22 research outputs found

    Broadband diamagnetism in anisotropic metamaterials

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    We discuss the strategy for achieving the values of the effective magnetic permeability much smaller than unity by employing an appropriate arrangement of metamaterial elements ("meta-atoms"). We demonstrate that strong diamagnetism over a very wide frequency range can be realized in metamaterials by employing nonresonant elements with deeply subwavelength dimensions. We analyze the effect of the lattice parameters on the diamagnetic response and find that selecting an appropriate lattice type is crucial for optimal performance. Finally, we discuss the optimal characteristics required to obtain the lowest possible values of magnetic permeability and point out an efficient tuning possibility. © 2013 American Physical Society

    Chronic Myeloid Leukemia Patient Registry in the Russian Federation: From Observational Studies to the Efficacy Evaluation in Clinical Practice

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    Background. Due to the significant increase in life expectancy and the quality of life in patients with chronic myeloid leukemia (CML) as well as the growing need for expensive tyrosine kinase inhibitors (TKI), the analysis of cost-effectiveness and lifelong monitoring of patients is especially important. Aim. We present the results of a multicenter observational study “The Russian Registry of Chronic Myeloid Leukemia in routine clinical practice (2011–2016)”. Materials & Methods. The study included Russian patients with CML, confirmed by the detection of a Ph-chromosome or a BCR-ABL transcript. The statistical analysis (July 1, 2016) included 7609 patients from 80 regions of the Russian Federation (covering 95 % of the population). The annual increase in the number of patients with newly diagnosed CML was 600–650 patients. At the time of the statistical analysis, 6995 (92 %) patients remained under observation, 473 (6 %) died and 141 (2 %) were withdrawn. The registry included 44 % of men and 56 % of women, the median age was 49 years (range 2–94 years). The peak incidence (46.3 %) occurred at the age of 40–60 years. The median disease duration by the time of the analysis was 6 years (range 0.1–30 years). Results. The disease was diagnosed in the chronic phase (CP), acceleration phase, and blast crisis in 6560 (93.8 %), 380 (5.5 %) and 47 (0.7 %) patients, respectively. The proportion of risk groups according to Sokal for low, intermediate and high risk in CP was 49 %, 30 %, and 21 %, respectively. TKI were administered to 6473 (92.5 %) patients. Imatinib and the second generation TKI (TKI2) were administered to 5570 (86 %) and 903 (14 %) patients, respectively. The total of 30.4 % of patients received the increased imatinib dose of 600–800 mg. In the TKI2 group, 558 (61.7 %) patients received nilotinib and 345 (38.2 %) patients received dasatinib. The proportion of patients with completed molecular genetic studies (MGS) in 2014, 2015 and the first 6 months of 2016 amounted to 61 %, 58 % and 23 %, respectively. The proportion of patients with cytogenetic studies (CS) for the same period was 28 %, 26 % and 7 %, respectively. No CS or MGS data were presented for 34 %, 35 % and 63 % of patients during this period. Optimal molecular response and major molecular response (MMR) for TKI therapy were observed in 23 % and 58 % of patients treated 12 months, respectively. When nilotinib was used in the second line, MMR was obtained in 42 % of patients, and a deep molecular response was obtained in 25 % of patients (BCR-ABL < 0.01 %). Conclusion. The high efficacy of TKI therapy was observed in the majority of patients with the possibility of achieving a minimal residual disease. The problems concerning untimely monitoring and suboptimal administration of second line treatment were identified. In general, the CML patient registry allowed the data integration of data and information management of population with CML in Russia

    Evolution of a New Function by Degenerative Mutation in Cephalochordate Steroid Receptors

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    Gene duplication is the predominant mechanism for the evolution of new genes. Major existing models of this process assume that duplicate genes are redundant; degenerative mutations in one copy can therefore accumulate close to neutrally, usually leading to loss from the genome. When gene products dimerize or interact with other molecules for their functions, however, degenerative mutations in one copy may produce repressor alleles that inhibit the function of the other and are therefore exposed to selection. Here, we describe the evolution of a duplicate repressor by simple degenerative mutations in the steroid hormone receptors (SRs), a biologically crucial vertebrate gene family. We isolated and characterized the SRs of the cephalochordate Branchiostoma floridae, which diverged from other chordates just after duplication of the ancestral SR. The B. floridae genome contains two SRs: BfER, an ortholog of the vertebrate estrogen receptors, and BfSR, an ortholog of the vertebrate receptors for androgens, progestins, and corticosteroids. BfSR is specifically activated by estrogens and recognizes estrogen response elements (EREs) in DNA; BfER does not activate transcription in response to steroid hormones but binds EREs, where it competitively represses BfSR. The two genes are partially coexpressed, particularly in ovary and testis, suggesting an ancient role in germ cell development. These results corroborate previous findings that the ancestral steroid receptor was estrogen-sensitive and indicate that, after duplication, BfSR retained the ancestral function, while BfER evolved the capacity to negatively regulate BfSR. Either of two historical mutations that occurred during BfER evolution is sufficient to generate a competitive repressor. Our findings suggest that after duplication of genes whose functions depend on specific molecular interactions, high-probability degenerative mutations can yield novel functions, which are then exposed to positive or negative selection; in either case, the probability of neofunctionalization relative to gene loss is increased compared to existing models

    Comparative Composition, Diversity and Trophic Ecology of Sediment Macrofauna at Vents, Seeps and Organic Falls

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    Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but there has yet to be a systematic comparison of the community-level attributes of sediment macrobenthos in various reducing ecosystems. Here we review key similarities and differences in the sediment-dwelling assemblages of each system with the goals of (1) generating a predictive framework for the exploration and study of newly identified reducing habitats, and (2) identifying taxa and communities that overlap across ecosystems. We show that deep-sea seep, vent and organic-fall sediments are highly heterogeneous. They sustain different geochemical and microbial processes that are reflected in a complex mosaic of habitats inhabited by a mixture of specialist (heterotrophic and symbiont-associated) and background fauna. Community-level comparisons reveal that vent, seep and organic-fall macrofauna are very distinct in terms of composition at the family level, although they share many dominant taxa among these highly sulphidic habitats. Stress gradients are good predictors of macrofaunal diversity at some sites, but habitat heterogeneity and facilitation often modify community structure. The biogeochemical differences across ecosystems and within habitats result in wide differences in organic utilization (i.e., food sources) and in the prevalence of chemosynthesis-derived nutrition. In the Pacific, vents, seeps and organic-falls exhibit distinct macrofaunal assemblages at broad-scales contributing to ß diversity. This has important implications for the conservation of reducing ecosystems, which face growing threats from human activities

    Enhancement strategies for transdermal drug delivery systems: current trends and applications

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    Tailoring lattice parameters for broadband artificial diamagnetism

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    We report a strategy to achieve the values of the effective magnetic permeability close to zero by using anisotropic metamaterial made of dense arrays of conductive loops. We present an extensive parametric analysis of the role of lattice parameters and symmetry, and also of the geometry of the loops. The magnitudes of the real part of the permeability reach 0.05 and are observed in a very broad frequency span, accompanied with negligible dissipation. Importantly, our analysis is applicable in a wide range of absolute sizes, being appropriate up to the THz range. Finally, we assess the dielectric properties of the optimal diamagnetic meta-materials, providing a complete picture of its interaction with the electromagnetic waves. © 2013 IEEE
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