Evolving trends in mechanical circulatory support: Clinical development of a fully magnetically levitated durable ventricular assist device.

Early generation left ventricular assist devices (LVAD) for treatment of refractory heart failure attempted to mimic the pulsatility of a native heart and were bulky and less durable due to valves within the inflow and outflow pathways. The next disruption came with the introduction of continuous flow pumps characterized by a low-pulse pressure circulation. Since the mechanism of action did not involve displacement of blood, these pumps were much smaller and less noisy in part due to fewer moving parts. Such devices include the HeartMate II axial-flow pathway pump which is implanted thoraco-abdominally and the HVAD, a centrifugal-flow pathway pump which is smaller and is implanted entirely within the thoracic cavity and uses a combination of hydrodynamic and magnetic levitation of the internal rotor. These pumps improved survival compared with the early generation LVADs and in a trial, the HVAD demonstrated non-inferiority compared with the HeartMate II but with an increase in ischemic and hemorrhagic strokes. The HeartMate 3 LVAD is an intrapericardial centrifugal-flow pathway pump with a full magnetically levitated, frictionless rotor with a fixed intrinsic pulse. In a randomized trial, the HeartMate 3 "hybrid" pump was associated with near-elimination of pump thrombosis, a reduction in strokes of any type or severity and lower mucosal bleeding rates. Despite improvements in hemocompatibility, right heart failure and infections contribute to significant morbidity, and devices designed to be internally contained with a wireless power source and physiological flow characteristics are still required despite great strides in the field.

Does Decreased Surgical Stress Really Improve the Psychosocial Health of Early-onset Scoliosis Patients?: A Comparison of Traditional Growing Rods and Magnetically-controlled Growing Rods Patients Reveals Disappointing Results.

STUDY DESIGN: Cross-sectional case-control study. OBJECTIVE: Compare psychosocial profile of magnetically-controlled growing rod (MCGR) patients to traditional-growing rod (TGR) with an array of psychiatric tools, expecting improvement in MCGR due to decreased number of surgical procedures. SUMMARY OF BACKGROUND DATA: TGR treatment has had positive clinical and radiographic results; however, upward of 10 surgical sessions and high complication rates have called into question the quality of life of these children. Improvement with the introduction of the MCGR is expected. METHODS: GR patients with minimum of 2-years follow-up were recruited. None had neurological conditions. All underwent testing with the Wechsler Intelligence Scale for Children-Revised, and only those in the normal range were included. Patients filled out questionnaires with mental health professionals to measure psychosocial status. MCGR patients' results were compared to TGR patients. RESULTS: Twenty-seven patients met criteria (10 MCGR, 17 TGR): average age at enrollment 11.8 years (range 5.9-17). MCGR group was significantly younger (9.1 vs. 13.3 yr) and had significantly shorter follow-up (45.6 vs. 82.8 mo) (P < 0.05). TGR patients underwent an average of 16 surgical procedures, MCGR an average of 1.5 (including complications, P < 0.05). Age at index surgery (6 yr), preoperative and postoperative major curve magnitudes (60°, 40° respectively) were statistically similar.There was no difference in current psychiatric diagnoses between the groups. MCGR patients scored worse than TGR patients in general functionality domains. TGR patients showed increased functionality and prosocial scores with increased number of procedures. This effect was not observed in MCGR. CONCLUSIONS: The expected improvement in psychosocial status with the MCGR was not observed at a 31.6-month-follow-up. It appears that provided the patient spends enough time in the treatment process to notice benefit and does not experience major complications, noninvasiveness of lengthening procedures does not show up as an advantage with the psychosocial tools utilized in this study. LEVEL OF EVIDENCE: 3.

Magnetic biosensors: Modelling and simulation.

In the past few years, magnetoelectronics has emerged as a promising new platform technology in various biosensors for detection, identification, localisation and manipulation of a wide spectrum of biological, physical and chemical agents. The methods are based on the exposure of the magnetic field of a magnetically labelled biomolecule interacting with a complementary biomolecule bound to a magnetic field sensor. This Review presents various schemes of magnetic biosensor techniques from both simulation and modelling as well as analytical and numerical analysis points of view, and the performance variations under magnetic fields at steady and nonstationary states. This is followed by magnetic sensors modelling and simulations using advanced Multiphysics modelling software (e.g. Finite Element Method (FEM) etc.) and home-made developed tools. Furthermore, outlook and future directions of modelling and simulations of magnetic biosensors in different technologies and materials are critically discussed.

Engineered Magnetic Core-Shell Structures.

In recent years, engineered magnetic core-shell structures are playing an important role in the wide range of various applications. These magnetic core-shell structures have attracted considerable attention because of their unique properties and various applications. Also, the synthesis of engineered magnetic core-shell structures has attracted practical interest because of potential applications in areas such as ferrofluids, medical imaging, drug targeting and delivery, cancer therapy, separations, and catalysis. So far a large number of engineered magnetic core-shell structures have been successfully synthesized. This review article focuses on the recent progress in synthesis and characterization of engineered magnetic core-shell structures. Also, this review gives a brief description of the various application of these structures. It is hoped that this review will play some small part in helping future developments in important field.

Neural network-based adaptive dynamic surface control for permanent magnet synchronous motors.

This brief considers the problem of neural networks (NNs)-based adaptive dynamic surface control (DSC) for permanent magnet synchronous motors (PMSMs) with parameter uncertainties and load torque disturbance. First, NNs are used to approximate the unknown and nonlinear functions of PMSM drive system and a novel adaptive DSC is constructed to avoid the explosion of complexity in the backstepping design. Next, under the proposed adaptive neural DSC, the number of adaptive parameters required is reduced to only one, and the designed neural controllers structure is much simpler than some existing results in literature, which can guarantee that the tracking error converges to a small neighborhood of the origin. Then, simulations are given to illustrate the effectiveness and potential of the new design technique.

Recent advances in the application of core-shell structured magnetic materials for the separation and enrichment of proteins and peptides.

Many endogenous proteins/peptides and proteins/peptides with post-translational modifications (PTMs) are presented at extremely low abundance, and they usually suffer strong interference with highly abundant proteins/peptides as well as other contaminants, resulting in low ionization efficiency in MS analysis. Therefore, the separation and enrichment of proteins/peptides from complex mixtures is of great importance to the successful identification of them. Core-shell structured magnetic microspheres have been widely used in the enrichment and isolation of proteins/peptides, thanks to unique properties such as strong magnetic responsiveness, outstanding binding capacity, excellent biocompatibility, robust mechanical strength and admirable recoverability. The aim of this review is to update the advances in the application of core-shell structured magnetic materials for proteomics analysis, including the separation and enrichment of low-concentration proteins/peptides, the selective enrichment of phosphoproteins and the selective enrichment of glycoproteins, and to compare the enrichment performance of magnetic microspheres with different kinds of functionalization.

Analisis poblacional del uso y eficiencia de los soportes plantares imantados / Population analysis use and efficiency orthotics magnetized

Todos los seres vivos se encuentran bajo la influencia de un campo magnético. Por esta afirmación han sido utilizados los dispositivos magnéticos en diversas patologías para aliviar la sintomatología. El objetivo del estudio es realizar una revisión de la literatura publicada acerca del tratamiento de diversas patologías mediante el uso de dispositivos imantados, principalmente el de los soportes plantares. Se diseña una encuesta (N=60) acerca del conocimiento poblacional sobre estos dispositivos. Los resultados obtenidos en las encuestas demuestran un escaso conocimiento de los dispositivos y poca creencia en los mismos. La revisión de la literatura pone de manifiesto que este tipo de tratamiento con imanes posee un gran componente placebo(AU)

All living beings are under the influence of a magnetic field. By this statement the magnetic devices in various pathologies have been used to relieve the symptoms. The objective of the study is to conduct a review of published literature on the treatment of various diseases using magnetic devices, mainly of magnetic insoles. Designing a survey (N = 60) of population knowledge on these devices. The results obtained in the surveys show a little knowledge of devices and little belief in them. The literature review shows that this type of treatment with magnets has a large placebo component(AU)

Perspectives for 10 terabits/in2 magnetic recording.

Magnetic recording technology has come a long way, since the introduction of the first hard disk drives (HDD) in 1956. The areal density has grown by a factor of 200 million times and the HDD has stayed as a main candidate for mass storage of information. In order to maintain its lead over other competing technologies, HDD industry continues to invent several technologies. Having introduced perpendicular recording technology in the last 5 years, the industry is looking at introducing bit-patterned media or heat-assisted magnetic recording in the next five years. The researchers--looking at a longer term--are investigating 10 Tbits/in2 as the next major milestone. The issues and probable candidates for 10 Tbits/in2 magnetic recording technology are described from a material perspective.

Magnetic materials and devices for the 21st century: stronger, lighter, and more energy efficient.

A new energy paradigm, consisting of greater reliance on renewable energy sources and increased concern for energy efficiency in the total energy lifecycle, has accelerated research into energy-related technologies. Due to their ubiquity, magnetic materials play an important role in improving the efficiency and performance of devices in electric power generation, conditioning, conversion, transportation, and other energy-use sectors of the economy. This review focuses on the state-of-the-art hard and soft magnets and magnetocaloric materials, with an emphasis on their optimization for energy applications. Specifically, the impact of hard magnets on electric motor and transportation technologies, of soft magnetic materials on electricity generation and conversion technologies, and of magnetocaloric materials for refrigeration technologies, are discussed. The synthesis, characterization, and property evaluation of the materials, with an emphasis on structure-property relationships, are discussed in the context of their respective markets, as well as their potential impact on energy efficiency. Finally, considering future bottlenecks in raw materials, options for the recycling of rare-earth intermetallics for hard magnets will be discussed.

Scanning probe microscopy: instrumentation and applications on thin films and magnetic multilayers.

In this article we present a review on instrumentation and the modes of operation of a scanning probe microscope. In detail, we review the main techniques of Scanning Probe Microscopy (SPM), which are Scanning Tunneling Microscopy (STM) and Atomic Force Microscopy (AFM), focusing our attention on the latter one. The AFM instrument provides information on the roughness and grain size of thin films. As an example we review recent results on two metallic thin film systems: thin Ag films deposited on glass, and Ni/Pt compositionally modulated multilayers deposited on glass, Si, and polyimide substrates. To show the validity of the grain size measurements, we compare the data with the ones resulting from X-ray diffraction (XRD) measurements. We show that the AFM results are reliable for grain diameters as small as 14 nm, which is approximately comparable to the tip radius. Finally, we deal with Magnetic Force Microscopy (MFM) results on Co/Pt and Co/Au multilayers. We observe perpendicularly magnetized domains. The domain configurations are correlated to the magnetization hysteresis curves.

Vagus nerve stimulation and magnet use: optimizing benefits.

More than 10 years ago, the vagus nerve stimulator became the first device approved by the Food and Drug Administration for use in persons with epilepsy. The vagus nerve stimulator has subsequently served to spearhead the concept of neurostimulation for seizures. Chronic intermittent electrical stimulation of the left vagus nerve is the foundation for vagus nerve stimulation, yet little is known about its capability to deliver acute, on-demand, activation of stimulation through use of a magnet. Thus far, clinical use of magnet-induced vagus nerve stimulation has not been elucidated. In an effort to help guide management, we highlight current and potential uses of acute abortive therapy with vagus nerve stimulation. We review the current evidence that is available for vagus nerve stimulator magnet use, discuss potential clinical applications that exist, offer a protocol for magnet application within the institutional setting, provide our approach to titrating the magnet parameters, and make recommendations for magnet use that support an evolving standard of care.

Chemical methodologies for preparation of micron and nanometer scale ferrites--a mini review of patents.

Ferrites, with wide range of chemical compositions, have been studied extensively over the years as they have a plethora of applications such as magnetic read/write heads, transformer cores, antennas, microwave absorbers, deflecting yoke, high frequency transformers, catalysis, pigments etc. Particles of submicron size have attracted the attention of scientists and technologists in different fields because they exhibit many unique physical properties as compared to those of bulk materials and are in great demand. Traditional high temperature solid-state method for preparation of ferrites is associated with several limitations. The quest for synthesis of ultrafine ferrite materials has led to the development of various preparative methods. Several patents disclose different wet chemical techniques namely sol-gel, coprecipitation, hydrothermal, combustion, spray pyrolysis etc for preparation of variety of ferrites for wide range of applications. In this mini-review, several patented chemical methods have been discussed critically with specific examples along with the effect of synthetic routes on particle size formation. Applications of ferrite powders with different compositions prepared by the above mentioned patented methods have also been discussed in this review.