15,866 research outputs found
Controlled release of human growth hormone fused with a human hybrid Fc fragment through a nanoporous polymer membrane
Nanotechnology has been applied to the development of more effective and compatible drug delivery systems for therapeutic proteins. Human growth hormone (hGH) was fused with a hybrid Fc fragment containing partial Fc domains of human IgD and IgG(4) to produce a long-acting fusion protein. The fusion protein, hGH-hyFc, resulted in the increase of the hydrodynamic diameter (ca. 11 nm) compared with the diameter (ca. 5 nm) of the recombinant hGH. A diblock copolymer membrane with nanopores (average diameter of 14.3 nm) exhibited a constant release rate of hGH-hyFc. The hGH-hyFc protein released in a controlled manner for one month was found to trigger the phosphorylation of Janus kinase 2 (JAK2) in human B lymphocyte and to exhibit an almost identical circular dichroism spectrum to that of the original hGH-hyFc, suggesting that the released fusion protein should maintain the functional and structural integrity of hGH. Thus, the nanoporous release device could be a potential delivery system for the long-term controlled release of therapeutic proteins fused with the hybrid Fc fragment.X111313sciescopu
Random-key cuckoo search for the travelling salesman problem
Combinatorial optimization problems are typically NP-hard, and thus very challenging to solve. In this paper, we present the random key cuckoo search (RKCS) algorithm for solving the famous Travelling Salesman Problem (TSP). We used a simplified random-key encoding scheme to pass from a continuous space (real numbers) to a combinatorial space. We also consider the displacement of a solution in both spaces using L\'evy flights. The performance of the proposed RKCS is tested against a set of benchmarks of symmetric TSP from the well-known TSPLIB library. The results of the tests show that RKCS is superior to some other metaheuristic algorithms
An Efficient Representation of Euclidean Gravity I
We explore how the topology of spacetime fabric is encoded into the local
structure of Riemannian metrics using the gauge theory formulation of Euclidean
gravity. In part I, we provide a rigorous mathematical foundation to prove that
a general Einstein manifold arises as the sum of SU(2)_L Yang-Mills instantons
and SU(2)_R anti-instantons where SU(2)_L and SU(2)_R are normal subgroups of
the four-dimensional Lorentz group Spin(4) = SU(2)_L x SU(2)_R. Our proof
relies only on the general properties in four dimensions: The Lorentz group
Spin(4) is isomorphic to SU(2)_L x SU(2)_R and the six-dimensional vector space
of two-forms splits canonically into the sum of three-dimensional vector spaces
of self-dual and anti-self-dual two-forms. Consolidating these two, it turns
out that the splitting of Spin(4) is deeply correlated with the decomposition
of two-forms on four-manifold which occupies a central position in the theory
of four-manifolds.Comment: 31 pages, 1 figur
Effects of principal stress rotation on the wave–seabed interactions
This paper simulates the wave–seabed interactions considering the principal stress rotation (PSR) by using the finite element method. The soil model is developed within the framework of kinematic hardening and the bounding surface concept, and it can properly consider the impact of PSR by treating the PSR generating stress rate independently. The simulation results are compared with centrifuge test results. The comparison indicates that the simulation with the soil model considering the PSR can better reproduce the test results on the development of pore water pressure and liquefaction than the soil model without considering the PSR. It indicates that it is important to consider the PSR impact in simulation of wave–seabed soil interactions
An assessment of validity and responsiveness of generic measures of health-related quality of life in hearing impairment
This article is made available through the Brunel Open Access Publishing Fund. This article is distributed under the terms of the
Creative Commons Attribution License which permits any use, distribution,
and reproduction in any medium, provided the original
author(s) and the source are credited.Purpose: This review examines psychometric performance of three widely used generic preference-based measures, that is, EuroQol 5 dimensions (EQ-5D), Health Utility Index 3 (HUI3) and Short-form 6 dimensions (SF-6D) in patients with hearing impairments.
Methods: A systematic search was undertaken to identify studies of patients with hearing impairments where health state utility values were measured and reported. Data were extracted and analysed to assess the reliability, validity (known group differences and convergent validity) and responsiveness of the measures across hearing impairments.
Results: Fourteen studies (18 papers) were included in the review. HUI3 was the most commonly used utility measures in hearing impairment. In all six studies, the HUI3 detected difference between groups defined by the severity of impairment, and four out of five studies detected statistically significant changes as a result of intervention. The only study available suggested that EQ-5D only had weak ability to discriminate difference between severity groups, and in four out of five studies, EQ-5D failed to detected changes. Only one study involved the SF-6D; thus, the information is too limited to conclude on its performance. Also evidence for the reliability of these measures was not found.
Conclusion: Overall, the validity and responsiveness of the HUI3 in hearing impairment was good. The responsiveness of EQ-5D was relatively poor and weak validity was suggested by limited evidence. The evidence on SF-6D was too limited to make any judgment. More head-to-head comparisons of these and other preference measures of health are required.Medical Research Counci
Hot Streaks in Artistic, Cultural, and Scientific Careers
The hot streak, loosely defined as winning begets more winnings, highlights a
specific period during which an individual's performance is substantially
higher than her typical performance. While widely debated in sports, gambling,
and financial markets over the past several decades, little is known if hot
streaks apply to individual careers. Here, building on rich literature on
lifecycle of creativity, we collected large-scale career histories of
individual artists, movie directors and scientists, tracing the artworks,
movies, and scientific publications they produced. We find that, across all
three domains, hit works within a career show a high degree of temporal
regularity, each career being characterized by bursts of high-impact works
occurring in sequence. We demonstrate that these observations can be explained
by a simple hot-streak model we developed, allowing us to probe quantitatively
the hot streak phenomenon governing individual careers, which we find to be
remarkably universal across diverse domains we analyzed: The hot streaks are
ubiquitous yet unique across different careers. While the vast majority of
individuals have at least one hot streak, hot streaks are most likely to occur
only once. The hot streak emerges randomly within an individual's sequence of
works, is temporally localized, and is unassociated with any detectable change
in productivity. We show that, since works produced during hot streaks garner
significantly more impact, the uncovered hot streaks fundamentally drives the
collective impact of an individual, ignoring which leads us to systematically
over- or under-estimate the future impact of a career. These results not only
deepen our quantitative understanding of patterns governing individual
ingenuity and success, they may also have implications for decisions and
policies involving predicting and nurturing individuals with lasting impact
Risk factors and prognosis for salivary gland adenoid cystic carcinoma in southern china: A 25-year retrospective study
published_or_final_versio
Chemo- and Thermosensory Responsiveness of Grueneberg Ganglion Neurons Relies on Cyclic Guanosine Monophosphate Signaling Elements
Neurons of the Grueneberg ganglion (GG) in the anterior nasal region of mouse pups respond to cool temperatures and to a small set of odorants. While the thermosensory reactivity appears to be mediated by elements of a cyclic guanosine monophosphate (cGMP) cascade, the molecular mechanisms underlying the odor-induced responses are unclear. Since odor-responsive GG cells are endowed with elements of a cGMP pathway, specifically the transmembrane guanylyl cyclase subtype GC-G and the cyclic nucleotide-gated ion channel CNGA3, the possibility was explored whether these cGMP signaling elements may also be involved in chemosensory GG responses. Experiments with transgenic mice deficient for GC-G or CNGA3 revealed that GG responsiveness to given odorants was significantly diminished in these knockout animals. These findings suggest that a cGMP cascade may be important for both olfactory and thermosensory signaling in the GG. However, in contrast to the thermosensory reactivity, which did not decline over time, the chemosensory response underwent adaptation upon extended stimulation, suggesting that the two transduction processes only partially overlap. Copyright (C) 2011 S. Karger AG, Base
RNA polymerase II stalling promotes nucleosome occlusion and pTEFb recruitment to drive immortalization by Epstein-Barr virus
Epstein-Barr virus (EBV) immortalizes resting B-cells and is a key etiologic agent in the development of numerous cancers. The essential EBV-encoded protein EBNA 2 activates the viral C promoter (Cp) producing a message of ~120 kb that is differentially spliced to encode all EBNAs required for immortalization. We have previously shown that EBNA 2-activated transcription is dependent on the activity of the RNA polymerase II (pol II) C-terminal domain (CTD) kinase pTEFb (CDK9/cyclin T1). We now demonstrate that Cp, in contrast to two shorter EBNA 2-activated viral genes (LMP 1 and 2A), displays high levels of promoter-proximally stalled pol II despite being constitutively active. Consistent with pol II stalling, we detect considerable pausing complex (NELF/DSIF) association with Cp. Significantly, we observe substantial Cp-specific pTEFb recruitment that stimulates high-level pol II CTD serine 2 phosphorylation at distal regions (up to +75 kb), promoting elongation. We reveal that Cp-specific pol II accumulation is directed by DNA sequences unfavourable for nucleosome assembly that increase TBP access and pol II recruitment. Stalled pol II then maintains Cp nucleosome depletion. Our data indicate that pTEFb is recruited to Cp by the bromodomain protein Brd4, with polymerase stalling facilitating stable association of pTEFb. The Brd4 inhibitor JQ1 and the pTEFb inhibitors DRB and Flavopiridol significantly reduce Cp, but not LMP1 transcript production indicating that Brd4 and pTEFb are required for Cp transcription. Taken together our data indicate that pol II stalling at Cp promotes transcription of essential immortalizing genes during EBV infection by (i) preventing promoter-proximal nucleosome assembly and ii) necessitating the recruitment of pTEFb thereby maintaining serine 2 CTD phosphorylation at distal regions
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