Improved tables for the evaluation of sphere size distributions including the effect of section thickness

Rose, Peter Edgar

doi:10.1111/j.1365-2818.1980.tb00256.x

Cited by 38 publications

(11 citation statements)

References 7 publications

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“…There was no significant difference between the observed and the true means of diameter average of casein micelles of the different camels' milks. Few mathematical procedures have been developed for correction of the apparent particle size of globular bodies such as that of the casein micelle (Goldsmith, 1967;Rose, 1980). Typical electron micrographs of camels' milks are shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Size distribution of casein micelles in camels′ milk

Ali

Robinson

1985

Journal of Dairy Research

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The particle size distribution of bovine milk has been the subject of recent reports, and different techniques have been used to determine the range of micellar sizes. These techniques have included light scattering and centrifugal fractionation (Lin et al. 1971); electron microscopy (Schmidt et al. 1973) and chromatography and photon correlation spectroscopy (Griffin & Anderson, 1983). The size of the micelles ranges between 20 and 600 nm with a maximum frequency of around 60-80 nm as reported by Holt et al. (1978) and Kimber et al. (1978); submicellar particles were observed by Schmidt et al. (1973).Despite its economic potential, the camel and its milk have received little attention. Moreover, the camel is well adapted to arid environments and can produce milk when its water intake is drastically restricted (Yagil & Etzion, 1980). Elamin (1980) gave an account of the dromedary camel of the Sudan and its milk constituents: the percentages of water, protein and fat were 86-90, 3 -6-4"7, 4-5 -5 respectively. Ahmed et al. (1979) studied some minor constituents of camels' milk: the amounts of Ca and P (mg/100 ml) detected were 137-312 and 39-152 respectively.The casein micelle size of camels' milk is an important parameter of the structure of the milk. This was studied using transmission electron microscopy to observe the relative particle size distribution. Some observations on the structure of casein micelles, together with a comparison of their average diameter, are also given. MATERIALS AND METHODS Collection of samplesSix samples of milk were collected from six individual Bedouin camels (Camelus dromedarius), reared by nomads, from the Sudan. The samples were collected from two different semi-desert sites: (a) 50 miles N. of Wad Medani (capital of the Gezira Region), samples no. 1, 2 and 3 and (b) 10 miles S.W. of Wad Medani, samples no. 4, 5 and 6. This choice of sites enabled all the samples to be taken from camels within the first 1-2 months of onset of lactation.To let down the milk, the baby camel (calf) was introduced to suckle its mother for about 10-15 min. Then after discarding the first 2-3 strips, about 2-3 ml milk were collected directly from each camel into test tubes containing an equal volume of 25 % glutaraldehyde in 0-2 M-sodium cacodylate-HCl buffer (pH 7-2), and then fixed for 1 h. Samples were mixed with an equal volume of 2-5% molten agar (60-70 °C), and the material poured on to glass slides and allowed to set. The gel was then cut into 1 mm 3 pieces and kept refrigerated (below 5 °C) inO -2 M-sodium cacodylate -HC1 buffer (pH 7-2) ready for further processing, within 3 weeks, at Reading University, UK. Both immediate processing and alternative preparative techniques on fresh milk were impossible in these geographical sites.

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Section: Resultsmentioning

confidence: 99%

Size distribution of casein micelles in camels′ milk

Ali

Robinson

1985

Journal of Dairy Research

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“…Different mathematical procedures and formulas for practical applications have been published. [16][17][18] The data gained from the two-dimensional determination of fracture diameters were used for different calculations. The mean particle size (by number) was calculated from the fracture diameters by two independent methods.…”

Section: Resultsmentioning

confidence: 99%

Investigation of the Particle Size Distribution of a Model Intravenous Emulsion

Westesen

Wehler²

1993

Journal of Pharmaceutical Sciences

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“…Second, the section cuts through different portions of the deposit, i.e., some small diameter measurements represent sections taken through the peripheral portions of larger-sized deposits [14]. The absolute density of deposits in each size class in 3D can be calculated from their size distribution in 2D using matrix algebra if it is assumed that the deposits are spherical and randomly distributed [23,48,56]. However, this method is not appropriate for Aβ deposits, because although many deposits may be approximately spherical, they are not randomly distributed but occur in distinct clusters [10,12].…”

Section: Discussionmentioning

confidence: 99%

Original article Size frequency distributions of β-amyloid (Aβ) deposits: a comparative study of four neurodegenerative disorders

Armstrong

2012

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A b s t r a c t Deposition of β-amyloid (Aβ), a 'signature' pathological lesion of Alzheimer's disease (AD), is also characteristic of Down's syndrome (DS), and has been observed in dementia with Lewy bodies (DLB) and corticobasal degeneration (CBD). To determine whether the growth of Aβ deposits was similar in these disorders, the size frequency distributions of the diffuse ('pre-amyloid'), primitive ('neuritic'), and classic ('dense-cored') Aβ deposits were compared in AD, DS, DLB, and CBD. All size distributions had essentially the same shape, i.e., they were unimodal and positively skewed. Mean size of Aβ deposits, however, varied between disorders. Mean diameters of the diffuse, primitive, and classic deposits were greatest in DS, DS and CBD, and DS, respectively, while the smallest deposits, on average, were recorded in DLB. Although the shape of the frequency distributions was approximately log-normal, the model underestimated the frequency of smaller deposits and overestimated the frequency of larger deposits in all disorders. A 'power-law

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Improved tables for the evaluation of sphere size distributions including the effect of section thickness

Cited by 38 publications

References 7 publications

Size distribution of casein micelles in camels′ milk

Size distribution of casein micelles in camels′ milk

Investigation of the Particle Size Distribution of a Model Intravenous Emulsion

Original article Size frequency distributions of β-amyloid (Aβ) deposits: a comparative study of four neurodegenerative disorders

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