57 research outputs found

    A Detailed Review on Cybercrime and Cyber Security

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    Cybercrime is changing into ever additional serious. Findings from the 2002 Computer Crime associate in nursing Security Survey show an upward trend that demonstrates a necessity for a timely review of existing approaches to fighting this new development within the modern era. During this paper, we have a tendency to outline differing types of crime and review previous analysis and current standing of fighting crime in several countries that deem legal, structure, and technological approaches. We have a tendency to specialize in a case study of fighting crime in India and discuss issues featured. Finally, we have a tendency to propose many recommendations to advance the work of fighting crime

    Mesenchymal stem cells and collagen patches for anterior cruciate ligament repair

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    AIM: To investigate collagen patches seeded with mesenchymal stem cells (MSCs) and/or tenocytes (TCs) with regards to their suitability for anterior cruciate ligament (ACL) repair. METHODS: Dynamic Intraligamentary Stabilization (DIS) utilizes a dynamic screw system to keep ACL remnants in place and promote biological healing, supplemented by collagen patches. How these scaffolds interact with cells and what type of benefit they provide has not yet been investigated in detail. Primary ACL-derived TCs and human bone marrow derived MSCs were seeded onto two different types of 3D collagen scaffolds, Chondro-Gide® (CG) and Novocart® (NC). Cells were seeded onto the scaffolds and cultured for 7 days either as a pure populations or as “premix” containing a 1 : 1 ratio of TCs to MSCs. Additionally, as controls, cells were seeded in monolayers and in co-cultures on both sides of porous high-density membrane inserts (0.4µm). We analyzed the patches by real time polymerase chain reaction (RT-PCR), glycosaminoglycan (GAG), DNA and hydroxy-proline (HYP) content, was determined. To determine cell spreading and adherence in the scaffolds microscopic imaging techniques, i.e. confocal laser scanning microscopy (cLSM) and scanning electron microscopy (SEM), were applied. RESULTS: CLSM and SEM imaging analysis confirmed cell adherence onto scaffolds. The metabolic cell activity revealed that patches promote adherence and proliferation of cells. The most dramatic increase in absolute metabolic cell activity was measured for CG samples seeded with tenocytes or a 1:1 cell premix. Analysis of DNA content and cLSM imaging also indicated MSCs were not proliferating as nicely as tenocytes on CG. The HYP to GAG ratio significantly changed for the premix group, resulting from a slightly lower GAG content, demonstrating that the cells are modifying the underlying matrix. Real-time quantitative polymerase chain reaction data indicated that MSCs showed a trend of differentiation towards a more tenogenic-like phenotype after 7 days. CONCLUSION: CG and NC are both cyto-compatible with primary MSCs and TCs; TCs seemed to perform better on these collagen patches than MSCs

    Nano-Stenciled RGD-Gold Patterns That Inhibit Focal Contact Maturation Induce Lamellipodia Formation in Fibroblasts

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    Cultured fibroblasts adhere to extracellular substrates by means of cell-matrix adhesions that are assembled in a hierarchical way, thereby gaining in protein complexity and size. Here we asked how restricting the size of cell-matrix adhesions affects cell morphology and behavior. Using a nanostencil technique, culture substrates were patterned with gold squares of a width and spacing between 250 nm and 2 µm. The gold was functionalized with RGD peptide as ligand for cellular integrins, and mouse embryo fibroblasts were plated. Limiting the length of cell-matrix adhesions to 500 nm or less disturbed the maturation of vinculin-positive focal complexes into focal contacts and fibrillar adhesions, as indicated by poor recruitment of α5-integrin. We found that on sub-micrometer patterns, fibroblasts spread extensively, but did not polarize. Instead, they formed excessive numbers of lamellipodia and a fine actin meshwork without stress fibers. Moreover, these cells showed aberrant fibronectin fibrillogenesis, and their speed of directed migration was reduced significantly compared to fibroblasts on 2 µm square patterns. Interference with RhoA/ROCK signaling eliminated the pattern-dependent differences in cell morphology. Our results indicate that manipulating the maturation of cell-matrix adhesions by nanopatterned surfaces allows to influence morphology, actin dynamics, migration and ECM assembly of adhering fibroblasts

    Effect of thermal processing on the tribology of nanocrystalline Ni/TiO2 coatings

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    yesThe tribological performance of a nanocrystalline coating is heavily influenced by its composition, morphology, and microstructural characteristics. This research work describes the effect of heat treatment temperature on the microstructural, morphological, and mechanical behavior of nanocrystalline Ni/TiO2 coatings produced by electrophoresis. The surface morphology and coating cross section were characterized by scanning electron microscopy (SEM). The composition of coatings and the percentage of TiO2 nanoparticles incorporated in the Ni matrix were studied and estimated by using an energy-dispersive spectroscopic (EDS) analysis, while x-ray diffractometry (XRD) was used to investigate the effect of heat treatment temperature on phase structure. The results showed agglomeration of TiO2 nanoparticles on the surface of the coating. The high hardness and wear resistance recorded for the as-deposited coating was attributed to the uniform distribution of TiO2 nanoparticle clusters throughout the cross section of the coating. Heat treatment of the Ni/TiO2 coatings to temperatures above 200 °C led to significant grain growth that changed the surface morphology of the coating and reduced the strengthening effects of the nanoparticles, thus causing a reduction in the hardness and wear resistance of the coatings

    Improvement in Tribological Performance of Ni-P-TiO2 Composite Coatings Using Taguchi Technique with Grey Relational Analysis

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    Tribological performance of Ni-P-TiO2 composite coatings is improved by varying the tribological test parameters such as normal load, wear track diameter, and duration of test aiming at minimum wear and friction of the coating. Taguchi technique with grey relational analysis is employed for optimization of multiresponse problem using L27 orthogonal array (OA). Analysis of variance (ANOVA) is used to find out the significant effect of test parameters and their interactions on friction and wear behavior of the coating. ANOVA results reveal that normal load and time (test duration) have the most significant effect in controlling wear and friction of the coating. Interaction between normal load and wear track diameter has some significant effect. Scanning electron microscopy of worn surface shows abrasive wear to be predominant. The surface morphology, composition, and phase structure analysis are done with the help of scanning electron microscopy (SEM), energy dispersive X-ray (EDX) analysis, and X-ray diffraction (XRD) analysis, respectively

    Cell force measurements in 3D microfabricated environments based on compliant cantilevers.

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    We report the fabrication, functionalization and testing of microdevices for cell culture and cell traction force measurements in three-dimensions (3D). The devices are composed of bent cantilevers patterned with cell-adhesive spots not lying on the same plane, and thus suspending cells in 3D. The cantilevers are soft enough to undergo micrometric deflections when cells pull on them, allowing cell forces to be measured by means of optical microscopy. Since individual cantilevers are mechanically independent of each other, cell traction forces are determined directly from cantilever deflections. This proves the potential of these new devices as a tool for the quantification of cell mechanics in a system with well-defined 3D geometry and mechanical properties
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