81 research outputs found

    Drexel University

    Get PDF
    We present a 3D matching framework based on a many-to-many matching algorithm that works with skeletal representations of 3D volumetric objects. We demonstrate the performance of this approach on a large database of 3D objects containing more than 1000 exemplars. The method is especially suited to matching objects with distinct part structure and is invariant to part articulation. Skeletal matching has an intuitive quality that helps in defining the search and visualizing the results. In particular, the matching algorithm produces a direct correspondence between two skeletons and their parts, which can be used for registration and juxtaposition. 1

    Arrays of Nano-Electromechanical Biosensors Functionalized by Microcontact Printing

    Full text link
    The biofunctionalization of nanoelectromechanical structures is critical for the development of new classes of biosensors displaying improved performances and higher-level of integration. We propose a modified microcontact printing method for the functionalization and passivation of large arrays of nanocantilevers in a single, self-aligned step. Using fluorescence microscopy and resonant frequency measurements, we demonstrate (1) the bioactivity and the anti-fouling property of deposited antibodies and BSA molecules and (2) the preservation of the nanostructures' mechanical integrity.Comment: 20 pages, 5 figure

    A vibrational circular dichroism implementation within a Slater-type-orbital based density functional framework and its application to hexa- and hepta-helicenes

    Get PDF
    We describe the implementation of the rotational strengths for vibrational circular dichroism (VCD) in the Slater-type orbital based Amsterdam Density Functional (ADF) package. We show that our implementation, which makes use of analytical derivative techniques and London atomic orbitals, yields origin independent rotational strengths. The basis set dependence in the particular case of Slater-type basis functions is also discussed. It turns out that the triple zeta STO basis sets with one set of polarization functions (TZP) are adequate for VCD calculations. The origin- dependence of the atomic axial tensors is checked by a distributed origin gauge implementation. The distributed and common origin gauge implementations yield virtually identical atomic axial tensors with the Slater-type basis sets employed here, proving that our implementation yields origin independent rotational strengths. We verify the implementation for a set of benchmark molecules, for which the dependence of the VCD spectra on the particular choice of the exchange–correlation functional is studied. The pure functionals BP86 and OLYP show a particularly good performance. Then, we apply this approach to study the VCD spectra of hexa- and hepta- helicenes. In particular we focus on relationships between the sign of the rotational strengths of the two helicenes

    Complete Set of Elastic Moduli of a Spin-Crossover Solid: Spin-State Dependence and Mechanical Actuation

    Get PDF
    Molecular spin crossover complexes are promising candidates for mechanical actuation purposes. The relationships between their crystal structure and mechanical properties remain, however, not well understood. In this study, combining high pressure synchrotron Xray diffraction and nuclear inelastic scattering measurements, we assessed the effective macroscopic bulk modulus (11.5 ± 2.0 GPa), Young’s modulus (10.9 ± 1.0 GPa) and Poisson’s ratio (0.34 ± 0.04) of the spin crossover complex [FeII(HB(tz)3)2] (tz = 1,2,4-triazol-1-yl) in its low spin state. Crystal structure analysis revealed a pronounced anisotropy of the lattice compressibility, which was correlated with the difference in spacing between the molecules in different crystallographic directions. Switching the molecules from the low spin to the high spin state leads to a remarkable drop of the Young’s modulus to 7.1 ± 0.5 GPa, which was also assessed in thin film samples by means of micromechanical measurements. These results are in agreement with the high cooperativity of the spin crossover in this compound and highlight its application potential in terms of recoverable stress (21 ± 1 MPa) and work density (15 ± 6 mJ/cm3)

    A review on development and application of plant-based bioflocculants and grafted bioflocculants

    Get PDF
    Flocculation is extensively employed for clarification through sedimentation. Application of eco-friendly plant-based bioflocculants in wastewater treatment has attracted significant attention lately with high removal capability in terms of solids, turbidity, color, and dye. However, moderate flocculating property and short shelf life restrict their development. To enhance the flocculating ability, natural polysaccharides derived from plants are chemically modified by inclusion of synthetic, nonbiodegradable monomers (e.g., acrylamide) onto their backbone to produce grafted bioflocculants. This review is aimed to provide an overview of the development and flocculating efficiencies of plant-based bioflocculants and grafted bioflocculants for the first time. Furthermore, the processing methods, flocculation mechanism, and the current challenges are discussed. All the reported studies about plant-derived bioflocculants are conducted under lab-scale conditions in wastewater treatment. Hence, the possibility to apply natural bioflocculants in food and beverage, mineral, paper and pulp, and oleo-chemical and biodiesel industries is discussed and evaluated

    Impaired Phagocytosis in Localized Aggressive Periodontitis: Rescue by Resolvin E1

    Get PDF
    Resolution of inflammation is an active temporally orchestrated process demonstrated by the biosynthesis of novel proresolving mediators. Dysregulation of resolution pathways may underlie prevalent human inflammatory diseases such as cardiovascular diseases and periodontitis. Localized Aggressive Periodontitis (LAP) is an early onset, rapidly progressing form of inflammatory periodontal disease. Here, we report increased surface P-selectin on circulating LAP platelets, and elevated integrin (CD18) surface expression on neutrophils and monocytes compared to healthy, asymptomatic controls. Significantly more platelet-neutrophil and platelet-monocyte aggregates were identified in circulating whole blood of LAP patients compared with asymptomatic controls. LAP whole blood generates increased pro-inflammatory LTB4 with addition of divalent cation ionophore A23187 (5 µM) and significantly less, 15-HETE, 12-HETE, 14-HDHA, and lipoxin A4. Macrophages from LAP subjects exhibit reduced phagocytosis. The pro-resolving lipid mediator, Resolvin E1 (0.1–100 nM), rescues the impaired phagocytic activity in LAP macrophages. These abnormalities suggest compromised resolution pathways, which may contribute to persistent inflammation resulting in establishment of a chronic inflammatory lesion and periodontal disease progression

    The thrombotic potential of oral pathogens

    Get PDF
    In recent times the concept of infectious agents playing a role in cardiovascular disease has attracted much attention. Chronic oral disease such as periodontitis, provides a plausible route for entry of bacteria to the circulation. Upon entry to the circulation, the oral bacteria interact with platelets. It has been proposed that their ability to induce platelet aggregation and support platelet adhesion is a critical step in the pathogenesis of the infection process. Many published studies have demonstrated multiple mechanisms through which oral bacteria are able to bind to and activate platelets. This paper will review the various mechanisms oral bacteria use to interact with platelets

    Od logistyki do e-logistyki na przykładzie Elektronicznej Giełdy Towarowej

    No full text
    Obecnie wykorzystanie technologii informatycznych może uczynić nasze życie lepszym i łatwiejszym, a rozwój Internetu może zasadniczo zmienić sposób działalności w firmach. Podmioty świadczące usługi logistyczne widzą potrzebę zmiany tradycyjnego modelu logistycznego na model e-logistyki. Jest to konieczne w celu dostosowania się do dynamicznych zmian w świecie globalnego handlu elektronicznego. Obecna gospodarka cyfrowa jest napędzana dużą ilością informacji, nowymi narzędziami ICT i technologiami wykorzystywanymi przez wszystkich do osiągnięcia rozwoju działalności. Korzystanie z e-logistyki może zminimalizować koszty nabycia, przesyłania, odbioru i sprzedaży nie tylko towarów, ale także usług. Celem niniejszego artykułu jest zdefiniowanie pojęć i określenie znaczenia wykorzystania systemów e-logistyki w biznesie na przykładzie Elektronicznej Giełdy Towarowej (EGT). W pierwszej części opracowania autorzy wyjaśniają różnice między logistyką i e-logistyką. Kolejna część pracy prezentuje aspekty i założenia dotyczące e-logistyki. Dalsza część artykułu skoncentrowana została na zbadaniu aktualnej sytuacji w zakresie wykorzystania systemów e-logistyki na przykładzie EGT, efektem czego jest analiza porównawcza wybranych elektronicznych giełd towarowych.Nowadays, the use of Information Technologies Systems can make our life better and easier, as the incredible growth of the Internet is changing the way corporations conduct their business. Logistic service operators see the need to change the traditional logistics system into e-logistics. It is necessary to accommodate the dynamic changes in the commercial world. The current digital economy is driven by modern information and new ICT tools, new technologies used by everyone for stronger development of their activities. Using e-logistics may minimize the costs of acquisition, transmission, reception and sales. The purpose of this article is to analyze the notion and importance of using e-logistic systems in business with the example of Electronic Freight Exchange (EFX). In the first part of the paper, the authors explain the difference between logistics and e-logistics. The next part of the paper is devoted to presenting the aspects and fundamentals of e-logistics and their advantages as well. Moreover, the areas which might be improved are indicated. The further part of the paper is focused on the situation in e-logistics systems with the EFX example. In that section a comparative analysis of selected electronic freight exchanges can be found. This study brings its contribution to the understanding of the changes in logistics, in particular, in the EFX systems
    corecore