Magnetic and magnetoelectric properties of M-type substitution hexaferrites TSc x Fe12 − x O19 (T = Ba, Sr)

There are >200 different types of human papilloma virus (HPV) of which >51 infect genital epithelium, with ~14 of these classed as high-risk being more commonly associated with cervical cancer. During development of the disease, high-risk types have an increased tendency to develop a truncated non-replicative life cycle, whereas low-risk, non-cancer-associated HPV types are either asymptomatic or cause benign lesions completing their full replicative life cycle. HPVs can also be present as non-replicative so-called “latent” infections and they can also show superinfection exclusion, where cells with pre-existing infections with one type cannot be infected with a different HPV type. Thus, the HPV repertoire and replication status present in an individual can form a complex dynamic meta-community which changes with respect to both time and exposure to different HPV types. In light of these considerations, it is not clear how current prophylactic HPV vaccines will affect this system and the potential for iatrogenic outcomes is discussed in light of recent outcome data.

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Significant improvements in dielectric, impedance, multiferroic and magnetoelectric properties of (1 − x)Co0.5Ni0.5Fe2O4−xBaTiO3 bulk composites (x = 0, 0.10 and 0.20)

Journal of Materials Science Materials in Electronics ◽

10.1007/s10854-021-06227-4 ◽

2021 ◽

Author(s):

S. Shankar ◽

O. P. Thakur ◽

M. Jayasimhadri

Keyword(s):

Magnetoelectric Properties

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Temperature effect in physicochemical and bioactive behavior of biogenic hydroxyapatite obtained from porcine bones

Scientific Reports ◽

10.1038/s41598-021-89776-2 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

P. A. Forero-Sossa ◽

J. D. Salazar-Martínez ◽

A. L. Giraldo-Betancur ◽

B. Segura-Giraldo ◽

E. Restrepo-Parra

Keyword(s):

Structural Changes ◽

Biological Fluid ◽

Treatment Temperature ◽

Mineral Phase ◽

Calcination Temperatures ◽

Bioactive Properties ◽

Temperature Ranges ◽

Compositional Changes ◽

Type Substitution ◽

Biogenic Hydroxyapatite

AbstractBiogenic hydroxyapatite (BHAp) is a widely used material in the biomedical area due to its similarities with the bone tissue mineral phase. Several works have been spotlighted on the thermal behavior of bone. However, little research has focused on determining the influence of calcination temperature in the physicochemical and bioactive properties of BHAp. In this work, a study of the physicochemical properties’ changes and bioactive response of BHAp produced from porcine femur bones using calcination temperatures between 900 to 1200 °C was conducted. The samples’ structural, morphological, and compositional changes were determined using XRD, SEM, and FTIR techniques. XRD results identified three temperature ranges, in which there are structural changes in BHAp samples and the presence of additional phases. Moreover, FTIR results corroborated that B-type substitution is promoted by increasing the heat treatment temperature. Likewise, samples were immersed in a simulated biological fluid (SBF), following the methodology described by Kokubo and using ISO 23317:2014 standard, for 3 and 7 days. FTIR and SEM results determined that the highest reaction velocity was reached for samples above 1000 °C, due to intensity increasing of phosphate and carbonate bands and bone-like apatite morphologies, compared to other temperatures evaluated.

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Thorium in crandallite-group minerals: an example from a Devonian bauxite deposit, Timan, Russia

Mineralogical Magazine ◽

10.1180/0026461046830200 ◽

2004 ◽

Vol 68 (3) ◽

pp. 489-497 ◽

Cited By ~ 5

Author(s):

L. E. Mordberg

Keyword(s):

Crystal Lattice ◽

Radiation Damage ◽

Mineral Composition ◽

Bauxite Deposit ◽

Weathering Profile ◽

Silicate Mineral ◽

Fe Content ◽

Very High ◽

Type Substitution ◽

Simplified Formula

AbstractA Th-rich mineral of the crandallite group has been investigated from the weathering profile of the Schugorsk bauxite deposit, Timan, Russia. It occurs within thin (up to 0.5 mm) organic-rich veinlets together with ‘leucoxene’ in the form of small shapeless grains which vary in size from 1—2 mm to 60—70 mm. Rare grains disseminated among boehmite crystals were also found. Microprobe analyses determined that the ThO2 content can be as high as 18 wt.%. The mineral composition is intermediate between crandallite CaAl3H(PO4)2(OH)6, goyazite SrAl3H(PO4)2(OH)6, Th-crandallite and svanbergite SrAl3PO4SO4(OH)6 in the beudantite group.Comparatively high contents of Fe and Si and a very high positive Th and Fe content correlation (r = +0.98) suggest that the formula of the hypothetical Th-bearing end-member is ThFe3(PO4,SiO4)2(OH)6 with Th and Si substituting for REE and Prespectively (woodhouseite-type substitution). Another possible substitution is Th4+ + Ca2+ ⇋ 2REE3+ (florencite-type). A deficiency of cations in the X site can be explained by either the presence of carbon, undetectable by microprobe, in the crystal lattice or a lack of X-site cations due to radiation damage induced by Th. Some excess of cations in the B site (Al and Fe3+) can be explained by the presence of very small boehmite and hematite inclusions on the crandallite grain surfaces. Th-rich crandallite may be the result of alteration of an unidentified silicate mineral from the parent rock with a composition close to the simplified formula Fe2+ThSiO4(OH)2.

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