Decellularized bovine meniscus in morphological assessment prior to bioscaffold preparation

Decellularization is a process of tissue treatment targeting cell removal. Sonication system was developed in order to decellularize meniscus tissues. The samples were sonicated in 0.1% sodium dodecyl sulphate (SDS) for 10 hours and at 40 kHz ultrasound frequency. All the samples were structurally examined using van Gieson, Picrosirius red, Safranin-O/Fast green staining, and scanning electron microscopic (SEM) observation. Histological analysis of sonication treated-samples by van Gieson staining demonstrated complete nuclei removal compared to the control samples. The Picrosirius red and Safranin-O/Fast green staining indicate the preservation of collagen and glycosaminoglycans (GAGs) structure, respectively. In addition, the morphological observation by SEM shows the availability of micropores on the surface of decellularized sample. Consequently, the sonication decellularization treatment did not affect extracellular matrix (ECM) properties, while forming micropores on the surface of meniscus tissues. This made it possible to proceed in other fulfillment of bioscaffold preparation

In vitro recellularization of aorta scaffolds prepared by sonication treatment

Sonication treatment is used in the preparation of bioscaffolds that was able to support repopulation of vascular smooth muscle cells (VSMCs) upon cell-seeding. The aim of this study is to investigate the ability of sonicatedly decellularized tissue to repopulate VSMCs after 6 days of cell-seeding. In this study, sample of aorta tissues are decellularized by sonication treatment in 0.1% and 2% sodium dodecyl sulfate (SDS) detergent for 10 hours. It was followed by washing process with PBS solution for 5 days. Decellularized aorta tissues are then cell seeded with VSMCs by static seeding in 96-well plate containing Dulbecco's Modified Eagle Medium (DMEM) at 37°C. The infiltrations of VSMCs onto decellularized tissues are evaluated by comparison of Hematoxylin-Eosin (H-E) staining at 0 and 6 days of cell-seeding. The histological results of cell-seeding showed that VSMCs are able to infiltrate onto the decellularized tissues. From the results, sonicatedly decellularized tissue treated in 0.1% and 2% SDS, seeded with VSMCs showed infiltration depth of 0.43 mm and 0.35 mm, respectively. Hence, a sonicated decellularized tissue treated with 0.1% and 2% SDS was shown to support the repopulation of VSMCs

Ultrafast dynamics of coherent optical phonons and nonequilibrium electrons in transition metals

The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time domain is well fitted by linear combination of a damped harmonic oscillation because of excitation of coherent $E_{2g}$ phonon and a subpicosecond transient response due to electron-phonon thermalization. The electron-phonon thermalization time monotonically increases with temperature, consistent with the thermomodulation scenario, where at high temperatures the system can be well explained by the two-temperature model, while below $\approx$ 50 K the nonthermal electron model needs to be applied. As the lattice temperature increases, the damping of the coherent $E_{2g}$ phonon increases, while the amplitudes of both fast electronic response and the coherent $E_{2g}$ phonon decrease. The temperature dependence of the damping of the $E_{2g}$ phonon indicates that population decay of the coherent optical phonon due to anharmonic phonon-phonon coupling dominates the decay process. We present a model that accounts for the observed temperature dependence of the amplitude assuming the photoinduced absorption mechanism, where the signal amplitude is proportional to the photoinduced change in the quasiparticle density. The result that the amplitude of the $E_{2g}$ phonon follows the temperature dependence of the amplitude of the fast electronic transient indicates that under the resonant condition both electronic and phononic responses are proportional to the change in the dielectric function.Comment: 10 pages, 9 figures, to appear in Physical Review

Immittance Matching for Multi-dimensional Open-system Photonic Crystals

An electromagnetic (EM) Bloch wave propagating in a photonic crystal (PC) is characterized by the immittance (impedance and admittance) of the wave. The immittance is used to investigate transmission and reflection at a surface or an interface of the PC. In particular, the general properties of immittance are useful for clarifying the wave propagation characteristics. We give a general proof that the immittance of EM Bloch waves on a plane in infinite one- and two-dimensional (2D) PCs is real when the plane is a reflection plane of the PC and the Bloch wavevector is perpendicular to the plane. We also show that the pure-real feature of immittance on a reflection plane for an infinite three-dimensional PC is good approximation based on the numerical calculations. The analytical proof indicates that the method used for immittance matching is extremely simplified since only the real part of the immittance function is needed for analysis without numerical verification. As an application of the proof, we describe a method based on immittance matching for qualitatively evaluating the reflection at the surface of a semi-infinite 2D PC, at the interface between a semi-infinite slab waveguide (WG) and a semi-infinite 2D PC line-defect WG, and at the interface between a semi-infinite channel WG and a semi-infinite 2D PC slab line-defect WG.Comment: 8 pages, 6 figure

Magnetized Accretion-Ejection Structures: 2.5D MHD simulations of continuous Ideal Jet launching from resistive accretion disks

We present numerical magnetohydrodynamic (MHD) simulations of a magnetized accretion disk launching trans-Alfvenic jets. These simulations, performed in a 2.5 dimensional time-dependent polytropic resistive MHD framework, model a resistive accretion disk threaded by an initial vertical magnetic field. The resistivity is only important inside the disk, and is prescribed as eta = alpha_m V_AH exp(-2Z^2/H^2), where V_A stands for Alfven speed, H is the disk scale height and the coefficient alpha_m is smaller than unity. By performing the simulations over several tens of dynamical disk timescales, we show that the launching of a collimated outflow occurs self-consistently and the ejection of matter is continuous and quasi-stationary. These are the first ever simulations of resistive accretion disks launching non-transient ideal MHD jets. Roughly 15% of accreted mass is persistently ejected. This outflow is safely characterized as a jet since the flow becomes super-fastmagnetosonic, well-collimated and reaches a quasi-stationary state. We present a complete illustration and explanation of the `accretion-ejection' mechanism that leads to jet formation from a magnetized accretion disk. In particular, the magnetic torque inside the disk brakes the matter azimuthally and allows for accretion, while it is responsible for an effective magneto-centrifugal acceleration in the jet. As such, the magnetic field channels the disk angular momentum and powers the jet acceleration and collimation. The jet originates from the inner disk region where equipartition between thermal and magnetic forces is achieved. A hollow, super-fastmagnetosonic shell of dense material is the natural outcome of the inwards advection of a primordial field.Comment: ApJ (in press), 32 pages, Higher quality version available at http://www-laog.obs.ujf-grenoble.fr/~fcass

Measurement of solution parameters on sonication decellularization treatment

We have developed a sonication decellularization system to decellularized biological scaffolds in short time by combining sonication and chemical method. The aim of this study is to investigate decellularization efficiency on the different treated solution parameters. As a result, decreasing of dissolved oxygen (DO) would increase the conductivity and pH of decellularization solution, and decreasing of pH would increase conductivity. We found that the solution concentrationhas relation to its parameters and may influence the efficiency of sonication decellularization treatment

Heat-capacity anomalies at TscT_{sc} and T∗T^{*} in the ferromagnetic superconductor UGe2_2

The heat-capacity and magnetization measurements under high pressure have been carried out in a ferromagnetic superconductor UGe$_2$. Both measurements were done using a same pressure cell in order to obtain both data for one pressure. Contrary to the heat capacity at ambient pressure, an anomaly is found in the heat capacity at the characteristic temperature $T^{*}$ where the magnetization shows an anomalous enhancement under high pressure where the superconductivity appears. This suggests that a thermodynamic phase transition takes place at $T^{*}$ at least under high pressure slightly below $P_{c}^{*}$ where $T^{*}$ becomes zero. The heat-capacity anomaly associated with the superconducting transition is also investigated, where a clear peak of $C/T$ is observed in a narrow pressure region ($\Delta P \sim 0.1$ GPa) around $P_{c}^{*}$ contrary to the previous results of the resistivity measurement. Present results suggest the importance of the thermodynamic critical point $P_{c}^{*}$ for the appearance of the superconductivity.Comment: 4 pages, 4 figures, to appear in Phys. Rev. B, Rapid Communication

Is CP Violation Observable in Long Baseline Neutrino Oscillation Experiments ?

We have studied CP violation originated by the phase of the neutrino mixing matrix in the long baseline neutrino oscillation experiments. The direct measurements of CP violation is the difference of the transition probabilities between CP-conjugate channels. In those experiments, the CP violating effect is not suppressed if the highest neutrino mass scale is taken to be 1\sim 5 \eV, which is appropriate for the cosmological hot dark matter. Assuming the hierarchy for the neutrino masses, the upper bounds of CP violation have been caluculated for three cases, in which mixings are constrained by the recent short baseline ones. The calculated upper bounds are larger than $10^{-2}$, which will be observable in the long baseline accelerator experiments. The matter effect, which is not CP invariant, has been also estimated in those experiments.Comment: 28 pages, LaTex file, 6 figures included using epsfig Matter effect is estimated(Figs.3(a) (b)). Physical parameters are change