Advanced Materials Research Vol. 749

Abstract: Visual-evoked potentials (VEPs) which is made up of electrical signals generated by the nervous system in response to a stimulus can be easily recorded from the visual cortex of the experiment animal. There are several types of VEPs, for example, flash evoked potential (FEP), pattern evoked potential [1-3]. The FEP is produced by a visual stimulation with a brief and diffuse flash light. It is frequently used to evaluate the neural activity and sensory processing in the visual system [ and to identify and characterize the changes occurring in the retina and the occipital cortex [4, 5]. VEPs can also provide a further therapeutic approach through the stimulate of monitoring neurophysiologic changes related to diseases [6, 7]. The pattern evoked potentials have been used to assess parametric characteristics of visual perception, detect neuronal irritability and diagnose neurological diseases [8-1.

Abstract: Phase is an important feature of the local field potential (LFP) and plays a significant role in transmission and processing information in visual system. In this paper, the LFP of Long Evans rats primary visual cortex is recorded by the microelectrode array through the visual stimuli of the checkerboard and different orientation gratings. Then, a multi-mode phase extraction model based on the firing spikes was built. We found that neurons selective orientation information using the third intrinsic mode functions of local field potential during firing spikes.

Abstract: Regulation of daily physiological functions with a ~24-hour periodicity, or circadian rhythms, exists in both eukaryotes and prokaryotes. So far, cyanobacteria are only known prokaryotes proved to have circadian rhythmicity. The circadian system in cyanobacteria comprises a post-translational oscillator (PTO) and a transcriptional/translational feedback loop (TTFL). The PTO comprise of three proteins (KaiA, KaiB, KaiC), and can be reconstituted in vitro with the existence of ATP. Phase of the PTO is associated with the phosphorylation states of KaiC, with KaiA promoting the phosphorylation of KaiC, and KaiB promoting the de-phosphorylation. Here we studied the dynamics of the KaiA protein of Thermosynechococcus elongatus. The result will be helpful in understanding the function of KaiA and its binding with KaiC.

Abstract: Poly (dimethylsiloxane) (PDMS) silicones have found many applications in biomedical devices, such as catheters and intraocular lenses. But their hydrophobicity makes the possibility of the unexpected bioadhesion. In this paper, we reported a facile and efficient anti-fouling surface modification method on PDMS via self-polymerization of dopamine and the followed hyaluronic acid immobilization. Dopamine, commonly used as a neurotransmitter, is also a small molecule mimic of the adhesive proteins of mussels. Self-polymerization of dopamine can produce a thin polydopamine (PDA) layer on PDMS surface. Subsequently, thiol group functionalized hyaluronic acid (denoted as HA-SH) was immobilized covalently onto the resultant surface by the coupling between thiol group and reactive polydopamine layer. Then, the in vitro adhesion behaviors of the lens epithelial cells (LECs) and macrophage were investigated for evalution the anti-fouling effect of the hyaluronic acid modified PDMS surface. The results indicated that the cellular adhesion on PDMS were greatly decreased after hyaluronic acid modification, which suggested the potential application of such hyaluronic acid modified PDMS in biomedical applications.

Abstract: In order to improve aqueous solubility of Sunitinib, based on the structure-activity relationship, four analogues were designed and synthesized. The obtained structures were identified by ¹H NMR, MS and elemental analysis. In vitro evaluation of antitumor bioactivity was performed by MTT method. All of synthesized compounds showed antitumor activities, especially, compounds A1, which were better than or equal to the antitumor activity of positive control.

Abstract: Dandelion (Taraxacum spp) is an medical active materials used in many traditional and modern herbal medical systems, its polysaccharides have many bioactivities. Taraxacum mongolicum is one of the most widely consumed as Chinese herbal medicine and root tea in Changbai Mountains area, Northeast China. In this study, a procedure for the extraction of polysaccharides from the root of T mongolicum(TMRPS) was established. Based on single-variable tests experiment to determine the ranges of the extraction parameters (extraction temperature (X1), extraction time (X2), and ratio of solvent to raw material (X3)), response surface methodology (RSM) was used to optimize for these extraction parameters (X1, X2, X3) enhancing the forward extraction efficiency of TMRPS by a three-level three-variable Box-Behnken experimental design. The results showed that the ranges of the extraction parameters were determined as 60°C-80°C(X1),1h-3h (X2),20-40(v/m)(X3) by single-variable tests and the maximal yield (9.01%) of TMRPS was reached at extraction temperature 70.2°C, extraction time 1.79 h and ratio of solvent to raw material 28.0 (v):1 (m). Convenient for experiment, appropriate readjustment of these extraction parameters was made. Under these readjusted conditions, the mean extraction yield of TMRPS was 8.85%, which was near to theoretical calculation and indicates that these results were agree closely with model predictions.

Abstract: The layer-by-layer (LbL) self-assembly of carbon nanotube (CNT)/polyelectrolyte has been widely investigated for various applications. In this study, multi-walled carbon nanotube (MWCNT) was LbL assembled with three positively charged polyelectrolytes, which was PEI, chitosan and PDDA respectively. In order to investigate its potential application in biomedical field, cell biocompatibility was examined by examining the viability and morphologies of NIH-3T3 fibroblasts cultured on the glass coated with the MWCNT/polyelectrolyte assembly multi-layers.

Abstract: To investigate the subtypes and distribution of hantavirus in Jilin area. Rattus norvegicus were collected from the main endemic areas of Jilin area and hantavirus in the lung were identified by indirect immunofluorescence assay. M segments of positive samples were partially amplified with Nested RT-PCR and sequenced. Phylogenetic analysis was used for genotyping. All hantaviruses from R. norvegicus were Seoul virus in Jilin area. Phylogenetic analysis of M segments showed that Seoul hantaviruses carried by R. norvegicus in Jilin city were the S3 subtype,and there was no HTNV and PUUV found. The results showed that the subtype of Seoul hantaviruses in Jilin area was S3.

Abstract: Uterus didelphys associated with unilateral imperforate vagina is a rare congenital anomaly. Clinically the patients present with nonspecific symptoms, an accurate and whenever possible noninvasive diagnosis is of utmost importance to permit corrective treatment and as little mutilation as possible, and to assure the future fertility of the patient ^{[1, 2]}. We report 3 cases and discuss the use of Magnetic resonance imaging (MRI), as a very reliable diagnostic tool in such cases. By characters of MRI, the congenital malformation was detected for these cases and appropriate treatment was implemented.

Abstract: Magnetic induction tomography (MIT) is a noninvasive and contactless imaging modality which aims at the reconstruction of the electrical conductivity in objects from alternating magnetic fields. Filtered back projection reconstruction algorithm is widely used in biomedical imaging field, and tried to use in MIT. Finite element analysis model has been established based on Scharfetter coil-coil model and perturbation theory, then simulated coaxial coil system by ANSYS software, the perturbation aroused by a target object moving on vertical coil axis. The sensitivity of a target object moves in vacuum and a salt solution were calculated respectively, the characteristics of the perturbation sensitivity in a salt solution were analyzed. The conditions of filtered back projection reconstruction algorithm in MIT were discussed.