High Payload Capacity Research Articles

An Approach of Robust High Capacity Audio Steganography and Cryptography Using LSB Algorithms

Increased use of electronic communication has given birth to new ways of transmitting information securely. Security has its importance and application in wide area. It is a measure of human negligence, in desire to seize the latest technological inventions. This measure may have adverse effect on human perception to the deployment of application, which needs serious concern in terms of security. Audio steganography is the science of hiding some secret text or audio information in a host message. The main challenge in audio steganography is to obtain high payload and robustness. A wide variety of techniques are existing such as LSB, Parity coding, phase coding for audio steganography. Here, a new approach with two level encryption of user data by combining cryptography and steganography is proposing to achieve high payload capacity and robust technique for Embedding information in Digital Audio data.

High-capacity reversible watermarking scheme of 2D-vector data

The application of two-dimensional (2D) vector map faces the security issues of copyright protection, which limit the usage of vector data in many scenarios. Reversible watermarking is a more feasible solution, which aims to restore the original data after watermark extraction. In this paper, high-capacity reversible watermarking scheme of 2D-vector data is proposed based on the idea of iterative embedding. It groups vertices as units for each polyline and selects highly correlated vertex units as cover data. Then the reversible embedding is carried out by iteratively modifying the median vertex coordinates of each selected embedding unit. This scheme can strictly recover the original vector data with watermark accurate extraction. Meanwhile, both higher payload capacity and perception invisibility are validated through theoretical analysis and comprehensive experiments. The experimental results show that the proposed reversible watermarking scheme is suitable for 2D-vector data applications where high-precision data are required.

Abstract B97: AS1411-Doxorubicin adduct for targeted liver cancer therapy.

Abstract Background: Aptamer-drug conjugates are promising to be applied to targeted cancer therapy, in which anticancer drugs were selectively delivered into cognate cancerous cells, but not to healthy tissues, in order to reduce side effects and enhance therapeutic efficacy. Methodology/Principal Findings: In this study, the technology of drug-DNA adduct (DDA) was utilized to prepare drug-aptamer conjugates. Particularly, an anticancer drug, Doxorubicin (Dox), was conjugated with AS1411, a DNA aptamer which specifically recognizes human hepatocellular carcinoma Huh7 cells. The technology enabled a simple and high-payload conjugation of drugs onto aptamers. The resultant AS1411-Dox adduct maintained selectively recognition ability to target liver cancer cells with strong binding affinity (demonstrated by flow cytometry), was able to selectively deliver the conjugated Dox into target cancer cells (observed with confocal microscopy), and exhibited selective and potent cytotoxicity in target liver cancer cells (evaluated by MTS cell viability assay). More importantly, as the first of its kind, AS1411-Dox adduct demonstrated selectively antitumor therapeutic efficacy of this drug-aptamer conjugation technology in a mouse model. The ability of drug-aptamer adducts to deliver anticancer drugs into target cancer cells, while inhibiting nonspecific drug uptake in nontarget cells, enables this technology promising to be implemented in targeted cancer therapy. Conclusions/Significance: Given the demonstrated ability of targeted liver cancer therapy combined with the aforementioned advantageous features as a simple preparation, the high drug payload capacity, and the wide applicability, this novel drug-DNA adduct technology is anticipated for wide implications for targeted cancer therapy. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):B97. Citation Format: Thu Le Trinh, Guizhi Zhu, Xilin Xiao, Xiaokui Zhang, Kwame Sefah, Weihong Tan, Chen Liu. AS1411-Doxorubicin adduct for targeted liver cancer therapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr B97.

High payload image steganography with reduced distortion using octonary pixel pairing scheme

The crucial challenge that decides the success of any steganographic algorithm lies in simultaneously achieving the three contradicting objectives namely--higher payload capacity, with commendable perceptual quality and high statistical un-detectability. This work is motivated by the interest in developing such a steganographic scheme, which is aimed for establishing secure image covert channel in spatial domain using Octonary PVD scheme. The goals of this paper are to be realized through: (1) pairing a pixel with all of its neighbors in all the eight directions, to offer larger embedding capacity (2) the decision of the number of bits to be embedded in each pixel based on the nature of its region and not done universally same for all the pixels, to enhance the perceptual quality of the images (3) the re-adjustment phase, which sustains any modified pixel in the same level in the stego-image also, where the difference between a pixel and its neighbor in the cover image belongs to, for imparting the statistical un-detectability factor. An extensive experimental evaluation to compare the performance of the proposed system vs. other existing systems was conducted, on a database containing 3338 natural images, against two specific and four universal steganalyzers. The observations reported that the proposed scheme is a state-of-the-art model, offering high embedding capacity while concurrently sustaining the picture quality and defeating the statistical detection through steganalyzers.

Enhanced photoprotection for photo-labile compounds using double-layer coated corn oil-nanoemulsions with chitosan and lignosulfonate

With the aim to establish a novel nanocarrier system with relatively high payload and high photoprotection capacity for photo-labile active compounds, in this work, deltamethrin (photo-labile compound) was encapsulated into corn oil-nanoemulsions (NE) by a hot high pressure homogenization technique followed by coating with chitosan as the first coating layer (CH-NE) and lignosulfonate as the second coating layer to form a double-layer coated NE (L-CH-NE). The optimal conditions for preparation of NE, chitosan coating and lignosulfonate coating were investigated. The results indicate that polymer coating and the number of coating layers significantly affected the release profile and photoprotection capacity of nanocarriers. In particular, after coating, the release rate became slower and photoprotection capacity became higher. Moreover, in the case of L-CH-NE after 24h of UV exposure in direct photolysis and 2.5h of UV exposure in indirect photolysis, the non-degraded amount of deltamethrin was approximately 4.5 times and 2.1 times, respectively, higher than that of the free-from deltamethrin. In the future, this novel nanocarrier system will show great potential and be widely applied to many fields related to protection of photo-labile compounds against photo-degradation.

Particles on the Move: Intracellular Trafficking and Asymmetric Mitotic Partitioning of Nanoporous Polymer Particles

Nanoporous polymer particles (NPPs) prepared by mesoporous silica templating show promise as a new class of versatile drug/gene delivery vehicles owning to their high payload capacity, functionality, and responsiveness. Understanding the cellular dynamics of such particles, including uptake, intracellular trafficking, and distribution, is an important requirement for their development as therapeutic carriers. Herein, we examine the spatiotemporal map of the cellular processing of submicrometer-sized disulfide-bonded poly(methacrylic acid) (PMASH) NPPs in HeLa cells using both flow cytometry and fluorescence microscopy. The data show that the PMASH NPPs are transported from the early endosomes to the lysosomes within a few minutes. Upon cell division, the lysosome-enclosed PMASH NPPs are distributed asymmetrically between two daughter cells. Statistical analysis of cells during cytokinesis suggests that partitioning of particles is biased with an average segregation deviation of 60%. Further, two-dimensional difference gel electrophoresis (2D-DIGE) analysis reveals that 127 out of 3059 identified spots are differentially regulated upon exposure to the PMASH NPPs. Pathway analysis of the proteomics data suggests that ubiquitylation, a reversible modification of cellular proteins with ubiquitin, plays a central role in overall cellular responses to the particles. These results provide important insights into the cellular dynamics and heterogeneity of NPPs, as well as the mechanisms that regulate the motility of these particles within cells, all of which have important implications for drug susceptibility characteristics in cancer cells using particle-based carriers.

Self-assembled, aptamer-tethered DNA nanotrains for targeted transport of molecular drugs in cancer theranostics

Nanotechnology has allowed the construction of various nanostructures for applications, including biomedicine. However, a simple target-specific, economical, and biocompatible drug delivery platform with high maximum tolerated doses is still in demand. Here, we report aptamer-tethered DNA nanotrains (aptNTrs) as carriers for targeted drug transport in cancer therapy. Long aptNTrs were self-assembled from only two short DNA upon initiation by modified aptamers, which worked like locomotives guiding nanotrains toward target cancer cells. Meanwhile, tandem "boxcars" served as carriers with high payload capacity of drugs that were transported to target cells and induced selective cytotoxicity. aptNTrs enhanced maximum tolerated dose in nontarget cells. Potent antitumor efficacy and reduced side effects of drugs delivered by biocompatible aptNTrs were demonstrated in a mouse xenograft tumor model. Moreover, fluorophores on nanotrains and drug fluorescence dequenching upon release allowed intracellular signaling of nanotrains and drugs. These results make aptNTrs a promising targeted drug transport platform for cancer theranostics.

Mechatronic Design of a Parallel Robot for Milling

The paper presents the process of development of a parallel manipulator for milling, and justifies why mechatronic approach can lead to successes. The resulting construction is a novel, versatile 3-RRPRR, fully-parallel manipulator with three translational degrees of freedom, characterizing in comparatively high payload capacity, large workspace and high attainable accelerations. The construction of the manipulator is shown, with analysis of its kinematics and dynamics. A controller is proposed, simulated and experimentally investigated. Finally, the conclusions and future works are presented.

Tank-Like Module-Based Climbing Robot Using Passive Compliant Joints

This paper proposes an underactuated modular climbing robot with flat dry elastomer adhesives. This robot is designed to achieve high speed, high payload, and dexterous motions that are typical drawbacks of previous climbing robots. Each module is designed as a tread-wheeled mechanism to simultaneously realize high speed and high adhesive force. Two modules are connected by compliant joints, which induce a positive preload on the front wheels resulting in stable climbing and high payload capacity. Compliant joints also help the robot to perform various transitions. An active tail is adopted to regulate the preload of the second module. Force transfer equations are derived and stable operating conditions are verified. The stiffness coefficients of the compliant joints and the active tail force are determined optimally to satisfy the constraints of stable operation. The prototype two-module robot achieves 6-cm/s speed and 500-g payload capacity on vertical surfaces. The abilities of flat surface locomotion, internal, external, and thin-wall transitions, and overcoming various sized obstacles are validated through experiment. The principle of joint compliance can be adopted in other climbing robots to enhance their stability and transition capability.

PEGylated Graphene Oxide-Mediated Protein Delivery for Cell Function Regulation

Delivery of proteins into cells may alter cellular functions as various proteins are involved in cellular signaling by activating or deactivating the corresponding pathways and, therefore, can be used in cancer therapy. In this study, we have demonstrated for the first time that PEGylated graphene oxide (GO) can be exploited as a nanovector for efficient delivery of proteins into cells. In this approach, GO was functionalized with amine-terminated 6-armed polyethylene glycol (PEG) molecules, thereby providing GO with proper physiological stability and biocompatibility. Proteins were then loaded onto PEG-grafted GO (GO-PEG) with high payload via noncovalent interactions. GO-PEG could deliver proteins to cytoplasm efficiently, protecting them from enzymatic hydrolysis. The protein delivered by GO-PEG reserves its biological activity that regulates the cell fate. As a result, delivery of ribonuclease A (RNase A) led to cell death and transport of protein kinase A (PKA) induced cell growth. Taken together, this work demonstrated the feasibility of PEGlyated GO as a promising protein delivery vector with high biocompatibility, high payload capacity and, more importantly, capabilities of protecting proteins from enzymatic hydrolysis and retaining their biological functions.

Varying radix numeral system based adaptive image steganography

A novel image steganographic scheme based on the primitive and renowned numerical model is proposed. In this adaptive scheme the data to be embedded is dissected into numerals, each having variable information carrying capacity. The dissection is based on the statistics of the host image pixels i.e. the amount of adulteration that a pixel can tolerate. The proposed method provides proficient visual quality despite high payload capacity. The experimental results evaluated on 300 natural images show that the new scheme is resistant to RS steganalysis and offers high visual quality when compared with typical LSB-based schemes as well as their edge adaptive versions, like pixel-value-differencing-based schemes.

A high payload frequency-based reversible image hiding method

To provide both a high payload capacity and a good stego-image quality, a high payload frequency-based reversible image hiding (HPFRIH) method was presented in this paper. These performances can be achieved by transforming a cover image from the spatial domain into the frequency domain through Haar digital wavelet transform (HDWT) method followed by an adaptive arithmetic coding method to encode the HDWT coefficients in a high-frequency band. The HPFRIH method was used to conceal both the compressed data and the secret data in the high-frequency band. This simple method can completely reconstruct the cover image only from the stego-image. Moreover, experimental results showed that the HPFRIH method offers both impressive hiding capacity and satisfied stego-image quality.

Selection of optimal machining parameters for hexapod machine tool

Parallel kinematic machine tools (PKM) have the advantages of higher stiffness, higher payload capacity and lower inertia. Still their penetration into the machine tool industry is very less. One of the difficulties in using PKMs such as hexapod machine tools is that the stiffness continuously varies with configuration change at every instant. This makes location of work piece and selection of machining parameters difficult and complicated. A methodology is presented in this article to select optimal machining parameters for hexapod machine tools. Particle swarm optimization is used as a tool in the optimization process. A profile-milling example is also presented to demonstrate the selection of machining parameters.

Quantum Dots Bearing Lectin-Functionalized Nanoparticles as a Platform for In Vivo Brain Imaging

Delivery of imaging agents to the brain is highly important for the diagnosis and treatment of central nervous system (CNS) diseases, as well as the elucidation of their pathophysiology. Quantum dots (QDs) provide a novel probe with unique physical, chemical, and optical properties, and become a promising tool for in vivo molecular and cellular imaging. However, their poor stability and low blood-brain barrier permeability severely limit their ability to enter into and act on their target sites in the CNS following parenteral administration. Here, we developed a QDs-based imaging platform for brain imaging by incorporating QDs into the core of poly(ethylene glycol)-poly(lactic acid) nanoparticles, which was then functionalized with wheat germ agglutinin and delivered into the brain via nasal application. The resulting nanoparticles, with high payload capacity, are water-soluble, stable, and showed excellent and safe brain targeting and imaging properties. With PEG functional terminal groups available on the nanoparticles surface, this nanoprobe allows for conjugation of various biological ligands, holding considerable potential for the development of specific imaging agents for various CNS diseases.

The response of carbon fibre composites to blast loading via the Europa CAFV programme

Modern military vehicles must balance the need for occupant protection against the competing requirements for high mobility and payload capacity. As such, there is continuing interest in the development of lightweight vehicle structures that reduce the overall mass of the hull and armour system, leading to a lighter vehicle. One way to achieve this is through the use of materials that can perform both structural and protective roles, reducing the mass of applique armour required to achieve a given level of protection. The aim of the 3-year EUROPA Carbon Fibre for Armoured Fighting Vehicles (CAFV) programme was to investigate the use of carbon fibre composites for use in military vehicle structures. Six nations took part in the programme, each assessing the benefits of carbon fibre composites in terms of their application to at least part of an armoured fighting vehicle (AFV) hull. For the UK, a lower hull section was selected as the focus for the research programme and, as part of the programme, assessed against mine blast threats.

Determination of the kinematically redundant active prismatic joint variable ranges of a planar parallel mechanism for singularity-free trajectories

Based on its simple structure, base-fixed actuators, high payload capacity , high accuracy, and high mechanical rigidity, the 3- R RR mechanism 1 The 3- R RR denotes three kinematic chains that connect the end-effector (moving platform) of a parallel mechanism to the ground and R denotes a revolute joint . Per standard usage, the underline represents an actuated joint throughout this paper. 1 is a practical planar parallel manipulator . However, the 3- R RR mechanism is known to have singular loci within its workspace affecting its use. A recent paper by these authors introduced a singularity avoidance algorithm for the 3- R RR mechanism using kinematic redundancy. This paper extends the earlier work and allows for determination of the required ranges of the kinematically redundant active prismatic joint variables of a mechanism to allow given trajectories to be singularity-free. Since for a kinematically redundant mechanism the initial configuration is crucial for redundancy resolution, the proposed algorithm uses permutations to consider all possible points where kinematic redundancy resolution begins. The efficacy of the algorithm is demonstrated through simulation.

Hiding Data Reversibly in an Image via Increasing Differences between Two Neighboring Pixels

This paper proposes a simple, efficient method that, based on increasing the differences between two neighboring pixels, losslessly embeds a message into a host image. The point at which the number of pixel differences in the image is at a maximum is selected to embed the message. The selected difference is increased by 1 or left unchanged if the embedded bit is “1” or “0”, respectively. On the other hand, differences larger than the selected difference are increased by 1. Increasing a difference is done by adding 1 to or subtracting 1 from the pixel if its value is larger or smaller than its preceding pixel, respectively. Experimental results show that the proposed method can achieve a high payload capacity while the image distortion of the stego-image remains minimal.

Kinematics of a New High-Precision Three-Degree-of-Freedom Parallel Manipulator

Closed-form direct and inverse kinematics of a new three-degree-of-freedom (DOF) parallel manipulator with inextensible limbs and base-mounted actuators are presented. The manipulator has higher resolution and precision than the existing three-DOF mechanisms with extensible limbs. Since all of the manipulator actuators are base mounted, higher payload capacity, smaller actuator sizes, and lower power dissipation can be obtained. The manipulator is suitable for alignment applications where only tip, tilt, and piston motions are significant. The direct kinematics of the manipulator is reduced to solving an eighth-degree polynomial in the square of the tangent of the half-angle between one of the limbs and the base plane. Hence, there are at most 16 assembly configurations for the manipulator. In addition, it is shown that the 16 solutions are eight pairs of reflected configurations with respect to the base plane. Numerical examples for the direct and inverse kinematics of the manipulator are also presented.

Mechatronic Design of Parallel Manipulators

The paper presents mechatronic procedure of parallel manipulators development and justifies why only such approach can lead to successes. The procedure has been applied to a case study - a novel, versatile 3-RRPRR (Revolute-Revolute-Prismatic-Revolute-Revolute joints), fully-parallel manipulator with three translational degrees of freedom, for pick-and-place and machining applications, characterising in comparatively high payload capacity, large workspace and high attainable accelerations. The resulting construction is shown, with analysis of its kinematics and dynamics. A controller are proposed, simulated and experimentally investigated. Finally, the conclusions and future works are presented.

Theoretical and experimental investigation of C 60-propellant for ion propulsion

The large mass as well as the low first ionization potential and the large electron impact ionization cross-section make Buckminsterfullerene (C 60) potentially attractive as an ion engine propellant. To evaluate the advantages of C 60 it was necessary to calculate characteristic quantities like the thrust-beam-power ratio and the different efficiencies. It was found that, compared with xenon, the use of C 60 would significantly reduce the necessary beam power by 57 percent for the same power level, resulting in a reduction of power supply mass and thus in a higher payload capacity. Calculations of the efficiencies show a clear increase in overall efficiency. Particularly, the mass efficiency and the electrical efficiency would increase significantly over that obtained with a xenon-fuelled ion engine. Together with the exceptionally high flexibility of the molecular structure of C 60, this results in a very low ablation in the grid system, and consequently in a longer lifetime. One of the most severe problems in using C 60 as propellant for ion engines is the temperature sensitivity of C 60. High temperatures cause fragmentation of the C 60 molecule, low temperatures lead to resublimation of C 60 on the inner walls of the engine. Both would result in a decrease of the mass efficiency. Therefore, extensive experiments with a special ion source were carried out to determine the temperature behavior of an ion thruster. This and the theoretical research yield in a temperature window (400–700°C) for systems operating with C 60.