scholarly journals Interfibril hydrogen bonding improves the strain-rate response of natural armour

2019 ◽  
Vol 16 (150) ◽  
pp. 20180775 ◽  
Author(s):  
D. Arola ◽  
S. Ghods ◽  
C. Son ◽  
S. Murcia ◽  
E. A. Ossa
Keyword(s):  
Mineral Content ◽  
Loading Rate ◽  
Polar Solvent ◽  
The Body ◽  
Collagen Fibrils ◽  
Tail Region ◽  
Puncture Resistance ◽  
Content Scales ◽  
Intermolecular Bonding ◽  
Twisted Plywood

Fish scales are laminated composites that consist of plies of unidirectional collagen fibrils with twisted-plywood stacking arrangement. Owing to their composition, the toughness of scales is dependent on the intermolecular bonding within and between the collagen fibrils. Adjusting the extent of this bonding with an appropriate stimulus has implications for the design of next-generation bioinspired flexible armours. In this investigation, scales were exposed to environments of water or a polar solvent (i.e. ethanol) to influence the extent of intermolecular bonding, and their mechanical behaviour was evaluated in uniaxial tension and transverse puncture. Results showed that the resistance to failure of the scales increased with loading rate in both tension and puncture and that the polar solvent treatment increased both the strength and toughness through interpeptide bonding; the largest increase occurred in the puncture resistance of scales from the tail region (a factor of nearly 7×). The increase in strength and damage tolerance with stronger intermolecular bonding is uncommon for structural materials and is a unique characteristic of the low mineral content. Scales from regions of the body with higher mineral content underwent less strengthening, which is most likely the result of interference posed by the mineral crystals to intermolecular bonding. Overall, the results showed that flexible bioinspired composite materials for puncture resistance should enrol constituents and complementary processing that capitalize on interfibril bonds.

The cuticle of adultNippostrongylus brasiliensis

Parasitology ◽  
1965 ◽  
Vol 55 (1) ◽  
pp. 173-181 ◽  
Author(s):  
D. L. Lee
Keyword(s):  
Electron Microscope ◽  
Body Wall ◽  
Technical Assistance ◽  
Cortical Layer ◽  
The Body ◽  
Collagen Fibrils ◽  
Intestinal Cells ◽  
Nippostrongylus Brasiliensis ◽  
Normal Appearance

The cuticle of adults ofNippostrongylus brasiliensishas been described using histological, histochemical and ultrastructural techniques.The cuticle has the following layers: an outer triple-layered membrane; a single cortical layer; a fluid-filled layer which is traversed by numerous collagen fibrils; struts which support the fourteen longitudinal ridges of the cuticle and which are suspended by collagen fibrils in the fluid-filled layer; two fibre layers, each layer apparently containing three layers of fibres; and a basement lamella.The fluid-filled layer contains haemoglobin and esterase.The muscles of the body wall are attached to either the basement lamella or to the fibre layers of the cuticle.The mitochondria of the hypodermis are of normal appearance.The longitudinal ridges of the cuticle appear to abrade the microvilli of the intestinal cells of the host.Possible functions of the cuticle are discussed.I wish to thank Dr P. Tate, in whose department this work was done, for helpful suggestions and criticism at all stages of this work, and Mr A. Page for technical assistance. I also wish to thank Professor Boyd for permission to use the electron microscope in the Department of Anatomy.

scholarly journals Structure and formation of the twisted plywood pattern of collagen fibrils in rat lamellar bone

Microscopy ◽  
2012 ◽  
Vol 61 (2) ◽  
pp. 113-121 ◽  
Author(s):  
Tsuneyuki Yamamoto ◽  
Tomoka Hasegawa ◽  
Muneteru Sasaki ◽  
Hiromi Hongo ◽  
Chihiro Tabata ◽  
...  
Keyword(s):  
Collagen Fibrils ◽  
Lamellar Bone ◽  
Twisted Plywood

The Role of the Coelomic Fluid in the Movements of Earthworms

1950 ◽  
Vol 27 (1) ◽  
pp. 110-122 ◽  
Author(s):  
G. E. NEWELL
Keyword(s):  
Short Review ◽  
The Body ◽  
Coelomic Fluid ◽  
Average Pressure ◽  
Normal Range ◽  
Tail Region ◽  
X Ray ◽  
Effective Barrier ◽  
Intrinsic Muscles

1. A short review is given of the coelom and of its morphological relations in the earthworm. 2. The arrangement of the intrinsic muscles in a typical septum is described. Four main sets of muscles are recognized: viz. radial muscles, circular muscles, oblique muscles, and the sphincter around the ventral foramen. 3. It is suggested that the function of the radial, circular and possibly of the oblique muscles is to control bulging of the septa, and so serve to localize differences in pressure in the coelomic fluid. Normally, in active worms, the sphincter of the ventral foramen is contracted and forms an effective barrier to the passage of fluid from one coelomic compartment to the next. This was verified experimentally and by X-ray photography. 4. A series of measurements of the pressure in the coelomic fluid in different regions of active worms was recorded by means of a capillary manometer and by the use of a spoon-gauge apparatus. Manometric measurements showed the average pressure in the anterior third of the body to be 16.0 cm. water and in the tail region to be 8.0 cm. water. The corresponding figures obtained with a spoon gauge were 13.5 and 8.5 cm. water. The pressure in narcotized worms is zero. 5. These results are discussed, and it is pointed out that the manometer readings suffer from the disadvantage of failing to show the rapid fluctuations in pressure which occur during wriggling movements of the worms. 6. It is calculated from these pressure readings that a worm can exert a forward thrust equivalent to forces of between 1.5 and 8.0 g. These figures agree well with those obtained by Gray & Lissman by the use of a special torsion balance. 7. The burrowing movements of earthworms are briefly described. 8. It is shown that the sphincters of the dorsal pores and of the nephridiopores do not normally allow of the escape of coelomic fluid, and will withstand a pressure well outside the normal range.

Caudal Fin and Body Movement in the Propulsion of some Fish

1963 ◽  
Vol 40 (1) ◽  
pp. 23-56 ◽  
Author(s):  
RICHARD BAINBRIDGE
Keyword(s):  
Body Movement ◽  
Wave Length ◽  
The Body ◽  
Whole Body ◽  
Tail Region ◽  
Caudal Fin ◽  
A Value ◽  
Total Thrust ◽  
Transverse Movement ◽  
Relationship Of

1. Observations made on bream, goldfish and dace swimming in the ‘Fish Wheel’ apparatus are described. These include: 2. An account of the complex changes in curvature of the caudal fin during different phases of the normal locomotory cycle. Measurements of this curvature and of the angles of attack associated with it are given. 3. An account of changes in area of the caudal fin during the cycle of lateral oscillation. Detailed measurements of these changes, which may involve a 30 % increase in height or a 20 % increase in area, are given. 4. An account of the varying speed of transverse movement of the caudal fin under various conditions and the relationship of this to the changes in area and amount of bending. Details of the way this transverse speed may be asymmetrically distributed relative to the axis of progression of the fish are given. 5. An account of the extent of the lateral propulsive movements in other parts of the body. These are markedly different in the different species studied. Measurements of the wave length of this movement and of the rate of progression of the wave down the body are given. 6. It is concluded that the fish has active control over the speed, the amount of bending and the area of the caudal fin during transverse movement. 7. The bending of the fin and its changes in area are considered to be directed to the end of smoothing out and making more uniform what would otherwise be an intermittent thrust from the oscillating tail region. 8. Some assessment is made of the proportion of the total thrust contributed by the caudal fin. This is found to vary considerably, according to the form of the lateral propulsive movements of the whole body, from a value of 45% for the bream to 84% for the dace.

Morphological characterization of Trichotylenchus gorganiensis n. sp. (Nematoda: Dolichodoridae) and photomicrographs of several other species of the subfamily Telotylenchinae Siddiqi, 1960

Zootaxa ◽  
2018 ◽  
Vol 4526 (4) ◽  
pp. 447
Author(s):  
REZA GHADERI ◽  
AKBAR KAREGAR ◽  
ESMAEIL MIRAEIZ
Keyword(s):  
New Species ◽  
Morphological Characterization ◽  
The Body ◽  
Morphometric Data ◽  
Tail Region ◽  
Body Contour ◽  
Closely Related Species ◽  
Pharyngeal Bulb ◽  
Anal Sac

Trichotylenchus gorganiensis n. sp. is described and illustrated based on morphological and morphometric data. The new species is characterized by its 760–1073 µm long body, conoid-rounded lip region continuous with the body contour and bearing 5–7 fine striae, 22.0–24.5 µm long stylet, basal pharyngeal bulb offset or slightly overlapping intestine, post-anal sac extending 50–73 % of the tail region, and cylindrical or subclavate tail with a striated terminus. Differences of the new species from the closely related species T. astriatus, T. astriatoides, T. changlingensis and T. papyrus are discussed. Photomicrographs and several taxonomic notes on 13 other species of Telotylenchinae, collected from Iran, are provided. 

scholarly journals Challenges in the Diagnosis of Magnesium Status

Nutrients ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1202 ◽  
Author(s):  
Jayme Workinger ◽  
Robert. Doyle ◽  
Jonathan Bortz
Keyword(s):  
Mineral Content ◽  
Magnesium Deficiency ◽  
The Body ◽  
Dietary Practices ◽  
Disease States ◽  
Metabolic Functions ◽  
Magnesium Status ◽  
Critical Mineral ◽  
Unique Mechanism

Magnesium is a critical mineral in the human body and is involved in ~80% of known metabolic functions. It is currently estimated that 60% of adults do not achieve the average dietary intake (ADI) and 45% of Americans are magnesium deficient, a condition associated with disease states like hypertension, diabetes, and neurological disorders, to name a few. Magnesium deficiency can be attributed to common dietary practices, medications, and farming techniques, along with estimates that the mineral content of vegetables has declined by as much as 80–90% in the last 100 years. However, despite this mineral’s importance, it is poorly understood from several standpoints, not the least of which is its unique mechanism of absorption and sensitive compartmental handling in the body, making the determination of magnesium status difficult. The reliance on several popular sample assays has contributed to a great deal of confusion in the literature. This review will discuss causes of magnesium deficiency, absorption, handling, and compartmentalization in the body, highlighting the challenges this creates in determining magnesium status in both clinical and research settings.

Analysis of physicochemical and thermo-mechanical characteristics of Iranian black seed (Nigella oxypetala Boiss)

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Seyed Mohammad Taghi Gharibzahedi ◽  
Seyed Mohammad Mousavi ◽  
Mohammad Jouki ◽  
Mohammad Ghahderijani
Keyword(s):  
Nutritional Value ◽  
Mineral Content ◽  
Mechanical Characteristics ◽  
Loading Rate ◽  
Static Friction ◽  
Terminal Velocity ◽  
Angle Of Repose ◽  
Engineering Properties ◽  
Mean Values ◽  
Black Seed

Abstract The study experimentally scrutinized nutritional and engineering properties of Iranian black seed at a moisture content of 5.1% (w.b.) in order to design processing equipment and machinery for various post-harvest operations. Analysis of chemical composition, mineral content and fatty acid profile illustrated that the seeds had high nutritional value. Bulk density, true density and porosity were 539.3 kg/m3, 1009.4 kg/m3 and 46.5%, respectively. Mean values for angle of repose and terminal velocity were 5.6 m/s and 32.5°, respectively. Static friction coefficient on plywood, mild steel, aluminum and galvanized iron sheet were 0.53, 0.36, 0.32 and 0.37, respectively. Specific heat, thermal conductivity and thermal diffusivity varied from 1642 to 2035 J/kgK, 0.17 to 0.22 W/mK and 9.3 to 10.4 × 10-8 m2/s, respectively. The force required for initiating seed rupture decreased from 57.36 to 35.1 N and 55.7 to 30.24 N, and the energy absorbed at seed rupture decreased from 51.24 to 21.31 mJ and 26.67 to 6.31 mJ, with increase in loading rate from 1 to 10mm/min, for vertical and horizontal orientations, respectively.

scholarly journals Lesions Associated with Mineral Deposition in the Lymph Node and Lung of the Dog

1996 ◽  
Vol 33 (1) ◽  
pp. 29-42 ◽  
Author(s):  
M. J. Day ◽  
G. R. Pearson ◽  
V. M. Lucke ◽  
S. J. Lane ◽  
R. S. J. Sparks
Keyword(s):  
Lymph Nodes ◽  
Mineral Content ◽  
Incidental Finding ◽  
Crystalline Material ◽  
The Body ◽  
Sodium Potassium ◽  
Mineral Deposition ◽  
Pathologic Features ◽  
Wide Range ◽  
Titanium Nickel

This report includes details of the clinical and pathologic features of 31 dogs with a range of systemic illness and granulomatous lymphadenopathy associated with the presence of birefringent crystalline material within lymph nodes. Similar crystalline material was found in the lymph nodes of dogs with lymphoma (n = 9) and as an incidental finding within the canine lung (n = 9). The mineral content of these crystals was determined by electron microprobe analysis and interpreted in light of the composition of known geological or human-made compounds. A wide range of elements was identified including silicon, sulfur, copper, calcium, and aluminium, with lesser proportions of phosphorus, sodium, potassium, iron, magnesium, titanium, nickel, and chromium. Many of these compounds may have originated from exogenous natural and human-made sources, but some compounds (notably phosphates and sulfates) are uncommon or not found in nature and may have been formed within the tissues of the body (biomineralization). The inflammatory response induced by the presence of these minerals within lymphoid tissue may trigger altered immunoregulation, accounting for the spectrum of disease observed.

Calcium absorption during lactation in sheep with demineralized skeletons

1975 ◽  
Vol 84 (2) ◽  
pp. 245-248 ◽  
Author(s):  
A. R. Sykes ◽  
R. A. Dingwall
Keyword(s):  
Crude Protein ◽  
Mineral Content ◽  
Calcium Absorption ◽  
Post Partum ◽  
Poor Quality ◽  
The Body ◽  
Stage Of Lactation ◽  
Rate Of Absorption ◽  
P Balance ◽  
Initial Mineral

SUMMARYOf a group of 24 pregnant Scottish Blackface sheep 12 were killed at the outset and the remainder offered, ad libitum, a poor quality hay. At the end of pregnancy seven more were killed and the remainder offered, during lactation, 3 kg/head/day of a semipurified diet of 64% dry-matter (D.M.) digestibility, and containing 18% crude protein (CP), 1·17% Ca and 0·82% P in the D.M. Milk production was determined at weekly intervals and milk samples obtained at these times for estimation of Ca and P concentrations. These sheep were killed 42 days post-partum. The shorn empty bodies were analysed for fat, protein, Ca and P contents.The feeding of the poor quality hay caused losses of 76, 37, 15 and 15% of the body contents of fat, protein, Ca and P, respectively, during pregnancy. Despite maintaining a moderate milk yield (1·5 kg/day) the ewes were in positive Ca and P balance during early lactation and had restored the skeleton to its initial mineral content by 42 days post-partum. The rate of absorption of Ca was calculated to have been at least 115 mg/ kg body weight (BW) which is double other estimates in the literature for sheep at this stage of lactation.These differences are discussed in relation to mechanisms for adaptation of Ca metabolism which have been proposed for other species.

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