Quading triangular meshes with certain topological constraints

AbstractIn computer graphics and geometric modeling, shapes are often represented by triangular meshes (also called 3D meshes or manifold triangulations). The quadrangulation of a triangular mesh has wide applications. In this paper, we present a novel method of quading a closed orientable triangular mesh into a quasi-regular quadrangulation, i.e., a quadrangulation that only contains vertices of degree four or five. The quasi-regular quadrangulation produced by our method also has the property that the number of quads of the quadrangulation is the smallest among all the quasi-regular quadrangulations. In addition, by constructing the so-called orthogonal system of cycles our method is more effective to control the quality of the quadrangulation

Influence of network structure on the crystallization behavior in chemically crosslinked hydrogels

The network structure of hydrogels is a vital factor to determine their physical properties. Two network structures within hydrogels based on eight-arm star-shaped poly(ethylene glycol)(8PEG) have been obtained; the distinction between the two depends on the way in which the macromonomers were crosslinked: either by (i) commonly-used photo-initiated chain-growth polymerization (8PEG–UV), or (ii) Michael addition step-growth polymerization (8PEG–NH3). The crystallization of hydrogels is facilitated by a solvent drying process to obtain a thin hydrogel film. Polarized optical microscopy (POM) results reveal that, while in the 8PEG–UV hydrogels only nano-scaled crystallites are apparent, the 8PEG–NH3 hydrogels exhibit an assembly of giant crystalline domains with spherulite sizes ranging from 100 to 400 µm. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analyses further confirm these results. A model has been proposed to elucidate the correlations between the polymer network structures and the crystallization behavior of PEG-based hydrogels.DFG, 325093850, Open Access Publizieren 2017 - 2018 / Technische Universität Berli

Synergistic enhancement of iron oxide nanoparticle and gadolinium for dual-contrast MRI

National Institute of Biomedical Imaging and Bioengineering (NIBIB), National Institutes of Health (NIH); National Science Foundation of China (NSFC) [81201086]Purpose: The use of MR contrast agents allows accurate diagnosis by exerting an influence on the longitudinal (T-1) or transverse (T-2) relaxation time of the surrounding tissue. In this study, we combined the use of iron oxide (IO) particles and nonspecific extracellular gadolinium chelate (Gd) in order to further improve the sensitivity and specificity of lesion detection. Procedures: With a 7-Tesla scanner, pre-contrasted, IO-enhanced and dual contrast agent enhanced MRIs were performed in phantom, normal animals, and animal models of lymph node tumor metastases and orthotopic brain tumor. For the dual-contrast (DC) MRI, we focused on the evaluation of T-2 weighted DC MRI with IO administered first, then followed by the injection of a bolus of gadolinium diethylenetriamine pentaacetic acid (Gd-DTPA). Results: Based on the C/N ratios and MRI relaxometry, the synergistic effect of coordinated administration of Gd-DTPA and IO was observed and confirmed in phantom, normal liver and tumor models. At 30 min after administration of Feridex, Gd-DTPA further decreased T-2 relaxation in liver immediately after the injection. Additional administration of Gd-DTPA also immediately increased the signal contrast between tumor and brain parenchyma and maximized the C/N ratio to -4.12 +/- 0.71. Dual contrast MRI also enhanced the delineation of tumor borders and small lesions. Conclusions: DC-MRI will be helpful to improve diagnostic accuracy and decrease the threshold size for lesion detection. (C) 2012 Elsevier Inc. All rights reserved

Instant Interfacial Self-Assembly for Homogeneous Nanoparticle Monolayer Enabled Conformal ‘lift on’ Thin Film Technology

Thin film fabrication is of great importance in the modern engineering. Here, we propose a universal and conformal thin film technique enabled by the wetting empowered interfacial self-assembly. By tailoring the contact angle of nanoparticle (NP), a NP monolayer can be assembled instantly (within 5 seconds) with an excellent harvesting efficiency (up to 97.5 wt). This self-assembly strategy presents a universal applicability on various materials, e.g. non-metal, metal and core-shell structures, and can achieve a monolayer with same in-plane area as 4-inch wafer in a single process, indicating great potential for scale-up manufacturing. Through a template transfer, we coat the surface of different substrates (plastic, paper, etc.) with the assembled film in a conformal and non-destructive ‘lift-on’ manner and subsequently demonstrate fluorescent micropatterns. This self-assembly strategy has great implications in advancing thin film technology with a user-friendly and cost-effective fashion, for the applications in anti-counterfeiting, actuators, and wearable/flexible electronic

UCP2 Mitigates the Loss of Human Spermatozoa Motility by Promoting mROS Elimination

Background/Aims: To demonstrate the function of uncoupling protein 2 (UCP2) in the regulation of human spermatozoa motility. Methods: Semen samples were collected from donors with either normal spermatozoa motility (normospermia [NS]) or poor spermatozoa motility (asthenospermia [AS]). UCP2 protein in spermatozoawas quantified by Western blotting. The level of mitochondrial reactive oxygen species (mROS) was evaluated by MitoSOX Red. The activity of mitochondrial membrane potential (MMP) in spermatozoa was evaluated by a JC-1 assay and the ATP level was monitored by a luciferin-luciferase assay. Results: UCP2 was expressed in both NS and AS groups, with the former exhibiting a higher level than the latter. Immunofluorescence analysis shows that UCP2 is mainly located at the mid-region of human spermatozoa. The inhibition of UCP2 by a highly selective inhibitor, Genipin, results in not only impaired spermatozoa mobility (P<.05) but also an elevated level of mROS (P<.05), suggesting that UCP2 is involved in the maintenance of the spermatozoa mobility, which probably is achieved by promoting mROS elimination. Furthermore, H2O2 treatment of spermatozoa increases the mROS level coupled with the loss of spermatozoa mobility. Unexpectedly, this treatment also has a positive impact on the expression of UCP2 within a certain range of supplemental H2O2, indicating the moderate mROS level possibly serves as a feedback signal to stimulate the expression of UCP2. Finally, the treatment of spermatozoa by an ROS scavenger, N-acetyl-l-cysteine (NAC),decreases the level of mROS and increases the curvilinear velocity (VCL) of spermatozoa, but the UCP2 level is not affected. Conclusion: These results suggest an UCP2–mROS–motility regulatory system exists for maintaining spermatozoa mobility in humans. In such a system, UCP2 fulfills its function by promoting mROS elimination, and slightly over-produced mROS in turn serves as a signal to stimulates the expression of UCP2. This regulatory system represents a new potential target for the discovery of novel pharmaceuticals for the treatment of patients with low spermatozoa motility

Diverse Applications of Nanomedicine

The design and use of materials in the nanoscale size range for addressing medical and health-related issues continues to receive increasing interest. Research in nanomedicine spans a multitude of areas, including drug delivery, vaccine development, antibacterial, diagnosis and imaging tools, wearable devices, implants, high-throughput screening platforms, etc. using biological, nonbiological, biomimetic, or hybrid materials. Many of these developments are starting to be translated into viable clinical products. Here, we provide an overview of recent developments in nanomedicine and highlight the current challenges and upcoming opportunities for the field and translation to the clinic. \ua9 2017 American Chemical Society

Characteristic Training Modes of Land Resources Management Major in Universities of Finance and Economics

With the development of the society, the undergraduates training modes of land resources management major have diversified developed. The land resources management majors in universities with different background have various features in China. Chongqing Technology and Business University was taken as a typical finance and economics university in this study. And the features, including training mode, feature training scheme and training effect of land resources management major, were discussed systematically. The results provide reference for the building of land resources management major in other colleges

Quaternary Depositional Framework of the Xiong’an New Area: A 3D Geological Modeling Approach Based on Vector and Grid Integration

The Quaternary stratigraphic unit is an important underground space resource for sustainable urban development. It is of great significance to understand the spatial variation characteristics of the Quaternary stratigraphic structure and its internal attributes. However, due to the openness and complexity of the Quaternary sedimentary environment, the sedimentary characteristics of Quaternary stratigraphic units are often very complex and difficult to accurately analyze. In this study, a method for analyzing Quaternary sedimentary characteristics via 3D geological modeling based on vector and grid integration is proposed. Based on this method, the Quaternary depositional framework of Xiong’an New Area is established. The results show that the study area is mainly composed of seven Quaternary strata with different sedimentary origins, and the 3D spatial variation characteristics of lithology in each stratum are unique. Taking the vector framework model as the constraint boundary, this study constructs the lithology stochastic model of each Quaternary stratigraphic unit respectively, and accurately simulates the 3D spatial variation characteristics of the inner lithology of Quaternary stratigraphic units in the study area, which is of great significance for the urban planning, construction, and environmental protection of Xiong’an New Area