9,335 research outputs found
Relating Gribov-Zwanziger theory to effective Yang-Mills theory
We consider the Gribov-Zwanziger (GZ) theory with appropriate horizon term
which exhibits the nilpotent BRST invariance. This infinitesimal BRST
transformation has been generalized by allowing the parameter to be finite and
field dependent (FFBRST). By constructing appropriate finite field dependent
parameter we show that the generating functional of GZ theory with horizon term
is related to that of Yang-Mills (YM) theory through FFBRST transformation.Comment: 14 pages, No figure, to appear in Europhysics Lette
A personalised medicine approach for ponatinib-resistant chronic myeloid leukaemia.
BACKGROUND: Chronic myeloid leukaemia (CML) is characterised by the presence of a fusion driver oncogene, BCR-ABL1, which is a constitutive tyrosine kinase. Tyrosine kinase inhibitors (TKIs) are the central treatment strategy for CML patients and have significantly improved survival rates, but the T315I mutation in the kinase domain of BCR-ABL1 confers resistance to all clinically approved TKIs, except ponatinib. However, compound mutations can mediate resistance even to ponatinib and remain a clinical challenge in CML therapy. Here, we investigated a ponatinib-resistant CML patient through whole-genome sequencing (WGS) to identify the cause of resistance and to find alternative therapeutic targets. PATIENTS AND METHODS: We carried out WGS on a ponatinib-resistant CML patient and demonstrated an effective combination therapy against the primary CML cells derived from this patient in vitro. RESULTS: Our findings demonstrate the emergence of compound mutations in the BCR-ABL1 kinase domain following ponatinib treatment, and chromosomal structural variation data predicted amplification of BCL2. The primary CD34(+) CML cells from this patient showed increased sensitivity to the combination of ponatinib and ABT-263, a BCL2 inhibitor with a negligible effect against the normal CD34(+) cells. CONCLUSION: Our results show the potential of personalised medicine approaches in TKI-resistant CML patients and provide a strategy that could improve clinical outcomes for these patients
Nonlinear Effects and Multisolitons in Metamaterials
AbstractIn this paper, we outline a novel class of materials, called metamaterials, with negative refractive index and a high degree of nonlinearity. A brief summary is given on the basic theory of optics to show how this condition arrives for metamaterials to be designed into an antenna with split-ring-resonator (SRR). An example is given on the modeling of such SRR-based metamaterials. On a continuum Hamiltonian, a Klein-Gordon equation was derived which gave rise to both dark and bright solitons that showed interesting behavior against nondimensional time, even to the extent of revealing bi- and tri-breathers
Microstructural Study of Galvanized coatings formed in Pure as well as Commercial Grade Zn Baths
The hot dip galvanizing is a complex metallurgical process wherein a steel strip is immersed in a zinc alloy bath normally between 450 and 480°C. The protective coating
that is formed consists of a series of intermetallic Fe—Zn compound layers, which have been identified as gamma (r), delta (6), zeta (4) and an outer eta (T) layer, highly rich in Zn. There is no apparent delay in the formation of 4 or 6 phases (less than 5 s reaction time) in pure Zn bath as well as the commercial grade Zn bath. The gamma (I') phase is formed after an incubation time of 30 s at a bath temperature of 470°C in the pure Zn bath. The forma-tion and growth of F phase, however, is delayed in the commercial grade Zn bath. The last morphological feature is the formation of a second 4 layer at the 4/6 interface in reaction time above 30 s. Presence of Pb in the comme-rcial grade Zn bath seems to increase the overall coating thickness. Commercial grade Zn, however, enhances the dross formation in the bath and detoriates the quality of the coating. Presence of transverse cracks as well as entrapment of dross particles in these coatings is attr-ibuted to the less compact coatings that are formed in the commercial grade Zn baths. The present investigation is an effort to have a better understanding of the kinetics of
growth and morphology of the coatings during the galva-nizing process in the pure as well as commercial grade Zn baths
Statistical Mechanics of DNA Rupture: Theory and Simulations
We study the effects of the shear force on the rupture mechanism on a double
stranded DNA. Motivated by recent experiments, we perform the atomistic
simulations with explicit solvent to obtain the distributions of extension in
hydrogen and covalent bonds below the rupture force. We obtain a significant
difference between the atomistic simulations and the existing results in the
iterature based on the coarse-grained models (theory and simulations). We
discuss the possible reasons and improve the coarse-grained model by
incorporating the consequences of semi-microscopic details of the nucleotides
in its description. The distributions obtained by the modified model
(simulations and theoretical) are qualitatively similar to the one obtained
using atomistic simulations.Comment: 18 pages, 9 figures. Accepted in J. Chem. Phys. (2013). arXiv admin
note: text overlap with arXiv:1104.305
Critical behavior at de-pinning of a driven disordered vortex matter in 2H-NbS2
We report unusual jamming in driven ordered vortex flow in 2H-NbS2.
Reinitiating movement in these jammed vortices with a higher driving force, and
halting it thereafter once again with a reduction in drive, unfolds a critical
behavior centered around the de-pinning threshold via divergences in the
lifetimes of transient states, validating the predictions of a recent
simulation study, which also pointed out a correspondence between plastic
de-pinning in vortex matter and the notion of random organization proposed in
the context of sheared colloids undergoing diffusive motion.Comment: Phys. Rev. B (in press, 2012). The paper has 14 pages of Text+ Refs.
with 4 figures. (Note as some of the figure files are large in size, to
enable faster download, the file size has been kept small and the figure
resolution are low. The online version of the paper to appear in PRB will
contain the higher resolution figures
Humoral and cytokine response elicited during immunisation with recombinant Immune Mapped protein-1 (EtIMP-1) and oocysts of Eimeria tenella
Eimeria tenella, the causative agent of caecal coccidiosis, is a pathogenic gut dwelling protozoan which can cause severe morbidity and mortality in farmed chickens. Immune mapped protein-1 (IMP-1) has been identified as an anticoccidial vaccine candidate; in the present study allelic polymorphism was assessed across the IMP-1 coding sequence in E. tenella isolates from four countries and compared with the UK reference Houghton strain. Nucleotide diversity was low, limited to expansion/contraction of a CAG triplet repeat and five substitutions, three of which were non-synonymous. The EtIMP-1 coding sequence from a cloned Indian E. tenella isolate was expressed in E. coli and purified as a His-tagged thioredoxin fusion protein. An in-vivo vaccination and challenge trial was conducted to test the vaccine potential of recombinant EtIMP-1 (rEtIMP-1) and to compare post-vaccination immune responses of chickens to those stimulated by live oocyst infection. Following challenge, parasite replication measured using quantitative PCR was significantly reduced in chickens that had been vaccinated with rEtIMP-1 (rIC group; 67% reduction compared to UC or unimmunised controls; 79% reduction compared to rTC group or recombinant thioredoxin mock-immunised controls, p < 0.05), or the birds vaccinated by infection with oocysts (OC group, 90% compared to unimmunised controls). Chickens vaccinated with oocysts (OC) had significantly higher levels of interferon gamma in their serum post-challenge, compared to rEtIMP-1 vaccinated birds (rIC). Conversely rEtIMP-1 (rIC) vaccinated birds had significantly higher antigen specific serum IgY responses, correlating with higher serum IL-4 (both p < 0.05)
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