345 research outputs found

    High frequency magnetic permeability of nanocomposite film

    Full text link
    The high frequency magnetic permeability of nanocomposite film consisting of the single-domain spherical ferromagnetic particles in the dielectric matrix is studied. The permeability is assumed to be determined by rotation of the ferromagnetic inclusion magnetic moments around equilibrium direction in AC magnetic field. The composite is modeled by a cubic array of ferromagnetic particles. The magnetic permeability tensor is calculated by solving the Landau-Lifshits-Gilbert equation accounting for the dipole interaction of magnetic particles. The permeability tensor components are found as functions of the frequency, temperature, ferromagnetic inclusions density and magnetic anisotropy. The obtained results show that nanocomposite films could have rather high value of magnetic permeability in the microwave range

    A Molecular Platinum Cluster Junction: A Single-Molecule Switch

    Full text link
    We present a theoretical study of the electronic transport through single-molecule junctions incorporating a Pt6 metal cluster bound within an organic framework. We show that the insertion of this molecule between a pair of electrodes leads to a fully atomically engineered nano-metallic device with high conductance at the Fermi level and two sequential high on/off switching states. The origin of this property can be traced back to the existence of a HOMO which consists of two degenerate and asymmetric orbitals, lying close in energy to the Fermi level of the metallic leads. Their degeneracy is broken when the molecule is contacted to the leads, giving rise to two resonances which become pinned close to the Fermi level and display destructive interference.Comment: 4 pages, 4 figures. Reprinted (adapted) with permission from J. Am. Chem. Soc., 2013, 135 (6), 2052. Copyright 2013 American Chemical Societ

    Magnetically recoverable graphene oxide supported Co@Fe 3 O 4 /L-dopa for C-C cross-coupling and oxidation reactions in aqueous medium

    Get PDF
    We report the synthesis of inexpensive and environmentally benign cobalt(0) nanoparticles on L-3,4-dihydroxyphenylalanine (L-dopa) functionalized and magnetite (Fe 3 O 4 ) grafted graphene oxide (Co@GO/Fe 3 O 4 /L-dopa) which was fully characterized with different techniques such as Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HR-TEM), X-Ray Photoelectron Spectroscopy (XPS), X-ray Powder Diffraction (XRD), Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Carbon Hydrogen Nitrogen (CHN) analysis, Energy Dispersive X-ray (EDX) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Graphene oxide was used as the core material due to its mechanical, electrical and thermal properties. In order to avoid the cumbersome process of separation, magnetite nanoparticles were coated over the graphene oxide. After the successful preparation of graphene oxide based magnetic nanoparticles, L-dopa was grafted over Fe 3 O 4 nanoparticles so as to provide firm anchoring agent for cobalt nanoparticles. Finally, cobalt(0) nanoparticles were immobilized on the developed magnetic support. The catalytic efficiency of the synthesized catalyst was tested for Suzuki cross-coupling and oxidation reactions, usually carried out by precious and expensive second and third row transition metals; products were obtained in good to excellent yields. The synthesized catalyst represents an attractive alternative to conventional catalysts for Suzuki cross-coupling and oxidation reactions, and is recyclable up to five runs

    Precision medicine in pediatric oncology: Lessons learned and next steps

    Full text link
    The maturation of genomic technologies has enabled new discoveries in disease pathogenesis as well as new approaches to patient care. In pediatric oncology, patients may now receive individualized genomic analysis to identify molecular aberrations of relevance for diagnosis and/or treatment. In this context, several recent clinical studies have begun to explore the feasibility and utility of genomics‐driven precision medicine. Here, we review the major developments in this field, discuss current limitations, and explore aspects of the clinical implementation of precision medicine, which lack consensus. Lastly, we discuss ongoing scientific efforts in this arena, which may yield future clinical applications.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/135962/1/pbc26288.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/135962/2/pbc26288_am.pd

    Current evidence and future perspectives on HuR and breast cancer development, prognosis, and treatment.

    Get PDF
    This is the Accepted Manuscript version of the following article, "Ioly Kotta-Loizou, et al., “Current Evidence and Future Perspectives on HuR and Breast Cancer Development, Prognosis, and Treatment”, Neoplasia, Vol. 18(11): 674-688, October 2016." The final published version is available at:https://doi.org/10.1016/j.neo.2016.09.002 Copyright © 2016, Elsevier.Hu-antigen R (HuR) is an RNA-binding posttranscriptional regulator that belongs to the Hu/ELAV family. HuR expression levels are modulated by a variety of proteins, microRNAs, chemical compounds, or the microenvironment, and in turn, HuR affects mRNA stability and translation of various genes implicated in breast cancer formation, progression, metastasis, and treatment. The aim of the present review is to critically summarize the role of HuR in breast cancer development and its potential as a prognosticator and a therapeutic target. In this aspect, all the existing English literature concerning HuR expression and function in breast cancer cell lines, in vivo animal models, and clinical studies is critically presented and summarized. HuR modulates many genes implicated in biological processes crucial for breast cancer formation, growth, and metastasis, whereas the link between HuR and these processes has been demonstrated directly in vitro and in vivo. Additionally, clinical studies reveal that HuR is associated with more aggressive forms of breast cancer and is a putative prognosticator for patients' survival. All the above indicate HuR as a promising drug target for cancer therapy; nevertheless, additional studies are required to fully understand its potential and determine against which types of breast cancer and at which stage of the disease a therapeutic agent targeting HuR would be more effective.Peer reviewedFinal Accepted Versio

    Transgene Expression Is Associated with Copy Number and Cytomegalovirus Promoter Methylation in Transgenic Pigs

    Get PDF
    Transgenic animals have been used for years to study gene function, produce important proteins, and generate models for the study of human diseases. However, inheritance and expression instability of the transgene in transgenic animals is a major limitation. Copy number and promoter methylation are known to regulate gene expression, but no report has systematically examined their effect on transgene expression. In the study, we generated two transgenic pigs by somatic cell nuclear transfer (SCNT) that express green fluorescent protein (GFP) driven by cytomegalovirus (CMV). Absolute quantitative real-time PCR and bisulfite sequencing were performed to determine transgene copy number and promoter methylation level. The correlation of transgene expression with copy number and promoter methylation was analyzed in individual development, fibroblast cells, various tissues, and offspring of the transgenic pigs. Our results demonstrate that transgene expression is associated with copy number and CMV promoter methylation in transgenic pigs

    Engineering Chimeric Antigen Receptor T-Cells for Racing in Solid Tumors: Don't Forget the Fuel.

    Get PDF
    T-cells play a critical role in tumor immunity. Indeed, the presence of tumor-infiltrating lymphocytes is a predictor of favorable patient prognosis for many indications and is a requirement for responsiveness to immune checkpoint blockade therapy targeting programmed cell death 1. For tumors lacking immune infiltrate, or for which antigen processing and/or presentation has been downregulated, a promising immunotherapeutic approach is chimeric antigen receptor (CAR) T-cell therapy. CARs are hybrid receptors that link the tumor antigen specificity and affinity of an antibody-derived single-chain variable fragment with signaling endodomains associated with T-cell activation. CAR therapy targeting CD19 has yielded extraordinary clinical responses against some hematological tumors. Solid tumors, however, remain an important challenge to CAR T-cells due to issues of homing, tumor vasculature and stromal barriers, and a range of obstacles in the tumor bed. Protumoral immune infiltrate including T regulatory cells and myeloid-derived suppressor cells have been well characterized for their ability to upregulate inhibitory receptors and molecules that hinder effector T-cells. A critical role for metabolic barriers in the tumor microenvironment (TME) is emerging. High glucose consumption and competition for key amino acids by tumor cells can leave T-cells with insufficient energy and biosynthetic precursors to support activities such as cytokine secretion and lead to a phenotypic state of anergy or exhaustion. CAR T-cell expansion protocols that promote a less differentiated phenotype, combined with optimal receptor design and coengineering strategies, along with immunomodulatory therapies that also promote endogenous immunity, offer great promise in surmounting immunometabolic barriers in the TME and curing solid tumors

    Anurans from the Lower Cretaceous Jehol Group of western Liaoning, China

    Get PDF
    BACKGROUND: To date, the Lower Cretaceous Jehol Group of western Liaoning, China has yielded five monotypic genera of anurans, including Liaobatrachus grabaui, Callobatrachus sanyanensis, Mesophryne beipiaoensis, Dalianbatrachus mengi, and Yizhoubatrachus macilentus. However, the validity and distinctness of these taxa have been questioned. METHODOLOGY/PRINCIPAL FINDING: We provide a comprehensive analysis of the Jehol frogs that includes a re-examination of the published taxa as well as an examination of a number of new specimens that have been collected over the past 10 years. The results show that the five previously named taxa can be referred to three species of one genus-Liaobatrachus grabaui, L. beipiaoensis comb. nov. and L. macilentus comb. nov.. The diagnosis of Liaobatrachus is revised, and a new diagnosis is provided for each species of this genus. We also establish Liaobatrachus zhaoi sp. nov., on the basis of a dozen well-preserved specimens from a new locality. This taxon is distinguished by a unique combination of characteristics, including relatively long hind limbs, a rounded rather than triangular acetabulum, and a gradually-tapering cultriform process of the parasphenoid. In addition, an unnamed frog from a higher horizon, which has narrow sacral diapophyses and particularly long legs, is different from Liaobatrachus and represents another form of anuran in the Jehol Biota. CONCLUSION/SIGNIFICANCE: Comparisons with other Mesozoic and extant anurans and the primary phylogenetic analysis both suggest that Liaobatrachus is a member of the anuran crown-group and forms a polytomy with leiopelmatids (Ascaphus and Leiopelma) and the remaining crown-group anurans (Lalagobatrachia).Liping Dong, Zbyněk Roček, Yuan Wang, Marc E H. Jone
    corecore