scholarly journals Control of Aptamer Function Using Radiofrequency Magnetic Field

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Kenichi Taira ◽  
Koichi Abe ◽  
Takayuki Ishibasi ◽  
Katsuaki Sato ◽  
Kazunori Ikebukuro
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Gold Nanoparticle ◽  
Inhibitory Activity ◽  
Protein Function ◽  
Local Heating ◽  
Activity Assay ◽  
Complementary Dna ◽  
Dna Strand ◽  
Control Protein

Remote control of aptamer function has allowed us to control protein function in space and time. Here, we propose a novel control system for aptamer function by radiofrequency magnetic field- (RFMF-) induced local heating of a gold nanoparticle conjugated with an aptamer. In this study, we used a 31-mer thrombin-binding aptamer (TBA), which can inhibit thrombin activity, as a model aptamer. We evaluated the RFMF control of the inhibitory activity of a gold nanoparticle-conjugated TBA. To evaluate the effect of RFMF on enzymatic activity, we utilized a complementary DNA strand that maintains the broken structure during the activity assay. We observed a decrease in the inhibitory activity of TBA after RFMF irradiation. It indicates that RFMF is capable of controlling the TBA structure. Because RFMF allows noninvasive control of aptamer function, this strategy is expected to be novel way of controlling aptamer drug activity.

Optobiochemistry: Genetically Encoded Control of Protein Activity by Light

2021 ◽  
Vol 90 (1) ◽  
Author(s):  
Jihye Seong ◽  
Michael Z. Lin
Keyword(s):  
Protein Function ◽  
Living Cells ◽  
Optical Methods ◽  
Annual Review ◽  
Publication Date ◽  
Protein Activity ◽  
Spatiotemporal Resolution ◽  
Protein Functions ◽  
Protein Classes ◽  
Control Protein

Optobiochemical control of protein activities allows the investigation of protein functions in living cells with high spatiotemporal resolution. Over the last two decades, numerous natural photosensory domains have been characterized and synthetic domains engineered and assembled into photoregulatory systems to control protein function with light.Here, we review the field of optobiochemistry, categorizing photosensory domains by chromophore, describing photoregulatory systems by mechanism of action, and discussing protein classes frequently investigated using optical methods. We also present examples of how spatial or temporal control of proteins in living cells has provided new insights not possible with traditional biochemical or cell biological techniques. Expected final online publication date for the Annual Review of Biochemistry, Volume 90 is June 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

THE ROTATIONAL EFFECT OF MAGNETIC PARTICLES ON CELLULAR APOPTOSIS BASED ON FOUR ELECTROMAGNET FEEDBACK CONTROL SYSTEM

2021 ◽  
pp. 2150045
Author(s):  
Jia Ji Lee ◽  
Chang Hong Pua ◽  
Misni Misran ◽  
Poh Foong Lee
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Field ◽  
Control System ◽  
Feedback Control ◽  
Cell Apoptosis ◽  
Magnetic Particles ◽  
Drug Carriers ◽  
Feedback Control System ◽  
Rotational Effect ◽  
Dynamic Magnetic Field

Objectives: Magnetic drug targeting offers the latest popular alternative option to deliver magnetic drug carriers into targeting region body parts through manipulation of an external magnetic field. However, the effectiveness of using an electromagnetic field to manipulate and directing magnetic particles is yet to be established. Methods: In this paper, a homemade cost-effective electromagnet system was built for the purpose of studying the control and directing the magnetic drug carriers. The electromagnet system was built with four electromagnetic sources and tested the capability in directing the particles’ movement in different geometry patterns. Besides that, the creation of the self-rotation of individual magnetic particle clusters was achieved by using fast switching between magnetic fields. This self-rotation allows the possibility of cell apoptosis study to carry out. The system was constructed with four electromagnets integrated with a feedback control system and built to manipulate a droplet of commercially available iron (II, III) oxide nanoparticles to steer the magnetic droplet along different arbitrary trajectories (square, circle, triangle, slanted line) in 2-dimensional. Results: A dynamic magnetic field of 25 Hz was induced for magnetic nanoparticles rotational effect to observe the cell apoptosis. A profound outcome shows that the declining cell viability of the cell lines by 40% and the morphology of shrinking cells after the exposure of the dynamic magnetic field. Conclusion: The outcome from the pilot study gives an idea on the laboratory setup serves as a fundamental model for studying the electromagnetic field strength in applying mechanical force to target and to rotate for apoptosis on cancer cell line study.

scholarly journals Synthesis and Heme Polymerization Inhibitory Activity (HPIA) Assay of Antiplasmodium of (1)-N-(3,4-Dimethoxybenzyl)-1,10-Phenanthrolinium Bromide from Vanillin

2014 ◽  
Vol 14 (1) ◽  
pp. 1-6
Author(s):  
Dhina Fitriastuti ◽  
Muhammad Idham Darussalam Mardjan ◽  
Jumina Jumina ◽  
Mustofa Mustofa
Keyword(s):  
Melting Point ◽  
Sodium Borohydride ◽  
Inhibitory Activity ◽  
Veratryl Alcohol ◽  
Activity Assay ◽  
Light Yellow ◽  
Grinding Method ◽  
Methylation Product ◽  
Ft Ir ◽  
Phenanthroline Monohydrate

The synthesis of (1)-N-(3,4-dimethoxy-benzyl)-1,10-phenanthrolinium bromide had been conducted from vanillin. Heme polymerization inhibitory activity assay of the synthesized antiplasmodium has also been carried out. The first step of reaction was methylation of vanillin using dimethylsulfate and NaOH. The mixture was refluxed for 2 h to yield veratraldehyde in the form of light yellow solid (79% yield). Methylation product was reduced using sodium borohydride (NaBH4) with grinding method and yielded veratryl alcohol in the form of yellow liquid (98% yield). Veratryl alcohol was brominated using PBr3 to yield yellowish black liquid (85% yield). The final step was benzylation of 1,10-phenanthroline monohydrate with the synthesized veratryl bromide under reflux condition in acetone for 14 h to afford (1)-N-(3,4-dimethoxy-benzyl)-1,10-phenanthrolinium bromide (84%) as yellow solid with melting point of 166-177 °C. The structures of products were characterized by FT-IR, GC-MS and 1H-NMR spectrometers. The results of heme polymerization inhibitory activity assay of (1)-N-(3,4-dimethoxybenzyl)-1,10-phenanthrolinium bromide showed that it had IC50 HPIA of 3.63 mM, while chloroquine had IC50 of4.37 mM. These results indicated that (1)-N-(3,4-dimethoxybenzyl)-1,10-phenanthrolinium bromide was more potential antiplasmodium than chloroquine.

scholarly journals The Detector Control System for the magnetic field sensors in New Small Wheel phase I upgrade of ATLAS detector

2021 ◽  
Vol 2105 (1) ◽  
pp. 012026
Author(s):  
Stamatios Tzanos
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Hadron Collider ◽  
Atlas Detector ◽  
Magnetic Field Sensors ◽  
Atlas Experiment ◽  
Data Rates ◽  
Level 1 ◽  
The Magnetic Field ◽  
Detector Control System

Abstract In conjunction with the High Luminosity upgrade of the Large Hadron Collider accelerator at CERN, the ATLAS detector is also undergoing an upgrade to handle the significantly higher data rates. The muon end-cap system upgrade in ATLAS, lies with the replacement of the Small Wheel. The New Small Wheel (NSW) is expected to combine high tracking precision with upgraded information for the Level-1 trigger. To accomplish this, small Thin Gap Chamber (sTGC) and MicroMegas detector technologies are being deployed. Due to their installation location in ATLAS, the effects of Barrel Toroid and End-Cap Toroid magnets on NSW must be measured. For the final experiment at ATLAS, each sTGC large double wedge will be equipped with magnetic field Hall effect sensors to monitor the magnetic field near the NSW. The readout is done with an Embedded Local Monitor Board (ELMB) called MDT DCS Module (MDM). For the integration of this hardware in the experiment, first, a detector control system was developed to test the functionality of all sensors before their installation on the detectors. Subsequently, another detector control system was developed for the commissioning of the sensors. Finally, a detector control system based on the above two is under development for the expert panels of ATLAS experiment. In this paper, the sensor readout, the connectivity mapping and the detector control systems will be presented.

Feasibility study of an adaptive mount system based on magnetorheological elastomer using real-time hybrid simulation

2018 ◽  
Vol 30 (5) ◽  
pp. 701-707 ◽  
Author(s):  
Seung-Hyun Eem ◽  
Jeong-Hoi Koo ◽  
Hyung-Jo Jung
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Real Time ◽  
Control Algorithm ◽  
Vibration Reduction ◽  
Hybrid Simulation ◽  
Shaking Table ◽  
Magnetorheological Elastomer ◽  
Experimental Part ◽  
Hybrid Simulations

This article investigates an adaptive mount system based on magnetorheological elastomer in reducing the vibration of an equipment on the isolation table. Incorporating MR elastomers, whose elastic modulus or stiffness can be adjusted depending on the applied magnetic field, the proposed mount system strives to alleviate the limitations of existing passive-type mount systems. The primary goal of this study is to evaluate the vibration reduction performance of the proposed MR elastomer mount using the hybrid simulation technique. For real-time hybrid simulations, the MR elastomer mount and the control system are used as an experimental part, which is installed on the shaking table, and an equipment on the table is used as a numerical part. A suitable control algorithm is designed for the real-time hybrid simulations to avoid the responses of the equipment’s natural frequency by tracking the frequencies of the responses. After performing a series of real-time hybrid simulation on the adaptive mount system and the passive-type mount system under sinusoidal excitations, this study compares the effectiveness of the adaptive mount system over its passive counterpart. The results show that the proposed adaptive elastomer mount system outperforms the passive-type mount system in reducing the responses of the equipment for the excitations considered in this study.

CONTROL SYSTEM OF PLASMA POSITION AND CURRENT IN A TOKAMAK WITH STRONG MAGNETIC FIELD

1983 ◽  
pp. 1185-1189
Author(s):  
B.A. Alekseev ◽  
B.A. Belyakov ◽  
V.I. Vasil'ev ◽  
Yu.A. Kostsov ◽  
I.V. Mozin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Strong Magnetic Field ◽  
Plasma Position

scholarly journals Precision Analysis and Design of Rotating Coil Magnetic Measurements System

2020 ◽  
Vol 10 (23) ◽  
pp. 8454
Author(s):  
Soontorn Odngam ◽  
Chaiyut Preecha ◽  
Prapaiwan Sanwong ◽  
Woramet Thongtan ◽  
Jiraphon Srisertpol
Keyword(s):  
Magnetic Field ◽  
Control System ◽  
Magnetic Measurements ◽  
Speed Control ◽  
Measuring Instruments ◽  
Dipole Magnet ◽  
Analysis And Design ◽  
Speed Control System ◽  
The Impact ◽  
The Magnetic Field

This research presents the design and construction of measuring instruments for a dipole magnetic field using a rotating coil technique. This technique is a closed-loop speed-control system where a Proportional-Integral (PI) controller works together with the intensity measurement of the magnetic field through the rotating coil. It was used to analyze the impact on the accuracy of the electromagnetic at speed ranges of 60, 90, and 120 rpm. The error estimation in the measurement of the normal dipole and skew dipole magnet caused by the steady-state error of the speed control system and the rotational search coil in whirling motion are demonstrated. Rotating unbalance, shaft coupling, and misalignment from its setup disturbed the performance of the speed control system as a nonlinear system.

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