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Results 301 - 350 of 1388
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Hammer Bruce E - - 2009
Diamagnetic samples placed in a strong magnetic field and a magnetic field gradient experience a magnetic force. Stable magnetic levitation occurs when the magnetic force exactly counter balances the gravitational force. Under this condition, a diamagnetic sample is in a simulated microgravity environment. The purpose of this study is to ...
Schuff Norbert - - 2009
Recent advancements in high field magnetic resonance imaging (MRI) technology (3 T and higher), providing increased signal sensitivity and images with more prominent contrasts intrinsic to the brain, offer new opportunities for assessing brain alterations in Parkinson's disease (PD). In this article, the principle benefits of high field MRI for ...
Wang Yi - - 2009
A new approach to generating MRI contrast by solving the magnetic field to susceptibility source inverse problem is presented to address the quantification difficulties associated with traditional T1/T2 relaxation and susceptibility weighted T2 * methods. The forward problem from source to field is reviewed. Its inverse field to source problem ...
Yoon Jung Hee - - 2009
Two-step magnetic transitions: An azide-bridged 1D Mn(III) coordination polymer with a unique single end-on mode was prepared; it displayed atypical antiferromagnetic couplings and field-induced two-step magnetic transitions (see figure). The spin-canted phenomenon in the antiferromagnetic chain complex plays a pivotal role in establishing the slow magnetic relaxation.
Jing Ying - - 2009
Magnetic nanoparticles play an important role in biomedical applications, such as MR imaging, drug delivery and hyperthermia. Nanoparticles made of high-moment materials like Fe-Co and Fe have become active in the field due to superior performance. Protected by a biocompatible shell (Au/Ag/Si/C), high-moment nanoparticles can retain their magnetic property over ...
Kim Dong-Hyun - - 2009
The delivery of hyperthermic thermoseeds to a specific target site with minimal side effects is an important challenge in targeted hyperthermia, which employs magnetic method and functional polymers. An external magnetic field is used to control the site-specific targeting of the magnetic nanoparticles. Polymer-coated magnetic nanoparticles can confer a higher ...
Abe Shigeaki - - 2009
Nano-sized particles have received much attention in view of their varied application in a wide range of fields. For example, magnetite (Fe(3)O(4)) nanoparticles have been investigated for various medical applications. In this study, we visualized the distribution of administered magnetic nanoparticles in mice using both X-ray scanning analytical microscopy (XSAM) ...
Mishra A - - 2009
We report a case of a 20-year-old girl who presented to the out-patients' department with congenital, progressive unilateral proptosis and reduced vision. Ultrasound, computed tomography (CT) scan and magnetic resonance imaging (MRI) were performed. Diagnosis of orbital lymphangioma was made on imaging. Authors highlight the crucial role of imaging in ...
Zeng Zhaowu - - 2009
The purpose was to study the preparation and properties of tegafur magnetic thermosensitive liposomes. The method was to employ an improved chemical coprecipitation method for preparing nano-magnetic particles and a reverse-phase evaporation and ultrasonic method for preparing tegafur magnetic thermosensitive liposomes. The results showed that tegafur magnetic thermosensitive liposomes were ...
Tohara Kiwamu - - 2009
The magnetic microstructure in a Co-CoO obliquely evaporated tape that was subjected to a recording bit length of 250 nm was studied using electron holography. The reconstructed phase image demonstrated a periodic pattern of magnetic flux loops that were inclined to the film normal due to a well-developed columnar structure. ...
Mykhaylyk Olga - - 2009
This chapter describes how to design and conduct experiments to deliver siRNA to adherent mammalian cells in vitro by magnetic force-assisted transfection using self-assembled complexes of small interfering RNA (siRNA) and cationic lipids or polymers that are associated with magnetic nanoparticles. These magnetic complexes are targeted to the cell surface ...
Wong Kelvin Kian Loong - - 2009
BACKGROUND: Motion tracking based on spatial-temporal radio-frequency signals from the pixel representation of magnetic resonance (MR) imaging of a non-stationary fluid is able to provide two dimensional vector field maps. This supports the underlying fundamentals of magnetic resonance fluid motion estimation and generates a new methodology for flow measurement that ...
Bassen Howard I - - 2009
BACKGROUND: Magnetic resonance imaging (MRI) of patients with implanted cardiac pacemakers is generally contraindicated but some clinicians condone scanning certain patients. We assessed the risk of inducing unintended cardiac stimulation by measuring electric fields (E) induced near lead tips by a simulated MRI gradient system. The objectives of this study ...
Silvers L J - - 2008
Magnetic fields are known to reside in many astrophysical objects and are now believed to be crucially important for the creation of phenomena on a wide variety of scales. However, the role of the magnetic field in the bodies that we observe has not always been clear. In certain situations, ...
Nazmy M S - - 2009
AIMS: To examine the potential role of magnetic resonance myelography (MRM) in defining the clinical target volume for the spinal field in craniospinal irradiation in children. MATERIALS AND METHODS: Of the 42 patients for whom magnetic resonance imaging (MRI) of the spine was carried out, 12 patients had MRM. The ...
Okano Hideyuki - - 2008
It is believed that static magnetic fields (SMF) cannot affect the pattern formation of the Belousov-Zhabotinsky (BZ) reaction, which has been frequently studied as a simplified experimental model of a nonequilibrium open system, because SMF produces no induced current and the magnetic force of SMF far below 1 T is ...
Lynch David K - - 2008
Reports and photographs claiming that visual observers can detect the curvature of the Earth from high mountains or high-flying commercial aircraft are investigated. Visual daytime observations show that the minimum altitude at which curvature of the horizon can be detected is at or slightly below 35,000 ft, providing that the ...
Guendouz Laouès - - 2008
Magnetic field gradients are nowadays indispensable to most nuclear magnetic resonance experiments and are at the basis of magnetic resonance imaging (MRI). Most of the time, gradients of the static magnetic field are employed. Gradients of the radio-frequency (rf) field may constitute an interesting alternative. Until now, they were produced ...
Huang Hsin-Hsiung - - 2008
The biological effects of extremely low frequency magnetic fields (ELF MFs) on living organisms have been explored in many studies. Most of them demonstrate the biological effects caused by 50/60 Hz magnetic fields or pulsed magnetic fields. However, as the development of power electronics flourishes, the magnetic fields induced are ...
Wang Xiaoke - - 2008
Magnetic particles are currently one of the most important materials in the industrial sector, where they have been widely used for biotechnological and biomedical applications. To investigate the effects of the imposed magnetic field on biomineralization in Magnetospirillum magneticum AMB-1 and to suggest a new approach that enhances formation of ...
Holzbach Thomas - - 2010
Adenoviral transduction of the VEGF gene in an oversized skin flap increases flap survival and perfusion. In this study, we investigated the potential of magnetofection of magnetic lipospheres containing VEGF(165)-cDNA on survival and perfusion of ischemic skin flaps and evaluated the method with respect to the significance of applied magnetic ...
Vidal Arvin - - 2008
Carotid atherosclerosis measurements for eight subjects at baseline and 14 +/- 2 days later were examined using 1.5 T and 3.0 T magnetic resonance imaging (MRI). A single observer blinded to field strength, subject and timepoint manually segmented carotid artery wall and lumen boundaries in randomized images in five measurement ...
Nandigam R N K - - 2009
The emergence of cerebral microbleeds (CMB) as common MR imaging findings raises the question of how MR imaging parameters influence CMB detection. To evaluate the effects of modified gradient recalled-echo (GRE) MR imaging methods, we performed an analysis of sequence, section thickness, and field strength on CMB imaging properties and ...
De Guio François - - 2009
Magnetic resonance imaging has proven its potential application in bread dough and gas cell monitoring studies, and dynamic processes such as dough proving and baking can be monitored. However, undesirable magnetic susceptibility effects often affect quantification studies, especially at high fields. A new low-field method is presented based on local ...
Zyss Tomasz - - 2008
Since antiquity, the phenomenon of magnetism has been known, and it has been tried for therapeutic purposes. Through history, people have made use of both natural sources of magnetic fields (magnetic iron ore) and artificial ones (magnets, electromagnets). It was as late as the 19th century that we started to ...
Primo Fernando L - - 2008
In this study a magnetic nanoemulsion (MNE) was developed from a mixture of two components, namely biodegradable surfactants and biocompatible citrate-coated cobalt ferrite-based magnetic fluid, for entrapment of Zn(II)-Phthalocyanine (ZnPc), the latter a classical photosensitizer (PS) species used in photodynamic therapy (PDT) procedures. The sample's stability was evaluated as a ...
Chen Shaowen - - 2008
We examine manipulating the electromagnetic (EM) wave with an external static magnetic field (ESMF) taking advantage of the versatility of the magnetic photonic crystal (PC). The effect of a nonuniform ESMF on the permeability of the constituent magnetic material in the PC is demonstrated to create a gradient of the ...
Chen Weitian - - 2008
Off-resonance effects can cause image blurring in spiral scanning and various forms of image degradation in other MRI methods. Off-resonance effects can be caused by both B0 inhomogeneity and concomitant gradient fields. Previously developed off-resonance correction methods focus on the correction of a single source of off-resonance. This work introduces ...
Coarna C - - 2009
A number of materials MR developments require that measurements be made in a large magnetic field gradient, including unilateral (single-sided) magnet designs for portability and open access. In such cases, all radiofrequency (RF) pulses are slice selective. Typically, little effort is made to tailor the shape of the selected slice, ...
László János - - 2009
AIMS: In recent years nuclear magnetic resonance (MR) systems have proliferated worldwide. This imaging/spectroscopy technique utilizes a strong homogeneous static magnetic field, much smaller time-varying gradient magnetic fields, and radiofrequency radiation. Many studies addressed the question of potential adverse side effects induced by MR, but less attention has been paid ...
Egami Shigeki - - 2009
A conventional method to measure the magnetic susceptibility of a microdroplet in a glass capillary has been constructed by using a magnetic circuit (2.82 T) with a high magnetic field gradient (B(dB/dz) = 3900 T(2)/m). The magnetophoretic velocity of a toluene droplet with ferrocene dispersed in 1 M HCl aqueous ...
Viard Romain - - 2009
INTRODUCTION: Surgical and interventional procedures increasingly rely on spatial measurement systems. One of the most popular is NDI's Polaris Vicra. Unfortunately, this system cannot be used for magnetic resonance imaging (MRI) procedures because of the image artifacts that it produces. MATERIALS AND METHODS: Here, a simple method for hardware electrical ...
Tan Ee Lim - - 2008
Implantable biosensors were developed for real-time monitoring of pressure and strain in the human body. The sensor, which was wireless and passive, consisted of a soft magnetic material and a permanent magnet. When exposed to a low frequency AC magnetic field, the soft magnetic material generated secondary magnetic fields that ...
Mourachkine A - - 2008
Low-cost spintronic devices functioning in zero applied magnetic field are required for bringing the idea of spin-based electronics into the real-world industrial applications. Here we present first microwave measurements performed on nanomagnet devices fabricated by electrodeposition inside porous membranes. In the paper, we discuss in details a microwave resonator consisting ...
Shenkar Robert - - 2008
We hypothesized that structural details that have not been described previously would be revealed in cerebral cavernous malformations (CCM) through the use of high-field magnetic resonance and confocal microscopy. The structural details of CCMs excised from patients were sought by examination with high-field magnetic resonance imaging (MRI) and correlated with ...
Seo Yongho - - 2008
The real-time atomic force microscope for biological sample is a challenging research field. We have demonstrated a real-time atomic force microscope by implementing a mechanical resonator type scanner called by "microscanner" The microscanner was designed to have a resonance frequency in the range of 5-10 kHz and an amplitude of ...
Szelényi Andrea - - 2008
OBJECTIVE: The intraoperative combination of an open magnetic resonance imaging (MRI) system with neurophysiological localization and continuous monitoring techniques allows for the best available anatomic and physiological orientation as well as real-time functional monitoring. Methodological aspects and technical adaptations for this combination of methods and the experience in 29 patients ...
de Rochefort Ludovic - - 2008
Magnetic properties characterized by susceptibility and chemical shift linearly modify the local magnetic field experienced by spins. A piece-wise constant solution using magnetic resonance imaging is found to the challenging inversion problem from field to magnetic properties. The magnetic field shifts were estimated from MR phase images. The MR magnitude ...
Mykhaylyk Olga - - 2008
Magnetofection is defined as the magnetically enhanced delivery of nucleic acids associated with magnetic nanoparticles and has been utilized to deliver synthetic siRNAs to cultured cells. Certain magnetic nanomaterials associate with siRNAs and are suitable for siRNA delivery, either alone or in combination with cationic polymers or cationic lipid enhancers; ...
Hogan S D - - 2008
We report the first experimental realization of magnetic trapping of a sample of cold radicals following multistage Zeeman deceleration of a pulsed supersonic beam. H atoms seeded in a supersonic expansion of Kr have been decelerated from an initial velocity of 520 m/s to 100 m/s in a 12-stage Zeeman ...
Stanley Sabine - - 2008
Mars' crustal magnetic field was most likely generated by dynamo action in the planet's early history. Unexplained characteristics of the field include its strength, concentration in the southern hemisphere, and lack of correlation with any surface features except for the hemispheric crustal dichotomy. We used numerical dynamo modeling to demonstrate ...
Zheng Xiaoli - - 2009
Low transfection efficiency in vivo and failure to deliver therapeutic nucleic acids to the target organs limit the use of cationic liposomes (CLs) in gene therapy. Magnetic drug targeting (MDT) was applied in this study to improve the transfection efficiency and overcome the limitations. Magnetic cationic liposomes (MCLs) were prepared ...
Saito M - - 2008
The possibility of a magnetic field controlling the chirality of matter has been debated for a long time. Here, we report the successful induction of chirality in the noncentrosymmetric canted antiferromagnet, CuB2O4, by application of a low intensity static magnetic field. The chirality is reversed by a 90 degrees rotation ...
Jin Xiaoxia - - 2008
Magnetic separation in biomedical applications is based on differential magnetophoretic mobility (MM) of microparticulate matter in viscous media. Typically, the difference in MM is obtained by selectively labeling the target cells with superparamagnetic iron oxide nanoparticles (SPIONs). We have measured the MM of monodisperse, polystyrene microspheres (PSMs), with and without ...
Li Guanglin - - 2008
We proposed a new approach to improve the control of prosthetic arm rotation in amputees. Arm rotation is sensed by implanting a small permanent magnet into the distal end of the residual bone, which produces a magnetic field. The position of the bone rotation can be derived from magnetic field ...
La Rivière Patrick J - - 2008
Most X-ray tubes comprise a rotating anode that is bombarded with electrons to produce X-rays. A substantial amount of heat is generated, and to increase the area of the anode exposed to the electrons, without increasing the apparent size of the focal spot, the focal track of the anode is ...
de Vos Hugo - - 2008
In areas of war and armed conflict it is difficult to get trustworthy and coherent information. Civil society and human rights groups often face problems of dealing with fragmented witness reports, disinformation of war propaganda, and difficult direct access to these areas. Turkish Kurdistan was used as a case study ...
Thiesen Burghard - - 2008
Magnetic fluids are increasingly used for clinical applications such as drug delivery, magnetic resonance imaging and magnetic fluid hyperthermia. The latter technique that has been developed as a cancer treatment for several decades comprises the injection of magnetic nanoparticles into tumors and their subsequent heating in an alternating magnetic field. ...
Barry Stephen E - - 2008
Certain iron-based particle formulations have useful magnetic properties that, when combined with low toxicity and desirable pharmacokinetics, encourage their development for therapeutic applications. This mini-review begins with background information on magnetic particle use as MRI contrast agents and the influence of material size on pharmacokinetics and tissue penetration. Therapeutic investigations, ...
Simi Silvana - - 2008
Magnetic resonance imaging is a diagnostic technique widely used in medicine and showing a growing impact in cardiology. Biological effects associated to magnetic resonance electromagnetic fields have received far little attention, but it cannot be ruled out that these fields can alter DNA structure. The present study aimed at to ...
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