Artificial Organs

The market of tools, devices, and processes for medical treatments and diagnosis has been growing at a very fast pace, driven by the multi-disciplinary development of integrated innovative technologies. In this article, the way artificial organs design is currently taught is analyzed and discussed relative to the evolution of the methods of artificial organs design as substitution of physical and metabolic bodily functions. Particular attention is devoted to the evolution from empirical attempts at providing generic replacement of a single mechanical function to a more systematic multi-purpose approach that increasingly accounts for biological issues. As a result, at the forefront of research, the paradigm is shifting from mechanical/electronic prostheses towards the development in vitro of tissue engineered organs/tissues, where the artificial part is fully integrated with the biological counterpart. Personalized solutions for each patient rather than a generic solution good for all patients are also sought.

Visual Orienting Attention was Influenced by Auditory Processing

Visual orienting is critical signal to ability of attention. In particular, eye gaze is one of important visual orienting to refer our belief, desires and feeling etc. However, in real life, visual orienting has been indicated to be influenced by others modality processing, such as auditory supplement. Less previous studies have been comprehensively investigated how visual orienting is influenced by auditory processing. In this study, the authors conduct two experiments to investigate how visual orienting effect would be influenced by auditory processing, when used nonsocial and social stimuli as cues respectively (i.e., arrow and eye gaze). The results indicate that visual orienting is clearly influenced by auditory processing in both social and non-social stimuli as cues. Functional MRI data suggest that DLPFC plays an important role in regulating visual and auditory attention.

Characterization of Signal Propagation through Limb Joints for Intrabody Communication

Intrabody communication (IBC) is one of the recent physical layers of the IEEE 802.15.6 Wireless Body Area Networks (WBAN) communication standard. It is employed for data transmission in low frequency bands (21 MHz as per standard, 0.3-120 MHz in literature), providing up to 10 Mbps data throughput. An effective way to increase data rate communication is to determine higher operation frequency bands. This paper reports empirical studies which explore signal propagation through the human body including limb joints within the 0.3-200 MHz frequency range. Results show that minimum signal attenuation points occur at 50 MHz and 150 MHz within the range of investigation. The presence of the joint segments along the signal propagation path causes on average 2.0 dB loss (at 50 MHz and 150 MHz), 6.0 dB loss (<1 MHz) and less than 3.0 dB (>150 MHz) compared to limb segments.

Development of Gelatin Films with Designed Antimicrobial Peptide and Silver Nanoparticles

Gelatin films from cold water fish skin filled with designed antimicrobial peptide or silver nanoparticles were formulated for biomedical applications. Antibacterial activities of gelatin films containing silver nanoparticles and lytic peptides were evaluated to study the growth of a Staphylococcus species. The results suggest that inclusion of silver nanoparticles and lytic peptides into the composition of biocompatible films is feasible, with significant retention of the antimicrobial activity for both agents. The results presented here give evidence that both the silver nanoparticles and lytic peptides retain their antibacterial activity in such film matrices and the surrounding medium. Therefore, such biocompatible films may have potential use in biomedical applications such as wound dressing, superficial infection and contamination control. Evaluation of the mechanical properties for silver nanoparticles gelatin films revealed that the tensile strength appeared to be optimal at 0.3% silver nanoparticles loading. However, the strain-to-failure decreased with respect to the neat film.

Development of Photocrosslinkable Urethane-Doped Polyester Elastomers for Soft Tissue Engineering

Finding an ideal biomaterial with the proper mechanical properties and biocompatibility has been of intense focus in the field of soft tissue engineering. This paper reports on the synthesis and characterization of a novel crosslinked urethane-doped polyester elastomer (CUPOMC), which was synthesized by reacting a previously developed photocrosslinkable poly (octamethylene maleate citrate) (POMC) prepolymers (pre-POMC) with 1,6-hexamethylene diisocyanate (HDI) followed by thermo- or photo-crosslinking polymerization. The mechanical properties of the CUPOMCs can be tuned by controlling the molar ratios of pre-POMC monomers, and the ratio between the prepolymer and HDI. CUPOMCs can be crosslinked into a 3D network through polycondensation or free radical polymerization reactions. The tensile strength and elongation at break of CUPOMC synthesized under the known conditions range from 0.73±0.12MPa to 10.91±0.64MPa and from 72.91±9.09% to 300.41±21.99% respectively. Preliminary biocompatibility tests demonstrated that CUPOMCs support cell adhesion and proliferation. Unlike the pre-polymers of other crosslinked elastomers, CUPOMC pre-polymers possess great processability demonstrated by scaffold fabrication via a thermally induced phase separation method. The dual crosslinking methods for CUPOMC pre-polymers should enhance the versatile processability of the CUPOMC used in various conditions. Development of CUPOMC should expand the choices of available biodegradable elastomers for various biomedical applications such as soft tissue engineering.

Elastic Modulus of Human Dental Enamel from Different Methods

Knowing the elastic modulus of human dental enamel is of high importance since dental filling materials should posses equal mechanical properties as enamel itself. If this demand is not fulfilled, the interaction between filling and enamel is not equivalent, so that healthy enamel could be simply abrased during chewing. Hence it is astonishing that the literature shows a big variety of suggestions for the elastic modulus. This paper will give a short overview about some existing results (maybe not all) and tries to compare and evaluate them. The experiments have been done too, trying to make it more easy for the experienced reader to make up his own mind about the elastic modulus of human dental enamel.