Use of Three Optical Systems to Obtain a Microscopic Profile of Asbestos and Other Nonopaque Particulate Matter Larger than 5 μm in Parenteral Drugs

1977 ◽  
Vol 60 (2) ◽  
pp. 289-296
Author(s):  
Leonora Auerbach

Abstract A comparative microscopic study of chrysotile fibers was conducted, using 3 sequential optical systems: plane polarized light (PL), phase contrast (PC), and Nomarski differential interference contrast (NDIC) for complementary image analyses. The introduction of NDIC for qualitative and quantitative analyses of particulate matter >5 μm resolves the problem of diffraction halos encountered in PC microscopy. High optical contrast, the instrumental characteristic of NDIC, is particularly useful for the detection of chrysotile fibers at a magnification of 500 ×.

1998 ◽  
Vol 4 (S2) ◽  
pp. 408-409
Author(s):  
A. Barty ◽  
K.A. Nugent ◽  
D. Paganin ◽  
A Roberts

At the University of Melbourne we have been pursuing an ongoing program of investigation into the recovery of phase information from intensity measurements [1-9]. In this paper we consider the implications of this work in optical and electron microscopy.Many objects of interest to biologists are phase objects which means that light is slowed and refracted in the object but not absorbed. Techniques such as phase-contrast microscopy and Nomarski differential interference contrast (DIC) microscopy are traditionally used to render the phase structure visible but do not directly map the phase distribution and are unable to produce quantitative data. These techniques also entangle the phase and amplitude information and so have limitations where both phase and amplitude information is required. In this paper, we demonstrate quantitative non-interferometric recovery of microscopic phase structure using incoherent illumination of the type commonly found in optical microscopes, and show that our results correlate with structure observed using Nomarski DIC techniques.


Author(s):  
Jerrold L. Abraham

Inorganic particulate material of diverse types is present in the ambient and occupational environment, and exposure to such materials is a well recognized cause of some lung disease. To investigate the interaction of inhaled inorganic particulates with the lung it is necessary to obtain quantitative information on the particulate burden of lung tissue in a wide variety of situations. The vast majority of diagnostic and experimental tissue samples (biopsies and autopsies) are fixed with formaldehyde solutions, dehydrated with organic solvents and embedded in paraffin wax. Over the past 16 years, I have attempted to obtain maximal analytical use of such tissue with minimal preparative steps. Unique diagnostic and research data result from both qualitative and quantitative analyses of sections. Most of the data has been related to inhaled inorganic particulates in lungs, but the basic methods are applicable to any tissues. The preparations are primarily designed for SEM use, but they are stable for storage and transport to other laboratories and several other instruments (e.g., for SIMS techniques).


Planta Medica ◽  
2008 ◽  
Vol 74 (09) ◽  
Author(s):  
T Jankovic ◽  
G Zdunic ◽  
K Savikin ◽  
I Beara ◽  
N Mimica-Dukić

Plants ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 123
Author(s):  
Mariangela Marrelli ◽  
Maria Rosaria Perri ◽  
Valentina Amodeo ◽  
Francesca Giordano ◽  
Giancarlo A. Statti ◽  
...  

Photochemotherapy is one of the most interesting current therapeutic approaches for the treatment of melanoma. Different classes of naturally occurring phytochemicals demonstrated interesting photoactive properties. The aim of this study was to evaluate the photocytotoxic potential of two Cachrys species from Southern Italy: C. sicula and C. libanotis (Apiaceae). The enriched-coumarin extracts were obtained from aerial parts through both traditional maceration and pressurized cyclic solid-liquid (PCSL) extraction using Naviglio extractor®. Qualitative and quantitative analyses of furanocoumarins were performed with GC-MS. The photocytotoxic effects were verified on C32 melanoma cells irradiated at a dose of 1.08 J/cm2. The apoptotic responses were also assessed. Moreover, phenolic content and the in vitro antioxidant potential were estimated. Xanthotoxin, bergapten, and isopimpinellin were identified. All the samples induced concentration-dependent photocytotoxic effects (IC50 ranging from 3.16 to 18.18 μg/mL). The C. libanotis sample obtained with Naviglio extractor® was the most effective one (IC50 = 3.16 ± 0.21 μg/mL), followed by C. sicula sample obtained with the same technique (IC50 = 8.83 ± 0.20 μg/mL). Both Cachrys samples obtained through PCSL induced up-regulation of apoptotic signals such as BAX (Bcl2-associated X protein) and PARP (poly ADP-ribose polymerase) cleavage. Moreover, these samples proved to be more photoactive, giving a greater upregulation of p21 protein in the presence of UVA radiation. Obtained results suggest that investigated species could be promising candidates for further investigations aimed to find new potential drugs for the photochemotherapy of skin cancer.


2020 ◽  
Vol 5 (12) ◽  
pp. e002938
Author(s):  
Austin Carter ◽  
Nadia Akseer ◽  
Kevin Ho ◽  
Oliver Rothschild ◽  
Niranjan Bose ◽  
...  

This paper introduces a framework for conducting and disseminating mixed methods research on positive outlier countries that successfully improved their health outcomes and systems. We provide guidance on identifying exemplar countries, assembling multidisciplinary teams, collecting and synthesising pre-existing evidence, undertaking qualitative and quantitative analyses, and preparing dissemination products for various target audiences. Through a range of ongoing research studies, we illustrate application of each step of the framework while highlighting key considerations and lessons learnt. We hope uptake of this comprehensive framework by diverse stakeholders will increase the availability and utilisation of rigorous and comparable insights from global health success stories.


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