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Background The clinical utility of cartilage oligomeric matrix protein (COMP) as a diagnostic and prognostic biomarker is currently under intense study. COMP has been associated primarily with musculoskeletal disorders such as rheumatoid and osteoarthritis (OA) or muscular and ligament trauma. Aside from its established role as a biomarker of arthritis, an increasing number of studies have also suggested the role of COMP in tumorigenesis, based on findings of its expression in breast, prostate, and colon cancers. Case Presentation We described the case of a 61-year-old man with knee osteoarthritis and was prescribed physical therapy and a course of prolotherapy injection. We found elevated sCOMP levels in our patient (twice higher than average). After a month of follow-up, he was diagnosed with colorectal cancer. Conclusion It makes us wonder about other conditions of the patients. There is no standard COMP parameter to differentiate OA patients from colorectal cancer patients, but it considers the increase is higher in colorectal cancer patients. We suggest to clinicians who use the COMP level to monitor OA condition to be aware of other conditions when the level is much higher than average OA patients. more...

Primary biliary cirrhosis (PBC) is an autoimmune liver disease of unknown etiology and is characterized by chronic progressive cholestasis with destruction of the small intrahepatic bile ducts and associated most commonly with antimitochondrial antibodies. PBC is most common in women and is often associated with other autoimmune disease such as autoimmune hemolityc anemia (AIHA), rheumatoid arthritis, thyroiditis, and systemic lupus eritomatosus. We report one case, a 20 years old woman with AIHA have been treated by corticosteroid since last year and she came to the outpatient department (OPD) with fatique and jaundice. The result of laboratory were haemoglobin 8.7 mg/dL, white blood cell 8700 mg/dL, coomb test +2, total bilirubin 33.2 mg/dL, direct bilirubin 29.3 mg/dL, γGT: 297 mg/dL and alkalyphospatase: 158 mg/dL. The result of Abdominal CT scan showed the size of liver and spleen increased and normal common bile duct (CBD). The result of ANA test, anti-nuclear (ANA) and antimitochondrial M2 (AMA M2) antibodies were positive. From the physical examination, laboratory and CT scan Abdomen; the diagnose of this patient was AIHA with PBC. After treatment with corticosteroid (prednison 1mg/kg/day) and ursodeoxicholic acid (UDCA) for several weeks, the clinical manifestation of PBC such as jaundice getting better (the laboratory result: total bilirubin 2.7 mg/dL, direct bilirubin 1.5 mg/dL, gamma GT 80 mg/dL). more...

A general model for the dynamics of arrays of coupled, spin-polarised lasers is derived, which is shown to reduce to both the spin flip model in a single cavity and the coupled mode model for a pair of guides in the appropriate limit. The general model is able to deal with waveguides of any geometry with any number of supported normal modes. A unique feature of the model is that it allows for independent polarisation of the pumping in each laser. The particular geometry is shown to be introduced via `overlap factors', which are a generalisation of the optical confinement factor. These factors play an important role in determining the laser dynamics. The model is specialised to the case of a general double-guided structure, which is then analysed and simulated numerically. For this case it is found that increasing the ellipticity of the pumping tends to enhance the regions where stable solutions are predicted in the plane of pumping strength versus guide separation., Comment: 55 pages, 14 figures more...

We consider branched Josephson junction created by planar superconductors connected to each other through the Y-junction insulator. Assuming that the structure interacts with the external constant magnetic field, we study static sine-Gordon solitons in such system by modeling them in terms of the stationary sine-Gordon equation on metric graph. Exact analytical solutions of the problem are obtained and their stability is analyzed. more...

We consider a damped, parametrically driven discrete nonlinear Klein-Gordon equation, that models coupled pendula and micromechanical arrays, among others. To study the equation, one usually uses a small-amplitude wave ansatz, that reduces the equation into a discrete nonlinear Schr��dinger equation with damping and parametric drive. Here, we justify the approximation by looking for the error bound with the method of energy estimates. Furthermore, we prove the local and global existence of {solutions to the discrete nonlinear} Schr��dinger equation. To illustrate the main results, we consider numerical simulations showing the dynamics of errors made by the discrete nonlinear equation. We consider two types of initial conditions, with one of them being a discrete soliton of the nonlinear Schr��dinger equation, that is expectedly approximate discrete breathers of the nonlinear Klein-Gordon equation., arXiv admin note: text overlap with arXiv:1911.01631 more...

The coupled discrete linear and Kerr nonlinear Schrodinger equations with gain and loss describing transport on dimers with parity-time PT symmetric potentials are considered. The model is relevant among others to experiments in optical couplers and proposals on Bose-Einstein condensates in PT symmetric double-well potentials. It is known that the models are integrable. Here, the integrability is exploited further to construct the phase-portraits of the system. A pendulum equation with a linear potential and a constant force for the phase-difference between the fields is obtained, which explains the presence of unbounded solutions above a critical threshold parameter. The behaviour of all solutions of the system, including changes in the topological structure of the phase-plane, is then discussed., Comment: To appear in Physical Review A more...

We investigate numerically parametrically driven coupled nonlinear Schrodinger equations modelling the dynamics of coupled wavefields in a periodically oscillating double-well potential. The equations describe among other things two coupled periodically-curved optical waveguides with Kerr nonlinearity or horizontally shaken Bose-Einstein condensates in a double-well magnetic trap. In particular, we study the persistence of equilibrium states of the undriven system due to the presence of the parametric drive. Using numerical continuations of periodic orbits and calculating the corresponding Floquet multipliers, we find that the drive can (de)stabilize a continuation of an equilibrium state indicated by the change of the (in)stability of the orbit. Hence, we show that parametric drives can provide a powerful control to nonlinear (optical or matter wave) field tunneling. Analytical approximations based on an averaging method are presented. Using perturbation theory the influence of the drive on the symmetry breaking bifurcation point is discussed. more...

Travelling solitary waves in the one-dimensional discrete nonlinear Schr��dinger equation (DNLSE) with saturable onsite nonlinearity are studied. A variational approximation (VA) for the solitary waves is derived in an analytical form. The stability is also studied by means of the VA, demonstrating that the solitons are stable, which is consistent with previously published results. Then, the VA is applied to predict parameters of travelling solitons with non-oscillatory tails (\textit{embedded solitons}, ESs). Two-soliton bound states are considered too. The separation distance between the solitons forming the bound state is derived by means of the VA. A numerical scheme based on the discretization of the equation in the moving coordinate frame is derived and implemented using the Newton--Raphson method. In general, a good agreement between the analytical and numerical results is obtained. In particular, we demonstrate the relevance of the analytical prediction of characteristics of the embedded solitons., This paper is to appear in Journal of Physics A more...

We consider a parametrically driven damped discrete nonlinear Schr��dinger (PDDNLS) equation. Analytical and numerical calculations are performed to determine the existence and stability of fundamental discrete bright solitons. We show that there are two types of onsite discrete soliton, namely onsite type I and II. We also show that there are four types of intersite discrete soliton, called intersite type I, II, III, and IV, where the last two types are essentially the same, due to symmetry. Onsite and intersite type I solitons, which can be unstable in the case of no dissipation, are found to be stabilized by the damping, whereas the other types are always unstable. Our further analysis demonstrates that saddle-node and pitchfork (symmetry-breaking) bifurcations can occur. More interestingly, the onsite type I, intersite type I, and intersite type III-IV admit Hopf bifurcations from which emerge periodic solitons (limit cycles). The continuation of the limit cycles as well as the stability of the periodic solitons are computed through the numerical continuation software Matcont. We observe subcritical Hopf bifurcations along the existence curve of the onsite type I and intersite type III-IV. Along the existence curve of the intersite type I we observe both supercritical and subcritical Hopf bifurcations., to appear in "Spontaneous Symmetry Breaking, Self-Trapping, and Josephson Oscillations in Nonlinear Systems", B.A. Malomed, ed. (Springer, Berlin, 2012) more...

A periodically inhomogeneous Schrodinger equation is considered. The inhomogeneity is reflected through a non-uniform coefficient of the linear and non-linear term in the equation. Due to the periodic inhomogeneity of the linear term, the system may admit spectral bands. When the oscillation frequency of a localized solution resides in one of the finite band gaps, the solution is a gap soliton, characterized by the presence of infinitely many zeros in the spatial profile of the soliton. Recently, how to construct such gap solitons through a composite phase portrait is shown. By exploiting the phase-space method and combining it with the application of a topological argument, it is shown that the instability of a gap soliton can be described by the phase portrait of the solution. Surface gap solitons at the interface between a periodic inhomogeneous and a homogeneous medium are also discussed. Numerical calculations are presented accompanying the analytical results., Comment: Comments and suggestions are welcome more...

We consider a spatially non-autonomous discrete sine-Gordon equation with constant forcing and its continuum limit(s) to model a 0-$��$ Josephson junction with an applied bias current. The continuum limits correspond to the strong coupling limit of the discrete system. The non-autonomous character is due to the presence of a discontinuity point, namely a jump of $��$ in the sine-Gordon phase. The continuum models admits static solitary waves which are called $��$-kinks and are attached to the discontinuity point. For small forcing, there are three types of $��$-kinks. We show that one of the kinks is stable and the others are unstable. There is a critical value of the forcing beyond all static $��$-kinks fail to exist. Up to this value, the (in)stability of the $��$-kinks can be established analytically in the strong coupling limits. Applying a forcing above the critical value causes the nucleation of $2��$-kinks and -antikinks. Besides a $��$-kink, the unforced system also admits a static $3��$-kink. This state is unstable in the continuum models. By combining analytical and numerical methods in the discrete model, it is shown that the stable $��$-kink remains stable, and that the unstable $��$-kinks cannot be stabilized by decreasing the coupling. The $3��$-kink does become stable in the discrete model when the coupling is sufficiently weak., figures are not included due to file size limit more...

We consider a long Josephson junction with alternating 0- and $\pi$-facets with different facet lengths between the 0- and the $\pi$-parts. Depending on the combinations between the 0- and the $\pi$-facet lengths, an antiferromagnetically ordered semifluxons array can be the ground state of the system. Due to the fact that in that case there are two independent ground states, an externally introduced 2$\pi$ fluxon will be splintered or fractionalized. The magnitude of the flux in the fractional fluxons is a function of the difference between the 0 and the $\pi$-facet lengths. Here, we present an analytical calculation of the flux of splintered Josephson fluxons for any combination of 0- and $\pi$-facet lengths. In the presence of an applied bias current, we show numerically that only one of the two fractional fluxons can be moved. We also consider the I–V characteristics of the ground state and the one of a 2$\pi$-fluxon in a zig-zag junction. more...

We consider the dynamics of two coupled miscible Bose-Einstein condensates, when an obstacle is dragged through them. The existence of two different speeds of sound provides the possibility for three dynamical regimes: when both components are subcritical, we do not observe nucleation of coherent structures; when both components are supercritical they both form dark solitons in one dimension (1D) and vortices or rotating vortex dipoles in two dimensions (2D); in the intermediate regime, we observe the nucleation of a structure in the form of a dark-antidark soliton in 1D; subcritical component; the 2D analog of such a structure, a vortex-lump, is also observed., 4 pages, 4 figures, submitted to Phys Rev E more...

In this thesis, the stability of fractional Josephson vortices in Josephson junctions with phase shifts is investigated analytically and numerically. A Josephson junction which is made of two superconductors separated by a thin insulator can have phase shifts in its phase difference due to, e.g., the unconventional symmetry of the superconductors or a pair of current-injectors. In such a system, a magnetic field can be spontaneously generated at the discontinuity points that characterize the position of the phase shifts. more...

We consider Josephson vortices at tricrystal boundaries. We discuss the specific case of a tricrystal boundary with a pi junction as one of the three arms. It is recently shown that the static system admits an (n+1/2)phi(0) flux, n=0,1,2 [ Phys. Rev. B 61, 9122 (2000) ]. Here we present an analysis to calculate the linear stability of the admitted states. In particular, we calculate the stability of a 3phi(0)/2 flux. This state is of interest, since energetically this state is preferable for some combinations of Josephson lengths, but we show that in general it is linearly unstable. Finally, we propose a system that can have a stable (n+1/2)phi(0) state. more...

Subject of this study is the free boundary problem of a liquid layer that is dried by evaporation. Using a Stefan type problem, we model the diffusion driven drying of a layer of liquid paint consisting of resin and solvent. The effect of a small perturbation of the flat boundary is considered. We include the discussion of evaporation constant as a free parameter. For both small and big wavenumber, the high speed of evaporation can lead to instability. We first recognize this instability in the linearized equation. Using numerical calculations, we show that the instability also happens in the full equation. more...

AIM: to estimate the occupational risk of HBV, HCV and HIV infections among Indonesian HCWs. METHODS: the model developed by WHO was used to calculate the risk. The input parameters were selected from the best available evidence in Indonesia through a literature review. RESULTS: in 2005, sharps injuries led to an estimated 1445 infections with HBV, 399 with HCV and 18 with HIV among health-care workers (HCWs) in Indonesia. The attributable fractions of these infections due to sharps injuries among HCWs in Indonesia were estimated to be approximately 44%, 47%, and 11% for HBV, HCV and HIV, respectively. CONCLUSION: those data show that HCWs in Indonesia may face significant occupational risks of contracting viral hepatitis due to sharps injuries. In order to produce better estimates prospective studies in different health care settings are urgently needed. more...