Magnetic Ball Research Articles

Exploring Application in Lung Cancer Treatment Evaluation via Construction of Exosomes/CTCs Isolation and Identification System and Determination of Hypoxia-Inducible Factor-1α/FGFR

This study aims to realize efficient enrichment of lung cancer exosomes/CTCs and identified by immunofluorescence technique. The multi-site immunolipid magnetic ball were designed using CD63 (for exosomes) and EGFR (for CTCs). Patient’s peripheral blood sample patients with lung cancer were collected (n = 42) before and after treatment with apatinib. The exosomes/CTCs it was it was isolated and identified by transmission electron microscopy, concentration, particle tracer, immunofluorescence check. In addition, the number and identification of CTCs in the included samples were also tested. The results showed that the peripheral blood exosomes increased and the plasma extracellular vesicle concentration decreased significantly after lung cancer treatment. Through detecting genes in the exosomes, Studies have shown that protein expression levels HIF and FGFR gene decreased after apatinib treatment. The decrease of exosomes level and the increase of recurrence after lung cancer may be helpful for tumor monitoring and evaluation of treatment effect. The EGFR-based CTC identification system has high detection ratio and good stability. This exosomal/CTC isolation system is a promising integrated analysis tool and a potential non-invasive diagnostic platform.

Appendicular-intestinal fistula caused by magnetic foreign bodies in a 2-year-old child

EDITORIAL COMMENT. Gripped aggressive foreign bodies (magnetic balls) in the gastrointestinal tract require emergency actions to clarify their localization and to remove them. The conservative approach with four-day observation described in the article should not be used.Introduction. Internal fistulas in foreign bodies of the digestive tract is a very rare complication.This publication is aimed to describe a rare case of fistula formation between the vermiform process and the ileum caused by magnetic foreign bodies.Clinical observation. As his parents said, a 2-year-old child swallowed magnetic balls; no clinical manifestations were noted. Plain radiography 3 days after the ingestion revealed foreign bodies (3) in the right lower quadrant of the abdomen. No foreign bodies were found on colonoscopy. Laparoscopy revealed a fistula between the appendix and the terminal ileum. The following steps were made: disconnection of fistula, appendectomy, suturing of fistula opening in the ileum.Conclusion. One of the complications after swallowing magnetic foreign bodies may be formation of internal intestinal fistulas. In our observation, the fistula was between the appendix and the ileum. No similar observations were found in literature.

Unnoticed ingestion of magnetic balls mimics acute appendicitis

Magnetic object ingestion is rare; however, it is important to be considered and recognized by physicians. Its incidence is expected to be 3.06 cases per 100000 children per year but during the last decade this number has grown fivefold owing to the growing popularity of magnetic toys. Although a single FB may pass spontaneously and uneventfully through the digestive tract, the ingestion of multiple magnetic can cause serious morbidity due to proximate attraction through the intestinal wall. In everyday clinical practice, physicians combine their clinical suspicion of acute appendicitis (AA) with laboratory tests findings and imaging studies to make a final diagnosis. CT scan can be useful in some cases to avoid per operative surprise. We report a case of an 8 years -old child who his admitted for query acute appendicitis. Radiological investigation shows three magnets ball at the right iliac fossa with air fluid level without any signs of perforations. Taking up the clinical history, the patient seems reliable and does not remember having ingested these balls. Colonoscopy fails to remove all the magnets. At surgery we found two perforations one at the terminal ilium and the other on the lateral side of cecum with perforation of the mesoappendix and inflamed appendix. An appendectomy was done with primary closure of both perforations. • Discordance between the clinical suspicion of acute appendicitis with laboratory tests findings and ultrasound study must alert the physician. • Multiple magnets balls ingestion may lead to intestinal perforation with no evident clinical signs.

Evolution of Controllers Under a Generalized Structure Encoding/Decoding Scheme With Application to Magnetic Levitation System

Evolutionary search has been widely implemented for the adjustment of controllers’ parameters. Nevertheless, the structure of controllers, which has a more important role in control systems, has been seldom studied. To this end, an evolutionary design method of controllers is proposed to optimize both structures and parameters simultaneously in this article. A controller is made up of a combination of some basic controller components and relevant parameters. The design of controllers can be transformed into an optimization problem involving the structure (represented by discrete vectors) and parameters (represented by real numbers). A generalized structure encoding/decoding scheme is developed. Guided by the performance indicators, intelligent algorithms for both combinatorial and numerical optimization are employed to iteratively and cooperatively evolve the controller structure and parameters, respectively. In order to effectively reduce some redundant or infeasible solutions, a set of generation rules for the controller structure are put forward, which also ensures the feasibility of the structure. Furthermore, this method is applied to a magnetic levitation ball system with nonlinear dynamics and external disturbance. Both simulation and experiment results demonstrate the effectiveness and practicability of the proposed method.

Wavelet CMAC for MIMO uncertain nonlinear systems using a modified social ski‐driver algorithm

AbstractThis study uses a Mexican hat wavelet membership function for a cerebellar model articulation controller (CMAC) to develop a more efficient adaptive controller for multiple input multiple output (MIMO) uncertain nonlinear systems. The main controller is called the adaptive Mexican hat wavelet CMAC (MWCMAC), and an auxiliary controller is used to remove the residual error. For the MWCMAC, the online learning laws are derived from the gradient descent method. In addition, the learning rate values are very important and have a great impact on the performance of the control system; however, they are difficult to choose accurately. Therefore, a modified social ski driver (SSD) algorithm is proposed to find optimal learning rates for the control parameters. Finally, a magnetic ball levitation system and a nine‐link biped robot are used to illustrate the effectiveness of the proposed SSD‐based MWCMAC control system. The comparisons with other existing control algorithms have shown the superiority of the proposed control system.

Recurrent neural network based high-precision position compensation control of magnetic levitation system

For improving the dynamic quality and steady-state performance, the hybrid controller based on recurrent neural network (RNN) is designed to implement the position control of the magnetic levitation ball system in this study. This hybrid controller consists of a baseline controller, an RNN identifier, and an RNN controller. In the hybrid controller, the baseline controller based on the control law of proportional-integral-derivative is firstly employed to provide the online learning sample and maintain the system stability at the early control phase. Then, the RNN identifier is trained online to learn the accurate inverse model of the controlled object. Next, the RNN controller shared the same structures and parameters with the RNN identifier is applied to add the precise compensation control quantity in real-time. Finally, the effectiveness and advancement of the proposed hybrid control strategy are comprehensively validated by the simulation and experimental tests of tracking step, square, sinusoidal, and trapezoidal signals. The results indicate that the RNN-based hybrid controller can obtain higher precision and faster adjustment than the comparison controllers and has strong anti-interference ability and robustness.

Sars-Cov-2 and COVID-19: Epidemiological, Diagnostic, and Therapeutic Aspects in Pointe-Noire, Republic of the Congo

Introduction: The novel coronavirus also called SARS-COV-2 was declared a global pandemic by the WHO in March 2020. In the Republic of Congo, the first imported case was introduced on March 14, 2020. Pointe-Noire, whose 1st case was reported on March 17, 2020, is described as the second epicenter of the disease after Brazzaville the capital. Objective: In this work, the authors described the epidemiological, diagnostic and therapeutic aspects that contributed to the management of COVID-19 patients in Pointe-Noire. Material and Method: This was a cross-sectional descriptive study. The situational analysis was based on the situation report (SITREP) n°: 434 including COVID-19 data from the department of Pointe-Noire since the declaration of the first case until June 19, 2021, a period of 15 months. The biological diagnosis was exclusively based on RT-PCR from a nasopharyngeal swab. The extraction was carried out using two processes: filter column extraction and magnetic ball extraction using different kits. Amplification was performed on five types of PCR instruments.

Effects of different mixing methods on the conductivities of poly(2-ethyl aniline)/graphene and poly(2-ethyl aniline)/expanded graphite composites

In this study, the preparation of poly(2-ethyl aniline) (PEAn)/Graphene and PEAn/Expanded Graphite (EG) composites using different mixing methods and the effect of the preparation conditions of composites on their electrical conductivities were investigated. Herein, it was examined both the effect of the sonication time of EG and Graphene in HCl medium before the polymerization on their homogeneous dispersion in the PEAn matrix and the effect of the three different mixing methods, including magnetic stirring, ultrasonication, and ball milling, on the formation of network in the composites. From the morphological characterization obtained by SEM, due to π-π* electron interaction, 2-EAn molecules were polymerized on the surface of graphene and EG. It was determined that the composite with the highest conductivity was obtained by in situ polymerization of 2-EAn in the presence of graphene via a ball milling method for 10 h, after the sonication of graphene in aqueous HCl medium for 6 h. The conductivity of this PEAn/Graphene (1:1 by weight) composite increased from 3.5x10−7 Scm−1 to 1.57 Scm−1 compared to pure PEAn.

Enhancing the wear resistance of a cemented carbide/titanium alloy under magnetofluid lubrication via the magnetic response

Pulsed magnetic field treatment (MT) was applied to cemented carbide (WC–12Co) for enhancing its wear resistance in contact titanium alloy (TC4). Based on the magnetic response after MT, ferromagnetic Ni and Fe3O4 nanoparticles and nonferromagnetic Cu were selected as additives to prepare lubricating fluids. The results reveal that the wear resistance of the cemented carbide/titanium alloy contact under cutting fluid lubrication was improved by MT. Significantly, the wear resistance was further enhanced by coupling of MT and Fe3O4 magnetofluid. The workpiece wear volume of coupling decreased by 33.9%, and the ball wear scar decreased by 36.4% compared with that of the untreated ball in cutting fluid lubricant. The enhanced wear resistance comes from the magnetic response of Fe3O4 to the treated magnetic ball (remanence) and improved hardness. The adsorption of Fe3O4 nanoparticles onto the treated magnetic ball reduces the adhesion of TC4 and forms a titanium alloy film containing Fe3O4 nanoparticles. In addition, increased hardness due to magnetostriction and magnetic domain enlargement during pulsed magnetization also contributes to the enhanced wear resistance.

Study of forming mechanics of magnetic field–assisted single point incremental forming

This paper describes the forming characteristics and mechanics of magnetic field–assisted single point incremental forming (M-SPIF) in which an Nd-Fe-B magnet ball tool is placed on top of a piece of sheet metal and is driven by an Nd-Fe-B magnet placed below the workpiece. To gain an understanding of the force mechanics that power M-SPIF, the tool motion and forming force were experimentally analyzed. In M-SPIF, the forming force is applied multi-directionally, and the resultant force direction is nearly colinear with the polarity of the permanent magnet ball tool. This suggests that the forming characteristics in M-SPIF may be controllable by controlling the magnetic polarity of the tool.

Dynamic detection of HER2 of circulating tumor cells in patients with gastric carcinoma and its clinical application.

The aim of the present study was to construct and characterize human epidermal growth factor receptor2 (HER2) lipid magnetic ball (H‑LMB) for separating circulating tumor cells (CTCs) in patients with gastric carcinoma (GC) and to compare the result of separated CTC counts with that of next‑generation sequencing (NGS) for single‑gene analysis to verify the consistency for evaluating the association between the detection results and the progress of clinical treatment, so as to facilitate early diagnosis and dynamic monitoring of GC. A lipid magnetic ball (LMB), coated with Fe3O4 nanoparticles, was synthesized by microemulsion technique and an anti‑HER2 antibody was conjugated to the surface of LMB to form H‑LMB, followed by the characterization of the prepared H‑LMB. The detection of capture efficiency of LMBs in GC cells was tested by MTT and expression of HER2 mRNA was determined by reverse transcription‑quantitative PCR. The positive detection rate of HER2 was verified by HER2‑fluorescence insitu hybridization (FISH) test on the separated CTCs from GC. Further verification was performed based on the consistency between the result of separated CTCs and that of single‑gene NGS assay of HER2, associated with the determination of clinical consistency. The constructed H‑LMB exhibited good stability and specificity. The mutation rate of HER2 by the FISH test was 14% in the blood samples of 50patients with GC and was 14% by NGS assay. The mutation rate of HER2 was 12% in H‑LMB and the positive detection rate was 85.7% compared with the results of the FISH test, indicating consistency with the clinical diagnosis and pathological examination results. In conclusion, the anti‑HER2 antibody‑modified LMB can separate CTCs with HER2 abnormal expression, which exhibits an application potential in GC diagnosis and treatment and is of great clinical significance for the diagnosis and evaluation of its therapeutic effect on GC.

Augmented hunger games search algorithm using logarithmic spiral opposition-based learning for function optimization and controller design

This paper explains the construction of a novel augmented hunger games search algorithm using a logarithmic spiral opposition-based learning technique. The proposed algorithm (LsOBL-HGS) is used as an efficient tool for both function optimization and controller design. To assess the performance of the algorithm for function optimization, benchmark functions from the CEC2017 test suite were employed and comparisons were made with available and good performing algorithms. In terms of controller design, the proposed LsOBL-HGS algorithm was utilized to design a FOPID controlled magnetic ball suspension system. Comparative assessments were also performed for FOPID controller design, as well using other state-of-the-art methods reported for the magnetic ball suspension system. The results showed that the proposed LsOBL-HGS algorithm has good capability for FOPID controller design employed in a magnetic ball suspension system as it provided an improvement of more than 13% in terms of the transient response-related parameters and more than 34% in terms of bandwidth compared to the best-reported approach used for comparisons.

Improvements of surface tribological properties by magnetic assisted ball burnishing

The effect of the magnetic assisted ball burnishing on a general, C45 steel was investigated considering tribological aspects. In engineering practice, the tribological properties of machined surfaces are characterized by amplitude roughness parameters from roughness profiles, as Rpk, Rk, Rvk, Rsk and Rku. Information about the sliding properties can be described by these parameters together with the oil retention capacity of the surface. Despite the conventional burnishing processes used as a post-machining operation, the authors applied a newly designed magnetic assisted ball burnishing method and tool, which can also burnish flat or harmonically changing surfaces and is able to round the edge of the workpiece in one pass as well, immediately after milling. To increase efficiency of the applied burnishing process, different types of burnishing strategies were applied and compared. The results of the investigations showed that the magnetic assisted ball burnishing decreases the frictional resistance, and at the same time it creates advantageous oil pockets on the machined surface.

Development of novel customized pressure distribution surface for reduction of pressure ulcers using additive manufacturing technology

PurposeThis research aims to focus on developing a customized support surface using additive manufacturing (AM) for effective pressure relief for patients who are in bed or wheelchair suffering from pressure ulcers (PU).Design/methodology/approachA novel customized support surface is developed using AM technology incorporated with magnetic levitation and ball and socket mechanisms. Magnetic levitation provides cushioning effect for the developed cushion to users who are sitting in a wheelchair and increases the rate of healing. The ball and socket mechanism provides the user body's self-adaptive mechanism and reduces shear and friction forces between the surfaces of the additive manufactured cushion and the human buttocks.FindingsFrom the results of ISO 16480-6 biomechanical standardized tests, the additive manufactured support surface performed better than, or on par with, the most widely available commercial cushions. It is evident that the developed cushion’s peak pressure values are lower when compared with other cushions. The overall efficiency of the developed cushion was qualitatively reported; 67% of people felt it was excellent and 22% of people responded as good and 11% were satisfactory. Henceforth, the overall effectiveness of the developed support surface provides a better experience to the end-user in the view of PU reduction.Originality/valueA developed additive manufactured customized support surface will be an alternative approach for the reduction of PU, and it overcomes the drawbacks faced by the currently available cushions.

Neural network compensation control of magnetic levitation ball position based on fuzzy inference

Aiming at the problem of poor transient performance of the control system caused by the control uncertainty of the undertrained neural network, a neural network compensation control method based on fuzzy inference is proposed in this paper. The method includes three control substructures: fuzzy inference block, neural network control block and basic control block. The fuzzy inference block adaptively adjusts the neural network compensation control quantity according to the control error and the error rate of change, and adds a dynamic adjustment factor to ensure the control quality at the initial stage of network learning or at the moment of signal transition. The neural network control block is composed of an identifier and a controller with the same network structure. After the identifier learns the dynamic inverse model of the controlled object online, its training parameters are dynamically copied to the controller for real-time compensation control. The basic control block uses a traditional PID controller to provide online learning samples for the neural network control block. The simulation and experimental results of the position control of the magnetic levitation ball show that the proposed method significantly reduces the overshoot and settling time of the control system without sacrificing the steady-state accuracy of neural network compensation control, and has good transient and steady-state performance and strong robustness simultaneously.

A novel modified opposition‐based hunger games search algorithm to design fractional order proportional‐integral‐derivative controller for magnetic ball suspension system

AbstractThis study focuses on construction of novel enhanced metaheuristic algorithm using a modified opposition‐based learning technique and the hunger games search algorithm. The proposed modified opposition‐based hunger games search (mOBL‐HGS) algorithm is aimed to be used as an efficient tool to tune a fractional order proportional‐integral‐derivative (FOPID) controller in order to control a magnetic ball suspension system with greater flexibility. The challenging benchmark functions from CEC2017 test suite are used to confirm the greater performance of the proposed mOBL‐HGS algorithm. The proposed mOBL‐HGS algorithm is also utilized to reach the optimum values of a FOPID controller employed in a magnetic ball suspension system in order to demonstrate its capability in terms of a complex real‐world engineering problem. The latter case is confirmed through comparative evaluations of statistical analysis, convergence profile, transient response, frequency response, disturbance rejection, and robustness. The demonstrated results confirm the greater ability of the proposed approach to control a magnetic ball suspension system.

Инородные тела в желудке у ребенка 5 лет: особенности клинической симптоматики (клиническое наблюдение)

Gastrointestinal foreign bodies (FB) are a relevant issue of present-day pediatrics due to non-specific clinical presentations, difficulties in collecting medical history because of child’s age, and low awareness of parents and practitioners. The authors describe a 5-year girl with multiple gastric FBs (a conglomeration of hundred 0.3-cm magnetic balls). The girl was twice admitted to different hospitals with different incoming diagnoses. Non-specific clinical symptoms and complaints resulted in late diagnosis, primary exclusion of other infectious (acute gastroenteritis) and inflammatory (ulcerative colitis) GI disorders, and unreasonable prescription of medications including antibiotics. The authors address the management strategy for gastric magnetic FBs in this child and difficulties with their endoscopic removal. More than three weeks (24 days) had passed from the first symptoms to the final diagnosis. This case report illustrates the need for the accurate collection of medical history and timely diagnostic search using X-ray and endoscopic imaging irrespective of a child’s age. KEYWORDS: foreign bodies, gastrointestinal tract, children, magnetic balls, endoscopy, X-ray. FOR CITATION: Bevz A.S., Bokova T.A., Elin L.M. Gastric foreign bodies in a 5-year child: pattern of clinical presentations (case report). Russian Journal of Woman and Child Health. 2022;5(2):173–177 (in Russ.). DOI: 10.32364/2618-8430-2022-5-2-173-177.

Optimal injection attack strategy for cyber-physical systems: a dynamic feedback approach

This paper investigates the system security problem of cyber-physical systems (CPSs), which is not only more practical but also more significant to deal with than the detecting faults problem. The purpose of this paper is to find an optimal attack strategy that maximizes the output error of the attacked system with low energy consumption. Based on a general model of linear time-invariant systems and a key technical lemma, a new optimal attack strategy for the meticulously designed false data injection attack is constructed. It is worth mentioning that compared with the existing model-based attack strategies, the designed one is more general and the corresponding attack strategy is more easily implemented when system states and external input are inaccessible. Key to overcoming the inaccessible information, a dynamic observer in the form of Luenberger is constructed. Finally, a networked magnetic levitation steel ball movement system is applied to illustrate the effectiveness of the proposed scheme.

Magnetic nano carbon balls - Synthesis and adsorption studies

Madhuca longifolia oil used as precursor oil for the synthesis of nano sized carbon balls with a size of 50 to 100 nm. An indigenously designed reactor assembly is used for this synthesis. Low temperature direct pyrolysis method is employed with the help of multi-metal catalyst derived from Alternanthera sessilis stem ash. The synthesized carbon balls have a bulk density of 0.124 g/mL and BET surface area of 805.87 m2/g. In-order to ensure the effective recovery of NCB, it is immobilized with a magnetic nano particle Fe3O4 and used for the adsorption studies of Acid Green 25 dye from aqueous solution under batch mode. Batch mode studies also proved the endothermic nature and physisorption mechanisms. The maximum Langmuir monolayer capacity of 243.90 mg/g has been achieved at a temperature of 45°C.

Polyaniline-based networks combined with Fe3O4 hollow spheres and carbon balls for excellent electromagnetic wave absorption

Polyaniline (PANI)-based networks combined with Fe 3 O 4 hollow spheres and carbon balls (FCP) for improved electromagnetic wave (EMW) absorption were investigated using an easy-to-industrialize solvothermal and physical method. Hollow structure Fe 3 O 4 spheres with a lower density than that of the common solid sphere were prepared. As a thin and light magnetic material, Fe 3 O 4 hollow spheres generate magnetic loss, carbon balls and PANI networks generate dielectric loss. The magnetic and conductive parts play appropriate roles in achieving complementarity in the EMW absorption. The relatively high specific surface area introduced by PANI networks promotes interfacial polarization and further supports dielectric loss. In conclusion, the above reasons provide multiple attenuation mechanisms. Samples FCP1 (−65.109 dB, at 12.800 GHz, 1.966 mm, from 5.6 to 18.0 GHz) and FCP2 (−61.033 dB, at 8.480 GHz, 3.328 mm, from 4.3 to 18.0 GHz) demonstrated a wide bandwidth, a small thickness, a minimum reflection loss (R L ), and a low loading ratio (25%) in paraffin-based composites. Specifically, their loading ration of 25% is much lower than the loading ratio of conventional materials (usually 50% and above). In addition, the bandwidth is excessively wide, above 12 GHz, possessing good absorption performance in continuous intervals with different thicknesses. Such excellent characteristics have rarely been reported in literature.