Embryonic mesenchymal cells mediate tooth formation during development as a result of physical and chemical interactions with their extracellular matrix (ECM) microenvironment. Engineering biomaterials relevant to tooth differentiation require a screening platform that incorporates both embryologically relevant properties relating to ECM stiffness as well as chemistry. Current ECM microarray technologies that screen for the effects of differences in substrate mechanical properties on cell differentiationare limited to ranges of high stiffness that are not relevant for the engineering of many cell types, such as stem cells and embryonic mesenchymal cell derivatives. Here, we describe the development of a novel polyacrylamide gel microarray platform and demonstrate its utility for the selection of odontogenic biomaterials. This microarray platform uses soft substrates (132, 558, and 1510 Pa) that closely mimic the embryonic microenvironment coatedwith the ECM proteins, Collagen VI and Tenascin (either alone or in combination), which have been shown to contribute to odontogenesis and permits combinatorial analysis of their effects on cell growth and differentiation. Using expression of the odontogenic transcription factor pax9 as a measure of tooth differentiation, we found that odontogenesis was the highest when mesenchymal cells isolated from embryonic mouse mandible (day 10) were cultured on 1510 Pa with Collagen VI (100 μg/ml). This screening method is useful for selection and design of engineered materials for dental applications, as well as any challenge that involves engineering of tissues that depends on compliant ECM materials in combination with chemical cues from the microenvironment.
The electroencephalogram (EEG) signal is widely used in clinical to investigate brain disorders and plays an important role in the diagnosis of epilepsy.We analyse and classify EEG signals using wavelets decomposition and support vector machines (SVM).In particular, we break the EEG waves into different time frames.Numerical experiment on a standard test data set demonstrates that the proposed algorithm can achieve high accuracy on the prediction of epilepsy even when short period of time duration is used.
Controlling human gait by wearable assistive devices is a dynamic and time critical activity and thus requires a dedicated real time control environment. The paper discusses an implementation strategy for real time control algorithm for GaExoD prototype. Control approach follows gait trajectory using feedback sensors and actuators for movement control. NI Lab VIEW, Robotics, FPGA and RT module were used and prove beneficial in shorter development time. Position control errors were estimated for standing and sitting functions provided which is significantly lower for sitting function.
For purposes of biodosimetry in the event of a large scale radiation disaster, one major and very promising point-of contact device is assessing dose using tooth enamel. This technique utilizes the capabilities of electron paramagnetic resonance to measure free radicals and other unpaired electron species, and the fact that the deposition of energy from ionizing radiation produces free radicals in most materials. An important stipulation for this strategy is that the measurements, need to be performed on a central incisor that is basically intact, i.e. which has an area of enamel surface that is as large as the probing tip of the resonator that is without decay or restorative care that replaces the enamel. Therefore, an important consideration is how to quickly assess whether the tooth has sufficient enamel to be measured for dose and whether there is resin present on the tooth being measured and to be able to characterize the amount of surface that is impacted. While there is a relatively small commercially available dielectric probe which could be used in this context, it has several disadvantages for the intended use. Therefore, a smaller, 1.19mm diameter 50 ohm, open-ended, coaxial dielectric probe has been developed as an alternative. The performance of the custom probe was validated against measurement results of known standards. Measurements were taken of multiple teeth enamel and dental resin samples using both probes. While the probe contact with the teeth samples was imperfect and added to measurement variability, the inherent dielectric contrast between the enamel and resin was sufficient that the probe measurements could be used as a robust means of distinguishing the two material types. The smaller diameter probe produced markedly more definitive results in terms of distinguishing the two materials.
Silicon photonic wire biosensors' homogenous detection sensitivities with TE and TM modes for typical test solutions have been investigated. The highest homogenous detection sensitivity of 0.8486 has been achieved when the silicon photonic wire's width and core thickness are of 0.5μm and 0.22μm for TM mode homogenous sensing. It was found that the homogenous detection sensitivity of TM mode of a silicon photonic wire is about 7 times of that of a TE mode. Silicon photonic wires' homogenous detection sensitivities are also compared with that of a Silicon on Silica (SOI) rib waveguide, and it was found that the homogenous detection sensitivity of a silicon photonic wire is generally a few thousand times of that of a SOI rib waveguide for either TE or TM mode.
Actuating mechanisms of orthotic devices are important aspects of today's robotic field. Controlling a linear actuator attached in an orthotic limb using PID controller with a suitable tuning method is the main discussion of this paper. Tuning methods like, Internal Model Control (IMC), Zeigler‐ Nichols and Tyreus‐Lyben are applied in this work and analyzed the response in time domain specification, by considering the aspects of orthotic devices. Since simulation is the best way to testing a design, here we use control and simulation module of LabVIEW to simulate our process. Simulation results have shown us the improvement of the system performance by the application of different tuning methods and we have found that IMC method is the best for PID controller to control the DC drive in case of an ambulatory gait orthotic.
AQPs (Aquaporins, AQPs) is the generic terms of homologous protein family, a group of membrane proteins with peculiar water permeability, which can adjust the aquaporin of cytomembrane. The discovery of AQPs reveals the regulatory mechanism of water transmembrane transfer at the molecular level. AQPs play an important role in the fluid balance of lungs. At present, thirteen kinds of AQPs have been found in mammals, among which there are six kinds of AQPs (AQP1, AQP3, AQP4, AQP5, AQP8, AQP9) expressed in different parts respectively in lung tissues and participating the absorption of alveolar fluid and the water capacity regulation of lungs in acute or subacute injury. This essay gives an overview of the distribution, function of AQPs in lung tissue and the relationship with pulmonary injury.
Effects of variable cushion densities on human gait are estimated by analyzing principle components of Ground Reaction Force (GRF) which includes Vertical Ground Reaction Forces (VGRF), Moments (M) and Center of Pressure (COP). This biomechanics study aims to identify design and parameters for quantification of a prosthetic foot. VGRF is important to analyze dynamics of human gait and predict the quality of prosthetic foot, and more accurate estimation is possible by inclusion of lower limb moments and COP. Experimental GRF data of human gait with cushion pads of different densities under heal area is acquired through force platform. Recorded gait data is correlated for variation in VGRF, moments and COP with respect to variation in Cushion Densities (CD). It is observed that VGRF (FZ1, FZ3) and Moment (M1) decrease significantly with the increase in cushion densities. Similarly, VGRF (Fz2), Moment (M2, M3) and COP increase with the increase in cushion densities and that VGRF reduces for walking at normal speed with added cushion heel as compared to bare foot (without cushion pads) walking.
To systematically study the chemical constituents in the rhizome of Acorus tatarinowii Schott, the seven compounds were identified by NMR spectroscopic methods and identified as N-trans-coumaroyl tyramine(1), N-trans-feruloyl tyramine (2), N-trans-coumaroyl octopamine (3), N-transferuloyl octopamine(4), 2-trans-3-(4-hydroxyphenyl)-N-[2- (4-hydroxyphenyl)-2-methoxyethyl]-acrylamide(5), 2-trans-3- ((4-hydroxy-3-methoxyphenyl)-N-[2-(4-hydroxyphenyl)-2-m ethoxyethyl]-acrylamide(6),2-cis-3-((4-hydroxy-3-methoxyph enyl)-N-[2-(4-hydroxyphenyl)-2-methoxyethyl]-acrylamide (7). Compound 1-7 are amide alkaloids obtained from Acorus for the first time, and compound 7 is a new compound. Theory basis is provided for the further study on acorus tatarinowii.
Nasopharyngeal carcinoma is a commonly occurring cancer among the Chinese population and post-irradiation neck fibrosis is a well-known late complication. Neck fibrosis reflected by the Young's modulus, YM, was measured by a tissue ultrasound palpation system (TUPS). YM is a biomechanical property that characterizes the deformability of the soft tissues. The study consisted of two phases: firstly, the construct validity of TUPS in differentiating normal subjects from post-irradiated patients was established. Secondly, a single blinded prospective randomized trial was conducted to assess the effects of a multimodal physiotherapy program on neck fibrosis. Patients suffering from NPC with their cancer in remission and were attending treatment in the physiotherapy department in a regional teaching hospital were invited. Those reluctant to participate or had signs of active metastases were excluded. Fifty patients were successfully recruited and they were randomly divided into two physiotherapy programs. Radiotherapy was predominantly the primary treatment. Their mean age was 49.6+/-7.7 years, and the average post radiotherapy period 98+/-45.2 months. A blinded research assistant measured the YM of the fibrotic neck muscles and the neck ranges of motion at three time points: baseline, at discharge and upon one-month post discharge. Repeated measures analyses of variance for YM and neck range of motions were performed on an intention-to-treat basis. The YM values of the right neck muscles and all neck ranges of motion attained significant drops across time (p＜0.05). This is the first documented study showing the YM values of fibrotic neck muscles and that neck ranges of movement can be improved with treatment.
Notch signal transduction pathway is one of the most important pathways that decide the cell fate and has large influence on the growth and development of cells. Signal transduction between adjacent cells with the Notch receptor, which has important regulating effects on the physiological and pathological process including embryonic development, hematopoiesis, blood cell development, angiogenesis, some nervous system diseases and tumorigenesis, can adjust the differentiation, multiplication and apoptosis of many kinds of cells including stem cells, the transformation from epithelial cells to mesenchyme, etc. Three are some relationships between the gene mutation of some molecules in the Notch signal transduction pathway and the genesis and development of many kinds of tumors. So designing the drugs with the molecules as target sports is brought to the forefront gradually.
An Electrical Impedance Mammography (EIM) planar array imaging system is being developed at the University of Sussex for the detection of breast cancers. Investigations have shown that during data collection, systematic errors and patient artefacts are frequently introduced during signal acquisition from different electrodes pairs. This is caused, in particular, by the large variations in the electrode-skin contact interface conditions occurring between separate electrode positions both with the same and different patients. As a result, the EIM image quality is seriously affected by these errors. Hence, this research aims to experimentally identify, analyse and propose effective methods to reduce the systematic errors at the electrode-skin interface. Experimental studies and subsequent analysis is presented to determine what ratio of electrode blockage seriously affects the acquired raw data which may in turn compromise the reconstruction. This leads to techniques for the fast and accurate detection of any such occurrences. These methodologies can be applied to any planar array based EIM system.
Central nervous system of mammals is known to be highly vulnerable to the environmental stimulus, including radiowaves. The aim of this work is to evaluate the chronic effect (one hour daily for 21 days) of low power radio frequency of 1 KHz square wave modulated 2.45 GHz on the electroencephalogram (EEG) in animal model. Experiments were carried out on male rats (n=10), weighing 100(20) gm and age of 9-10 weeks divided in two groups: (i) control (n=4) and (ii) experimental (n=6). After 21 day of experiments, three hours of single channel bipolar EEG signals were recorded from parietal cortex of rats’ brain on 22nd day continuously, under anesthetized condition (Urethane anesthesia: 1.6 gm/kg of body weight, i.p.). The power spectra of the EEG signals were calculated for analysis of changes in EEG frequency spectrum. The core body temperature was also recorded and evaluated for the thermal nature of the exposure. Student t-test was applied to the EEG spectral results as well as on temperature data to analyze the significance of changes. The analyses suggest that this experimental setup of exposure produces nonthermal effects, however, significantly increased (P<0.05 or better) the power of EEG signals. The EEG spectral changes were found most prominent on the higher frequency side. On the basis of results of this study, it can be suggested that the chronic exposure of low power radio frequencies have sufficient energy to change the brain function that may lead to the development of different psychopahological disorders.
There has been an increasing amount of interest in the design and preparation of new biomaterials that can be used in the fabrication of medical devices for artificial prostheses and implant applications. In this research, core-shell nanostructured poly (methyl methacrylate)-polystyrene (PMMAPS) was prepared using a two-step semibatch microemulsion polymerization system with PMMA and PS as the core and shell respectively. The Gemini surfactant 12-3-12, i.e., trimethylene-1,3-bis(dodecyldimethylammonium bromide) was employed as the emulsifier. PMMA and PMMA-PS latex nanoparticles with a small particle diameter of 14.7 nm and 38.4 nm, respectively, have spherical morphology. The prepared core-shell PMMA-PS polymers have great potential to be used as functional materials for prosthesis and implant applications.
Neurodegenerative disease occurs due to deterioration of cells specially the myelin sheath of the neurons; of brain, spinal cord, and peripheral nerves. The economic and social burden of neurodegenerative diseases is massive and rising too rapidly. Among several of different neurodegenerative disorders, present work is focused on the three most common; Alzheimer’s disease, Parkinson’s disease, and Huntington’s disease. Although the most consistent risk factor for developing a neurodegenerative disorders is increasing age, it has been observed that the symptoms of all the three diseases overlap with each other, clinically and pathologically. Therefore, their practical classification is quite challenging and thus needing an automated tool to classify them. In the present model, backpropagation artificial neural network (ANN) has been designed to classify neurodegenerative disorders according to their symptoms. The 27:70:3 architecture of ANN has been used to predict the clinical outcome from the complex overlapped symptoms that are routinely available to clinicians. The model has found to be effective in differentiating the different types of focused diseases with an overall performance of 96.42%.
Artificial Immune System (AIS-MACA) a novel computational intelligence technique is can be used for strengthening the automated protein prediction system with more adaptability and incorporating more parallelism to the system. Most of the existing approaches are sequential which will classify the input into four major classes and these are designed for similar sequences. AIS-MACA is designed to identify ten classes from the sequences that share twilight zone similarity and identity with the training sequences with mixed and hybrid variations. This method also predicts three states (helix, strand, and coil) for the secondary structure. Our comprehensive design considers 10 feature selection methods and 4 classifiers to develop MACA (Multiple Attractor Cellular Automata) based classifiers that are build for each of the ten classes. We have tested the proposed classifier with twilight-zone and 1-high-similarity benchmark datasets with over three dozens of modern competing predictors shows that AIS-MACA provides the best overall accuracy that ranges between 80% and 89.8% depending on the dataset.
A new liquid chromatographic method has been developed for the chiral separation and quantitative determination of the enantiomers of ketoprofen. The enantiomers were separated by a Chiralpak IC (250×4.6 mm, 5 μm) at 25˚C and detected at 268 nm, and the mobile phase used was n-hexane-isopropanol (90/10, V/V; 0.1%TFA), with a flow rate of 0.8 mL·min -1 . The enantiomers of ketoprofen were separated and the resolution was 2.16. The content of ketoprofen sustained release capsules and enteric-coated capsules were 98.69%, 97.50%, respectively. By comparing the chromatograms(on Chiralcel OJ-H) of ketoprofen enantiomers and the first effluent on Chiralpak IC, it was determined that the first effluent was (S)-ketoprofen.
Cardiovascular tissue engineering has emerged as a promising approach to overcome limitations of conventional heart valve substitutes regarding lack of growth, repair, and remodeling capability by mimicking a native heart valve. The present study has demonstrated that long-term conditioning of decellularized and re-seeded aortic homografts in a low-flow pulsatile bioreactor results in an improved quality of tissue engineering constructs. Cryopreserved and thawed homografts were decellularized by a detergent mixture. Decellularized homografts were primarily seeded with fibroblasts (FB) followed by colonization with endothelial cells (EC), both isolated from human saphenous vein segments. Re-seeded homografts were exposed to low-flow conditions (750-1 100 mL/min) for a time period of 12 d. Topographical examination was performed by scanning electron microscopy (SEM). Cell layer thickness, composition of extracellular matrix (ECM) and inflammatory response was investigated by immunohistochemistry (IHC). SEM analysis of re-seeded homografts showed a confluent and intact cellular coverage before and after conditioning. IHC demonstrated a distinct thickening of cellular layer. Cell specific staining demonstrated a confluent EC lining with a multilayer of FB underneath. The expression of ECM components, cytoskeletal and gap junctional proteins increased by conditioning. Inflammatory proteins were expressed in a low level. The novel pulsatile bioreactor provides a strong tool for conditioning of re-seeded decellularized homografts. Moreover, conditioning results in an increased quality of ECM in regard to connectivity, stability and cell communication, creating native-like heart valve prostheses.
