1,727 research outputs found
Interacting dimers on the honeycomb lattice: An exact solution of the five-vertex model
The problem of close-packed dimers on the honeycomb lattice was solved by
Kasteleyn in 1963. Here we extend the solution to include interactions between
neighboring dimers in two spatial lattice directions. The solution is obtained
by using the method of Bethe ansatz and by converting the dimer problem into a
five-vertex problem. The complete phase diagram is obtained and it is found
that a new frozen phase, in which the attracting dimers prevail, arises when
the interaction is attractive. For repulsive dimer interactions a new
first-order line separating two frozen phases occurs. The transitions are
continuous and the critical behavior in the disorder regime is found to be the
same as in the case of noninteracting dimers characterized by a specific heat
exponent \a=1/2.Comment: latex, 29 pages + 7 figure
Long-Term Follow-Up of Intravitreal Ranibizumab for the Treatment of Choroidal Neovascularization due to Choroidal Osteoma
Choroidal osteoma is an uncommon benign osseous intraocular tumor that typically affects young adult women. Choroidal neovascularization (CNV) is one of the complications that can develop in eyes with choroidal osteoma. We present a case of CNV secondary to choroidal osteoma treated with intravitreal ranibizumab. A 57-year-old lady presented with painless loss of vision with a right-eye visual acuity of 20/800. Fundus examination showed a well-demarcated yellowish peripapillary choroidal osteoma with associated retinal and subretinal hemorrhage due to CNV. Three intravitreal ranibizumab injections at monthly intervals were given and her visual acuity improved to 20/30 following treatment. After 1.2 years of follow-up, the right eye visual acuity was maintained at 20/30 with no evidence of CNV recurrence. Our findings suggest that intravitreal ranibizumab may be an effective therapeutic option for treating CNV secondary to choroidal osteoma
K-Ras and β-catenin mutations cooperate with Fgfr3 mutations in mice to promote tumorigenesis in the skin and lung, but not in the bladder
The human fibroblast growth factor receptor 3 (FGFR3) gene is frequently mutated in superficial urothelial cell carcinoma (UCC). To test the functional significance of FGFR3 activating mutations as a ‘driver’ of UCC, we targeted the expression of mutated Fgfr3 to the murine urothelium using Cre-loxP recombination driven by the uroplakin II promoter. The introduction of the Fgfr3 mutations resulted in no obvious effect on tumorigenesis up to 18 months of age. Furthermore, even when the Fgfr3 mutations were introduced together with K-Ras or β-catenin (Ctnnb1) activating mutations, no urothelial dysplasia or UCC was observed. Interestingly, however, owing to a sporadic ectopic Cre recombinase expression in the skin and lung of these mice, Fgfr3 mutation caused papilloma and promoted lung tumorigenesis in cooperation with K-Ras and β-catenin activation, respectively. These results indicate that activation of FGFR3 can cooperate with other mutations to drive tumorigenesis in a context-dependent manner, and support the hypothesis that activation of FGFR3 signaling contributes to human cancer
The lifetime of B_c-meson and some relevant problems
The lifetime of the B_c-meson is estimated with consistent considerations on
all of the heavy mesons () and the double
heavy meson B_c. In the estimate, the framework, where the non-spectator
effects for nonleptonic decays are taken into account properly, is adopted, and
the parameters needed to be fixed are treated carefully and determined by
fitting the available data. The bound-state effects in it are also considered.
We find that in decays of the meson B_c, the QCD correction terms of the
penguin diagrams and the main component terms c_1O_1, c_2O_2 of the effective
interaction Lagrangian have direct interference that causes an enhancement
about 3 ~ 4% in the total width of the B_c meson.Comment: 27 pages, 0 figur
Characteristics and Sensing Properties of the La1-xNdxCo0.3Fe0.7O3 System for CO Gas Sensors
A series of nanostructured La1-xNdxCo0.3Fe0.7O3 perovskite-type (x ranging from 0 to 1) were prepared using the co-precipitation method. CO gas sensing properties of La1-xNdxCo0.3Fe0.7O3 sensors were performed. La0.7Nd0.3Co0.3Fe0.7O3 sensor showed the highest response at 250 °C (S=52.8)
Applicability of perturbative QCD to decays
We develop perturbative QCD factorization theorem for the semileptonic heavy
baryon decay , whose form factors are
expressed as the convolutions of hard quark decay amplitudes with universal
and baryon wave functions. Large logarithmic
corrections are organized to all orders by the Sudakov resummation, which
renders perturbative expansions more reliable. It is observed that perturbative
QCD is applicable to decays for velocity transfer
greater than 1.2. Under requirement of heavy quark symmetry, we predict the
branching ratio , and determine
the and baryon wave functions.Comment: 12 pages in Latex file, 3 figures in postscript files, some results
are changed, but the conclusion is the sam
Genetics of diabetic microvascular disease
Publisher Copyright: © 2020 John Wiley & Sons, Inc.Diabetic microvascular complications, affecting the kidneys, retina, and the nervous system, are a heavy burden for both the diabetic individual and society. The complications seem to cluster in families suggesting a genetic component in their pathogenesis. However, the actual genetic factors have long remained unknown. During the past few years, major advances have been made with large-scale genetic studies that have identified common genetic risk factors, e.g. in the AFF3 and CNKSR3 gene loci affecting the risk of diabetic kidney disease (DKD) end-stage renal disease. There is increasing evidence that genetic factors affecting kidney disease in non-diabetic individuals also affect the risk in individuals with type 2 diabetes (T2D), while less evidence is found for individuals with type 1 diabetes (T1D). While genetic explorations for diabetic retinopathy remain limited in sample size, a recent genome-wide association study (GWAS) identified variants associated with retinopathy on the GRB2 gene. Nevertheless, the field is still lacking strong validated genetic markers. In the future, better phenotyping, larger studies, and exploration of the rare variation are essential to identify the genetic causes behind diabetic microvascular complications, and to understand the interplay between genes and environment.Peer reviewe
Detecting the intermediate-mass Higgs boson through the associate production channel pp --> t + anti-t + H + X
We examine the detection of the intermediate-mass Higgs boson (IMH) at LHC
through the associate production channel pp-->t+(anti-t)+H+X-->l+photon+
photon+X'. It is shown that by applying kinematic cuts or b-tagging on the
final state jets, the main backgrounds of W(-->l+nu)+photon+photon+(n-jet) can
be reduced substantially without significant loss of signals. It is possible to
detect the Higgs boson at LHC through the pp-->t+(anti-t)+H+X channel using a
modest photon detector with mass resolution of about 3% of the photon pair
invariant mass.Comment: 10 pages, standard LaTex fil
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