is the closest to the object AB, forms a real image, A′B′. By adjusting the distance between the objective and the eyepiece, the image A′B′ can be placed very near the focus of the eyepiece lens. Using the ray tracing rules discussed above, we can show that the rays coming from the real image after passing through the eyepiece create a virtual image (see Figure 2.9e), which is magnified to a large degree compared with the size of the original object. Magnification, also called the power, of modern optical microscopes can be as high as 1000.
Fundamental Techniques Of Microvascular Anastomosis
Waldemar L. Olszewski in CRC Handbook of Microsurgery, 2019
Figure 1 shows the Zeiss® OPMi-6 fiberoptic diploscope which was very recently installed in our new operating theater. It has recently been remodeled from the standard OPMi-6 for neurosurgery or ENT [ear-nose-throat (oto-rhino-laryngology)] use to a diploscope, which is quite similar to the OPMi-7 for orthopedic and plastic surgery. This microscope, with an electromotive ceiling mount, has motorized zoom magnification and zoom focusing controlled by a foot switch. In addition to preserving several merits of the original OPMi-6, such as the ability to focus without losing sight of the operating field when the microscope is tilted, modern accessories such as a tilting system for the binocular tubes (which can be tilted through an arc of 60°) and a X-Y coupling which allows horizontal movements with the foot control are attached to this model. This type of microscope is much better than the OPMi-7 in its movability and handling of the scope. If the eyepieces with 12.5 × magnifications and the objective lens with a 200-mm focusing distance and 160-mm optical tube length are mounted on this microscope, a range of magnification factors from 0.5 to 2.5 will give a series of variable magnifications from 6.25 to 31.25 × — optical tube length/focusing distance × 12.5 × magnification factors = actual magnification.
A feature-based analysis identifies COL1A2 as a regulator in pancreatic cancer
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2019
Jie Wu, Jing Liu, XiaoQing Wei, Qi Yu, XiangHuan Niu, ShuHong Tang, Lei Song
Transwell chamber (Corning Costar, NY) was used to perform migrative or invasive assay. Cells of 1 × 105 were seeded into the upper chambers with serum-free. The lower chambers were added with DMEM containing 10% FBS. After being incubated at 37 °C in a 5% CO2 incubator for 24 h transfection, the cells were fixed 15 min with methanol, stained 15 min with 0.05% crystal violet in PBS and counted under a microscope (Olympus, Tokyo, Japan). After migration or invasion, cells in upper chamber were wiped with cotton swabs carefully and fixed with PBS containing 4% formaldehyde and subsequently immersed in a 2% ethanol solution containing 1% crystal violet. An optical microscope (100×) was used to observe and take photographs for cells. For invasion detection, Matrigel (BD Biosciences, Franklin Lakes, NJ) was added to the upper chamber of Transwell.
The Diagnostic Value of ischemia-modified albumin (IMA) and signal peptide-CUB-EGF domain-containing protein-1 (SCUBE-1) in an Experimental Model of Strangulated Mechanical Bowel Obstruction
Published in Journal of Investigative Surgery, 2022
Arif Burak Cekic, Ozgen Gonenc Cekic, Ali Aygun, Sinan Pasli, Serap Yaman Ozer, Suleyman Caner Karahan, Suleyman Turedi, Sami Acar, Ozgur Tatli, Esin Yulug
At histopathological analysis the ileum specimens were examined macroscopically, after which 1-cm sections were taken and examined in terms of histopathological changes. IMA and SCUBE-1 levels were determined for each group, and macro- and microscopic tissue examination findings were compared between the groups. A light microscope was employed for microscopic examination. Tissues were placed in 10% formaldehyde for light microscopic examination. Following routine application of xylol and alcohol, the specimens were embedded in paraffin blocks. Five-micrometer sections were taken using a microtome (Leica RM2255, Japan), and stained with hematoxylin-eosin and cresyl violet. The ileum preparates were than analyzed by an experienced histologist blinded to the study groups. Semi-quantitative ileum damage scoring was employed to assess the groups’ ileum tissues. Under this system, ileum specimens from the study groups were assessed in terms of villus apical surface epithelial degeneration, inflammatory cell infiltration, villous fusion, and hemorrhage. As a result of the histopathologic examinations, it was scored according to the following scale (Table 1); mean scores were then calculated for each group.13
Chronic exposure to ethanol alters the expression of miR-155, miR-122 and miR-217 in alcoholic liver disease in an adult zebrafish model
Published in Biomarkers, 2021
Amanda Pasqualotto, Raquel Ayres, Larisse Longo, Diego Del Duca Lima, Diogo Losch de Oliveira, Mário Reis Alvares-da-Silva, Themis Reverbel da Silveira, Carolina Uribe-Cruz
Hepatic tissue samples were collected and fixed in Tissue Tek® O.T.C. Compound (Sakura, California, USA), cryosectioned (Leica Biosvystems, Wetzlar, Germany) (3–5 μm) and stained with H&E and Oil Red (5 mg/mL in propylene glycol) to evaluate the presence of lipids. All sections were examined under an optical microscope. Microphotographs were used to record the samples (n = 5). The sections stained with Oil Red were quantified using the Image J software for the amount of lipids (n = 5). Lipid deposits in the liver were quantified using a modified Gómez-Lechon protocol (Gómez-Lechón et al. 2007). Hepatic tissue had been previously homogenized with PBS (20 mg tissue/ml) and incubated with 1 μl of Nile Red solution (1 mg/ml in acetone) (Sigma-Aldrich, WGK Germany) for 15 min at 37 °C. Fluorescence was measured at 488 nm of excitation and 550 nm of emission (SpectraMax M3). The results were normalized for total proteins present in the homogenate (n = 8), which were obtained by the Bradford method (Bradford 1976).
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