Planck Constraints on Holographic Dark Energy

We perform a detailed investigation on the cosmological constraints on the holographic dark energy (HDE) model by using the Planck data. HDE can provide a good fit to Planck high-l (l>40) temperature power spectrum, while the discrepancy at l=20-40 found in LCDM remains unsolved in HDE. The Planck data alone can lead to strong and reliable constraint on the HDE parameter c. At 68% CL, we get c=0.508+-0.207 with Planck+WP+lensing, favoring the present phantom HDE at > 2sigma CL. Comparably, by using WMAP9 alone we cannot get interesting constraint on c. By combining Planck+WP with the BAO measurements from 6dFGS+SDSS DR7(R)+BOSS DR9, the H0 measurement from HST, the SNLS3 and Union2.1 SNIa data sets, we get 68% CL constraints c=0.484+-0.070, 0.474+-0.049, 0.594+-0.051 and 0.642+-0.066. Constraints can be improved by 2%-15% if we further add the Planck lensing data. Compared with the WMAP9 results, the Planck results reduce the error by 30%-60%, and prefer a phantom-like HDE at higher CL. We find no evident tension between Planck and BAO/HST. Especially, the strong correlation between Omegam h^3 and dark energy parameters is helpful in relieving the tension between Planck and HST. The residual chi^2_{Planck+WP+HST}-chi^2_{Planck+WP} is 7.8 in LCDM, and is reduced to 1.0 or 0.3 if we switch dark energy to the w model or the holographic model. We find SNLS3 is in tension with all other data sets; for Planck+WP, WMAP9 and BAO+HST, the corresponding Delta chi^2 is 6.4, 3.5 and 4.1, respectively. Comparably, Union2.1 is consistent with these data sets, but the combination Union2.1+BAO+HST is in tension with Planck+WP+lensing, corresponding to a Delta chi^2 8.6 (1.4% probability). Thus, it is not reasonable to perform an all-combined (CMB+SNIa+BAO+HST) analysis for HDE when using the Planck data. Our tightest self-consistent constraint is c=0.495+-0.039 obtained from Planck+WP+BAO+HST+lensing.Comment: 29 pages, 11 figures, 3 tables; version accepted for publication in JCA

Temporospatial Precision of Integrin Response to Fibronectin Matrikine: Unveiling an Osteoarthritis-perpetuating Pathway

Integrin endocytosis plays a pivotal role in intracellular signaling, yet its involvement in the remodeling of damaged extracellular matrix remains poorly understood. Matrikines, which are bioactive protein fragments resulting from the degradation of the extracellular matrix, are key contributors to various degenerative diseases, including osteoarthritis. In the context of osteoarthritis, fibronectin, an extracellular matrix protein, assumes a significant role as it is upregulated in osteoarthritis tissue and subsequently targeted for degradation by several proteases. This proteolytic activity leads to the generation of fibronectin fragments of various sizes. Notably, these fibronectin fragments, including those containing the Arg-Gly-Asp (RGD) attachment site, activate catabolic signaling pathways, resulting in the release of proteases, as well as cytokines and chemokines associated with the innate immune system. Given the limited repair capacity of cartilage, the presence of matrix degradation products such as fibronectin matrikines can fuel a destructive cycle of progressive matrix degradation and joint tissue inflammation, culminating in structural changes accompanied by symptoms of pain and loss of function. Our research has provided insights into the internalization of a specific fibronectin matrix protein fragment (FN7-10) along with α5β1 integrin by articular chondrocytes, which triggers the formation of signaling redoxosomes. Through a precisely orchestrated temporal and spatial mechanism, redoxosome formation and the generation of hydrogen peroxide by NADPH oxidase 2 (Nox2) regulate the activation of MAP kinases, subsequently triggering the production of matrix metalloproteinase-13. The redox-regulated tyrosine kinase Src colocalizes with α5 integrin at the Nox2-containing redoxosomes. Furthermore, in vivo studies using human osteoarthritic cartilage have demonstrated the formation of redoxosomes during osteoarthritis pathogenesis, capable of transmitting and sustaining redox signaling that promotes further matrix damage. Consequently, α5β1 integrin signaling, initiated by a fibronectin matrikine, is facilitated by redoxosome formation, perpetuating a self-amplifying cycle of matrix degradation. By unraveling the intricacies of integrin response and redoxosome formation in a precise temporal and spatial manner, this research provides support for the development of novel therapies for osteoarthritis that specifically target signaling pathways with subcellular precision. Such targeted interventions hold promise for addressing the destructive matrix degradation observed in OA and potentially other related degenerative conditions.Doctor of Philosoph

High Order Projection Plane Method for Evaluation of Supersingular Curved Boundary Integrals in BEM

Boundary element method (BEM) is a very promising approach for solving various engineering problems, in which accurate evaluation of boundary integrals is required. In the present work, the direct method for evaluating singular curved boundary integrals is developed by considering the third-order derivatives in the projection plane method when expanding the geometry quantities at the field point as Taylor series. New analytical formulas are derived for geometry quantities defined on the curved line/plane, and unified expressions are obtained for both two-dimensional and three-dimensional problems. For the two-dimensional boundary integrals, analytical expressions for the third-order derivatives are derived and are employed to verify the complex-variable-differentiation method (CVDM) which is used to evaluate the high order derivatives for three-dimensional problems. A few numerical examples are given to show the effectiveness and the accuracy of the present method

Transient Structures and Possible Limits of Data Recording in Phase-Change Materials

Phase-change materials (PCMs) represent the leading candidates for universal data storage devices, which exploit the large difference in the physical properties of their transitional lattice structures. On a nanoscale, it is fundamental to determine their performance, which is ultimately controlled by the speed limit of transformation among the different structures involved. Here, we report observation with atomic-scale resolution of transient structures of nanofilms of crystalline germanium telluride, a prototypical PCM, using ultrafast electron crystallography. A nonthermal transformation from the initial rhombohedral phase to the cubic structure was found to occur in 12 ps. On a much longer time scale, hundreds of picoseconds, equilibrium heating of the nanofilm is reached, driving the system toward amorphization, provided that high excitation energy is invoked. These results elucidate the elementary steps defining the structural pathway in the transformation of crystalline-to-amorphous phase transitions and describe the essential atomic motions involved when driven by an ultrafast excitation. The establishment of the time scales of the different transient structures, as reported here, permits determination of the possible limit of performance, which is crucial for high-speed recording applications of PCMs

Operando and three-dimensional visualization of anion depletion and lithium growth by stimulated Raman scattering microscopy

Visualization of ion transport in electrolytes provides fundamental understandings of electrolyte dynamics and electrolyte-electrode interactions. However, this is challenging because existing techniques are hard to capture low ionic concentrations and fast electrolyte dynamics. Here we show that stimulated Raman scattering microscopy offers required resolutions to address a long-lasting question: how does the lithium-ion concentration correlate to uneven lithium deposition? In this study, anions are used to represent lithium ions since their concentrations should not deviate for more than 0.1 mM, even near nanoelectrodes. A three-stage lithium deposition process is uncovered, corresponding to no depletion, partial depletion, and full depletion of lithium ions. Further analysis reveals a feedback mechanism between the lithium dendrite growth and heterogeneity of local ionic concentration, which can be suppressed by artificial solid electrolyte interphase. This study shows that stimulated Raman scattering microscopy is a powerful tool for the materials and energy field

Study of Mid-Infrared Optical Properties of ZnS Thin Films by Spectroscopic Ellipsometry

In order to obtain the mid-infrared optical properties of ZnS thin films, ZnS films with different thickness were prepared on K9 glass substrate by electronic beam evaporation. They were denoted by Aã€Bã€C . The optical properties of thin films were studied by Spectroscopic Ellipsometry. The measured date of film A ã€Bã€C were fitted by Brendel oscillator, and based on ZnS film properties and the film forming characteristic of the ZnS film, building the model“substrate(K9 glass)/EMA(50% K9 glass and 50% ZnS)/ZnS/rough surface layer(50% ZnS and 50% air)/airâ€. The optical constants curve and thickness of ZnS thin film were got. The results shown that the evaluation function MSE is small when Brendel model is used in data fitting. Within the wavelength range of 3000nm ~ 12500nm, the ZnS thin films refractive index and extinction coefficient are reduced with increasing wavelength. The Extinction coefficient tends to zero near the long wavelengh. The thickness of ZnS measured value was closest to the theoretical value. The results have certain reference value to measurement and preparation of high quality ZnS thin film