1,365 research outputs found
BMP2/BMPR1A is linked to tumour progression in dedifferentiated liposarcomas
Bone Morphogenic Protein 2 (BMP2) is a multipurpose cytokine, important in the development of bone and cartilage, and with a role in tumour initiation and progression. BMP2 signal transduction is dependent on two distinct classes of serine/threonine kinase known as the type I and type II receptors. Although the type I receptors (BMPR1A and BMPR1B) are largely thought to have overlapping functions, we find tissue and cellular compartment specific patterns of expression, suggesting potential for distinct BMP2 signalling outcomes dependent on tissue type. Herein, we utilise large publicly available datasets from The Cancer Genome Atlas (TCGA) and Protein Atlas to define a novel role for BMP2 in the progression of dedifferentiated liposarcomas. Using disease free survival as our primary endpoint, we find that BMP2 confers poor prognosis only within the context of high BMPR1A expression. Through further annotation of the TCGA sarcoma dataset, we localise this effect to dedifferentiated liposarcomas but find overall BMP2/BMP receptor expression is equal across subsets. Finally, through gene set enrichment analysis we link the BMP2/BMPR1A axis to increased transcriptional activity of the matrisome and general extracellular matrix remodelling. Our study highlights the importance of continued research into the tumorigenic properties of BMP2 and the potential disadvantages of recombinant human BMP2 (rhBMP2) use in orthopaedic surgery. For the first time, we identify high BMP2 expression within the context of high BMPR1A expression as a biomarker of disease relapse in dedifferentiated liposarcomas
Fuels and Burners for Domestic Heating
Discusses fuels and burners for domestic heating, including hand-fired coal or coke, automatic coal stoker, gas-fired heaters, oil burners. INlcudes table of comparative fuel costs
Order induced by dipolar interactions in a geometrically frustrated antiferromagnet
We study the classical Heisenberg model for spins on a pyrochlore lattice
interacting via long range dipole-dipole forces and nearest neighbor exchange.
Antiferromagnetic exchange alone is known not to induce ordering in this
system. We analyze low temperature order resulting from the combined
interactions, both by using a mean-field approach and by examining the energy
cost of fluctuations about an ordered state. We discuss behavior as a function
of the ratio of the dipolar and exchange interaction strengths and find two
types of ordered phase. We relate our results to the recent experimental work
and reproduce and extend the theoretical calculations on the pyrochlore
compound, GdTiO, by Raju \textit{et al.}, Phys. Rev. B {\bf 59},
14489 (1999).Comment: 5 pages, 5 figures, AMSLaTe
Ensemble dependence in the Random transverse-field Ising chain
In a disordered system one can either consider a microcanonical ensemble,
where there is a precise constraint on the random variables, or a canonical
ensemble where the variables are chosen according to a distribution without
constraints. We address the question as to whether critical exponents in these
two cases can differ through a detailed study of the random transverse-field
Ising chain. We find that the exponents are the same in both ensembles, though
some critical amplitudes vanish in the microcanonical ensemble for correlations
which span the whole system and are particularly sensitive to the constraint.
This can \textit{appear} as a different exponent. We expect that this apparent
dependence of exponents on ensemble is related to the integrability of the
model, and would not occur in non-integrable models.Comment: 8 pages, 12 figure
The Kagome Antiferromagnet with Defects: Satisfaction, Frustration, and Spin Folding in a Random Spin System
It is shown that site disorder induces noncoplanar states, competing with the
thermal selection of coplanar states, in the nearest neighbor, classical kagome
Heisenberg antiferromagnet (AFM). For weak disorder, it is found that the
ground state energy is the sum of energies of separately satisfied triangles of
spins. This implies that disorder does not induce conventional spin glass
behavior. A transformation is presented, mapping ground state spin
configurations onto a folded triangular sheet (a new kind of ``spin origami'')
which has conformations similar to those of tethered membranes.Comment: REVTEX, 11 pages + 3 pictures upon reques
Anisotropic Release of the Residual Zero-point Entropy in the Spin Ice Compound Dy2Ti2O7: Kagome-ice Behavior
We report the specific heat and entropy of single crystals of the spin ice
compound Dy2Ti2O7 at temperatures down to 0.35 K. We apply magnetic fields
along the four characteristic directions: [100], [110], [111] and [112].
Because of Ising anisotropy, we observe anisotropic release of the residual
zero-point entropy, attributable to the difference in frustration
dimensionality. In the high magnetic field along these four directions, the
residual entropy is almost fully released and the activation entropy reaches
Rln2. However, in the intermediate field region, the entropy in fields along
the [111] direction is different from those for the other three field
directions. For the [111] direction the frustration structure changes from that
of three-dimensional(3D) pyrochlore to that of two-dimensional(2D) Kagome-like
lattice with constraint due to the ice rule, leading to different values of
zero-point entropy.Comment: 4 pages, 4 figures, to appear in Phys. Rev.
Linear Field Dependence of the Normal-State In-Plane Magnetoresistance of Sr2RuO4
The transverse and longitudinal in-plane magnetoresistances in the normal
state of superconducting Sr2RuO4 single crystals have been measured. At low
temperatures, both of them were found to be positive with a linear
magnetic-field dependence above a threshold field, a result not expected from
electronic band theory. We argue that such behavior is a manifestation of a
novel coherent state characterized by a spin pseudo gap in the quasi-particle
excitation spectrum in Sr2RuO4.Comment: 4 pages + 5 figure
Susceptibility and dilution effects of the kagome bi-layer geometrically frustrated network. A Ga-NMR study of SrCr_(9p)Ga_(12-9p)O_(19)
We present an extensive gallium NMR study of the geometrically frustrated
kagome bi-layer compound SrCr_(9p)Ga_(12-9p)O_(19) (Cr^3+, S=3/2) over a broad
Cr-concentration range (.72<p<.95). This allows us to probe locally the kagome
bi-layer susceptibility and separate the intrinsic properties due to the
geometric frustration from those related to the site dilution. Our major
findings are: 1) The intrinsic kagome bi-layer susceptibility exhibits a
maximum in temperature at 40-50 K and is robust to a dilution as high as ~20%.
The maximum reveals the development of short range antiferromagnetic
correlations; 2) At low-T, a highly dynamical state induces a strong wipe-out
of the NMR intensity, regardless of dilution; 3) The low-T upturn observed in
the macroscopic susceptibility is associated to paramagnetic defects which stem
from the dilution of the kagome bi-layer. The low-T analysis of the NMR
lineshape suggests that the defect can be associated with a staggered
spin-response to the vacancies on the kagome bi-layer. This, altogether with
the maximum in the kagome bi-layer susceptibility, is very similar to what is
observed in most low-dimensional antiferromagnetic correlated systems; 4) The
spin glass-like freezing observed at T_g=2-4 K is not driven by the
dilution-induced defects.Comment: 19 pages, 19 figures, revised version resubmitted to PRB Minor
modifications: Fig.11 and discussion in Sec.V on the NMR shif
Overexpression of mineralocorticoid receptors does not affect memory and anxiety-like behavior in female mice
On the origin of carbon dioxide released from rewetted soils
When dry soils are rewetted a pulse of CO2 is invariably released, and whilst this phenomenon has been studied for decades, the precise origins of this CO2 remain obscure. We postulate that it could be of chemical (i.e. via abiotic pathways), biochemical (via free enzymes) or biological (via intact cells) origin. To elucidate the relative contributions of the pathways, dry soils were either sterilised (double autoclaving) or treated with solutions of inhibitors (15% trichloroacetic acid or 1% silver nitrate) targeting the different modes. The rapidity of CO2 release from the soils after the drying:rewetting (DRW) cycle was remarkable, with maximal rates of evolution within 6 min, and 41% of the total efflux over 96 h released within the first 24 h. The complete cessation of CO2 eflux following sterilisation showed there was no abiotic (dissolution of carbonates) contribution to the CO2 release on rewetting, and clear evidence for an organismal or biochemical basis to the flush. Rehydration in the presence of inhibitors indicated that there were approximately equal contributions from biochemical (outside membranes) and organismal (inside membranes) sources within the first 24 h after rewetting. This suggests that some of the flux was derived from microbial respiration, whilst the remainder was a consequence of enzyme activity, possibly through remnant respiratory pathways in the debris of dead cells
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