scholarly journals Some observations on plant assemblages and elemental content of plants in mineralized areas of the Walker Lake 1 degree x 2 degrees Quadrangle, California-Nevada

1986 ◽  
Author(s):  
Helen L. Cannon
Keyword(s):  
Elemental Content ◽  
Walker Lake ◽  
Plant Assemblages

Electron Probe Microanalysis of Frozen Hydrated Kidneys, Isolated Cells, and Cultured Cells

1982 ◽  
Vol 40 ◽  
pp. 402-403 ◽  
Author(s):  
Claude Lechene
Keyword(s):  
Liquid Nitrogen ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Cultured Cells ◽  
Liquid Nitrogen Temperature ◽  
Elemental Content ◽  
Isolated Cells ◽  
Renal Tubular Cells ◽  
Diamond Saw ◽  
Saw Blade

Electron probe microanalysis of frozen hydrated kidneysThe goal of the method is to measure on the same preparation the chemical elemental content of the renal luminal tubular fluid and of the surrounding renal tubular cells. The following method has been developed. Rat kidneys are quenched in solid nitrogen. They are trimmed under liquid nitrogen and mounted in a copper holder using a conductive medium. Under liquid nitrogen, a flat surface is exposed by sawing with a diamond saw blade at constant speed and constant pressure using a custom-built cryosaw. Transfer into the electron probe column (Cameca, MBX) is made using a simple transfer device maintaining the sample under liquid nitrogen in an interlock chamber mounted on the electron probe column. After the liquid nitrogen is evaporated by creating a vacuum, the sample is pushed into the special stage of the instrument. The sample is maintained at close to liquid nitrogen temperature by circulation of liquid nitrogen in the special stage.

Preparation of cultured astrocytes for x-ray microanalysis

1989 ◽  
Vol 47 ◽  
pp. 988-989
Author(s):  
N.K.R. Smith ◽  
K.E. Hunter ◽  
P. Mobley ◽  
L.P. Felpel
Keyword(s):  
Cultured Cells ◽  
Elemental Content ◽  
Elemental Distribution ◽  
Sprague Dawley ◽  
X Ray ◽  
Cultured Astrocytes ◽  
Freeze Dried ◽  
Ultimate Objective

Electron probe energy dispersive x-ray microanalysis (XRMA) offers a powerful tool for the determination of intracellular elemental content of biological tissue. However, preparation of the tissue specimen , particularly excitable central nervous system (CNS) tissue , for XRMA is rather difficult, as dissection of a sample from the intact organism frequently results in artefacts in elemental distribution. To circumvent the problems inherent in the in vivo preparation, we turned to an in vitro preparation of astrocytes grown in tissue culture. However, preparations of in vitro samples offer a new and unique set of problems. Generally, cultured cells, growing in monolayer, must be harvested by either mechanical or enzymatic procedures, resulting in variable degrees of damage to the cells and compromised intracel1ular elemental distribution. The ultimate objective is to process and analyze unperturbed cells. With the objective of sparing others from some of the same efforts, we are reporting the considerable difficulties we have encountered in attempting to prepare astrocytes for XRMA.Tissue cultures of astrocytes from newborn C57 mice or Sprague Dawley rats were prepared and cultured by standard techniques, usually in T25 flasks, except as noted differently on Cytodex beads or on gelatin. After different preparative procedures, all samples were frozen on brass pins in liquid propane, stored in liquid nitrogen, cryosectioned (0.1 μm), freeze dried, and microanalyzed as previously reported.

Recent Advances in Speciation Analyses of Tobacco and Other Important Economic Crops

2020 ◽  
Vol 17 ◽  
Author(s):  
Zhiping Jiang ◽  
Zhizhang Tian ◽  
Chuntao Zhang ◽  
Dengke Li ◽  
Ruoxin Wu ◽  
...  
Keyword(s):  
Method Comparison ◽  
Chemical Species ◽  
Complete Information ◽  
Speciation Analysis ◽  
Elemental Content ◽  
Specific Element ◽  
Balance Accuracy ◽  
Comprehensive Knowledge ◽  
Total Elemental Content ◽  
The Impact

Background: Speciation analysis is defined as the analytical activities of identifying and/or measuring the quantities of one or more individual chemical species in a sample. The knowledge of elemental species provides more complete information about mobility, bioavailability and the impact of elements on ecological systems or biological organisms. It is no longer sufficient to quantitate the total elemental content of samples to define toxicity or essentiality. Thus speciation analysis is of vital importance and generally offers a better understanding of a specific element. Discussion: Thorough speciation scheme consisting of sampling, sample preparation, species analysis and evaluation were described. Special emphasis is placed on recent speciation analysis approaches including both direct and coupling methods. A current summary of advantages and limitations of the various methods as well as an illustrative method comparison are presented. Certain elements and species of interest are briefly mentioned and practical examples of speciation applications in tobacco and other important economic crops are also discussed. Aim/Conclusion: This review aims to offer comprehensive knowledge about elemental speciation and provide readers with valuable information. Many strategies have been developed for the determination of multiple elemental species in tobacco and other important economic crops. Nevertheless, it is an eternal pursuit to establish speciation methods which can balance accuracy, agility as well as universality.

Elemental analysis of medicinal plants from different sites by instrumental neutron activation analysis

2016 ◽  
Vol 5 (03) ◽  
pp. 4892 ◽  
Author(s):  
Ratna Raju M.* ◽  
Madhusudhana Rao P. V. ◽  
Seshi Reddy T. ◽  
Raju M. K. ◽  
Brahmaji Rao J. S. ◽  
...  
Keyword(s):  
Neutron Activation Analysis ◽  
Instrumental Neutron Activation Analysis ◽  
Activation Analysis ◽  
Medicinal Plants ◽  
Neutron Activation ◽  
Gamma Ray ◽  
Elemental Content ◽  
Soil Composition ◽  
Gamma Ray Spectrometer ◽  
Instrumental Neutron Activation

A study was undertaken to evaluate the inorganic elements for humans in two Indian medicinal plants leaves, namely Sphaeranthus indicus, and Cassia fistula by Instrumental Neutron Activation Analysis (INAA). INAA experiment was performed by using 20 kW KAMINI Reactor at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam. The emitted gamma rays were measured using gamma ray spectrometer. The concentrations of Al, Br, Ca, Fe, K, La, Mg, Mn, Na, Sc, V and Zn were determined in the selected medicinal plants. The medicinal leaves are using in treatment of various important ailments. The elemental content in selected medicinal leaves is various proportions depending on the soil composition, location of plant specimen and the climate in which the plant grows.

scholarly journals Physicochemical and Antimicrobial Properties of Cocoa Pod Husk Pectin Intended as a Versatile Pharmaceutical Excipient and Nutraceutical

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Ofosua Adi-Dako ◽  
Kwabena Ofori-Kwakye ◽  
Samuel Frimpong Manso ◽  
Mariam EL Boakye-Gyasi ◽  
Clement Sasu ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Antimicrobial Properties ◽  
Microbiological Quality ◽  
Elemental Content ◽  
Moderate Activity ◽  
Pharmaceutical Excipient ◽  
E Coli ◽  
Swelling Capacity ◽  
Weak Activity ◽  
Cocoa Pod Husk

The physicochemical and antimicrobial properties of cocoa pod husk (CPH) pectin intended as a versatile pharmaceutical excipient and nutraceutical were studied. Properties investigated include pH, moisture content, ash values, swelling index, viscosity, degree of esterification (DE), flow properties, SEM, FTIR, NMR, and elemental content. Antimicrobial screening and determination of MICs against test microorganisms were undertaken using agar diffusion and broth dilution methods, respectively. CPH pectin had a DE of 26.8% and exhibited good physicochemical properties. Pectin had good microbiological quality and exhibited pseudoplastic, shear thinning behaviour, and high swelling capacity in aqueous media. The DE, FTIR, and NMR results were similar to those of previous studies and supported highly acetylated low methoxy pectin. CPH pectin was found to be a rich source of minerals and has potential as a nutraceutical. Pectin showed dose-dependent moderate activity against gram positive and gram negative microorganisms but weak activity against Listeria spp. and A. niger. The MICs of pectin ranged from 0.5 to 4.0 mg/mL, with the highest activity against E. coli and S. aureus (MIC: 0.5–1.0 mg/mL) and the lowest activity against A. niger (MIC: 2.0–4.0 mg/mL). The study has demonstrated that CPH pectin possesses the requisite properties for use as a nutraceutical and functional pharmaceutical excipient.

scholarly journals N-doped graphene foam obtained by microwave-assisted exfoliation of graphite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Malgorzata Skorupska ◽  
Anna Ilnicka ◽  
Jerzy P. Lukaszewicz
Keyword(s):  
Electron Microscopy ◽  
Electrode Materials ◽  
Elemental Content ◽  
Research Approach ◽  
Pristine Graphene ◽  
Active Electrode ◽  
Graphene Foam ◽  
Practical Applications ◽  
Microwave Reactor ◽  
Doped Graphene

AbstractThe synthesis of metal-free but electrochemically active electrode materials, which could be an important contributor to environmental protection, is the key motivation for this research approach. The progress of graphene material science in recent decades has contributed to the further development of nanotechnology and material engineering. Due to the unique properties of graphene materials, they have found many practical applications: among others, as catalysts in metal-air batteries, supercapacitors, or fuel cells. In order to create an economical and efficient material for energy production and storage applications, researchers focused on the introduction of additional heteroatoms to the graphene structure. As solutions for functionalizing pristine graphene structures are very difficult to implement, this article presents a facile method of preparing nitrogen-doped graphene foam in a microwave reactor. The influence of solvent type and microwave reactor holding time was investigated. To characterize the elemental content and structural properties of the obtained N-doped graphene materials, methods such as elemental analysis, high-resolution transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy were used. Electrochemical activity in ORR of the obtained materials was tested using cyclic voltamperometry (CV) and linear sweep voltamperometry (LSV). The tests proved the materials’ high activity towards ORR, with the number of electrons reaching 3.46 for tested non-Pt materials, while the analogous value for the C-Pt (20 wt% loading) reference was 4.

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