10 research outputs found
Polymer based electricity generation inspired by eel electrocytes
Electricity-generating devices are among the most popular recent topics due to increasing global energy requirements, which have propelled many researchers to investigate different approaches. One approach involves electroreceptive animals. In this regard, we proposed a polymer-based energy generator converting Gibbs free energy into usable electricity. We developed a polymer-based device inspired by electric eels and modified it to extend the maximum power generation limits by adding nickel-nickel and aluminum-copper current collector (CC) backings. Thus, the imitation of electrocytes and the aims to increase the voltage, which was generated by taking advantage of electrochemical reactions between metals and polymers, were successfully achieved. In each tetrameric package ((Formula presented.)) supported by nickel-nickel CCs, the voltage output was more than 350 mV, while tetrameric cells with copper-aluminum CC pairs led to an open-circuit voltage of more than 900 mV. The conversion of free energy into electricity is attributed to the electricity generation of cells supported by the Ni-Ni CC pair to the ion gradient between the layers, as in electrocyte. In the case of using Cu-Al CCs, electrochemical reactions between the supporting metals and polymers are prominent. The generation of such high voltages is due to the ion concentration gradient and electrochemical interactions. Only slight changes in the output voltage value related to the corrosion on the aluminum CC in time provide a distinctive advantage for long-term power needs. Thus, it can be stated that this bioinspired energy-generating device offers the potential for eventually becoming a power source for small-scale electrical systems and for fulfilling daily personal energy needs
Steam flow condensation on superhydrophobic surfaces in a high aspect ratio microchannel
Steam flow condensation has a wide range of applications in the industry such as in air conditioning, refrigeration, and thermal power plants. Condensation of steam on highly hydrophobic surfaces has resulted in notable heat transfer improvement compared to conventional hydrophilic surfaces. Dropwise condensation and increased droplet mobility are the main reason for thermal performance enhancement of superhydrophobic surfaces. Although there are considerable reports of enhanced thermal transport behavior of highly hydrophobic surfaces on steam condensation, the literature lacks sufficient investigation on flow condensation of steam, such as the effect of average vapor quality change on heat transfer rate. Unlike gravity-driven droplet departure in quiescent dropwise condensation, droplet departure sizes in flow condensation are governed by flow-droplet shear forces and droplet-surface adhesive forces. This work experimentally investigates steam flow condensation on nanotextured highly hydrophobic and slightly hydrophobic surfaces. The experimental setup consists of a reservoir, boiler, superheater, condensation chamber (test section), pre-condenser (to adjust the inlet quality), a post condenser, and a pump. A high aspect ratio microchannel was used as the test section. Different mass fluxes and inlet vapor qualities were used for the experimentations. Visualization studies were performed to analyze droplet dynamics such as droplet departure and coalescence in flow condensation. It is shown that for both surfaces increase condensation heat transfer coefficient were a function of both average quality and mass flux. Increase in mass flux from G=8 kg/m2s to G=14 kg/m2s, resulted in 65% and 60% enhancement in condensation heat transfer coefficient of slightly hydrophobic and highly hydrophobic surfaces respectively
Local Carpet Bombardment of Immobilized Cancer Cells With Hydrodynamic Cavitation
This study presents a method based on carpet bombardment of immobilized cells with cavitating flows. For this, immobilized cancer cell lines are exposed to micro scale cavitating flows from the tip of a micro nozzle under the effect of cavitation microbubbles. The deformation as a result of cavitation bubbles on exposed cells differs from one cell type to another. Therefore, the difference in cell deformation upon cavitation exposure (carpet bombardment) acts as a valuable indicator for cancer diagnosis. The developed system is tested on HCT-116 (Human Colorectal Carcinoma), MDA-MB-231 (Breast Adenocarcinoma), ONCO-DG-1 (Ovarian Adenocarcinoma) cell lines due to their clinical importance. The mechanical effects of cavitation are examined by considering the single-cell lysis effect (the cell membrane is ruptured, and the cell is destroyed) with the help of the Scanning Electron Microscopy (SEM) technique. Our study proposes a promising label-free method for the potential use in cancer diagnosis with cavitation bubble collapse, where microbubbles could be precisely controlled and directed to the desired locations, as well as the characterization of the biophysical properties of cancer cells. The proposed approach tool has the advantages of label-free approach, simple structure and low cost and is a substantial alternative for the existing tools
Development and Implementation of Microbial Antifreeze Protein Based Coating for Anti‐Icing
Abstract Ice formation on a solid surface is a major challenge in industrial applications, it causes higher energy consumption and performance deterioration and may lead to catastrophic results. The preparation of anti‐icing surfaces to prohibit ice accumulation on a surface is crucial to reduce operational costs and to extend the surface's lifetime. The utilization of cryoprotectants to obtain anti‐icing surfaces is an effective method and is applicable in multiple fields. Antifreeze proteins (AFPs) are natural cryoprotectants to obtain anti‐icing surfaces, which have the ability to decrease the freezing point and to prevent ice‐crystal growth via thermal hysteresis (TH) and ice recrystallization inhibition (IRI). This study reports the molecular cloning, expression, and production of AFP protein from Escherichia coli (E. Coli). This wok also demonstrates the activity of coated AFP on aluminum surfaces. The expressed AFP is immobilized on aluminum surfaces treated by oxygen plasma. The coated AFP exhibits promising antifreeze activity with a high anti‐icing ability on aluminum surfaces in the size of evaporator fins (40 × 40 cm). The outcome of this study provides new insights into the biotechnological implementation of AFPs to various industrial applications for energy‐saving and higher performance
Biomedical Applications of Microfluidic Devices: A Review
Both passive and active microfluidic chips are used in many biomedical and chemical applications to support fluid mixing, particle manipulations, and signal detection. Passive microfluidic devices are geometry-dependent, and their uses are rather limited. Active microfluidic devices include sensors or detectors that transduce chemical, biological, and physical changes into electrical or optical signals. Also, they are transduction devices that detect biological and chemical changes in biomedical applications, and they are highly versatile microfluidic tools for disease diagnosis and organ modeling. This review provides a comprehensive overview of the significant advances that have been made in the development of microfluidics devices. We will discuss the function of microfluidic devices as micromixers or as sorters of cells and substances (e.g., microfiltration, flow or displacement, and trapping). Microfluidic devices are fabricated using a range of techniques, including molding, etching, three-dimensional printing, and nanofabrication. Their broad utility lies in the detection of diagnostic biomarkers and organ-on-chip approaches that permit disease modeling in cancer, as well as uses in neurological, cardiovascular, hepatic, and pulmonary diseases. Biosensor applications allow for point-of-care testing, using assays based on enzymes, nanozymes, antibodies, or nucleic acids (DNA or RNA). An anticipated development in the field includes the optimization of techniques for the fabrication of microfluidic devices using biocompatible materials. These developments will increase biomedical versatility, reduce diagnostic costs, and accelerate diagnosis time of microfluidics technology
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Association of the 1236C >T variant of the multidrug resistance 1 gene with esophageal squamous cell carcinoma development and prognosis
Background:
Esophageal squamous cell carcinoma (ESCC) is a common cause of cancer related mortality. There is a growing body of evidence showing an association between genetic variants in the 7q21.12 gene locus and an increased risk of cancer. Here we have explored the association between the 1236C >T; rs1128503 genetic variant of the ABCB1/MDR1 gene with the development and prognosis of ESCC.
Method:
Data from the computer-based patient records (CPRs) of 10 years (between 2005-2014) of the Mashhad University of Medical Sciences were used to identify patients with ESCC. Ninety-three ESCC patients and two hundred and twenty-four healthy subjects were recruited. DNA was extracted and genotyped using a Taq-Man based real-time PCR method. The association of the variant with overall-survival (OS) and progression-free survival (PFS) was analyzed using Kaplan–Meier curves, log-rank tests, and Cox model.
Results:
Patients with ESCC had a higher frequency of the C allele compared to the control group with Minor allele frequency (MAF) of 1.5. Moreover, 22%, and 56% of cases had TT and TC genotypes, compared to 22% for CC. Patients with TT genotype, versus CC had a higher risk of ESCC (OR: 2.3; 95%CI: 1.08-4.8, P= 0.03), although it was not associated with PFS and OS (e.g., OS of TT genotype: 56.8±6.9 months versus OS of CC genotype: 60.5±5.7 59 months).
Conclusion
Our data showed a relationship between a genetic polymorphism of the ABCB1 gene with clinical outcomes of the ESCC-patients, supporting further studies in a larger, and multi-centre settings followed by functional assays to assess the prognostic value of this emerging marker in esophageal squamous cell carcinoma patients