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  • 1
    Publication Date: 2015-09-12
    Description: The study on structural, microstructural, magnetic, and hyperfine properties of nanosized Co 0.2 Zn 0.8 Fe 2 O 4 having particle size ∼18 nm (CZM) synthesized by high energy ball milling of Co 0.2 Zn 0.8 Fe 2 O 4 nanoparticles of size ∼20 nm (CZ) produced by flow rate controlled coprecipitation method has revealed that the inclusion of strain induced anisotropy produced by mechanical treatment and escalation of oxygen mediated intersublattice exchange interaction of spinel ferrites by tuning cation distribution properly, can improve the magnetic quality of nanosized ferrites significantly. This upshot will be of immense help in promoting the technological application of nanostructured ferrites. The Rietveld refinement of powder x-ray diffraction pattern and the analysis of transmission electron micrographs, energy dispersive x-ray spectrum, and FTIR spectrum of the sample have confirmed that CZM is single phase cubic nanometric spinel ferrite of Fd 3 ¯ m symmetry and it possesses large microstrain within its crystal lattice. The dc magnetic and Mössbauer spectroscopic studies together with indicate that the particles in the sample are composed of ferrimagnetically aligned core and spin-glass like shell and the system behaves superparamagnetically at 300 K. The saturation magnetization (44 and 87 emu g −1 at 300 and 10 K) and hyperfine field of the sample are substantially higher than its counterparts reported earlier. In spite of its lower size compared to CZ, the blocking temperature (∼220 K) of CZM is higher than that of CZ (70 K) and also that of its counterparts synthesized by chemical methods. The strengthening of the intersublattice A-O-B superexchange interaction because of migration of Fe 3+ ions from octahedral [B] to tetrahedral (A) sites in lieu of the relocation of Zn 2+ among (A) and [B] sites helps in enhancement of magnetization and hyperfine field of CZM. The giant coercivity (H C  ∼ 5600 Oe at 10 K) of CZM is accounted by the presence of spin glass like surface layer in the sample. Moreover, the system exhibits striking memory effect which can be suitably utilized in storing binary bits (0, 1) through magnetic field change in the cooling cycle of magnetization versus temperature profile, and the stored binary coded number can be faithfully retrieved in the heating cycle.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
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  • 2
    Publication Date: 2019
    Description: 〈p〉Metastable phenotypic state transitions in cancer cells can lead to the development of transient adaptive resistance or tolerance to chemotherapy. Here, we report that the acquisition of a phenotype marked by increased abundance of CD44 (CD44〈sup〉Hi〈/sup〉) by breast cancer cells as a tolerance response to routinely used cytotoxic drugs, such as taxanes, activated a metabolic switch that conferred tolerance against unrelated standard-of-care chemotherapeutic agents, such as anthracyclines. We characterized the sequence of molecular events that connected the induced CD44〈sup〉Hi〈/sup〉 phenotype to increased activity of both the glycolytic and oxidative pathways and glucose flux through the pentose phosphate pathway (PPP). When given in a specific order, a combination of taxanes, anthracyclines, and inhibitors of glucose-6-phosphate dehydrogenase (G6PD), an enzyme involved in glucose metabolism, improved survival in mouse models of breast cancer. The same sequence of the three-drug combination reduced the viability of patient breast tumor samples in an explant system. Our findings highlight a convergence between phenotypic and metabolic state transitions that confers a survival advantage to cancer cells against clinically used drug combinations. Pharmacologically targeting this convergence could overcome cross-drug tolerance and could emerge as a new paradigm in the treatment of cancer.〈/p〉
    Print ISSN: 1945-0877
    Electronic ISSN: 1937-9145
    Topics: Biology , Medicine
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  • 3
    Publication Date: 2016-02-28
    Description: Burg’s entropy plays an important role in this age of information euphoria, particularly in understanding the emergent behavior of a complex system such as statistical mechanics. For discrete or continuous variable, maximization of Burg’s Entropy subject to its only natural and mean constraint always provide us a positive density function though the Entropy is always negative. On the other hand, Burg’s modified entropy is a better measure than the standard Burg’s entropy measure since this is always positive and there is no computational problem for small probabilistic values. Moreover, the maximum value of Burg’s modified entropy increases with the number of possible outcomes. In this paper, a premium has been put on the fact that if Burg’s modified entropy is used instead of conventional Burg’s entropy in a maximum entropy probability density (MEPD) function, the result yields a better approximation of the probability distribution. An important lemma in basic algebra and a suitable example with tables and graphs in statistical mechanics have been given to illustrate the whole idea appropriately.
    Electronic ISSN: 2227-7390
    Topics: Mathematics
    Published by MDPI
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  • 4
    Publication Date: 2019
    Description: Abstract The seasonal and interannual variability of the Brazil Current (BC) at 22°S is examined using expendable bathythermograph (XBT) transect and satellite altimetry data from 1993 to 2017. The XBT‐based mean absolute geostrophic transport of the BC is estimated as 4.7 ± 1.9 Sv, with additional 0.9 ± 0.9 Sv along the shelf. The strong agreement between the absolute dynamic height and altimetric sea surface height is used in two methods to reconstruct a daily time series of the BC transport since 1993. The altimetry‐based methods can represent well the BC transport seasonal cycle, whereas the XBT‐based estimates are slightly aliased by the strong regional mesoscale variability. At interannual timescales, the BC transport is significantly correlated (r = 0.43) with the wind stress curl in the western half of the basin with a lag of 19 months, which is consistent with baroclinic adjustment timescales. Other sources of variability can be observed in a case study of the summer 2009/2010 event, which was characterized by strong sea surface temperature anomalies of approximately 3 °C. During the event, the BC reached 11 Sv for nearly 3 months, partly driven by an increased coastal upwelling from a cyclonic wind stress anomaly, a standing eddy along the section, and thermosteric anomalies that reached the offshore side of section in February. Heat anomalies were transported southward along the subtropical gyre following the BC path in a period of 2 months, which is consistent with advective timescales. Potential implications for extreme sea level and summer precipitation events in South America are discussed.
    Print ISSN: 2169-9275
    Electronic ISSN: 2169-9291
    Topics: Geosciences , Physics
    Published by Wiley on behalf of American Geophysical Union (AGU).
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  • 5
    Publication Date: 2014-08-13
    Description: The authors find that for mechanically milled Ni 0.5 Zn 0.5 Fe 2 O 4 (∼10 nm), the mechanical strain induced enhancement of anisotropy energy helps to retain stable magnetic order. The reduction of magnetization can be prevented by keeping the cation distribution of nanometric ferrites at its equilibrium ratio. Moreover, the sample can be used in coding, storing, and retrieving of binary bit (“0” and “1”) through magnetic field change.
    Print ISSN: 0003-6951
    Electronic ISSN: 1077-3118
    Topics: Physics
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  • 6
    Publication Date: 2008-03-26
    Description: The neuronal repressor REST (RE1-silencing transcription factor; also called NRSF) is expressed at high levels in mouse embryonic stem (ES) cells, but its role in these cells is unclear. Here we show that REST maintains self-renewal and pluripotency in mouse ES cells through suppression of the microRNA miR-21. We found that, as with known self-renewal markers, the level of REST expression is much higher in self-renewing mouse ES cells than in differentiating mouse ES (embryoid body, EB) cells. Heterozygous deletion of Rest (Rest+/-) and its short-interfering-RNA-mediated knockdown in mouse ES cells cause a loss of self-renewal-even when these cells are grown under self-renewal conditions-and lead to the expression of markers specific for multiple lineages. Conversely, exogenously added REST maintains self-renewal in mouse EB cells. Furthermore, Rest+/- mouse ES cells cultured under self-renewal conditions express substantially reduced levels of several self-renewal regulators, including Oct4 (also called Pou5f1), Nanog, Sox2 and c-Myc, and exogenously added REST in mouse EB cells maintains the self-renewal phenotypes and expression of these self-renewal regulators. We also show that in mouse ES cells, REST is bound to the gene chromatin of a set of miRNAs that potentially target self-renewal genes. Whereas mouse ES cells and mouse EB cells containing exogenously added REST express lower levels of these miRNAs, EB cells, Rest+/- ES cells and ES cells treated with short interfering RNA targeting Rest express higher levels of these miRNAs. At least one of these REST-regulated miRNAs, miR-21, specifically suppresses the self-renewal of mouse ES cells, corresponding to the decreased expression of Oct4, Nanog, Sox2 and c-Myc. Thus, REST is a newly discovered element of the interconnected regulatory network that maintains the self-renewal and pluripotency of mouse ES cells.〈br /〉〈br /〉〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830094/" target="_blank"〉〈img src="https://static.pubmed.gov/portal/portal3rc.fcgi/4089621/img/3977009" border="0"〉〈/a〉   〈a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2830094/" target="_blank"〉This paper as free author manuscript - peer-reviewed and accepted for publication〈/a〉〈br /〉〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Singh, Sanjay K -- Kagalwala, Mohamedi N -- Parker-Thornburg, Jan -- Adams, Henry -- Majumder, Sadhan -- CA81255/CA/NCI NIH HHS/ -- CA97124/CA/NCI NIH HHS/ -- P30 CA016672/CA/NCI NIH HHS/ -- R01 CA081255/CA/NCI NIH HHS/ -- R01 CA081255-10/CA/NCI NIH HHS/ -- R01 CA097124/CA/NCI NIH HHS/ -- R01 CA097124-07/CA/NCI NIH HHS/ -- England -- Nature. 2008 May 8;453(7192):223-7. doi: 10.1038/nature06863. Epub 2008 Mar 23.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Cancer Genetics, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/18362916" target="_blank"〉PubMed〈/a〉
    Keywords: Animals ; Biomarkers ; Cell Differentiation ; Cell Line ; Cell Lineage ; Cell Proliferation ; Chromatin/genetics/metabolism ; Embryonic Stem Cells/*cytology/*metabolism ; Mice ; Mice, Inbred C57BL ; Pluripotent Stem Cells/*cytology/*metabolism ; Repressor Proteins/genetics/*metabolism ; Transcription Factors/deficiency/genetics/*metabolism
    Print ISSN: 0028-0836
    Electronic ISSN: 1476-4687
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
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  • 7
    Publication Date: 2013-08-21
    Description: The primary antigen receptor repertoire is sculpted by the process of V(D)J recombination, which must strike a balance between diversification and favoring gene segments with specialized functions. The precise determinants of how often gene segments are chosen to complete variable region coding exons remain elusive. We quantified Vβ use in...
    Print ISSN: 0027-8424
    Electronic ISSN: 1091-6490
    Topics: Biology , Medicine , Natural Sciences in General
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  • 8
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 116 (1994), S. 3261-3270 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 38 (1982), S. 1251-1253 
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Feeding various dosages of benzene hexachloride (100, 250, 750 and 1500 ppm) in the diet to weanling male albino rats for 90 days resulted in marked hypertrophy of the adrenals with large, vacuolated cells in the cortex at 750 and 1500 ppm. Accumulation of cholesterol-positive lipids and marked reduction in the activities of steroidogenic enzymes such asΔ 5 3β HSDH, 11β HSDH, G-6-PDH and SDH were seen using histochemical methods in the adrenal cortex of rats fed 750 and 1500 ppm. The results are suggestive of steroidogenic inhibition at 750 and 1500 ppm of dietary BHC while 100 and 250 ppm did not produce any discernible changes in the adrenal cortex.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of food science 21 (1956), S. 0 
    ISSN: 1750-3841
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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