Development of a Biomimetic Semicircular Canal with MEMS Sensors to Restore Balance

© 2001-2012 IEEE. A third of adults over the age of 50 suffer from chronic impairment of balance, posture, and/or gaze stability due to partial or complete impairment of the sensory cells in the inner ear responsible for these functions. The consequences of impaired balance organ can be dizziness, social withdrawal, and acceleration of the further functional decline. Despite the significant progress in biomedical sensing technologies, current artificial vestibular systems fail to function in practical situations and in very low frequencies. Herein, we introduced a novel biomechanical device that closely mimics the human vestibular system. A microelectromechanical systems (MEMS) flow sensor was first developed to mimic the vestibular haircell sensors. The sensor was then embedded into a three-dimensional (3D) printed semicircular canal and tested at various angular accelerations in the frequency range from 0.5Hz to 1.5Hz. The miniaturized device embedded into a 3D printed model will respond to mechanical deflections and essentially restore the sense of balance in patients with vestibular dysfunctions. The experimental and simulation studies of semicircular canal presented in this work will pave the way for the development of balance sensory system, which could lead to the design of a low-cost and commercially viable medical device with significant health benefits and economic potential

Antidiabetic potential of salvianolic acid B in multiple low-dose streptozotocin-induced diabetes

Context: Salvianolic acids are the most abundant water-soluble compounds extracted from the herb Salvia miltiorrhiza L. (Lamiaceae) with antioxidant and protective effects. Objective: This study evaluates the antidiabetic effect of salvianolic acid B (Sal B) in multiple low-dose streptozotocin (MLDS)-induced diabetes in rat. Materials and methods: Rats were divided into control, Sal B40-treated control, diabetic, Sal B20-, and Sal B40-treated diabetic groups. Sal B was daily administered at doses of 20 or 40 mg/kg (i.p.), started on third day post-STZ injection for 3 weeks. Serum glucose and insulin level and some oxidative stress markers in pancreas were measured in addition to the oral glucose tolerance test (OGTT), histological assessment, and apoptosis determination. Results: After 3 weeks, treatment of diabetic rats with Sal B20 and Sal B40 caused a significant decrease of the serum glucose (p<0.05-0.01) and improvement of OGTT. Meanwhile, serum insulin was significantly higher in Sal B20- and Sal B40-treated diabetics (p<0.01) and treatment of diabetics with Sal B40 significantly lowered malondialdehyde (MDA) (p<0.05), raised glutathione (GSH) (p<0.05), and activity of catalase (p<0.01) with no significant change of nitrite. Furthermore, the number of pancreatic islets (p<0.05) and their area (p<0.01) was significantly higher and apoptosis reactivity was significantly lower (p<0.05) in the Sal B40-treated diabetic group versus diabetics. Discussion and conclusion: Three-week treatment of diabetic rats with Sal B exhibited antidiabetic activity which is partly exerted via attenuation of oxidative stress and apoptosis and augmentation of antioxidant system. © 2015 Informa Healthcare USA, Inc

Cloning, expression, purification and antigenicity of antigenic region of MOMP protein from chlamydia trachomatis

Introduction: Chlamydia trachomatis is an obligate intracellular parasites, gram-negative bacteria and also is one of the most common sexually transmitted infections. Correspondingly, the MOMP protein contains more than 60 of the extra-membrane proteins, which indicates the importance of this protein for the detection of Chlamydia trachomatis. The purpose of the study is to produce recombinant protein composed of antigenic regions of the MOMP protein and its antigenicity. Materials and Methods: In this study, the regions with the highest antigenic property of the omp1 gene, with a length of 674 bp, were obtained based on bioinformatics software's and linked with flexible linker. Then, it was cloned and expressed in plasmid vector pET32a. After purification of the recombinant protein, its antigenicity was evaluated using Western blot technique with serum of infected people with Chlamydia. Results: Based on the results, in all serum samples of patients with chlamydial infections, antibody response bands were observed in nitrocellulose paper. Anyway, no antibody response band was detected in the serum samples of healthy people. Conclusion: Data showed that antigenic region of MOMP protein can be expressed by in E. coli. This protein was recognized by sera patients suffering from Chlamydia trachomatis infection. Conclusively, the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. © 2017, Semnan University of Medical Sciences. All rights reserved

Cloning, expression, purification and antigenicity of antigenic region of MOMP protein from chlamydia trachomatis

Introduction: Chlamydia trachomatis is an obligate intracellular parasites, gram-negative bacteria and also is one of the most common sexually transmitted infections. Correspondingly, the MOMP protein contains more than 60 of the extra-membrane proteins, which indicates the importance of this protein for the detection of Chlamydia trachomatis. The purpose of the study is to produce recombinant protein composed of antigenic regions of the MOMP protein and its antigenicity. Materials and Methods: In this study, the regions with the highest antigenic property of the omp1 gene, with a length of 674 bp, were obtained based on bioinformatics software's and linked with flexible linker. Then, it was cloned and expressed in plasmid vector pET32a. After purification of the recombinant protein, its antigenicity was evaluated using Western blot technique with serum of infected people with Chlamydia. Results: Based on the results, in all serum samples of patients with chlamydial infections, antibody response bands were observed in nitrocellulose paper. Anyway, no antibody response band was detected in the serum samples of healthy people. Conclusion: Data showed that antigenic region of MOMP protein can be expressed by in E. coli. This protein was recognized by sera patients suffering from Chlamydia trachomatis infection. Conclusively, the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. © 2017, Semnan University of Medical Sciences. All rights reserved

3D Printing of Inertial Microfluidic Devices.

Inertial microfluidics has been broadly investigated, resulting in the development of various applications, mainly for particle or cell separation. Lateral migrations of these particles within a microchannel strictly depend on the channel design and its cross-section. Nonetheless, the fabrication of these microchannels is a continuous challenging issue for the microfluidic community, where the most studied channel cross-sections are limited to only rectangular and more recently trapezoidal microchannels. As a result, a huge amount of potential remains intact for other geometries with cross-sections difficult to fabricate with standard microfabrication techniques. In this study, by leveraging on benefits of additive manufacturing, we have proposed a new method for the fabrication of inertial microfluidic devices. In our proposed workflow, parts are first printed via a high-resolution DLP/SLA 3D printer and then bonded to a transparent PMMA sheet using a double-coated pressure-sensitive adhesive tape. Using this method, we have fabricated and tested a plethora of existing inertial microfluidic devices, whether in a single or multiplexed manner, such as straight, spiral, serpentine, curvilinear, and contraction-expansion arrays. Our characterizations using both particles and cells revealed that the produced chips could withstand a pressure up to 150 psi with minimum interference of the tape to the total functionality of the device and viability of cells. As a showcase of the versatility of our method, we have proposed a new spiral microchannel with right-angled triangular cross-section which is technically impossible to fabricate using the standard lithography. We are of the opinion that the method proposed in this study will open the door for more complex geometries with the bespoke passive internal flow. Furthermore, the proposed fabrication workflow can be adopted at the production level, enabling large-scale manufacturing of inertial microfluidic devices

Fabrication of unconventional inertial microfluidic channels using wax 3D printing.

Inertial microfluidics has emerged over the past decade as a powerful tool to accurately control cells and microparticles for diverse biological and medical applications. Many approaches have been proposed to date in order to increase the efficiency and accuracy of inertial microfluidic systems. However, the effects of channel cross-section and solution properties (Newtonian or non-Newtonian) have not been fully explored, primarily due to limitations in current microfabrication methods. In this study, we overcome many of these limitations using wax 3D printing technology and soft lithography through a novel workflow, which eliminates the need for the use of silicon lithography and polydimethylsiloxane (PDMS) bonding. We have shown that by adding dummy structures to reinforce the main channels, optimizing the gap between the dummy and main structures, and dissolving the support wax on a PDMS slab to minimize the additional handling steps, one can make various non-conventional microchannels. These substantially improve upon previous wax printed microfluidic devices where the working area falls into the realm of macrofluidics rather than microfluidics. Results revealed a surface roughness of 1.75 μm for the printed channels, which does not affect the performance of inertial microfluidic devices used in this study. Channels with complex cross-sections were fabricated and then analyzed to investigate the effects of viscoelasticity and superposition on the lateral migration of the particles. Finally, as a proof of concept, microcarriers were separated from human mesenchymal stem cells using an optimized channel with maximum cell-holding capacity, demonstrating the suitability of these microchannels in the bioprocessing industry

Epitope Prediction by Novel Immunoinformatics Approach: A State-of-the-art Review

Immunoinformatics is a science that helps to create significant immunological information using bioinformatics softwares and applications. One of the most important applications of immunoinformatics is the prediction of a variety of specific epitopes for B cell recognition and T cell through MHC class I and II molecules. This method reduces costs and time compared to laboratory tests. In this state-of-the-art review, we review about 50 papers to find the latest and most used immunoinformatic tools as well as their applications for predicting the viral, bacterial and tumoral structural and linear epitopes of B and T cells. In the clinic, the main application of prediction of epitopes is for designing peptide-based vaccines. Peptide-based vaccines are a considerably potential alternative to low-cost vaccines that may reduce the risks related to the production of common vaccines. © 2019, Springer Nature B.V

Coupling of CFD and semiempirical methods for designing three-phase condensate separator: case study and experimental validation

This study presents an approach to determine the dimensions of three-phase separators. First, we designed different vessel configurations based on the fluid properties of an Iranian gas condensate field. We then used a comprehensive computational fluid dynamic (CFD) method for analyzing the three-phase separation phenomena. For simulation purposes, the combined volume of fluid–discrete particle method (DPM) approach was used. The discrete random walk (DRW) model was used to include the effect of arbitrary particle movement due to variations caused by turbulence. In addition, the comparison of experimental and simulated results was generated using different turbulence models, i.e., standard k–ε, standard k–ω, and Reynolds stress model. The results of numerical calculations in terms of fluid profiles, separation performance and DPM particle behavior were used to choose the optimum vessel configuration. No difference between the dimensions of the optimum vessel and the existing separator was found. Also, simulation data were compared with experimental data pertaining to a similar existing separator. A reasonable agreement between the results of numerical calculation and experimental data was observed. These results showed that the used CFD model is well capable of investigating the performance of a three-phase separator