Chemical disorder effects in transport and magnetic properties of perovskite manganite

2005 ◽  
Vol 20 (4) ◽  
pp. 813-817
Author(s):  
Subhayan Biswas ◽  
Sandip Chatterjee ◽  
P. Chatterjee ◽  
A.K. Nigam ◽  
S.K. De
Keyword(s):  
Magnetic Properties ◽  
Colossal Magnetoresistance ◽  
Lattice Mismatch ◽  
Perovskite Manganite ◽  
The Novel ◽  
Ionic Radii ◽  
Three Samples ◽  
Moderate Magnetic Field ◽  
A Site

The dependence of the novel properties observed in colossal magnetoresistance (CMR) materials, other than average ionic radii 〈rA〉 and Mn valence ratio (Mn3+/Mn4+), was investigated through examination of the transport and magnetic properties of Pr0.65(Ca0.7Sr0.3)0.35MnO3, La0.123Pr0.527(Ca0.8Sr0.2)0.35MnO3, and Pr0.65(Ca0.866Ba0.134)0.35MnO3. The average ionic radii 〈rA〉 and valence ratio of all three samples have been kept equal. The results of this investigation indicate a more intense role of the nature of individual A-site cation and the lattice mismatch. A remarkably large magnetoresistance of the order of 108 at moderate magnetic field has been observed for Ba-doped sample.

Lattice Distortions and Domain Structure in Epitaxial Manganite Thin Films

1999 ◽  
Vol 602 ◽  
Author(s):  
Y. Suzuki ◽  
Yan Wu ◽  
U. Rüdiger ◽  
J. Yu ◽  
A.D. Kent ◽  
...  
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Hydrostatic Pressure ◽  
Magnetic Anisotropy ◽  
Domain Structure ◽  
Colossal Magnetoresistance ◽  
Lattice Mismatch ◽  
Magnetic Domain ◽  
Lattice Distortions

AbstractLattice distortions, be they in the form of chemical and hydrostatic pressure in bulk or lattice mismatch between film and substrate, have significant effects on the transport as well as the magnetic properties of colossal magnetoresistance (CMR) materials. We summarize here our results on tensilely and compressively strained La0.7Sr0.3MnO3 (LSMO) thin films that indicate the important role of lattice distortions due to the lattice mismatch between the film and substrate. The strain due to lattice distortions can be used to tune the magnetic domain structure, magnetization, magnetic anisotropy and magnetotransport of LSMO thin films.

scholarly journals Quantitative analysis of APP axonal transport in neurons: role of JIP1 in enhanced APP anterograde transport

2014 ◽  
Vol 25 (22) ◽  
pp. 3569-3580 ◽  
Author(s):  
Kyoko Chiba ◽  
Masahiko Araseki ◽  
Keisuke Nozawa ◽  
Keiko Furukori ◽  
Yoichi Araki ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Axonal Transport ◽  
High Frequency ◽  
Coiled Coil ◽  
Tetratricopeptide Repeat ◽  
The Novel ◽  
Anterograde Transport ◽  
Interacting Protein ◽  
A Site

Alzheimer's β-amyloid precursor protein (APP) associates with kinesin-1 via JNK-interacting protein 1 (JIP1); however, the role of JIP1 in APP transport by kinesin-1 in neurons remains unclear. We performed a quantitative analysis to understand the role of JIP1 in APP axonal transport. In JIP1-deficient neurons, we find that both the fast velocity (∼2.7 μm/s) and high frequency (66%) of anterograde transport of APP cargo are impaired to a reduced velocity (∼1.83 μm/s) and a lower frequency (45%). We identified two novel elements linked to JIP1 function, located in the central region of JIP1b, that interact with the coiled-coil domain of kinesin light chain 1 (KLC1), in addition to the conventional interaction of the JIP1b 11–amino acid C-terminal (C11) region with the tetratricopeptide repeat of KLC1. High frequency of APP anterograde transport is dependent on one of the novel elements in JIP1b. Fast velocity of APP cargo transport requires the C11 domain, which is regulated by the second novel region of JIP1b. Furthermore, efficient APP axonal transport is not influenced by phosphorylation of APP at Thr-668, a site known to be phosphorylated by JNK. Our quantitative analysis indicates that enhanced fast-velocity and efficient high-frequency APP anterograde transport observed in neurons are mediated by novel roles of JIP1b.

scholarly journals Essential Role of the Oocyte in Estrogen Amplification of Follicle-Stimulating Hormone Signaling in Granulosa Cells

Endocrinology ◽  
2005 ◽  
Vol 146 (8) ◽  
pp. 3362-3367 ◽  
Author(s):  
Fumio Otsuka ◽  
R. Kelly Moore ◽  
Xia Wang ◽  
Shweta Sharma ◽  
Tomoko Miyoshi ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Granulosa Cells ◽  
Essential Role ◽  
Primary Cultures ◽  
The Novel ◽  
Camp Production ◽  
Lh Receptor ◽  
Cell Responses ◽  
A Site

Abstract The establishment of dominant ovarian follicles that are capable of ovulating fertilizable oocytes is a fundamental determinant of female fertility. This process is governed by pituitary gonadotropins as well as local ovarian factors. Within the follicle, estrogen acts in an autocrine/paracrine manner to enhance FSH action in the granulosa cells. These effects include the augmentation of P450aromatase expression and estradiol production. This feed-forward effect of estrogen is believed to play a key role in follicle dominance. Here we found the essential role of the oocyte in this physiological process using primary cultures of rat granulosa cells. In the presence, but not absence, of oocytes, estrogen amplified FSH-stimulated increases in mRNA expression of P450aromatase, FSH receptor, LH receptor, and inhibin α-, βA-, and βB-subunits as well as cAMP production. Thus, oocytes mediate the estrogen enhancement of FSH action in the granulosa cells. In comparison with FSH, cotreatment with estrogen and oocytes failed to amplify the stimulatory effects of forskolin or 8-bromoadenosine-cAMP on granulosa cell responses including P450aromatase mRNA expression and cAMP production, indicating that estrogen/oocytes amplify FSH action at a site upstream of adenylate cyclase. These findings support the novel conclusion that communication between the oocyte and granulosa cells plays a crucial role in mediating estrogen action during FSH-dependent folliculogenesis.

Domestic Poetics: Hippias' House in Achilles Tatius

2010 ◽  
Vol 29 (2) ◽  
pp. 327-348 ◽  
Author(s):  
Tim Whitmarsh
Keyword(s):  
The Novel ◽  
Love Elegy ◽  
Achilles Tatius ◽  
Roman Literature ◽  
Patriarchal Ideology ◽  
A Site ◽  
And Control

Other Greek novels open in poleis, before swiftly shunting their protagonists out of them and into the adventure world. Why does Achilles Tatius' Leucippe and Clitophon open in a house (with no sign of any political apparatus), and stay there for almost one quarter of the novel? This article explores the cultural, psychological, and metaliterary role of the house in Achilles, reading it as a site of conflict between the dominant, patriarchal ideology of the father and the subversive intent of the young lovers. If the house principally embodies the authoritarian will of the father to order and control, it nevertheless provides the lovers with opportunities to re-encode space opportunistically as erotic. The house cannot be reconstructed archaeologically (Clitophon is too flittish a narrator for that), but it is nevertheless clearly divided into different qualitative zones—diningroom, bedrooms, garden—each of which has its own psychosocial and emotional texture, its own challenges, and its own resources. Achilles' modelling of the house may reflect Roman ideas of domestic aristocratic display, and perhaps even the influence of Roman literature (particularly love elegy).

scholarly journals Influence of the B-site cation nature on crystal structure and magnetic properties of Ca2BMoO6 (B = Cr, La, Sm) double perovskite

2014 ◽  
Vol 22 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Ioana A. Gorodea
Keyword(s):  
Magnetic Properties ◽  
Sol Gel ◽  
Double Perovskite ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Ionic Radii ◽  
Auto Combustion ◽  
The Fourier Transform ◽  
First Time

Abstract Double perovskite-type oxide Ca2BMoO6 materials, where B = Cr, La and Sm, were prepared by the sol-gel auto-combustion method for the first time. The role of different B-site cations on their synthesis, structures, and magnetic properties was investigated. The synthesis progress was followed by the Fourier transform infrared spectroscopy and the samples’ structure was investigated by X-ray diffraction. The increase of the ionic radii B leads to the decrease of the t-value which reflects the structural distortion from the ideal cubic perovskite. Magnetization measurements were made with a SQUID magnetometer. All compounds are ferimagnetic and magnetic properties are indirectly influenced by the distortion degree of the lattice and disorder on the B/B’ positions

scholarly journals A novel carcinogenic PI3Kα mutation suggesting the role of helical domain in transmitting nSH2 regulatory signals to kinase domain

2020 ◽  
Author(s):  
Safoura Ghalamkari ◽  
Shahryar Alavi ◽  
Hamidreza Mianesaz ◽  
Farinaz Khosravian ◽  
Amir Bahreini ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Protein Function ◽  
Md Simulations ◽  
Binding Pocket ◽  
Kinase Domain ◽  
The Novel ◽  
Mutant Proteins ◽  
Helical Domain ◽  
Three Samples

Abstract Background Mutations in PIK3CA, which encodes p110 subunit of PI3K class IA enzyme, are highly frequent in breast cancer. Here, we aimed to probe mutations in exon 9 of PIK3CA and computationally simulate their function. Method PCR/HRM and PCR/sequencing were used for mutation detection in 40 breast cancer specimens. The identified mutations were queried via in silico algorithms to check the pathogenicity. The molecular dynamics (MD) simulations were utilized to assess the function of mutant proteins. Result Three samples were found to harbor at least one of the E542K, E545K and L551Q mutations of which L511Q has not been reported previously. All mutations were confirmed to be pathogenic and MD simulations revealed their impact on protein function and regulation. The novel L551Q mutant dynamics was similar to that of previously found carcinogenic mutants, E542K and E545K. A functional role for the helical domain was also suggested by which the inhibitory signal of p85α is conducted to kinase domain via helical domain. Helical domain mutations lead to impairment of kinase domain allosteric regulation. Interestingly, our results show that p110α substrate binding pocket of helical domain in mutants may have differential affinity for enzyme substrates, including anit-p110α drugs. Conclusion The novel p110α L551Q mutation could has carcinogenic feature similar to previously known mutations.

Performing Gender: Female Masculinity in D. H. Lawrence’s The Rainbow

2020 ◽  
Vol 10 ◽  
pp. 27-39
Author(s):  
Gol Man Gurung
Keyword(s):  
New Woman ◽  
Private Property ◽  
Theoretical Concept ◽  
Individual Identity ◽  
The Novel ◽  
Female Masculinity ◽  
Lesbian Woman ◽  
Women's Role ◽  
A Site

This paper analyses Ursula, the female protagonist of D. H. Lawrence’s the novel The Rainbow, who reflects her masculinity. Many feminist critics have perceived this novel as man-centered. In response to this analysis of the novel, the paper tries to look at the novel from the perspective of Judith Halberstam’s theoretical concept of female masculinity, especially Ursula as a masculine woman who acts like a man. Female masculinity is not an identity but a site for identification where different identities can flourish, but masculine women possess confidence, assertiveness, and independence. Lawrence gives justice to women’s role by presenting Ursula as a new woman who seeks her individual identity in the traditional world. Through the reading of the novel as its theoretical tool, the research concludes that females can be as males and males can be like females. She acts like a man and that means she has masculine qualities. The novelist portrays Ursula as a woman with masculinity because she can flourish different identities of her life. She plays the role of an independent woman, a liberated woman, a Lesbian woman, and a new woman, etc. She behaves like a tomboy who refuses to accept the Victorian conventions of society. So, she is a masculine woman rather than a feminine woman. This paper emphasizes how a woman can perform like a man; this suggests masculinity is not the private property of a male; it is a social position that can be practiced in an individual way.

scholarly journals A novel carcinogenic PI3Kα mutation suggesting the role of helical domain in transmitting nSH2 regulatory signals to kinase domain

2019 ◽  
Author(s):  
Safoura Ghalamkari ◽  
Sayed Shahryar Alavi Hejazi ◽  
Hamidreza Mianesaz ◽  
Farinaz Khosravian ◽  
Amir Bahreini ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Protein Function ◽  
Md Simulations ◽  
Binding Pocket ◽  
Kinase Domain ◽  
The Novel ◽  
Mutant Proteins ◽  
Helical Domain ◽  
Three Samples

Abstract Background Mutations in PIK3CA, which encodes p110 subunit of PI3K class IA enzyme, are highly frequent in breast cancer. Here, we aimed to probe mutations in exon 9 of PIK3CA and computationally simulate their function. Method PCR/HRM and PCR/sequencing were used for mutation detection in 40 breast cancer specimens. The identified mutations were queried via in silico algorithms to check the pathogenicity. The molecular dynamics (MD) simulations were utilized to assess the function of mutant proteins. Result Three samples were found to harbor at least one of the E542K, E545K and L551Q mutations of which L511Q has not been reported previously. All mutations were confirmed to be pathogenic and MD simulations revealed their impact on protein function and regulation. The novel L551Q mutant dynamics was similar to that of previously found carcinogenic mutants, E542K and E545K. A functional role for the helical domain was also suggested by which the inhibitory signal of p85α is conducted to kinase domain via helical domain. Helical domain mutations lead to impairment of kinase domain allosteric regulation. Interestingly, our results show that p110α substrate binding pocket of helical domain in mutants may have differential affinity for enzyme substrates, including anit-p110α drugs. Conclusion The novel p110α L551Q mutation could has carcinogenic feature similar to previously known mutations.

scholarly journals A novel carcinogenic PI3Kα mutation suggesting the role of helical domain in transmitting nSH2 regulatory signals to kinase domain

2020 ◽  
Author(s):  
Safoura Ghalamkari ◽  
Shahryar Alavi ◽  
Hamidreza Mianesaz ◽  
Farinaz Khosravian ◽  
Amir Bahreini ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Protein Function ◽  
Md Simulations ◽  
Binding Pocket ◽  
Kinase Domain ◽  
The Novel ◽  
Mutant Proteins ◽  
Helical Domain ◽  
Three Samples

Abstract Background Mutations in PIK3CA, which encodes p110 subunit of PI3K class IA enzyme, are highly frequent in breast cancer. Here, we aimed to probe mutations in exon 9 of PIK3CA and computationally simulate their function. Method PCR/HRM and PCR/sequencing were used for mutation detection in 40 breast cancer specimens. The identified mutations were queried via in silico algorithms to check the pathogenicity. The molecular dynamics (MD) simulations were utilized to assess the function of mutant proteins. Result Three samples were found to harbor at least one of the E542K, E545K and L551Q mutations of which L511Q has not been reported previously. All mutations were confirmed to be pathogenic and MD simulations revealed their impact on protein function and regulation. The novel L551Q mutant dynamics was similar to that of previously found carcinogenic mutants, E542K and E545K. A functional role for the helical domain was also suggested by which the inhibitory signal of p85α is conducted to kinase domain via helical domain. Helical domain mutations lead to impairment of kinase domain allosteric regulation. Interestingly, our results show that p110α substrate binding pocket of helical domain in mutants may have differential affinity for enzyme substrates, including anit-p110α drugs. Conclusion The novel p110α L551Q mutation could has carcinogenic feature similar to previously known mutations.

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