94 research outputs found
On Fenchel-Nielsen coordinates on Teichm\"uller spaces of surfaces of infinite type
We introduce Fenchel-Nielsen coordinates on Teicm\"uller spaces of surfaces
of infinite type. The definition is relative to a given pair of pants
decomposition of the surface. We start by establishing conditions under which
any pair of pants decomposition on a hyperbolic surface of infinite type can be
turned into a geometric decomposition, that is, a decomposition into hyperbolic
pairs of pants. This is expressed in terms of a condition we introduce and
which we call Nielsen convexity. This condition is related to Nielsen cores of
Fuchsian groups. We use this to define the Fenchel-Nielsen Teichm\"uller space
associated to a geometric pair of pants decomposition. We study a metric on
such a Teichm\"uller space, and we compare it to the quasiconformal
Teichm\"uller space, equipped with the Teichm\"uller metric. We study
conditions under which there is an equality between these Teichm\"uller spaces
and we study topological and metric properties of the identity map when this
map exists
A sequential linear programming (SLP) approach for uncertainty analysis-based data-driven computational mechanics
In this article, an efficient sequential linear programming algorithm (SLP)
for uncertainty analysis-based data-driven computational mechanics (UA-DDCM) is
presented. By assuming that the uncertain constitutive relationship embedded
behind the prescribed data set can be characterized through a convex
combination of the local data points, the upper and lower bounds of structural
responses pertaining to the given data set, which are more valuable for making
decisions in engineering design, can be found by solving a sequential of linear
programming problems very efficiently. Numerical examples demonstrate the
effectiveness of the proposed approach on sparse data set and its robustness
with respect to the existence of noise and outliers in the data set
Subsurface Engineering Induced Fermi Level De-pinning in Metal Oxide Semiconductors for Photoelectrochemical Water Splitting
Photoelectrochemical (PEC) water splitting is a promising approach for renewable solar light conversion. However, surface Fermi level pinning (FLP), caused by surface trap states, severely restricts the PEC activities. Theoretical calculations indicate subsurface oxygen vacancy (sub-O-v) could release the FLP and retain the active structure. A series of metal oxide semiconductors with sub-O-v were prepared through precisely regulated spin-coating and calcination. Etching X-ray photoelectron spectroscopy (XPS), scanning transmission electron microscopy (STEM), and electron energy loss spectra (EELS) demonstrated O-v located at sub similar to 2-5 nm region. Mott-Schottky and open circuit photovoltage results confirmed the surface trap states elimination and Fermi level de-pinning. Thus, superior PEC performances of 5.1, 3.4, and 2.1 mA cm(-2) at 1.23 V vs. RHE were achieved on BiVO4, Bi2O3, TiO2 with outstanding stability for 72 h, outperforming most reported works under the identical conditions
PRP coating on different modified surfaces promoting the osteointegration of polyetheretherketone implant
Introduction: Polyetheretherketone (PEEK) material implants have been applied more and more clinically recently. In order to increase the osteogenic activity of PEEK material, the microstructure change of the material surface and the construction of functional microcoatings have become a hot research topic. This study investigated the ability of PEEK surfaces modified by different methods to carry Platelet-rich plasma (PRP) and the osteogenic ability of different PEEK microstructures after carrying PRP in vivo/in vitro.Methods: In this study, PEEK surfaces were modified by sulfuric acid, gaseous sulfur trioxide and sandpaper. Next, PRP from SD rats was prepared and incubated on PEEK material with different surface microstructures. Lactate dehydrogenase test, scanning electron microscope and Elisa assay was used to evaluate adhesion efficiency of PRP. Then in vitro tests such as CCK-8, ALP staining, ARS staining and RT-qPCR et al were used to further evaluate osteogenesis ability of the PRP coating on PEEK surface. Finally, The tibia defects of SD rats were established, and the new bone was evaluated by Micro-CT, HE staining, and immunofluorescence staining.Results: The sandpaper-polished PEEK with the strongest PRP carrying capacity showed the best osteogenesis. Our study found that the modified PEEK surface with PRP coating has excellent osteogenic ability and provided the basis for the interface selection of PRP for the further application of PEEK materials.Discussion: Among the three PEEK modified surfaces, due to the most PRP carrying and the strongest osteogenic ability in vitro/vivo, the frosted surface was considered to be the most suitable surface for the preparation of PRP coating
Proteomic characterization reveals that MMP-3 correlates with bronchiolitis obliterans syndrome following allogeneic hematopoietic cell and lung transplantation
Improved diagnostic methods are needed for bronchiolitis obliterans
syndrome (BOS), a serious complication after allogeneic hematopoietic cell
transplantation (HCT) and lung transplantation. For proteins candidate
discovery, we compared plasma pools from HCT transplantation recipients with:
BOS at onset (n=12), pulmonary infection (n=16), chronic graft-versus-host
disease without pulmonary involvement (n=15), and no chronic complications
post-HCT (n=15). Pools were labeled with different tags [isobaric Tags for
Relative and Absolute Quantification (iTRAQ)], and two software tools identified
differentially expressed proteins (≥1.5-fold change). Candidate proteins
were further selected using a six-step computational biology approach. The
diagnostic value of the lead candidate, matrix metalloproteinase-3 (MMP-3), was
evaluated by ELISA in plasma of a verification cohort (n=112) with and without
BOS following HCT (n=76) or lung transplantation (n=36). MMP-3 plasma
concentrations differed significantly between patients with and without BOS
(AUC=0.77). Thus, MMP-3 represents a potential non-invasive blood test for
diagnosis of BOS
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