Discovery of blood-brain barrier penetrating peptides by phage display technology to deliver biologics into the brain

Biologics as macromolecules can’t deliver to the brain without the blood-brain barrier (BBB) transport carriers. A phage display peptide library was employed to screen the BBB shuttling peptides by biopanning against an in vitro BBB model. We identified several novel and efficient BBB permeable peptides. A series of in vivo and in vitro studies were conducted to validate the capability of these peptides to transport the BBB and the brain extracellular matrix (ECM). The findings demonstrated that our peptides, Pep-3 and Pep-9 are able to shuttle across BBB and deliver to the brain parenchyma in vivo. Thereafter, Pep-9 was selected to develop IgG-Pep-9 conjugate formulation by click chemistry. In vivo delivery of IgG-Pep-9 indicated that Pep-9 can carry antibody molecules to transport BBB and deliver to the brain parenchyma.Pharmaceutical Science

RSHSC-Routing Algorithm Based on Simplified Harmony Search and Coding for UWSNs

With the development of wireless networks and increasingly interest of people in underwater resources and environment, UWSNs are being paid more and more attention. Because of the characteristics of underwater channel and acoustic signal, the protocols used in the terrestrial networks cannot be directly used in UWSNs. In this paper, a reliable and energy-efficient routing protocol based on SHS and coding, called RSHSC, is proposed. Firstly, regular nodes are assigned to cluster heads according to simplified harmony search algorithm. Secondly, partial network encoding is introduced and the next two-hop information is considered when data packets are transmitted to sink nodes from the source node. Only the best next-hop forwards data packets. All data packets from neighbor nodes are used for decoding. Thirdly, two schemes of updating routing are designed and compared. Lastly, extensive simulations prove RSHSC is effective in improving reliability and decreasing energy consumption

An Ultra-Lightweight Encryption Scheme in Underwater Acoustic Networks

We tackle a fundamental security problem in underwater acoustic networks (UANs). The S-box in the existing block encryption algorithm is more energy consuming and unsuitable for resources-constrained UANs. In this paper, instead of S-box, we present a lightweight, 8-round iteration block cipher algorithm for UANs communication based on chaotic theory and increase the key space by changing the number of iteration round. We further propose secure network architecture of UANs. By analysis, our algorithm can resist brute-force searches and adversarial attacks. Simulation results show that, compared with traditional AES-128 and PRESENT algorithms, our cryptographic algorithm can make a good trade-off between security and overhead, has better energy efficiency, and applies to UANs

An Ultra-Lightweight Encryption Scheme in Underwater Acoustic Networks

We tackle a fundamental security problem in underwater acoustic networks (UANs). The S-box in the existing block encryption algorithm is more energy consuming and unsuitable for resources-constrained UANs. In this paper, instead of S-box, we present a lightweight, 8-round iteration block cipher algorithm for UANs communication based on chaotic theory and increase the key space by changing the number of iteration round. We further propose secure network architecture of UANs. By analysis, our algorithm can resist brute-force searches and adversarial attacks. Simulation results show that, compared with traditional AES-128 and PRESENT algorithms, our cryptographic algorithm can make a good trade-off between security and overhead, has better energy efficiency, and applies to UANs

Synergic catalytic effect of Ti hydride and Nb nanoparticles for improving hydrogenation and dehydrogenation kinetics of Mg-based nanocomposite

The Mg-9.3 wt% (TiH1.971-TiH)−0.7 wt% Nb nanocomposite has been synthesized by hydrogen plasma-metal reaction (HPMR) approach to enhance the hydrogen sorption kinetics of Mg at moderate temperatures by providing nanosizing effect of increasing H “diffusion channels” and adding transition metallic catalysts. The Mg nanoparticles (NPs) were in hexagonal shape range from 50 to 350 nm and the average size of the NPs was 177 nm. The small spherical TiH1.971, TiH and Nb NPs of about 25 nm uniformly decorated on the surface of the big Mg NPs. The Mg-TiH1.971-TiH-Nb nanocomposite could quickly absorb 5.6 wt% H2 within 5 min at 573 K and 4.5 wt% H2 within 5 min at 523 K, whereas the pure Mg prepared by HPMR could only absorb 4 and 1.5 wt% H2 at the same temperatures. TiH1.971, TiH and Nb NPs transformed into TiH2 and NbH during hydrogenation and recovered after dehydrogenation process. The apparent activation energies of the nanocomposite for hydrogenation and dehydrogenation were 45.0 and 50.7 kJ mol−1, which are much smaller than those of pure Mg NPs, 123.8 and 127.7 kJ mol−1. The improved sorption kinetics of the Mg-based nanocomposite at moderate temperatures and the small activation energy can be interpreted by the nanostructure of Mg and the synergic catalytic effects of Ti hydrides and Nb NPs

A lumped model for rotational modes in periodic solid composites

We present a lumped model to study the rotational modes in a type of two-dimensional periodic solid composites comprised of a square array of rubber-coated steel cylinders embedded in an epoxy matrix. The model captures the physical essence of rotational modes in such systems for various combinations of material parameters, and, therefore it is able to describe the transition behaviour when the system is gradually adjusted from an elastic metamaterial to an elastic phononic crystal. From the model, we can define a transition zone which separates the typical elastic metamaterials and the phononic crystals