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Sample records for biomagnetism

  1. Biomagnetism an interdisciplinary approach

    CERN Document Server

    Romani, Gian-Luca; Kaufman, Lloyd; Modena, Ivo

    1983-01-01

    Biomagnetism is the study of magnetic fields that originate in biological systems. This is a relatively new discipline that has attracted considerable interest throughout the scientific commu- ty. The study of biomagnetic fields requires the use of techniques and concepts drawn from widely disparate scientific disciplines. To make these techniques and concepts available to a wide spectrum of the scientific community, a NATO Advanced study Institute on B- magnetism was held near Frascati at Grottaferrata, Italy, in S- tember 1982. This volume is based on the lectures delivered by scholars representing many different scientific areas, ranging from solid state physics to psychology. It attempts to preserve the - herent development of concepts drawn from physiology, psychology, biology, physics, medicine, occupational health and geology that was evident during the Institute. The reader will quickly become aware that the progress in biomagnetism over the past decade was due principally to the efforts of interdisci...

  2. Pharyngeal transit time measured by scintigraphic and biomagnetic method

    International Nuclear Information System (INIS)

    Miquelin, C.A.; Braga, F.J.H.N.; Baffa, O.

    1996-01-01

    A comparative evaluation between scintigraphic and biomagnetic method to measure the pharyngeal transit is presented. Three volunteers have been studied. The aliment (yogurt) was labeled with 9 9 m Technetium for the scintigraphic test and with ferrite for the biomagnetic one. The preliminary results indicate a difference between the values obtained, probably due to the biomagnetic detector resolution

  3. Biomagnetics and bioimaging for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, Shoogo [Department of Biomedical Engineering, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)]. E-mail: ueno@medes.m.u-tokyo.ac.jp; Sekino, Masaki [Department of Biomedical Engineering, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2006-09-15

    This paper reviews medical applications of the recently developed techniques in biomagnetics and bioimaging such as transcranial magnetic stimulation, magnetoencephalography, magnetic resonance imaging, cancer therapy based on magnetic stimulation, and magnetic control of cell orientation and cell growth. These techniques are leading medicine and biology into a new horizon through the novel applications of magnetism.

  4. Biomagnetics and bioimaging for medical applications

    International Nuclear Information System (INIS)

    Ueno, Shoogo; Sekino, Masaki

    2006-01-01

    This paper reviews medical applications of the recently developed techniques in biomagnetics and bioimaging such as transcranial magnetic stimulation, magnetoencephalography, magnetic resonance imaging, cancer therapy based on magnetic stimulation, and magnetic control of cell orientation and cell growth. These techniques are leading medicine and biology into a new horizon through the novel applications of magnetism

  5. SQUIDs in biomagnetism: a roadmap towards improved healthcare

    OpenAIRE

    Körber, Rainer; Storm, Jan-Hendrik; Seton, Hugh; Mäkelä, Jyrki P; Paetau, Ritva; Parkkonen, Lauri; Pfeiffer, Christoph; Riaz, Bushra; Schneiderman, Justin F; Dong, Hui; Hwang, Seong-min; You, Lixing; Inglis, Ben; Clarke, John; Espy, Michelle A

    2016-01-01

    Globally, the demand for improved health care delivery while managing escalating costs is a major challenge. Measuring the biomagnetic fields that emanate from the human brain already impacts the treatment of epilepsy, brain tumours and other brain disorders. This roadmap explores how superconducting technologies are poised to impact health care. Biomagnetism is the study of magnetic fields of biological origin. Biomagnetic fields are typically very weak, often in the femtotesla range, making...

  6. Integrated Giant Magnetoresistance Technology for Approachable Weak Biomagnetic Signal Detections.

    Science.gov (United States)

    Shen, Hui-Min; Hu, Liang; Fu, Xin

    2018-01-07

    With the extensive applications of biomagnetic signals derived from active biological tissue in both clinical diagnoses and human-computer-interaction, there is an increasing need for approachable weak biomagnetic sensing technology. The inherent merits of giant magnetoresistance (GMR) and its high integration with multiple technologies makes it possible to detect weak biomagnetic signals with micron-sized, non-cooled and low-cost sensors, considering that the magnetic field intensity attenuates rapidly with distance. This paper focuses on the state-of-art in integrated GMR technology for approachable biomagnetic sensing from the perspective of discipline fusion between them. The progress in integrated GMR to overcome the challenges in weak biomagnetic signal detection towards high resolution portable applications is addressed. The various strategies for 1/ f noise reduction and sensitivity enhancement in integrated GMR technology for sub-pT biomagnetic signal recording are discussed. In this paper, we review the developments of integrated GMR technology for in vivo/vitro biomagnetic source imaging and demonstrate how integrated GMR can be utilized for biomagnetic field detection. Since the field sensitivity of integrated GMR technology is being pushed to fT/Hz 0.5 with the focused efforts, it is believed that the potential of integrated GMR technology will make it preferred choice in weak biomagnetic signal detection in the future.

  7. Biomagnetic Signals of the Large Intestine

    International Nuclear Information System (INIS)

    Cordova, T.; Sosa, M.; Bradshaw, L. A.; Adilton, A.

    2008-01-01

    Large intestine is part of the gastrointestinal tract with an average length, in adults, of 1.5 m. The gold standard technique in clinical medicine is the colonoscopy. Nevertheless, other techniques are capable of presenting information on physiological processes which take place in this part of the gastrointestinal system. Three recent studies are discussed in this paper in order to make this information more widely available. The authors consider that the biomagnetic technique could be easily implemented in hospitals around the world. Options will be available for research and clinical medicine

  8. New horizons in biomagnetics and bioimaging

    International Nuclear Information System (INIS)

    Ueno, Shogo; Sekino, Masaki

    2006-01-01

    This paper reviews recently developed techniques in biomagnetics and bioimaging such as transcranial magnetic stimulation (TMS), magnetic resonance imaging (MRI), and cancer therapy based on magnetic stimulation. The technique of localized and vectorial TMS has made it possible to obtain non-invasive functional mapping of the human brain, and the development of new bioimaging technologies such as current distribution MRI and conductivity MRI may make it possible to understand the dynamics of brain functions, which include millisecond-level changes in functional regions and dynamic relations between brain neuronal networks. These techniques are leading medicine and biology toward new horizons through novel applications of magnetism. (author)

  9. Proceedings of the biomagnetic effects workshop. [Lead abstract

    Energy Technology Data Exchange (ETDEWEB)

    Tenforde, T.S. (ed.)

    1978-01-01

    Separate abstracts were prepared for six of the eight chapters contained in these proceedings. The other two chapters contain introductory material (Chapter 1) dealing with the rationale for the work shop, and a summary (Chapter 8) of the major objectives that were accomplished at the workshop relative to the current status of awareness in the field of biomagnetic effects. (ERB)

  10. Bio-magnetic signatures of fetal breathing movement

    International Nuclear Information System (INIS)

    Ulusar, U D; Wilson, J D; Murphy, P; Govindan, R B; Preissl, H; Lowery, C L; Eswaran, H

    2011-01-01

    The purpose of fetal magnetoencephalography (fMEG) is to record and analyze fetal brain activity. Unavoidably, these recordings consist of a complex mixture of bio-magnetic signals from both mother and fetus. The acquired data include biological signals that are related to maternal and fetal heart function as well as fetal gross body and breathing movements. Since fetal breathing generates a significant source of bio-magnetic interference during these recordings, the goal of this study was to identify and quantify the signatures pertaining to fetal breathing movements (FBM). The fMEG signals were captured using superconducting quantum interference devices (SQUIDs) The existence of FBM was verified and recorded concurrently by an ultrasound-based video technique. This simultaneous recording is challenging since SQUIDs are extremely sensitive to magnetic signals and highly susceptible to interference from electronic equipment. For each recording, an ultrasound-FBM (UFBM) signal was extracted by tracing the displacement of the boundary defined by the fetal thorax frame by frame. The start of each FBM was identified by using the peak points of the UFBM signal. The bio-magnetic signals associated with FBM were obtained by averaging the bio-magnetic signals time locked to the FBMs. The results showed the existence of a distinctive sinusoidal signal pattern of FBM in fMEG data

  11. Biomagnetic localization from transient quasi-static events

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, J.C.; Leahy, R.M.; Lewis, P.S. [Los Alamos National Lab., NM (United States)]|[University of Southern California, Los Angeles, CA (United States). Signal and Image Processing Inst.

    1993-02-01

    Sensory stimuli, such as auditory, visual, or somatosensory, evoke neural responses in very localized regions of the brain. A SQUID biomagnetometer can measure the very weak fields that are generated outside of the head by this response. A simple source and head model of current dipoles inside a conducting sphere is typically used to interpret these magnetic field measurements or magnetoencephalogram (MEG). Locating dipole sources using data recorded from an array of biomagnetic sensors is distinguished from conventional array source localization techniques by the quasi-static transient nature of the data. Here, the basic MEG model is reviewed, then a localization example is given to motivate the need for partitioning the data to improve estimator performance. Tune-eigenspectrum analysis is introduced as a means of partitioning and interpreting spatio-temporal biomagnetic data. Examples using both simulated and somatosensory data are presented.

  12. Biomagnetic localization from transient quasi-static events

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, J.C.; Leahy, R.M.; Lewis, P.S. (Los Alamos National Lab., NM (United States) University of Southern California, Los Angeles, CA (United States). Signal and Image Processing Inst.)

    1993-01-01

    Sensory stimuli, such as auditory, visual, or somatosensory, evoke neural responses in very localized regions of the brain. A SQUID biomagnetometer can measure the very weak fields that are generated outside of the head by this response. A simple source and head model of current dipoles inside a conducting sphere is typically used to interpret these magnetic field measurements or magnetoencephalogram (MEG). Locating dipole sources using data recorded from an array of biomagnetic sensors is distinguished from conventional array source localization techniques by the quasi-static transient nature of the data. Here, the basic MEG model is reviewed, then a localization example is given to motivate the need for partitioning the data to improve estimator performance. Tune-eigenspectrum analysis is introduced as a means of partitioning and interpreting spatio-temporal biomagnetic data. Examples using both simulated and somatosensory data are presented.

  13. Biomagnetic Monitoring of Atmospheric Pollution: A Review of Magnetic Signatures from Biological Sensors.

    Science.gov (United States)

    Hofman, Jelle; Maher, Barbara A; Muxworthy, Adrian R; Wuyts, Karen; Castanheiro, Ana; Samson, Roeland

    2017-06-20

    Biomagnetic monitoring of atmospheric pollution is a growing application in the field of environmental magnetism. Particulate matter (PM) in atmospheric pollution contains readily measurable concentrations of magnetic minerals. Biological surfaces, exposed to atmospheric pollution, accumulate magnetic particles over time, providing a record of location-specific, time-integrated air quality information. This review summarizes current knowledge of biological material ("sensors") used for biomagnetic monitoring purposes. Our work addresses the following: the range of magnetic properties reported for lichens, mosses, leaves, bark, trunk wood, insects, crustaceans, mammal and human tissues; their associations with atmospheric pollutant species (PM, NO x , trace elements, PAHs); the pros and cons of biomagnetic monitoring of atmospheric pollution; current challenges for large-scale implementation of biomagnetic monitoring; and future perspectives. A summary table is presented, with the aim of aiding researchers and policy makers in selecting the most suitable biological sensor for their intended biomagnetic monitoring purpose.

  14. Biomagnetic Pair Therapy and Typhoid Fever: A Pilot Study.

    Science.gov (United States)

    Frank, Bryan L

    2017-10-01

    Objective: This pilot study examined the laboratory responses of patients with laboratory-documented typhoid fever who were treated with Biomagnetic Pair Therapy (BPT; medical biomagnetism), a specific application of pairs of magnets for various ailments that are infectious and otherwise. Materials and Methods: This study was an assessment of patients' response to treatment with only BPT for Salmonella typhi infections (typhoid fever) using standard conventional laboratory techniques. The research was conducted in an outpatient village clinic in Kenya. There were 52 participants who were evaluated for possible systemic illness, including typhoid fever, from an open-label study. Participants who felt sick and requested testing for possible typhoid fever were tested with a standard Widal test by a certified laboratory technician. Participants who tested positive (13 patients) were then treated with BPT (a "First Aid" approach) only. These participants then returned for follow-up laboratory and clinical evaluations after 2 days. Results: Most of the participants (10 of 13) retested as negative, and all patients reported symptomatic clinical improvement. Conclusions: As a significant majority of participants demonstrated clearing of their S. typhi after BPT, this technique should be studied further in larger trials for its efficacy in treating typhoid fever.

  15. Pharyngeal transit time measured by scintigraphic and biomagnetic method; Tempo de transito faringeano medido atraves dos metodos cintilografico e biomagnetico

    Energy Technology Data Exchange (ETDEWEB)

    Miquelin, C.A.; Braga, F.J.H.N.; Baffa, O. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica; Dantas, R.O.; Oliveira, R.B. [Faculdade de Medicina de Ribeirao Preto, SP (Brazil)

    1996-12-31

    A comparative evaluation between scintigraphic and biomagnetic method to measure the pharyngeal transit is presented. Three volunteers have been studied. The aliment (yogurt) was labeled with {sup 9}9{sup m} Technetium for the scintigraphic test and with ferrite for the biomagnetic one. The preliminary results indicate a difference between the values obtained, probably due to the biomagnetic detector resolution 3 refs., 2 figs., 1 tab.

  16. Multichannel DC SQUID sensor array for biomagnetic applications

    International Nuclear Information System (INIS)

    Hoenig, H.E.; Daalmans, G.M.; Bar, L.; Bommel, F.; Paulus, A.; Uhl, D.; Weisse, H.J.; Schneider, S.; Seifert, H.; Reichenberger, H.; Abraham-Fuchs, K.

    1991-01-01

    This paper reports on a biomagnetic multichannel system for medical diagnosis of brain and heart KRENIKON has been developed. 37 axial 2st order gradiometers - manufactured as flexible superconducting printed circuits - are arranged in a circular flat array of 19 cm diameter. Additionally, 3 orthogonal magnetometers are provided. The DC SQUIDs are fabricated in all-Nb technology, ten on a chip. The sensor system is operated in a shielded room with two layers of soft magnetic material and one layer of Al. The every day noise level is 10 fT/Hz 1/2 at frequencies above 10 Hz. Within 2 years of operation in a normal urban surrounding, useful clinical applications have been demonstrated (e.g. for epilepsy and heart arrhythmias)

  17. Biomagnetic techniques for evaluating gastric emptying, peristaltic contraction and transit time.

    Science.gov (United States)

    la Roca-Chiapas, Jose María De; Cordova-Fraga, Teodoro

    2011-10-15

    Biomagnetic techniques were used to measure motility in various parts of the gastrointestinal (GI) tract, particularly a new technique for detecting magnetic markers and tracers. A coil was used to enhance the signal from a magnetic tracer in the GI tract and the signal was detected using a fluxgate magnetometer or a magnetoresistor in an unshielded room. Estimates of esophageal transit time were affected by the position of the subject. The reproducibility of estimates derived using the new biomagnetic technique was greater than 85% and it yielded estimates similar to those obtained using scintigraphy. This technique is suitable for studying the effect of emotional state on GI physiology and for measuring GI transit time. The biomagnetic technique can be used to evaluate digesta transit time in the esophagus, stomach and colon, peristaltic frequency and gastric emptying and is easy to use in the hospital setting.

  18. Development of improved superconductive axial gradiometers for biomagnetic SQUID applications

    Science.gov (United States)

    Budnyk, M. M.; Minov, Yu. D.; Lyakhno, V. Yu.; Desnenko, V. A.; Linnik, A. S.; Shopen, O. B.

    2018-03-01

    SQUID magnetometers for biomagnetic measurements are equipped with superconductive gradiometers which are required to provide a high signal-to-noise ratio at low frequencies, sufficient mechanical strength and sustained performance under repeated thermal cycles, as well as a low level of intrinsic magnetic noise. This paper describes the design of a gradiometer made with a carbon-fiber reinforced composite material for magnetic cardiography measurements. The thermal coefficient of linear expansion (TCLE) of the carbon fiber composite can be precisely adjusted to match that of the superconducting detector coil wire. This is achieved thanks to the difference in the TCLE of carbon fibers in the longitudinal and transverse directions and is realized by varying the laying directions of the fiber in the composite. The data of magnetic susceptibility measurements on carbon fiber composite are reported, showing the magnetic susceptibility about six times smaller than that of graphite. The presented gradiometer design provides a high degree of balancing and is patented along side other specific techniques.

  19. SQUIDs in biomagnetism: a roadmap towards improved healthcare

    Science.gov (United States)

    Körber, Rainer; Storm, Jan-Hendrik; Seton, Hugh; Mäkelä, Jyrki P.; Paetau, Ritva; Parkkonen, Lauri; Pfeiffer, Christoph; Riaz, Bushra; Schneiderman, Justin F.; Dong, Hui; Hwang, Seong-min; You, Lixing; Inglis, Ben; Clarke, John; Espy, Michelle A.; Ilmoniemi, Risto J.; Magnelind, Per E.; Matlashov, Andrei N.; Nieminen, Jaakko O.; Volegov, Petr L.; Zevenhoven, Koos C. J.; Höfner, Nora; Burghoff, Martin; Enpuku, Keiji; Yang, S. Y.; Chieh, Jen-Jei; Knuutila, Jukka; Laine, Petteri; Nenonen, Jukka

    2016-11-01

    Globally, the demand for improved health care delivery while managing escalating costs is a major challenge. Measuring the biomagnetic fields that emanate from the human brain already impacts the treatment of epilepsy, brain tumours and other brain disorders. This roadmap explores how superconducting technologies are poised to impact health care. Biomagnetism is the study of magnetic fields of biological origin. Biomagnetic fields are typically very weak, often in the femtotesla range, making their measurement challenging. The earliest in vivo human measurements were made with room-temperature coils. In 1963, Baule and McFee (1963 Am. Heart J. 55 95-6) reported the magnetic field produced by electric currents in the heart (‘magnetocardiography’), and in 1968, Cohen (1968 Science 161 784-6) described the magnetic field generated by alpha-rhythm currents in the brain (‘magnetoencephalography’). Subsequently, in 1970, Cohen et al (1970 Appl. Phys. Lett. 16 278-80) reported the recording of a magnetocardiogram using a Superconducting QUantum Interference Device (SQUID). Just two years later, in 1972, Cohen (1972 Science 175 664-6) described the use of a SQUID in magnetoencephalography. These last two papers set the scene for applications of SQUIDs in biomagnetism, the subject of this roadmap. The SQUID is a combination of two fundamental properties of superconductors. The first is flux quantization—the fact that the magnetic flux Φ in a closed superconducting loop is quantized in units of the magnetic flux quantum, Φ0 ≡ h/2e, ≈ 2.07 × 10-15 Tm2 (Deaver and Fairbank 1961 Phys. Rev. Lett. 7 43-6, Doll R and Näbauer M 1961 Phys. Rev. Lett. 7 51-2). Here, h is the Planck constant and e the elementary charge. The second property is the Josephson effect, predicted in 1962 by Josephson (1962 Phys. Lett. 1 251-3) and observed by Anderson and Rowell (1963 Phys. Rev. Lett. 10 230-2) in 1963. The Josephson junction consists of two weakly coupled superconductors

  20. Spatial distribution assessment of particulate matter in an urban street canyon using biomagnetic leaf monitoring of tree crown deposited particles

    International Nuclear Information System (INIS)

    Hofman, Jelle; Stokkaer, Ines; Snauwaert, Lies; Samson, Roeland

    2013-01-01

    Recently, biomagnetic monitoring of tree leaves has proven to be a good estimator for ambient particulate concentration. This paper investigates the usefulness of biomagnetic leaf monitoring of crown deposited particles to assess the spatial PM distribution inside individual tree crowns and an urban street canyon in Ghent (Belgium). Results demonstrate that biomagnetic monitoring can be used to assess spatial PM variations, even within single tree crowns. SIRM values decrease exponentially with height and azimuthal effects are obtained for wind exposed sides of the street canyon. Edge and canyon trees seem to be exposed differently. As far as we know, this study is the first to present biomagnetic monitoring results of different trees within a single street canyon. The results not only give valuable insights into the spatial distribution of particulate matter inside tree crowns and a street canyon, but also offer a great potential as validation tool for air quality modelling. Highlights: ► Spatial distribution of tree crown deposited PM was evaluated. ► SIRM values decrease exponentially with height. ► Azimuthal effects were observed at wind exposed sides of the street canyon. ► Edge and canyon trees seem to be exposed differently. ► Biomagnetic monitoring offers a great potential as validation of air quality models. -- Biomagnetic leaf monitoring provides useful insights into the spatial distribution of particulates inside individual tree crowns and an urban street canyon in Ghent (Belgium)

  1. Innovative biomagnetic imaging sensors for breast cancer: A model-based study

    International Nuclear Information System (INIS)

    Deng, Y.; Golkowski, M.

    2012-01-01

    Breast cancer is a serious potential health problem for all women and is the second leading cause of cancer deaths in the United States. The current screening procedures and imaging techniques, including x-ray mammography, clinical biopsy, ultrasound imaging, and magnetic resonance imaging, provide only 73% accuracy in detecting breast cancer. This gives the impetus to explore alternate techniques for imaging the breast and detecting early stage tumors. Among the complementary methods, the noninvasive biomagnetic breast imaging is attractive and promising, because both ionizing radiation and breast compressions that the prevalent x-ray mammography suffers from are avoided. It furthermore offers very high contrast because of the significant electromagnetic properties' differences between the cancerous, benign, and normal breast tissues. In this paper, a hybrid and accurate modeling tool for biomagnetic breast imaging is developed, which couples the electromagnetic and ultrasonic energies, and initial validations between the model predication and experimental findings are conducted.

  2. Biomagnetic monitoring as a validation tool for local air quality models: a case study for an urban street canyon.

    Science.gov (United States)

    Hofman, Jelle; Samson, Roeland

    2014-09-01

    Biomagnetic monitoring of tree leaf deposited particles has proven to be a good indicator of the ambient particulate concentration. The objective of this study is to apply this method to validate a local-scale air quality model (ENVI-met), using 96 tree crown sampling locations in a typical urban street canyon. To the best of our knowledge, the application of biomagnetic monitoring for the validation of pollutant dispersion modeling is hereby presented for the first time. Quantitative ENVI-met validation showed significant correlations between modeled and measured results throughout the entire in-leaf period. ENVI-met performed much better at the first half of the street canyon close to the ring road (r=0.58-0.79, RMSE=44-49%), compared to second part (r=0.58-0.64, RMSE=74-102%). The spatial model behavior was evaluated by testing effects of height, azimuthal position, tree position and distance from the main pollution source on the obtained model results and magnetic measurements. Our results demonstrate that biomagnetic monitoring seems to be a valuable method to evaluate the performance of air quality models. Due to the high spatial and temporal resolution of this technique, biomagnetic monitoring can be applied anywhere in the city (where urban green is present) to evaluate model performance at different spatial scales. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Advances in biomagnetic research using high- T{sub c} superconducting quantum interference devices

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hong-Chang [Department of Physics/Institute of Applied Physics, National Taiwan University, Taipei 106, Taiwan (China); Horng, Herng-Er; Yang, S Y [Institute of Electro-Optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan (China); Liao, Shu-Hsien, E-mail: hcyang@phys.ntu.edu.t [Department of Physics, National Taiwan Normal University, Taipei 116, Taiwan (China)

    2009-09-15

    This review reports the advances of biomagnetic research using high- T{sub c} superconducting quantum interference devices (SQUIDs). It especially focuses on SQUID-detected magnetocardiography (MCG), magnetically labeled immunoassays (MLIs) as well as nuclear magnetic resonance and imaging (NMR/MRI). The progress in MCG that scientists have made and the encountered challenges are discussed here. This study includes the early detection of the electromagnetic change in cardiac activity in animal studies of hypercholesterolemic rabbits, which suggests the possibility of early diagnosis of cardiac disease in clinical applications. The progress on MLIs using measurements of remanence, magnetic relaxation and magnetic susceptibility reduction is presented. The wash-free immunomagnetic reduction shows both high sensitivity and high specificity. NMR/MRI of high spectral resolution and of high signal-to-noise ratio are addressed and discussed. The proton-phosphate J-coupling of trimethyl phosphate ((CH{sub 3}){sub 3}PO{sub 4}) in one shot in microtesla fields is demonstrated. The prospects of biomagnetic applications are addressed. (topical review)

  4. Biomagnetic Measurement System on Mice-Evaluation of System Performance by MCG and Application to MEG

    International Nuclear Information System (INIS)

    Nakamura, T; Shirai, K; Ono, Y; Kasai, N; Odawara, A; Ishiyama, A

    2006-01-01

    We developed a biomagnetic measurement system on mice. Our initial model of the system has the magnetic field sensitivity of 1.3 pT/Hz 1/2 in the white-noise region (10 Hz-10 kHz). And using the system, we succeeded to obtain magnetically the heart activity on mice. However, in its application to measure the brain activity on mice, it was necessary to improve the magnetic field sensitivity of the system. Therefore, we changed the material of the window cap, which holds a sapphire glass window on the dewar tail, to ceramic. The system noise was decreased and the magnetic field sensitivity of the system was improved to 0.75 pT/Hz 1/2 in the white-noise region. For an initial measurement of the brain activity, we also developed a whisker stimulation system using a piezoelectric element to evoke somatosensory responses

  5. Interpretation of the MEG-MUSIC scan in biomagnetic source localization

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, J.C.; Lewis, P.S. [Los Alamos National Lab., NM (United States); Leahy, R.M. [University of Southern California, Los Angeles, CA (United States). Signal and Image Processing Inst.

    1993-09-01

    MEG-Music is a new approach to MEG source localization. MEG-Music is based on a spatio-temporal source model in which the observed biomagnetic fields are generated by a small number of current dipole sources with fixed positions/orientations and varying strengths. From the spatial covariance matrix of the observed fields, a signal subspace can be identified. The rank of this subspace is equal to the number of elemental sources present. This signal sub-space is used in a projection metric that scans the three dimensional head volume. Given a perfect signal subspace estimate and a perfect forward model, the metric will peak at unity at each dipole location. In practice, the signal subspace estimate is contaminated by noise, which in turn yields MUSIC peaks which are less than unity. Previously we examined the lower bounds on localization error, independent of the choice of localization procedure. In this paper, we analyzed the effects of noise and temporal coherence on the signal subspace estimate and the resulting effects on the MEG-MUSIC peaks.

  6. A proposal to study the esophageal transit by biomagnetic and scintigraphic study

    International Nuclear Information System (INIS)

    Daghastanli, N.A.; Braga, F.J.H.N.; Baffa, O.

    1996-01-01

    The initial results for a new apparatus to study the esophageal transit time is studied in asymptomatic persons for a yogurt bolus (10 ml). The bolus is uniformly labeled with 5 g of ferrite powder (biomagnetic study, B) or 350 MBq of 99m Tc (scintigraphic study, C). For the B study the detection is made by means two pair of coils in opposite phase excited by a 10 k Hz sinusoidal voltage. The signal response is obtained when the bolus traverses the coils placed on the regions-of-interest (ROIs) of the esophagus (furcula, F and xiphoid process, X) and produces a signal voltage that is measured by a lock-in amplifier Stanford SR530. For C studies an Orbiter Siemens scintillation camera is used linked to a computer. The data analysis shows a (4.1±0.7)s in B studies and (3.7±0.9)s in C studies (R=0.6, P<0.07)

  7. Subspace-based interference removal methods for a multichannel biomagnetic sensor array

    Science.gov (United States)

    Sekihara, Kensuke; Nagarajan, Srikantan S.

    2017-10-01

    Objective. In biomagnetic signal processing, the theory of the signal subspace has been applied to removing interfering magnetic fields, and a representative algorithm is the signal space projection algorithm, in which the signal/interference subspace is defined in the spatial domain as the span of signal/interference-source lead field vectors. This paper extends the notion of this conventional (spatial domain) signal subspace by introducing a new definition of signal subspace in the time domain. Approach. It defines the time-domain signal subspace as the span of row vectors that contain the source time course values. This definition leads to symmetric relationships between the time-domain and the conventional (spatial-domain) signal subspaces. As a review, this article shows that the notion of the time-domain signal subspace provides useful insights over existing interference removal methods from a unified perspective. Main results and significance. Using the time-domain signal subspace, it is possible to interpret a number of interference removal methods as the time domain signal space projection. Such methods include adaptive noise canceling, sensor noise suppression, the common temporal subspace projection, the spatio-temporal signal space separation, and the recently-proposed dual signal subspace projection. Our analysis using the notion of the time domain signal space projection reveals implicit assumptions these methods rely on, and shows that the difference between these methods results only from the manner of deriving the interference subspace. Numerical examples that illustrate the results of our arguments are provided.

  8. International Conference on Superconducting Interference Devices (2nd) and Workshop on Biomagnetism (3rd) Held 6-9 May 1980, West Berlin.

    Science.gov (United States)

    1980-11-06

    cryogenics. L. Holborn and W. Wien performed thermometric measurements there at the turn of the century, and in 1913, W. Nernst installed a hydrogen...Heinonen, M. Tuomola and J. Lekkala W 22 "AN ALUMINIUM SHIELDED ROOM FOR BIOMAGNETIC MEASUREMENTS" G. Stroink, B. Brown, B. Blackford and M. Horacek

  9. Modeling and analysis of biomagnetic blood Carreau fluid flow through a stenosis artery with magnetic heat transfer: A transient study.

    Science.gov (United States)

    Abdollahzadeh Jamalabadi, Mohammad Yaghoub; Daqiqshirazi, Mohammadreza; Nasiri, Hossein; Safaei, Mohammad Reza; Nguyen, Truong Khang

    2018-01-01

    We present a numerical investigation of tapered arteries that addresses the transient simulation of non-Newtonian bio-magnetic fluid dynamics (BFD) of blood through a stenosis artery in the presence of a transverse magnetic field. The current model is consistent with ferro-hydrodynamic (FHD) and magneto-hydrodynamic (MHD) principles. In the present work, blood in small arteries is analyzed using the Carreau-Yasuda model. The arterial wall is assumed to be fixed with cosine geometry for the stenosis. A parametric study was conducted to reveal the effects of the stenosis intensity and the Hartman number on a wide range of flow parameters, such as the flow velocity, temperature, and wall shear stress. Current findings are in a good agreement with recent findings in previous research studies. The results show that wall temperature control can keep the blood in its ideal blood temperature range (below 40°C) and that a severe pressure drop occurs for blockages of more than 60 percent. Additionally, with an increase in the Ha number, a velocity drop in the blood vessel is experienced.

  10. Biomagnetic monitoring of particulate matter (PM through leaves of an invasive alien plant Lantana camara in an Indo-Burma hot spot region

    Directory of Open Access Journals (Sweden)

    Prabhat Kumar Rai

    2016-03-01

    Full Text Available Present study was performed in urban forests of Aizawl, Mizoram, North East India falling under an Indo-Burma hot spot region of existing ecological relevance and pristine environment. Phyto-sociolology of invasive weeds has been performed and results revealed that Lantana camara was the most dominant invasive weed. Further, the air quality studies revealed high suspended particulate matter (SPM as well as respirable suspended particulate matter (RSPM in ambient air of Aizawl, Mizoram, North East India. Bio-magnetic monitoring through plant leaves has been recognised as recent thrust area in the field of particulate matter (PM science. We aimed to investigate that whether magnetic properties of Lantana camara leaves may act as proxy of PM pollution and hence an attempt towards it's sustainable management. Magnetic susceptibility (χ, Anhyste reticremanent magnetization (ARM and Saturation isothermal remanent magnetization (SIRM of Lantana camara plant leaves were assessed and concomitantly correlated these magnetic properties with ambient PM in order to screen this invasive plant which may act as proxy for ambient PM concentrations. Results revealed high χ, ARM, SIRM of Lantana camara leaves and moreover, these parameters were having significant and positive correlation with ambient SPM as well as RSPM. Therefore, present study recommended the use of Lantana camara as bio-magnetic monitor which may further have sustainable management implications of an invasive plant.

  11. A proposal to study the esophageal transit by biomagnetic and scintigraphic study; Uma nova proposta para o estudo do transito esofagiano atraves das tecnicas biomagneticas e cintilograficas

    Energy Technology Data Exchange (ETDEWEB)

    Daghastanli, N.A.; Braga, F.J.H.N.; Baffa, O. [Sao Paulo Univ., Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Fisica; Oliveira, R.B. [Faculdade de Medicina de Ribeirao Preto, SP (Brazil)

    1996-12-31

    The initial results for a new apparatus to study the esophageal transit time is studied in asymptomatic persons for a yogurt bolus (10 ml). The bolus is uniformly labeled with 5 g of ferrite powder (biomagnetic study, B) or 350 MBq of {sup 99m} Tc (scintigraphic study, C). For the B study the detection is made by means two pair of coils in opposite phase excited by a 10 k Hz sinusoidal voltage. The signal response is obtained when the bolus traverses the coils placed on the regions-of-interest (ROIs) of the esophagus (furcula, F and xiphoid process, X) and produces a signal voltage that is measured by a lock-in amplifier Stanford SR530. For C studies an Orbiter Siemens scintillation camera is used linked to a computer. The data analysis shows a (4.1{+-}0.7)s in B studies and (3.7{+-}0.9)s in C studies (R=0.6, P<0.07) 8 refs., 3 figs.

  12. The high temperature superconductor YBa2Cu3O7-δ: symmetry of the order parameter, and gradiometers for biomagnetic applications

    International Nuclear Information System (INIS)

    Kouznetsov, Konstantin A.

    1999-01-01

    for operation in biomagnetic systems in an unshielded environment. They demonstrate a practical multichannel SQUID system for MagnetoCardioGraphy. Using this system, they are able to detect magnetic signals from the human heart in an unshielded environment, thereby demonstrating the applicability of their technology to practical applications. Their gradiometers are readily manufacturable devices that could be used in clinical applications in the near future

  13. The high temperature superconductor YBa2Cu3O7-δ: symmetry of the order parameter, and gradiometers for biomagnetic applications

    Energy Technology Data Exchange (ETDEWEB)

    Kouznetsov, Konstantin Alexander [Univ. of California, Berkeley, CA (US). Dept. of Physics; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    1999-12-01

    pickup up loop of a directly coupled magnetometer. The long baseline of the gradiometer, 48 mm, and the intrinsic. Balance of better than 1 part in 100 make it an ideal candidate for operation in biomagnetic systems in an unshielded environment. They demonstrate a practical multichannel SQUID system for MagnetoCardioGraphy. Using this system, they are able to detect magnetic signals from the human heart in an unshielded environment, thereby demonstrating the applicability of their technology to practical applications. Their gradiometers are readily manufacturable devices that could be used in clinical applications in the near future.

  14. A novel biomagnetic nanoparticle based on hydroxyapatite

    International Nuclear Information System (INIS)

    Wu, H-C; Wang, T-W; Sun, J-S; Wang, W-H; Lin, F-H

    2007-01-01

    In the present study, magnetic HAP was synthesized at different ratios of Fe:Ca (X Fe/Ca ) by the co-precipitation method. We have evaluated the present essential properties including the crystal structure and cell parameters by XRD, lattice arrangement by HR-TEM, composition analysis by ICP-MS, and functional groups by FTIR. The morphology and magnetization were investigated by SEM and AFM and SQUID, respectively. The in vitro biocompatibility was also investigated with a lactate dehydrogenase assay. The results showed that the crystal and molecular structure of the synthesized magnetic-HAP nanoparticle remained unaltered without collapse with the addition of iron ions. The lattice constants of m-HAP were similar to reference JCPDS card no. 9-432. The magnetization of m-HAP nanoparticles increased with increasing X Fe/Ca and possessed the superparamagnetic property with size distribution around 20 nm. The hydroxyapatite-based magnetic nanoparticles were also examined with good biocompatibility. With the appropriate physico-chemical and biological properties, the magnetic-HAP nanoparticles would have great potential to be applied in biomedical applications

  15. Design and operation of a biomagnetic multichannel system

    International Nuclear Information System (INIS)

    Schneider, S.; Seifert, H.; Reichenberger, H.; Hoenig, H.E.

    1992-01-01

    This paper describes the design and optimization of the KRENIKON system for the measurement of magnetic fields of the brain and the heart. Aspects for the configuration of the sensor array are discussed. Special emphasis is given to the suppression of interferences by a combination of magnetic shielding with first-order gradiometers and to the construction of the gradiometer array in foil technology. (orig.)

  16. Biomagnetic effects: a consideration in fusion reactor development

    International Nuclear Information System (INIS)

    Mahlum, D.D.

    1976-02-01

    Fusion as a power source is receiving an increasing amount of attention. Several designs have been proposed and the feasibility of each alternative is being studied. As we move closer to a working design, attention can be paid to potential biological hazards. Large magnetic fields and the emission of tritium and lithium are unique to some fusion reactor designs. The results of a review of the current state of knowledge concerning the biological effects of magnetic fields alone and in combination with ionizing radiation are summarized in this report. The purpose of the review is to help identify areas where additional biomedical research is needed for establishing guidelines for reactor design and operation. 64 references

  17. Effect of biomagnetic therapy versus physiotherapy for treatment of knee osteoarthritis: a randomized controlled trial.

    Science.gov (United States)

    Gremion, Gerald; Gaillard, David; Leyvraz, Pierre-Francois; Jolles, Brigitte M

    2009-11-01

    To assess the effectiveness of pulsed signal therapy in the treatment of knee osteoarthritis (Kellgren II or III). A randomized, double-blind controlled clinical trial. The first 95 patients sent to the clinic with knee osteo-arthritis were selected and randomized into treatment with pulsed signal therapy or conventional physiotherapy. Assessment included recording of usual demographic data, pertinent history, baseline medication and radiographs. Clinical evaluation was made at baseline, 6 weeks and 6 months after the end of treatment by the same blinded doctor. At each follow-up time, the patient was asked to complete a visual analogue pain scale and a Lequesne score. The doctor recorded the degree of pain on motion and the ability to move the affected knee. Both treatments resulted in significant improvements in pain and physical function. A statistical difference was observed only for activities of daily living, where the physiotherapy was more efficient (pphysiotherapy. Like physiotherapy, pulsed signal therapy has improved the clinical state of treated patients but with no significant statistical difference. Pulsed signal therapy is, however, more expensive.

  18. Development of a bio-magnetic measurement system and sensor configuration analysis for rats

    Science.gov (United States)

    Kim, Ji-Eun; Kim, In-Seon; Kim, Kiwoong; Lim, Sanghyun; Kwon, Hyukchan; Kang, Chan Seok; Ahn, San; Yu, Kwon Kyu; Lee, Yong-Ho

    2017-04-01

    Magnetoencephalography (MEG) based on superconducting quantum interference devices enables the measurement of very weak magnetic fields (10-1000 fT) generated from the human or animal brain. In this article, we introduce a small MEG system that we developed specifically for use with rats. Our system has the following characteristics: (1) variable distance between the pick-up coil and outer Dewar bottom (˜5 mm), (2) small pick-up coil (4 mm) for high spatial resolution, (3) good field sensitivity (45 ˜ 80 fT /cm/√{Hz} ) , (4) the sensor interval satisfies the Nyquist spatial sampling theorem, and (5) small source localization error for the region to be investigated. To reduce source localization error, it is necessary to establish an optimal sensor layout. To this end, we simulated confidence volumes at each point on a grid on the surface of a virtual rat head. In this simulation, we used locally fitted spheres as model rat heads. This enabled us to consider more realistic volume currents. We constrained the model such that the dipoles could have only four possible orientations: the x- and y-axes from the original coordinates, and two tangentially layered dipoles (local x- and y-axes) in the locally fitted spheres. We considered the confidence volumes according to the sensor layout and dipole orientation and positions. We then conducted a preliminary test with a 4-channel MEG system prior to manufacturing the multi-channel system. Using the 4-channel MEG system, we measured rat magnetocardiograms. We obtained well defined P-, QRS-, and T-waves in rats with a maximum value of 15 pT/cm. Finally, we measured auditory evoked fields and steady state auditory evoked fields with maximum values 400 fT/cm and 250 fT/cm, respectively.

  19. Insolation driven biomagnetic response to Holocene Warm Period in semi-arid East Asia

    OpenAIRE

    Liu, S.; Deng, Chenglong; Xiao, Jule; Li, Jinhua; Paterson, Greig; Chang, Liao; Yi, Liang; Qin, Huafeng; Pan, Yongxin; Zhu, Rixiang

    2015-01-01

    The Holocene Warm Period (HWP) provides valuable insights into the climate system and biotic responses to environmental variability and thus serves as an excellent analogue for future global climate changes. Here we document, for the first time, that warm and wet HWP conditions were highly favourable for magnetofossil proliferation in the semi-arid Asian interior. The pronounced increase of magnetofossil concentrations at ~9.8 ka and decrease at ~5.9 ka in Dali Lake coincided respectively wit...

  20. Insolation driven biomagnetic response to the Holocene Warm Period in semi-arid East Asia

    Science.gov (United States)

    Liu, Suzhen; Deng, Chenglong; Xiao, Jule; Li, Jinhua; Paterson, Greig A.; Chang, Liao; Yi, Liang; Qin, Huafeng; Pan, Yongxin; Zhu, Rixiang

    2015-01-01

    The Holocene Warm Period (HWP) provides valuable insights into the climate system and biotic responses to environmental variability and thus serves as an excellent analogue for future global climate changes. Here we document, for the first time, that warm and wet HWP conditions were highly favourable for magnetofossil proliferation in the semi-arid Asian interior. The pronounced increase of magnetofossil concentrations at ~9.8 ka and decrease at ~5.9 ka in Dali Lake coincided respectively with the onset and termination of the HWP, and are respectively linked to increased nutrient supply due to postglacial warming and poor nutrition due to drying at ~6 ka in the Asian interior. The two-stage transition at ~7.7 ka correlates well with increased organic carbon in middle HWP and suggests that improved climate conditions, leading to high quality nutrient influx, fostered magnetofossil proliferation. Our findings represent an excellent lake record in which magnetofossil abundance is, through nutrient availability, controlled by insolation driven climate changes.

  1. Insolation driven biomagnetic response to the Holocene Warm Period in semi-arid East Asia

    OpenAIRE

    Liu, Suzhen; Deng, Chenglong; Xiao, Jule; Li, Jinhua; Paterson, Greig A.; Chang, Liao; Yi, Liang; Qin, Huafeng; Pan, Yongxin; Zhu, Rixiang

    2015-01-01

    The Holocene Warm Period (HWP) provides valuable insights into the climate system and biotic responses to environmental variability and thus serves as an excellent analogue for future global climate changes. Here we document, for the first time, that warm and wet HWP conditions were highly favourable for magnetofossil proliferation in the semi-arid Asian interior. The pronounced increase of magnetofossil concentrations at ~9.8?ka and decrease at ~5.9?ka in Dali Lake coincided respectively wit...

  2. Insolation driven biomagnetic response to Holocene Warm Period in semi-arid East Asia

    NARCIS (Netherlands)

    Liu, S.; Deng, Chenglong; Xiao, Jule; Li, Jinhua; Paterson, Greig; Chang, Liao; Yi, Liang; Qin, Huafeng; Pan, Yongxin; Zhu, Rixiang

    2015-01-01

    The Holocene Warm Period (HWP) provides valuable insights into the climate system and biotic responses to environmental variability and thus serves as an excellent analogue for future global climate changes. Here we document, for the first time, that warm and wet HWP conditions were highly

  3. Algorithms for biomagnetic source imaging with prior anatomical and physiological information

    Energy Technology Data Exchange (ETDEWEB)

    Hughett, Paul William [Univ. of California, Berkeley, CA (United States). Dept. of Electrical Engineering and Computer Sciences

    1995-12-01

    This dissertation derives a new method for estimating current source amplitudes in the brain and heart from external magnetic field measurements and prior knowledge about the probable source positions and amplitudes. The minimum mean square error estimator for the linear inverse problem with statistical prior information was derived and is called the optimal constrained linear inverse method (OCLIM). OCLIM includes as special cases the Shim-Cho weighted pseudoinverse and Wiener estimators but allows more general priors and thus reduces the reconstruction error. Efficient algorithms were developed to compute the OCLIM estimate for instantaneous or time series data. The method was tested in a simulated neuromagnetic imaging problem with five simultaneously active sources on a grid of 387 possible source locations; all five sources were resolved, even though the true sources were not exactly at the modeled source positions and the true source statistics differed from the assumed statistics.

  4. Advances in Biomagnetic Interfacing Concepts Derived from Polymer-Magnetic Particle Complexes

    National Research Council Canada - National Science Library

    Riffle, Judy S

    2005-01-01

    Our research on the development and characterization of magnetic nanoparticle-polymer complexes for tile project period 6/1/03-12/31/04 has yielded approximately 10-nm diameter cobalt particles coated...

  5. High-resolution room-temperature sample scanning superconducting quantum interference device microscope configurable for geological and biomagnetic applications

    Science.gov (United States)

    Fong, L. E.; Holzer, J. R.; McBride, K. K.; Lima, E. A.; Baudenbacher, F.; Radparvar, M.

    2005-05-01

    We have developed a scanning superconducting quantum interference device (SQUID) microscope system with interchangeable sensor configurations for imaging magnetic fields of room-temperature (RT) samples with submillimeter resolution. The low-critical-temperature (Tc) niobium-based monolithic SQUID sensors are mounted on the tip of a sapphire and thermally anchored to the helium reservoir. A 25μm sapphire window separates the vacuum space from the RT sample. A positioning mechanism allows us to adjust the sample-to-sensor spacing from the top of the Dewar. We achieved a sensor-to-sample spacing of 100μm, which could be maintained for periods of up to four weeks. Different SQUID sensor designs are necessary to achieve the best combination of spatial resolution and field sensitivity for a given source configuration. For imaging thin sections of geological samples, we used a custom-designed monolithic low-Tc niobium bare SQUID sensor, with an effective diameter of 80μm, and achieved a field sensitivity of 1.5pT/Hz1/2 and a magnetic moment sensitivity of 5.4×10-18Am2/Hz1/2 at a sensor-to-sample spacing of 100μm in the white noise region for frequencies above 100Hz. Imaging action currents in cardiac tissue requires a higher field sensitivity, which can only be achieved by compromising spatial resolution. We developed a monolithic low-Tc niobium multiloop SQUID sensor, with sensor sizes ranging from 250μm to 1mm, and achieved sensitivities of 480-180fT /Hz1/2 in the white noise region for frequencies above 100Hz, respectively. For all sensor configurations, the spatial resolution was comparable to the effective diameter and limited by the sensor-to-sample spacing. Spatial registration allowed us to compare high-resolution images of magnetic fields associated with action currents and optical recordings of transmembrane potentials to study the bidomain nature of cardiac tissue or to match petrography to magnetic field maps in thin sections of geological samples.

  6. Biomagnetic and bioelectric detection of gastric slow wave activity in normal human subjects—a correlation study

    International Nuclear Information System (INIS)

    Somarajan, S; Muszynski, N D; Obioha, C; Bradshaw, L A; Richards, W O

    2012-01-01

    We measured gastric slow wave activity simultaneously with a Superconducting Quantum Interference Device (SQUID) magnetometer, mucosal electrodes and cutaneous electrodes in 18 normal human subjects (11 women and 7 men). We processed signals with Fourier spectral analysis and SOBI blind-source separation techniques. We observed a high waveform correlation between the mucosal electromyogram (EMG) and multichannel SQUID magnetogastrogram (MGG). There was a lower waveform correlation between the mucosal EMG and cutaneous electrogastrogram (EGG), but the correlation improved with the application of SOBI. There was also a high correlation between the frequency of the electrical activity recorded in the MGG and in mucosal electrodes (r = 0.97). We concluded that SQUID magnetometers noninvasively record gastric slow wave activity that is highly correlated with the activity recorded by invasive mucosal electrodes. (paper)

  7. Ultra-sensitive sensors for weak electromagnetic fields using high-Tc SQUIDS for biomagnetism, NDE, and corrosion currents

    International Nuclear Information System (INIS)

    Kraus, R.H. Jr.; Flynn, E.R.; Espy, M.; Jia, Q.X.; Wu, X.D.; Reagor, D.

    1998-01-01

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The research has directly contributed to a new DOE supported project, three patents (one granted and two submitted), and several potential opportunities for new program funding at the Laboratory. The authors report significant developments extending from basic understanding of and fabrication techniques for high critical-temperature (high-T c ) SQUID devices to the development of high-level applications such as the SQUID Microscope. The development of ramp edge geometry and silver-doped YBa 2 Cu 3 O 7-x (YBCO) electrodes has tremendously improved the performance of high-T c SQUIDS. Recent experiments have proven and quantified the LANL-patented superconducting imaging plane gradiometry concept. A SQUID microscope, developed largely under this project, has recently acquired data that demonstrated exceptional sensitivity and resolution. New techniques for background noise suppression, needed to use the extraordinarily sensitive SQUID sensors in unshielded environments, have also been developed. Finally, initial investigations to use SQUIDs in a basic physics experiment to measure the electric dipole moment of the neutron were very successful

  8. Signal Space Separation Method for a Biomagnetic Sensor Array Arranged on a Flat Plane for Magnetocardiographic Applications: A Computer Simulation Study

    Science.gov (United States)

    2018-01-01

    Although the signal space separation (SSS) method can successfully suppress interference/artifacts overlapped onto magnetoencephalography (MEG) signals, the method is considered inapplicable to data from nonhelmet-type sensor arrays, such as the flat sensor arrays typically used in magnetocardiographic (MCG) applications. This paper shows that the SSS method is still effective for data measured from a (nonhelmet-type) array of sensors arranged on a flat plane. By using computer simulations, it is shown that the optimum location of the origin can be determined by assessing the dependence of signal and noise gains of the SSS extractor on the origin location. The optimum values of the parameters LC and LD, which, respectively, indicate the truncation values of the multipole-order ℓ of the internal and external subspaces, are also determined by evaluating dependences of the signal, noise, and interference gains (i.e., the shield factor) on these parameters. The shield factor exceeds 104 for interferences originating from fairly distant sources. However, the shield factor drops to approximately 100 when calibration errors of 0.1% exist and to 30 when calibration errors of 1% exist. The shielding capability can be significantly improved using vector sensors, which measure the x, y, and z components of the magnetic field. With 1% calibration errors, a vector sensor array still maintains a shield factor of approximately 500. It is found that the SSS application to data from flat sensor arrays causes a distortion in the signal magnetic field, but it is shown that the distortion can be corrected by using an SSS-modified sensor lead field in the voxel space analysis. PMID:29854364

  9. Signal Space Separation Method for a Biomagnetic Sensor Array Arranged on a Flat Plane for Magnetocardiographic Applications: A Computer Simulation Study

    Directory of Open Access Journals (Sweden)

    Kensuke Sekihara

    2018-01-01

    Full Text Available Although the signal space separation (SSS method can successfully suppress interference/artifacts overlapped onto magnetoencephalography (MEG signals, the method is considered inapplicable to data from nonhelmet-type sensor arrays, such as the flat sensor arrays typically used in magnetocardiographic (MCG applications. This paper shows that the SSS method is still effective for data measured from a (nonhelmet-type array of sensors arranged on a flat plane. By using computer simulations, it is shown that the optimum location of the origin can be determined by assessing the dependence of signal and noise gains of the SSS extractor on the origin location. The optimum values of the parameters LC and LD, which, respectively, indicate the truncation values of the multipole-order ℓ of the internal and external subspaces, are also determined by evaluating dependences of the signal, noise, and interference gains (i.e., the shield factor on these parameters. The shield factor exceeds 104 for interferences originating from fairly distant sources. However, the shield factor drops to approximately 100 when calibration errors of 0.1% exist and to 30 when calibration errors of 1% exist. The shielding capability can be significantly improved using vector sensors, which measure the x, y, and z components of the magnetic field. With 1% calibration errors, a vector sensor array still maintains a shield factor of approximately 500. It is found that the SSS application to data from flat sensor arrays causes a distortion in the signal magnetic field, but it is shown that the distortion can be corrected by using an SSS-modified sensor lead field in the voxel space analysis.

  10. Geomagnetism solid Earth and upper atmosphere perspectives

    CERN Document Server

    Basavaiah, Nathani

    2011-01-01

    This volume elaborates several important aspects of solid Earth geomagnetism. It covers all the basics of the subject, including biomagnetism and instrumentation, and offers a number of practical applications with carefully selected examples and illustrations.

  11. Mossbauer and magnetic study of solid phases formed by dissimilatory iron-reducing bacteria

    Czech Academy of Sciences Publication Activity Database

    Chistyakova, N.I.; Rusakov, V.S.; Shapkin, A.A.; Pigalev, P.A.; Kazakov, A.P.; Zhilina, T.N.; Zavarzina, D.G.; Lančok, Adriana; Kohout, J.; Greneche, J. M.

    2012-01-01

    Roč. 190, JUNE (2012), s. 721-724 ISSN 1012-0394 Institutional research plan: CEZ:AV0Z40320502 Keywords : Mossbauer spectroscopy * dissimilatory iron-reducing bacteria * iron oxides * biomagnetism Subject RIV: CA - Inorganic Chemistry

  12. Scanning high-Tc SQUID imaging system for magnetocardiography

    International Nuclear Information System (INIS)

    Yang, H-C; Wu, T-Y; Horng, H-E; Wu, C-C; Yang, S Y; Liao, S-H; Wu, C-H; Jeng, J T; Chen, J C; Chen, Kuen-Lin; Chen, M J

    2006-01-01

    A scanning magnetocardiography (MCG) system constructed from SQUID sensors offers potential to basic or clinical research in biomagnetism. In this work, we study a first order scanning electronic high-T c (HTS) SQUID MCG system for biomagnetic signals. The scanning MCG system was equipped with an x-y translation bed powered by step motors. Using noise cancellation and μ-metal shielding, we reduced the noise level substantially. The established scanning HTS MCG system was used to study the magnetophysiology of hypercholesterolaemic (HC) rabbits. The MCG data of HC rabbits were analysed. The MCG contour map of HC rabbits provides experimental models for the interpretation of human cardiac patterns

  13. Auditory Evoked Responses in Neonates by MEG

    International Nuclear Information System (INIS)

    Hernandez-Pavon, J. C.; Sosa, M.; Lutter, W. J.; Maier, M.; Wakai, R. T.

    2008-01-01

    Magnetoencephalography is a biomagnetic technique with outstanding potential for neurodevelopmental studies. In this work, we have used MEG to determinate if newborns can discriminate between different stimuli during the first few months of life. Five neonates were stimulated during several minutes with auditory stimulation. The results suggest that the newborns are able to discriminate between different stimuli despite their early age

  14. Pacific Northwest Laboratory annual report for 1977 to the DOE Assistant Secretary for Environment. Part 1. Biomedical sciences

    Energy Technology Data Exchange (ETDEWEB)

    Wiley, W.R.

    1978-02-01

    Separate abstracts were prepared for 68 sections of this report that discuss the health hazards associated with the nuclear fuel cycle, fossil fuel cycle, oil shale processing, and biomagnetic effects associated with fusion. A list is included of 52 publications during the time period covered by this report.

  15. Review: Bioenergetic Fields and Their Biologic Effects Mechanism

    Directory of Open Access Journals (Sweden)

    Zahra Movaffaghi

    2007-04-01

    Full Text Available As interests in complementary and alternative medicine grows, the scientists are looking forward in researches which determine the mechanisms in which they exert their effectiveness. Some of these modalities like Yoga, Acupuncture, and especially other bio-field therapies such as none contact therapeutic touch, affects the bio-field which spreads throughout the body and into the space around it. According to physic’s law, when electricity flows throw the living tissues, like what happens in our heart and brain, biomagnetic fields are being induced in the surrounding space. Beside that moving charges like ions and free radicals which finally produce electromagnetic fields. Using very sensitive magnetometers, biomagnetic fields have been detected and get amplified up to 1000 times by meditation. This phenomenon could be the basis for most of most complementaty therapeutic approaches like therapeutic touch. On the other hand the electrical, magnetic and bio-magnetic fields have a well known application in conventional medicine. Modern research about bio-magnetism and magneto-biology suggests that in term of both aspects, the effects and the mechanisms for all the different looking modalities used in conventional medicine and complementary medicine which have commons in their fundamentals. This article reviews some of the recent works on biological effects of natural or artificial electromagnetic fields.

  16. Dynamic shielding of the magnetic fields

    Directory of Open Access Journals (Sweden)

    RAU, M.

    2010-11-01

    Full Text Available The paper presents a comparative study of the methods used to control and compensate the direct and alternative magnetic fields. Two frequently used methods in the electromagnetic compatibility of the complex biomagnetism installations were analyzed. The two methods refer to the use of inductive magnetic field sensors (only for alternative fields and of fluxgate magnetometers as active transducers which measures both the direct and alternative components of the magnetic field. The applications of the dynamic control of the magnetic field are: control of the magnetic field of the military ships, control of parasite magnetic field produced by power transformers and the electrical networks, protection of the mass spectrometers, electronic microscopes, SQUID and optical pumping magnetometers for applications in biomagnetism.

  17. Design of a hysteretic SQUID as the readout for a dc SQUID

    International Nuclear Information System (INIS)

    Gershenson, M.

    1991-01-01

    This paper present a design for an optimal hysteretic SQUID readout circuit for a DC SQUID, thus eliminating the need for bulky output transformers or resonance matching circuits. The hysteretic readout system, which is based in part on standard sampling theory, is compared to another similar system and shown to be superior in terms of slew rate and immunity of electromagnetic interference. The circuit will be useful in optimizing the performance of biomagnetic systems

  18. Feasibility study of the application of biotechnology to nuclear waste treatment

    International Nuclear Information System (INIS)

    Ashley, N.V.; Pope, N.R.; Roach, D.J.W.

    1987-12-01

    A number of biotechnology areas applicable to the removal of radionuclides from industrial nuclear effluents were considered, namely: use of Biopolymers; Biosorption using biomass; microbial leaching and solubilisation of metal ions. The potential of biomagnetic separation technology, genetic engineering and monoclonal antibody technology was also examined. It appeared that the most appropriate technologies to develop for radionuclide removal in the short term were based on biosorptions of radionuclides by biomass and modified and unmodified biopolymers. (author)

  19. Biomedical Engineering at the Technical University of Denmark

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt; Andersen, Ole Trier; Wilhjelm, Jens Erik

    1998-01-01

    The paper gives a brief overview of the biomedical engineering research and education at the Technical University of Denmark. An account of the research activities since the 1950?s is given, and examples of major efforts within ultrasound, biomagnetism, and neuroimaging are described. The evolution...... of the teaching activities since the late 1960?s along with an account of the recent initiatives to make a biomedical engineering profile at the university is described....

  20. On the temporal variation of leaf magnetic parameters: seasonal accumulation of leaf-deposited and leaf-encapsulated particles of a roadside tree crown.

    Science.gov (United States)

    Hofman, Jelle; Wuyts, Karen; Van Wittenberghe, Shari; Samson, Roeland

    2014-09-15

    Understanding the accumulation behaviour of atmospheric particles inside tree leaves is of great importance for the interpretation of biomagnetic monitoring results. In this study, we evaluated the temporal variation of the saturation isothermal remanent magnetisation (SIRM) of leaves of a roadside urban Platanus × acerifolia Willd. tree in Antwerp, Belgium. We hereby examined the seasonal development of the total leaf SIRM signal as well as the leaf-encapsulated fraction of the deposited dust, by washing the leaves before biomagnetic analysis. On average 38% of the leaf SIRM signal was exhibited by the leaf-encapsulated particles. Significant correlations were found between the SIRM and the cumulative daily average atmospheric PM10 and PM2.5 measurements. Moreover, a steady increase of the SIRM throughout the in-leaf season was observed endorsing the applicability of biomagnetic monitoring as a proxy for the time-integrated PM exposure of urban tree leaves. Strongest correlations were obtained for the SIRM of the leaf-encapsulated particles which confirms the dynamic nature of the leaf surface-accumulated particles. Copyright © 2014 Elsevier B.V. All rights reserved.

  1. Magnetic therapy is ineffective for the treatment of snoring and obstructive sleep apnea syndrome.

    Science.gov (United States)

    Dexter, D

    1997-03-01

    Snoring and the obstructive sleep apnea syndrome are common and chronic ailments with potentially serious medical complications. There are several accepted treatments, but these can be uncomfortable, inconvenient, and expensive. A number of alternative treatments have been reported to be beneficial in the treatment of obstructive sleep apnea and snoring. They are advertised in magazines, on the radio and television, and on the Internet. The lay press is reporting about the effectiveness of these treatments without the benefit of clinical trials or scientific studies. Among the therapies currently being promoted for the treatment of snoring and sleep apnea is biomagnetic therapy. Unlike many of the other treatments which have not undergone scientific evaluation, biomagnetic therapy has been evaluated in the past. In fact, the evaluation of biomagnetic therapy is one of the first controlled scientific investigations found in the literature. This report showed that magnet therapy had no medicinal value. Despite this clear evidence, magnetic therapy continues to be utilized today and currently is being promoted for the treatment of snoring and sleep apnea. At out Sleep Disorder Center, we have had the opportunity to evaluate a patient with severe obstructive sleep apnea both before and after treatment with magnetic therapy, as well as with conventional therapy. Our study clearly indicates there was no benefit from magnetic therapy in this case. While alternative therapy may be helpful in the treatment of certain medical conditions, extreme care must be exercised to prevent inappropriate treatment or undertreat-ment of significant medical problems. Close clinical follow-up and controlled studies are important in determining the effectiveness of therapies.

  2. Imaging systems for medical diagnostics

    International Nuclear Information System (INIS)

    Krestel, E.

    1990-01-01

    This book provides physicians and clinical physicists with detailed information on today's imaging modalities and assists them in selecting the optimal system for each clinical application. Physicists, engineers and computer specialists engaged in research and development and sales departments will also find this book to be of considerable use. It may also be employed at universities, training centers and in technical seminars. The physiological and physical fundamentals are explained in part 1. The technical solutions contained in part 2 illustrate the numerous possibilities available in X-ray diagnostics, computed tomography, nuclear medical diagnostics, magnetic resonance imaging, sonography and biomagnetic diagnostics. (orig.)

  3. On alternative solutions of interchannel crosstalk problem in multichannel gradiometers

    International Nuclear Information System (INIS)

    Manka, J.; Zrubec, V.

    1990-01-01

    For biomagnetic measurement, the multichannel systems has become the most prospective solution which is, however, associated with the problem of mutual affection of individual signals caused by mutual inductances between the gradiometers. H.J.M. ter Brake et. al. solved this problem by installation of the negative feedback into the input circuit, so that input inductivity of the magnetometer arose to a great value and gradiometer currents were attenuated. Heat breaking of the superconducting state was used for the proof of damping of crosstalk between two gradiometers. This paper deals with specifying the crosstalk coefficients in systems with internal feedback in the working regime

  4. Pacific Northwest Laboratory annual report for 1983 to the DOE Office of Energy Research. Part 1. Biomedical sciences

    Energy Technology Data Exchange (ETDEWEB)

    Drucker, H.

    1983-02-01

    Biomedical and health effects research conducted at PNL in 1982 on the evaluation of risk to man from existing and/or developing energy-related technologies are described. Most of the studies described in this report relate to activities for three major energy technologies: nuclear fuel cycle; fossil fuel cycle (oil, gas, and coal process technologies, mining, and utilization; synfuel development), and fudion (biomagnetic effects). The report is organized under these technologies. In addition, research reports are included on the application of nuclear energy to biomedical problems. Individual projects are indexed separately.

  5. Francis Bitter National Magnet Laboratory annual report, July 1989 through June 1990

    International Nuclear Information System (INIS)

    1990-01-01

    Contents: Reports on laboratory research programs: Magneto-optics and semiconductor physics, Magnetism, Superconductivity, Solid state nuclear magnetic resonance, Condensed matter chemistry, Biomagnetism, Magnet technology, Molecular biophysics; Reports of visiting scientists: Reports of users of the High Magnetic Field Facility, Reports of users of the pulsed field facility, Reports of users of the squid magnetometer and Mossbauer facility, Reports of users of the high field NMR facility; Appendices: Publications and meeting speeches, Organization, Summary of high magnetic field facility use, User tables, Geographic distribution of high magnetic field facility users, Summary of educational activities

  6. Pacific Northwest Laboratory annual report for 1983 to the DOE Office of Energy Research. Part 1. Biomedical sciences

    International Nuclear Information System (INIS)

    Drucker, H.

    1983-02-01

    Biomedical and health effects research conducted at PNL in 1982 on the evaluation of risk to man from existing and/or developing energy-related technologies are described. Most of the studies described in this report relate to activities for three major energy technologies: nuclear fuel cycle; fossil fuel cycle (oil, gas, and coal process technologies, mining, and utilization; synfuel development), and fudion (biomagnetic effects). The report is organized under these technologies. In addition, research reports are included on the application of nuclear energy to biomedical problems. Individual projects are indexed separately

  7. Non-nutritive sucking recorded in utero via fetal magnetography

    International Nuclear Information System (INIS)

    Popescu, E A; Popescu, M; Gustafson, K M; Wang, J; Barlow, S M

    2008-01-01

    Several studies in term and pre-term infants have investigated the rhythmic pattern of non-nutritive sucking (NNS) indicating correlations between the quantitative measures derived from sucking pressure variation and/or electromyographic (EMG) recordings and a range of factors that include age, perinatal stress and sequelae. In the human fetus, NNS has been reported from 13 weeks of gestation and has been studied using real-time Doppler ultrasonography exclusively. The present study indicates that NNS in fetus can be reliably recorded and quantified using non-invasive biomagnetic measurements that have been recently introduced as an investigational tool for the assessment of fetal neurophysiologic development. We show that source separation techniques, such as independent component analysis, applied to the high-resolution multichannel recordings allow the segregation of an explicit waveform that represents the biomagnetic equivalent of the ororhythmic sucking pressure variation or EMG signal recorded in infants. This enables the morphological study of NNS patterning over different temporal scales, from the global quantitative measures to the within burst fine structure characterization, in correlation with the fetal cardiac rhythm

  8. Recent advancements in the SQUID magnetospinogram system

    Science.gov (United States)

    Adachi, Yoshiaki; Kawai, Jun; Haruta, Yasuhiro; Miyamoto, Masakazu; Kawabata, Shigenori; Sekihara, Kensuke; Uehara, Gen

    2017-06-01

    In this study, a new superconducting quantum interference device (SQUID) biomagnetic measurement system known as magnetospinogram (MSG) is developed. The MSG system is used for observation of a weak magnetic field distribution induced by the neural activity of the spinal cord over the body surface. The current source reconstruction for the observed magnetic field distribution provides noninvasive functional imaging of the spinal cord, which enables medical personnel to diagnose spinal cord diseases more accurately. The MSG system is equipped with a uniquely shaped cryostat and a sensor array of vector-type SQUID gradiometers that are designed to detect the magnetic field from deep sources across a narrow observation area over the body surface of supine subjects. The latest prototype of the MSG system is already applied in clinical studies to develop a diagnosis protocol for spinal cord diseases. Advancements in hardware and software for MSG signal processing and cryogenic components aid in effectively suppressing external magnetic field noise and reducing the cost of liquid helium that act as barriers with respect to the introduction of the MSG system to hospitals. The application of the MSG system is extended to various biomagnetic applications in addition to spinal cord functional imaging given the advantages of the MSG system for investigating deep sources. The study also includes a report on the recent advancements of the SQUID MSG system including its peripheral technologies and wide-spread applications.

  9. A Room Temperature Ultrasensitive Magnetoelectric Susceptometer for Quantitative Tissue Iron Detection

    Science.gov (United States)

    Xi, Hao; Qian, Xiaoshi; Lu, Meng-Chien; Mei, Lei; Rupprecht, Sebastian; Yang, Qing X.; Zhang, Q. M.

    2016-07-01

    Iron is a trace mineral that plays a vital role in the human body. However, absorbing and accumulating excessive iron in body organs (iron overload) can damage or even destroy an organ. Even after many decades of research, progress on the development of noninvasive and low-cost tissue iron detection methods is very limited. Here we report a recent advance in a room-temperature ultrasensitive biomagnetic susceptometer for quantitative tissue iron detection. The biomagnetic susceptometer exploits recent advances in the magnetoelectric (ME) composite sensors that exhibit an ultrahigh AC magnetic sensitivity under the presence of a strong DC magnetic field. The first order gradiometer based on piezoelectric and magnetostrictive laminate (ME composite) structure shows an equivalent magnetic noise of 0.99 nT/rt Hz at 1 Hz in the presence of a DC magnetic field of 0.1 Tesla and a great common mode noise rejection ability. A prototype magnetoelectric liver susceptometry has been demonstrated with liver phantoms. The results indicate its output signals to be linearly responsive to iron concentrations from normal iron dose (0.05 mg Fe/g liver phantom) to 5 mg Fe/g liver phantom iron overload (100X overdose). The results here open up many innovative possibilities for compact-size, portable, cost-affordable, and room-temperature operated medical systems for quantitative determinations of tissue iron.

  10. Hydromagnetic transport phenomena from a stretching or shrinking nonlinear nanomaterial sheet with Navier slip and convective heating: A model for bio-nano-materials processing

    Energy Technology Data Exchange (ETDEWEB)

    Uddin, M.J., E-mail: jashim_74@yahoo.com [Department of Mathematics, American International University-Bangladesh, Banani Dhaka 1213 (Bangladesh); Bég, O. Anwar [Gort Engovation Research (Propulsion/Biomechanics), Gabriel' s Wing House, 15 Southmere Ave., Bradford, BD7 3NU England (United Kingdom); Amin, N. [Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM Johor (Malaysia)

    2014-11-15

    Steady two-dimensional magnetohydrodynamic laminar free convective boundary layer slip flow of an electrically conducting Newtonian nanofluid from a translating stretching/shrinking sheet in a quiescent fluid is studied. A convective heating boundary condition is incorporated. The transport equations along with the boundary conditions are first converted into dimensionless form and following the implementation of a linear group of transformations, the similarity governing equations are developed. The transformed equations are solved numerically using the Runge–Kutta–Fehlberg fourth fifth order method from Maple. Validation of the Maple solutions is achieved with previous non-magnetic published results. The effects of the emerging thermophysical parameters; namely, stretching/shrinking, velocity slip, magnetic field, convective heat transfer and buoyancy ratio parameters, on the dimensionless velocity, temperature and concentration (nanoparticle fraction) are depicted graphically and interpreted at length. It is found that velocity increases whilst temperature and concentration reduce with the velocity slip. Magnetic field causes to reduce velocity and enhances temperature and concentration. Velocity, temperature as well as concentration rises with convective heating parameter. The study is relevant to the synthesis of bio-magnetic nanofluids of potential interest in wound treatments, skin repair and smart coatings for biological devices. - Highlights: • This paper analyses MHD slip flow of nofluid with convective boundary conditions. • Group method is used to transform governing equations into similarity equations. • The Runge–Kutta–Fehlberg method is used for numerical computations. • The study is relevant to synthesis of bio-magnetic nanofluids.

  11. A blood-oxygenation-dependent increase in blood viscosity due to a static magnetic field

    International Nuclear Information System (INIS)

    Yamamoto, Toru; Nagayama, Yuki; Tamura, Mamoru

    2004-01-01

    As the magnetic field of widely used MR scanners is one of the strongest magnetic fields to which people are exposed, the biological influence of the static magnetic field of MR scanners is of great concern. One magnetic interaction in biological subjects is the magnetic torque on the magnetic moment induced by biomagnetic substances. The red blood cell is a major biomagnetic substance, and the blood flow may be influenced by the magnetic field. However, the underlying mechanisms have been poorly understood. To examine the mechanisms of the magnetic influence on blood viscosity, we measured the time for blood to fall through a glass capillary inside and outside a 1.5 T MR scanner. Our in vitro results showed that the blood viscosity significantly increased in a 1.5 T MR scanner, and also clarified the mechanism of the interaction between red blood cells and the external magnetic field. Notably, the blood viscosity increased depending on blood oxygenation and the shear rate of the blood flow. Thus, our findings suggest that even a 1.5 T magnetic field may modulate blood flow

  12. Influence of compression forces on tablets disintegration by AC Biosusceptometry.

    Science.gov (United States)

    Corá, Luciana A; Fonseca, Paulo R; Américo, Madileine F; Oliveira, Ricardo B; Baffa, Oswaldo; Miranda, José Ricardo A

    2008-05-01

    Analysis of physical phenomena that occurs during tablet disintegration has been studied by several experimental approaches; however none of them satisfactorily describe this process. The aim of this study was to investigate the influence of compression force on the tablets by associating the AC Biosusceptometry with consolidated methods in order to validate the biomagnetic technique as a tool for quality control in pharmaceutical processes. Tablets obtained at five compression levels were submitted to mechanical properties tests. For uncoated tablets, water uptake and disintegration force measurements were performed in order to compare with magnetic data. For coated tablets, magnetic measurements were carried out to establish a relationship between physical parameters of the disintegration process. According to the results, differences between the compression levels were found for water uptake, force development and magnetic area variation measurements. ACB method was able to estimate the disintegration properties as well as the kinetics of disintegration process for uncoated and coated tablets. This study provided a new approach for in vitro investigation and validated this biomagnetic technique as a tool for quality control for pharmaceutical industry. Moreover, using ACB will also be possible to test these parameters in humans allowing to establish an in vitro/in vivo correlation (IVIVC).

  13. Yves Rocard or the last of the Mohicans

    International Nuclear Information System (INIS)

    Deschamps, Andre

    2013-01-01

    The author proposes a biography of Yves Rocard, the man at the origin of the development of physics in France after the Second World War, and also often considered as the father of the French atomic bomb. He briefly recalls his youth, his studies in the Ecole Normale Superieure (ENS), his works dealing with automotive construction and with applied electronics, his activities in the French Resistance during the war, his role at the head of the ENS Physics Laboratory, his works in the field of ionosphere predictions, radio-astronomy, and development of the first linear accelerator. As far as the French nuclear bomb is concerned, his role is still a matter of debate. He worked on explosion detection, and initiated the creation of a CEA department dedicated to military applications, but was not really involved in the activities of this department. His last works addressed geophysics and bio-magnetism

  14. Solid Test Meal to Measure the Gastric Emptying with Magnetogastrography

    International Nuclear Information System (INIS)

    Reynaga-Ornelas, M. G.; Roca-Chiapas, J. M. de ls; Cordova-Fraga, T.; Bernal, J. J.; Sosa, M.

    2008-01-01

    The gastric emptying is the time of evacuating the food ingested from the stomach to the duodenum in a controlled rate. Diverse studies express the results of the gastric emptying in form of half-time (t 1/2 ). The Magnetogastrography (MGG) is a biomagnetic technique that has the advantage of not being invasive, radiation free and does not interfere with the privacy of the subject. The objective was to analyze the magnetic signal of magnetic tracers mixed in a solid food to measure gastric emptying using Magnetogastrography. The ingested test meal displayed a magnetic signal, which served to obtain the signal registered by the fluxgate and the peristaltic contractions could be calculated while the stomach was emptying. The solid food product developed results to work satisfactorily in magnetogastrography

  15. Mathematical Methods in Tomography

    CERN Document Server

    Louis, Alfred; Natterer, Frank

    1991-01-01

    The conference was devoted to the discussion of present and future techniques in medical imaging, including 3D x-ray CT, ultrasound and diffraction tomography, and biomagnetic ima- ging. The mathematical models, their theoretical aspects and the development of algorithms were treated. The proceedings contains surveys on reconstruction in inverse obstacle scat- tering, inversion in 3D, and constrained least squares pro- blems.Research papers include besides the mentioned imaging techniques presentations on image reconstruction in Hilbert spaces, singular value decompositions, 3D cone beam recon- struction, diffuse tomography, regularization of ill-posed problems, evaluation reconstruction algorithms and applica- tions in non-medical fields. Contents: Theoretical Aspects: J.Boman: Helgason' s support theorem for Radon transforms-a newproof and a generalization -P.Maass: Singular value de- compositions for Radon transforms- W.R.Madych: Image recon- struction in Hilbert space -R.G.Mukhometov: A problem of in- teg...

  16. Technology for SQUID systems for the application in magnetically disturbed environment. Final report

    International Nuclear Information System (INIS)

    Schultze, V.; Fritzsch, L.; Thrum, F.; Stolz, R.; Chwala, A.

    1996-06-01

    International available SQUID systems, as used for example in biomagnetic research, obtain high sensitivities for magnetic fields or magnetic fieldgradients. However, these systems were optimised for operation in magnetically shielded rooms. Goal of this project was to develop SQUIDs suppressing the external noise and therefore are able to operate without external shielding in normal environments. As a consequence, the required Nb/AlO x /Nb technology has also been developed. The resulting planar SQUID gradiometers as produced at the IPHT, reached a suppression of homogeneous fields up to 5 x 10 4 for a magnetic field sensitivity c , project. SQUID gradiometers, produced using YBCO technology, were successfully operated in non shielded eddy current NDE measurements in the lab. (orig.) [de

  17. Applied superconductivity handbook on devices and applications

    CERN Document Server

    2015-01-01

    This wide-ranging presentation of applied superconductivity, from fundamentals and materials right up to the latest applications, is an essential reference for physicists and engineers in academic research as well as in the field. Readers looking for a systematic overview on superconducting materials will expand their knowledge and understanding of both low and high Tc superconductors, including organic and magnetic materials. Technology, preparation and characterization are covered for several geometries, but the main benefit of this work lies in its broad coverage of significant applications in power engineering or passive devices, such as filter and antenna or magnetic shields. The reader will also find information on superconducting magnets for diverse applications in mechanical engineering, particle physics, fusion research, medicine and biomagnetism, as well as materials processing. SQUIDS and their usage in medicine or geophysics are thoroughly covered as are applications in quantum metrology, and, las...

  18. Ephaptic Coupling of Cortical Neurons: Possible Contribution of Astroglial Magnetic Fields?

    Science.gov (United States)

    Martinez-Banaclocha, Marcos

    2018-02-01

    The close anatomical and functional relationship between neuronal circuits and the astroglial network in the neocortex has been demonstrated at several organization levels supporting the idea that neuron-astroglial crosstalk can play a key role in information processing. In addition to chemical and electrical neurotransmission, other non-synaptic mechanisms called ephaptic interactions seem to be important to understand neuronal coupling and cognitive functions. Recent interest in this issue comes from the fact that extra-cranial electric and magnetic field stimulations have shown therapeutic actions in the clinical practice. The present paper reviews the current knowledge regarding the ephaptic effects in mammalian neocortex and proposes that astroglial bio-magnetic fields associated with Ca 2+ transients could be implicated in the ephaptic coupling of neurons by a direct magnetic modulation of the intercellular local field potentials. Copyright © 2017 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. Review of biotechnology applications to nuclear waste treatment

    International Nuclear Information System (INIS)

    Ashley, N.V.; Roach, D.J.W.

    1990-01-01

    This paper gives an overview of the feasibility of the application of biotechnology to nuclear waste treatment. Many living and dead organisms accumulate heavy metals and radionuclides. The controlled use of this phenomenon forms the basis for the application of biotechnology to the removal of radionuclides from nuclear waste streams. An overview of biotechnology areas, namely the use of biopolymers and biosorption using biomass applicable to the removal of radionuclides from industrial nuclear effluents is given. The potential of biomagnetic separation technology, genetic engineering and monoclonal antibody technology is also to be examined. The most appropriate technologies to develop for radionuclide removal in the short term appear to be those based on biosorption of radionuclides by biomass and the use of modified and unmodified biopolymers in the medium term. (author)

  20. SQUID (superconducting quantum interference device) arrays for simultaneous magnetic measurements: Calibration and source localization performance

    Science.gov (United States)

    Kaufman, Lloyd; Williamson, Samuel J.; Costaribeiro, P.

    1988-02-01

    Recently developed small arrays of SQUID-based magnetic sensors can, if appropriately placed, locate the position of a confined biomagnetic source without moving the array. The authors present a technique with a relative accuracy of about 2 percent for calibrating such sensors having detection coils with the geometry of a second-order gradiometer. The effects of calibration error and magnetic noise on the accuracy of locating an equivalent current dipole source in the human brain are investigated for 5- and 7-sensor probes and for a pair of 7-sensor probes. With a noise level of 5 percent of peak signal, uncertainties of about 20 percent in source strength and depth for a 5-sensor probe are reduced to 8 percent for a pair of 7-sensor probes, and uncertainties of about 15 mm in lateral position are reduced to 1 mm, for the configuration considered.

  1. A novel inversion scheme for a magnetic dipole

    International Nuclear Information System (INIS)

    Koka, S.; Valsakumar, M.C.; Janawadkar, M.P.; Radhakrishnan, T.S.

    1997-01-01

    In a number of applications of SQUID devices such as biomagnetism, there is a need to infer the position and strength of the source(s) of the magnetic field on the basis of measurements of magnetic fields H and magnetic field gradients δH j /δx k at suitable observation point(s). It is well known that while a specification of sources uniquely determines the resulting field distribution, the inverse problem, in general, does not admit of a unique solution. However, there exist circumstances under which the source may be modeled reasonably well as a single magnetic dipole m. A novel method, which gives a unique solution to localize such a dipole source by measuring all the magnetic field components and their spatial derivatives at a single arbitrary point in space is reported

  2. Nitrogen-Vacancy color center in diamond-emerging nanoscale applications in bioimaging and biosensing.

    Science.gov (United States)

    Balasubramanian, Gopalakrishnan; Lazariev, Andrii; Arumugam, Sri Ranjini; Duan, De-Wen

    2014-06-01

    Nitrogen-Vacancy (NV) color center in diamond is a flourishing research area that, in recent years, has displayed remarkable progress. The system offers great potential for realizing futuristic applications in nanoscience, benefiting a range of fields from bioimaging to quantum-sensing. The ability to image single NV color centers in a nanodiamond and manipulate NV electron spin optically under ambient condition is the main driving force behind developments in nanoscale sensing and novel imaging techniques. In this article we discuss current status on the applications of fluorescent nanodiamonds (FND) for optical super resolution nanoscopy, magneto-optical (spin-assisted) sub-wavelength localization and imaging. We present emerging applications such as single molecule spin imaging, nanoscale imaging of biomagnetic fields, sensing molecular fluctuations and temperatures in live cellular environments. We summarize other current advances and future prospects of NV diamond for imaging and sensing pertaining to bio-medical applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Francis Bitter National Magnet Laboratory annual report, July 1988 through June 1989

    International Nuclear Information System (INIS)

    1989-01-01

    Contents include: reports on laboratory research programs--magneto-optics and semiconductor physics, magnetism, superconductivity, solid-state nuclear magnetic resonance, condensed-matter chemistry, biomagnetism, magnet technology, instrumentation for high-magnetic-field research, molecular biophysics; reports of visiting scientists--reports of users of the High Magnetic Field Facility, reports of users of the Pulsed Field Facility, reports of users of the SQUID Magnetometer and Moessbauer Facility, reports of users of the High-Field NMR Facility; Appendices--publications and meeting speeches, organization, summary of High-Field Magnet Facility use January 1, 1981 through December 31, 1988; geographic distribution of High-Field Magnet users (excluding laboratory staff); and summary of educational activities

  4. Sensitivity optimization of Bell-Bloom magnetometers by manipulation of atomic spin synchronization

    Science.gov (United States)

    Ranjbaran, M.; Tehranchi, M. M.; Hamidi, S. M.; Khalkhali, S. M. H.

    2018-05-01

    Many efforts have been devoted to the developments of atomic magnetometers for achieving the high sensitivity required in biomagnetic applications. To reach the high sensitivity, many types of atomic magnetometers have been introduced for optimization of the creation and relaxation rates of atomic spin polarization. In this paper, regards to sensitivity optimization techniques in the Mx configuration, we have proposed a novelty approach for synchronization of the spin precession in the Bell-Bloom magnetometers. We have utilized the phenomenological Bloch equations to simulate the spin dynamics when modulation of pumping light and radio frequency magnetic field were both used for atomic spin synchronization. Our results showed that the synchronization process, improved the magnetometer sensitivity respect to the classical configurations.

  5. A venture capital view of superconductivity electronics

    International Nuclear Information System (INIS)

    Kressel, H.

    1987-01-01

    Many venture capital backed start-up companies have followed major technological innovations in recent years. However, the field of electronics based on the use of superconducting devices (i.e. the Josephson Junction) has been a noteworthy exception. Until 1983, the bulk of the American development effort on superconductivity electronics was conducted by IBM where the focus was to demonstrate the feasibility of a superconducting computer prototype. Other activities using Josephson Junctions involved the development and production of magnetic sensing instruments and modest quantities of magnetometers which were marketed by several very small companies primarily for laboratory use. In addition, other applications in radiation sensing and biomagnetism and research leading to practical systems were ongoing in several organizations

  6. Physics and engineering of medical imaging

    International Nuclear Information System (INIS)

    Guzzardi, R.

    1987-01-01

    The ever-growing development in the technology of Medical Imaging has a continuous and significant impact in the practice of Medicine as well as in the clinical research activity. The information and accuracy obtained by whatever imaging methodology is a complex result of a multidisciplinary effort of several sciences, such as Physics, Engineering, Electronics, Chemistry and Medicine. In this book, the state-of-the-art is described of the technology at the base of NMR, Ultrasound, X-ray CT, Nuclear Medicine, Positron Tomography and other Imaging Modalities such as Thermography or Biomagnetism, considering both the research and industrial point of view. For every imaging modality the most important clinical applications are described, together with the delineation of problems and future needs. Furthermore, specific sections of the book are devoted to general aspects of Medical Imaging, such as Reconstruction Techniques, 2-D and 3-D Display, Quality Control, Archiving, Market Trends and Correlative Assessment. (Auth.)

  7. Frontiers in European radiology 8

    International Nuclear Information System (INIS)

    Baert, A.L.; Heuck, F.H.W.

    1991-01-01

    Out of the eight contributions to this volume, the last two have been analysed for the data base. The articles deal with 'Progress in Biomagnetic Imaging of heat arrhythmias', 'Selective Endovascular Treatment of Intracranial Aneurysms by means of Latex Balloons Filled with a Polymerizing Substance', 'Self-Expandable Endoprotheses as an Adjunct to Balloon Angioplasty in the Treatment of Peripheral Arterial Lesions', 'Laser-Induced Shock Wave Angioplasty: Discrimination between Calcified and Other Plaque Material Before Generation of Laser-Induced Shock Waves', 'Contrast Agents in Clinical Angiography - Relevance to Thromboembolic Phenomena', 'Sodium and Oxygen Addition to Nonionic Contrast Media Effects on Contractile Force and Risk of Ventricular Fibrillation in the Isolated Rabbit Heart', 'Clinical Magnetic Resonance Spectroscopy - The Present State' and 'Image Contour Spread in Computed Tomography'. (UWA). 49 figs., 9 tabs

  8. Acceleration of superparamagnetic particles with magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Stange, R., E-mail: Robert.stange@tu-dresden.de; Lenk, F.; Bley, T.; Boschke, E.

    2017-04-01

    High magnetic capture efficiency in the context of Biomagnetic Separation (BMS) using superparamagnetic particles (SMPs) requires efficient mixing and high relative velocities between cellular and other targets and SMPs. For this purpose, batch processes or microfluidic systems are commonly used. Here, we analyze the characteristics of an in-house developed batch process experimental setup, the Electromagnetic Sample Mixer (ESM) described earlier. This device uses three electromagnets to increase the relative velocity between SMPs and targets. We carry out simulations of the magnetic field in the ESM and in a simpler paradigmatic setup, and thus were able to calculate the force field acting on the SMPs and to simulate their relative velocities and fluid dynamics due to SMP movement. In this way we were able to show that alternate charging of the magnets induces a double circular stream of SMPs in the ESM, resulting in high relative velocities of SMPs to the targets. Consequently, due to the conservation of momentum, the fluid experiences an acceleration induced by the SMPs. We validated our simulations by microscopic observation of the SMPs in the magnetic field, using a homemade apparatus designed to accommodate a long working-distance lens. By comparing the results of modeling this paradigmatic setup with the experimental observations, we determined that the velocities of the SMPs corresponded to the results of our simulations. - Highlights: • Investigation of a batch process setup for complex forming at Biomagnetic Separation. • Simulation of fluid flow characteristics in this Electro Magnetic Samplemixer. • Simulation of relative velocities between magnetic particles and fluid in the setup. • Simulation of fluid flow induced by the acceleration of magnet particles. • Validation of magnetic fields and flow characteristics in paradigmatic setups. • Reached relative velocity is higher than the sedimentation velocity of the particles • Alternating

  9. An ultra-sensitive and wideband magnetometer based on a superconducting quantum interference device

    Science.gov (United States)

    Storm, Jan-Hendrik; Hömmen, Peter; Drung, Dietmar; Körber, Rainer

    2017-02-01

    The magnetic field noise in superconducting quantum interference devices (SQUIDs) used for biomagnetic research such as magnetoencephalography or ultra-low-field nuclear magnetic resonance is usually limited by instrumental dewar noise. We constructed a wideband, ultra-low noise system with a 45 mm diameter superconducting pick-up coil inductively coupled to a current sensor SQUID. Thermal noise in the liquid helium dewar is minimized by using aluminized polyester fabric as superinsulation and aluminum oxide strips as heat shields. With a magnetometer pick-up coil in the center of the Berlin magnetically shielded room 2 (BMSR2), a noise level of around 150 aT Hz-1/2 is achieved in the white noise regime between about 20 kHz and the system bandwidth of about 2.5 MHz. At lower frequencies, the resolution is limited by magnetic field noise arising from the walls of the shielded room. Modeling the BMSR2 as a closed cube with continuous μ-metal walls, we can quantitatively reproduce its measured field noise.

  10. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Murillo L., E-mail: murillolongo@gmail.com [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Instituto de Biociências, Universidade Estadual Paulista, CP 510, 18618–970 Botucatu SP (Brazil); Calabresi, Marcos F.; Quini, Caio; Matos, Juliana F.; Miranda, José R.A.; Saeki, Margarida J. [Instituto de Biociências, Universidade Estadual Paulista, CP 510, 18618–970 Botucatu SP (Brazil); Bordallo, Heloisa N. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark)

    2015-03-01

    Alternate Current Biosusceptometry (ACB) is a promising bio-magnetic method, radiation free and easily performed used for gastric emptying exams. Due to development on its sensitivity level, interesting nature, noninvasiveness and low cost it has attracted a lot of attention. In this work, magnetic nanoparticles of Mn–Zn ferrite as well as dextrose-modified nanoparticles were synthesized to be used as possible tracers in ACB gastric emptying exams. In addition, a magnetic muco-adhesive gel was obtained by modifying the ferrite nanoparticles with cellulose. Based on in-vivo tests in rats, we show that the pure ferrite nanoparticles, whose isoelectric point was found to be at pH = 3.2, present a great sensitivity to pH variations along the gastrointestinal tract, while the reduction of the isoelectric point by the dextrose modification leads to suitable nanoparticles for rapid gastric emptying examinations. On the other hand, the in-vivo tests show that the muco-adhesive cellulose gel presents substantial stomach adhesion and is a potential drug delivery system easily traceable by the ACB system.

  11. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel

    International Nuclear Information System (INIS)

    Martins, Murillo L.; Calabresi, Marcos F.; Quini, Caio; Matos, Juliana F.; Miranda, José R.A.; Saeki, Margarida J.; Bordallo, Heloisa N.

    2015-01-01

    Alternate Current Biosusceptometry (ACB) is a promising bio-magnetic method, radiation free and easily performed used for gastric emptying exams. Due to development on its sensitivity level, interesting nature, noninvasiveness and low cost it has attracted a lot of attention. In this work, magnetic nanoparticles of Mn–Zn ferrite as well as dextrose-modified nanoparticles were synthesized to be used as possible tracers in ACB gastric emptying exams. In addition, a magnetic muco-adhesive gel was obtained by modifying the ferrite nanoparticles with cellulose. Based on in-vivo tests in rats, we show that the pure ferrite nanoparticles, whose isoelectric point was found to be at pH = 3.2, present a great sensitivity to pH variations along the gastrointestinal tract, while the reduction of the isoelectric point by the dextrose modification leads to suitable nanoparticles for rapid gastric emptying examinations. On the other hand, the in-vivo tests show that the muco-adhesive cellulose gel presents substantial stomach adhesion and is a potential drug delivery system easily traceable by the ACB system

  12. A study of unsteady physiological magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping.

    Science.gov (United States)

    Tripathi, Dharmendra; Bég, O Anwar

    2012-08-01

    Magnetohydrodynamic peristaltic flows arise in controlled magnetic drug targeting, hybrid haemodynamic pumps and biomagnetic phenomena interacting with the human digestive system. Motivated by the objective of improving an understanding of the complex fluid dynamics in such flows, we consider in the present article the transient magneto-fluid flow and heat transfer through a finite length channel by peristaltic pumping. Reynolds number is small enough and the wavelength to diameter ratio is large enough to negate inertial effects. Analytical solutions for temperature field, axial velocity, transverse velocity, pressure gradient, local wall shear stress, volume flowrate and averaged volume flowrate are obtained. The effects of the transverse magnetic field, Grashof number and thermal conductivity on the flow patterns induced by peristaltic waves (sinusoidal propagation along the length of channel) are studied using graphical plots. The present study identifies that greater pressure is required to propel the magneto-fluid by peristaltic pumping in comparison to a non-conducting Newtonian fluid, whereas, a lower pressure is required if heat transfer is effective. The analytical solutions further provide an important benchmark for future numerical simulations.

  13. A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

    International Nuclear Information System (INIS)

    Moral, A. del; Azanza, María J.

    2015-01-01

    A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca 2+ Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B 0 ≅0.2–15 mT) AC-MF of frequency f M =50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca 2+ Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons

  14. Enhancing the versatility of alternate current biosusceptometry (ACB) through the synthesis of a dextrose-modified tracer and a magnetic muco-adhesive cellulose gel.

    Science.gov (United States)

    Martins, Murillo L; Calabresi, Marcos F; Quini, Caio; Matos, Juliana F; Miranda, José R A; Saeki, Margarida J; Bordallo, Heloisa N

    2015-03-01

    Alternate Current Biosusceptometry (ACB) is a promising bio-magnetic method, radiation free and easily performed used for gastric emptying exams. Due to development on its sensitivity level, interesting nature, noninvasiveness and low cost it has attracted a lot of attention. In this work, magnetic nanoparticles of Mn-Zn ferrite as well as dextrose-modified nanoparticles were synthesized to be used as possible tracers in ACB gastric emptying exams. In addition, a magnetic muco-adhesive gel was obtained by modifying the ferrite nanoparticles with cellulose. Based on in-vivo tests in rats, we show that the pure ferrite nanoparticles, whose isoelectric point was found to be at pH=3.2, present a great sensitivity to pH variations along the gastrointestinal tract, while the reduction of the isoelectric point by the dextrose modification leads to suitable nanoparticles for rapid gastric emptying examinations. On the other hand, the in-vivo tests show that the muco-adhesive cellulose gel presents substantial stomach adhesion and is a potential drug delivery system easily traceable by the ACB system. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Synthesis and characterization of highly-magnetic biodegradable poly(D,L-lactide-co-glycolide) nanospheres.

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X.; Kaminski, M. D.; Chen, H.; Torno, M.; Taylor, L.; Rosengart, A. J.; Univ. of Chicago

    2007-05-14

    The objective of this study was to develop high magnetization, biodegradable/biocompatible polymer-coated magnetic nanospheres for biomedical applications. Magnetic spheres were prepared by a modified single oil-in-water emulsion-solvent evaporation method utilizing highly-concentrated hydrophobic magnetite and poly(d,l lactide-co-glycolide) (PLGA). Hydrophobic magnetite prepared using oleic acid exhibited high magnetite concentrations (84 wt.%) and good miscibility with biopolymer solvents to form a stable oily suspension. The oily suspension was then emulsified within an aqueous solution containing poly(vinyl alcohol). After rapid evaporation of the organic solvent, we obtained solid magnetic nanospheres. We characterized these spheres in terms of external morphology, microstructure, size and zeta potential, magnetite content and distribution within the nanospheres, and magnetic properties. The results showed good encapsulation where the magnetite distorted the smooth surface morphology only at the highest magnetite concentrations. The mean diameter was 360-370 nm with polydispersity indices of 0.12-0.20. We obtained high magnetite content (40-60%) and high magnetization (26-40 emu/g). The high magnetization properties were obtained while leaving sufficient polymer to retain drugs making these biodegradable spheres suitable as a potential platform for the design of magnetically-guided drug delivery and other in vivo biomagnetic applications.

  16. Numerical Investigation of Oxygenated and Deoxygenated Blood Flow through a Tapered Stenosed Arteries in Magnetic Field.

    Directory of Open Access Journals (Sweden)

    M Y Abdollahzadeh Jamalabadi

    Full Text Available Current paper is focused on transient modeling of blood flow through a tapered stenosed arteries surrounded a by solenoid under the presence of heat transfer. The oxygenated and deoxygenated blood are considered here by the Newtonian and Non-Newtonian fluid (power law and Carreau-Yasuda models. The governing equations of bio magnetic fluid flow for an incompressible, laminar, homogeneous, non-Newtonian are solved by finite volume method with SIMPLE algorithm for structured grid. Both magnetization and electric current source terms are well thought-out in momentum and energy equations. The effects of fluid viscosity model, Hartmann number, and magnetic number on wall shear stress, shearing stress at the stenosis throat and maximum temperature of the system are investigated and are optimized. The current study results are in agreement with some of the existing findings in the literature and are useful in thermal and mechanical design of spatially varying magnets to control the drug delivery and biomagnetic fluid flows through tapered arteries.

  17. A model explaining synchronization of neuron bioelectric frequency under weak alternating low frequency magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Moral, A. del, E-mail: delmoral@unizar.es [Laboratorio de Magnetismo, Departamento de Física de Materia Condensada and Instituto de Ciencia de Materiales, Universidad de Zaragoza and Consejo Superior de Investigaciones Científicas, 50009 Zaragoza (Spain); Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain); Azanza, María J., E-mail: mjazanza@unizar.es [Laboratorio de Magnetobiología, Departamento de Anatomía e Histología, Facultad de Medicina, Universidad de Zaragoza, 50009 Zaragoza (Spain); Centro de Tecnología Biomédica, Universidad Politécnica de Madrid, 28223 Madrid (Spain)

    2015-03-01

    A biomagnetic-electrical model is presented that explains rather well the experimentally observed synchronization of the bioelectric potential firing rate (“frequency”), f, of single unit neurons of Helix aspersa mollusc under the application of extremely low frequency (ELF) weak alternating (AC) magnetic fields (MF). The proposed model incorporates to our widely experimentally tested model of superdiamagnetism (SD) and Ca{sup 2+} Coulomb explosion (CE) from lipid (LP) bilayer membrane (SD–CE model), the electrical quadrupolar long range interaction between the bilayer LP membranes of synchronized neuron pairs, not considered before. The quadrupolar interaction is capable of explaining well the observed synchronization. Actual extension of our SD–CE-model shows that the neuron firing frequency field, B, dependence becomes not modified, but the bioelectric frequency is decreased and its spontaneous temperature, T, dependence is modified. A comparison of the model with synchronization experimental results of pair of neurons under weak (B{sub 0}≅0.2–15 mT) AC-MF of frequency f{sub M}=50 Hz is reported. From the deduced size of synchronized LP clusters under B, is suggested the formation of small neuron networks via the membrane lipid correlation. - Highlights: • Neuron pair synchronization under low frequency alternating (AC) magnetic field (MF). • Superdiamagnetism and Ca{sup 2+} Coulomb explosion for AC MF effect in synchronized frequency. • Membrane lipid electrical quadrupolar pair interaction as synchronization mechamism. • Good agreement of model with electrophysiological experiments on mollusc Helix neurons.

  18. Detection of materials of interest to nonproliferation: A novel approach

    International Nuclear Information System (INIS)

    Ze, Frederic; Tittmann, Bernhard R.; Lenahan, P.M.

    2002-01-01

    We propose the development of a novel detector that can locate and identify materials of interest to Nuclear Arms Non Proliferation. The device will combine nuclear acoustic resonance (NAR) with superconducting quantum interference device (SQUID) widely used in nuclear magnetic resonance (NMR), geophysics, nondestructive evaluations, and biomagnetism, to name only few. NAR works like NMR. Thus resonant absorption (of applied ultrasonic energy) by a nuclear spin system occurs when the ultrasonic frequency is equal to the appropriate frequency separations between the magnetic nuclear energy levels. Ultrasonic energy couples to the nuclear spin system via spin-phonon interaction. The resulting nuclear acoustic resonance can be detected via the changes in (a) ultrasonic attenuation, (b) ultrasonic velocity, (c) material magnetization, (d) or nuclear magnetic susceptibility, all of which carries 'intrinsic and unique signatures' of the material under investigation. The device's sensitivity and penetration depth (into metals) will be enhanced by incorporating SQUID technology into the design. We will present the details of interaction physics and outline a plan of action needed to successfully transform the concepts into a practical detector

  19. Study of blood flow inside the stenosis vessel under the effect of solenoid magnetic field using ferrohydrodynamics principles

    Science.gov (United States)

    Badfar, Homayoun; Motlagh, Saber Yekani; Sharifi, Abbas

    2017-10-01

    In this paper, biomagnetic blood flow in the stenosis vessel under the effect of the solenoid magnetic field is studied using the ferrohydrodynamics (FHD) model. The parabolic profile is considered at an inlet of the axisymmetric stenosis vessel. Blood is modeled as electrically non-conducting, Newtonian and homogeneous fluid. Finite volume and the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm are utilized to discretize governing equations. The investigation is studied at different magnetic numbers ( MnF=164, 328, 1640 and 3280) and the number of the coil loops (three, five and nine loops). Results indicate an increase in heat transfer, wall shear stress and energy loss (pressure drop) with an increment in the magnetic number (ratio of Kelvin force to dynamic pressure force), arising from the FHD, and the number of solenoid loops. Furthermore, the flow pattern is affected by the magnetic field, and the temperature of blood can be decreased up to 1.48 {}°C under the effect of the solenoid magnetic field with nine loops and reference magnetic field ( B0) of 2 tesla.

  20. FY1995 report on the analyses of functional living systems using magnetic stimulation and magnetic fields; 1995 nendo jiki shigeki oyobi kyojiba ni yoru seitai kino kaimei

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-05-01

    The purpose of the project is to widen the understanding of the biological effects o magnetic fields and to search potential applications of biomagnetics to medical diagnosis and treatments. We developed a method of localized magnetic stimulation of the brain. By concentrating induced eddy currents on a target with a pair of opposing pulsed magnetic fields produced by a figure-eight coil, they were able to stimulate the human cortex within a 5 mm resolution. We studied the properties of diamagnetic water in static magnetic fields. The phenomenon that the surface of the water was pushed back by magnetic fields of higher gradients was observed. The behavior of oxygen dissolved in an aqueous solution under magnetic fields of up to 8T with a gradient of 50T/m was studied. For oxygen concentrations greater than 11 mg/l, a clear redistribution of dissolved oxygen was observed. Effects of strong magnetic fields on a process of dissolution of fibrin clots was studied. Fibrin polymers in water magneto-phoresically drifted in the direction of increasing magnetic fields, and dissolution of fibrin polymers by plasmin was accelerated. (NEDO)

  1. Single-layer 2nd-order high-Tc SQUID gradiometer for use in unshielded environments

    International Nuclear Information System (INIS)

    Lee, Soon-Gul; Park, Seung Moon; Kang, Chan Seok; Kim, In-Seon; Kim, Sang-Jae

    2006-01-01

    We have studied the fabrication of second-order SQUID gradiometers from single-layer high-T c film and the feasibility of using those gradiometers in magnetocardiography. The gradiometer contains three parallel-connected pickup loops that are directly coupled to a step-edge junction SQUID with the coupling polarity of the center loop opposite to those of the two side loops. For a well-balanced gradiometer with a balancing factor of 10 3 , we achieved an unshielded gradient noise of 0.84 pT/cm 2 /Hz 1/2 at 1 Hz, which corresponds to an equivalent field noise of 280 fT/Hz 1/2 . A gradiometer with a 5.8-mm baseline successfully recorded the magnetocardic signals of a human subject, demonstrating the feasibility of using the device in biomagnetism. We have also studied the use of submicron YBCO bridges as Josephson elements of long-baseline gradiometers. The bridges were fabricated from 3-μm-wide, 300-nm-thick YBCO lines with a thin layer of Au on top by using a focused-ion-beam (FIB) patterning method. The temperature-dependent critical currents, I c (T), and the normal state resistances, R N (T), showed SIS-type behaviors, which are believed to be due to naturally formed grain boundaries.

  2. Physics Division semiannual report, July 1-December 31, 1982

    International Nuclear Information System (INIS)

    Trela, W.J.

    1983-09-01

    The Physics Division is organized into three major research areas: Fusion Physics, Weapons Physics, and Basic Research. In Fusion Physics, the KrF laser project reached two important milestones: successful testing of a 1-m 2 electron diode for KrF gas excitation and completion of a combined aperture demonstration showing the feasibility of accurate alignment of spherical mirrors. In the CO 2 program, the 5-kJ Helios lasers were used to evaluate many physics issues concerning the use of 10-μm light for inertial fusion and the 30- to 40-kJ Antares laser construction projects is on schedule for completion in October 1983. In Weapons Physics, significant progress was made on developing continuous time-dependent imaging systems using tomographic techniques with 400-ps shuttering capability, fiber-optic Cerenkov detector systems for fast fusion measurements, and iron-doped indium-phosphide detectors with 70-ps impulse response. A proposal to build x-ray beam lines at the National Synchrotron Light Source was approved and we expect funding in 1984. In Basic Physics Research, we have begun new initiatives to study biomagnetism in collaboration with the Life Sciences Division and to develop a neutrino physics program. During this period numerous significant experiments were completed in our nuclear physics, condensed matter physics, and thermal physics programs

  3. Pulse-driven magnetoimpedance sensor detection of cardiac magnetic activity.

    Directory of Open Access Journals (Sweden)

    Shinsuke Nakayama

    Full Text Available This study sought to establish a convenient method for detecting biomagnetic activity in the heart. Electrical activity of the heart simultaneously induces a magnetic field. Detection of this magnetic activity will enable non-contact, noninvasive evaluation to be made. We improved the sensitivity of a pulse-driven magnetoimpedance (PMI sensor, which is used as an electric compass in mobile phones and as a motion sensor of the operation handle in computer games, toward a pico-Tesla (pT level, and measured magnetic fields on the surface of the thoracic wall in humans. The changes in magnetic field detected by this sensor synchronized with the electric activity of the electrocardiogram (ECG. The shape of the magnetic wave was largely altered by shifting the sensor position within 20 mm in parallel and/or perpendicular to the thoracic wall. The magnetic activity was maximal in the 4th intercostals near the center of the sterna. Furthermore, averaging the magnetic activity at 15 mm in the distance between the thoracic wall and the sensor demonstrated magnetic waves mimicking the P wave and QRS complex. The present study shows the application of PMI sensor in detecting cardiac magnetic activity in several healthy subjects, and suggests future applications of this technology in medicine and biology.

  4. Effects of high-gradient magnetic fields on living cell machinery

    International Nuclear Information System (INIS)

    Zablotskii, V; Lunov, O; Kubinova, S; Polyakova, T; Dejneka, A; Sykova, E

    2016-01-01

    A general interest in biomagnetic effects is related to fundamental studies of the influence of magnetic fields on living objects on the cellular and whole organism levels. Emerging technologies offer new directions for the use of high-gradient magnetic fields to control cell machinery and to understand the intracellular biological processes of the emerging field of nanomedicine. In this review we aim at highlighting recent advances made in identifying fundamental mechanisms by which magnetic gradient forces act on cell fate specification and cell differentiation. The review also provides an analysis of the currently available magnetic systems capable of generating magnetic fields with spatial gradients of up to 10 MT m −1 , with the focus on their suitability for use in cell therapy. Relationships between experimental factors and underlying biophysical mechanisms and assumptions that would ultimately lead to a deeper understanding of cell machinery and the development of more predictive models for the evaluation of the effects of magnetic fields on cells, tissue and organisms are comprehensively discussed. (topical review)

  5. Single-crystalline MFe(2)O(4) nanotubes/nanorings synthesized by thermal transformation process for biological applications.

    Science.gov (United States)

    Fan, Hai-Ming; Yi, Jia-Bao; Yang, Yi; Kho, Kiang-Wei; Tan, Hui-Ru; Shen, Ze-Xiang; Ding, Jun; Sun, Xiao-Wei; Olivo, Malini Carolene; Feng, Yuan-Ping

    2009-09-22

    We report a general thermal transformation approach to synthesize single-crystalline magnetic transition metal oxides nanotubes/nanorings including magnetite Fe(3)O(4), maghematite gamma-Fe(2)O(3), and ferrites MFe(2)O(4) (M = Co, Mn, Ni, Cu) using hematite alpha-Fe(2)O(3) nanotubes/nanorings template. While the straightforward reduction or reduction-oxides process was employed to produce Fe(3)O(4) and gamma-Fe(2)O(3), the alpha-Fe(2)O(3)/M(OH)(2) core/shell nanostructure was used as precursor to prepare MFe(2)O(4) nanotubes via MFe(2)O(4-x) (0 MFe(2)O(4) nanocrystals with tunable size, shape, and composition have exhibited unique magnetic properties. Moreover, they have been demonstrated as a highly effective peroxidase mimic catalysts for laboratory immunoassays or as a universal nanocapsules hybridized with luminescent QDs for magnetic separation and optical probe of lung cancer cells, suggesting that these biocompatible magnetic nanotubes/nanorings have great potential in biomedicine and biomagnetic applications.

  6. Magnetic nanoparticles: A multifunctional vehicle for modern theranostics.

    Science.gov (United States)

    Angelakeris, M

    2017-06-01

    Magnetic nanoparticles provide a unique multifunctional vehicle for modern theranostics since they can be remotely and non-invasively employed as imaging probes, carrier vectors and smart actuators. Additionally, special delivery schemes beyond the typical drug delivery such as heat or mechanical stress may be magnetically triggered to promote certain cellular pathways. To start with, we need magnetic nanoparticles with several well-defined and reproducible structural, physical, and chemical features, while bio-magnetic nanoparticle design imposes several additional constraints. Except for the intrinsic requirement for high quality of magnetic properties in order to obtain the maximum efficiency with the minimum dose, the surface manipulation of the nanoparticles is a key aspect not only for transferring them from the growth medium to the biological environment but also to bind functional molecules that will undertake specific targeting, drug delivery, cell-specific monitoring and designated treatment without sparing biocompatibility and sustainability in-vivo. The ability of magnetic nanoparticles to interact with matter at the nanoscale not only provides the possibility to ascertain the molecular constituents of a disease, but also the way in which the totality of a biological function may be affected as well. The capacity to incorporate an array of structural and chemical functionalities onto the same nanoscale architecture also enables more accurate, sensitive and precise screening together with cure of diseases with significant pathological heterogeneity such as cancer. This article is part of a Special Issue entitled "Recent Advances in Bionanomaterials" Guest Editor: Dr. Marie-Louise Saboungi and Dr. Samuel D. Bader. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Changes in the electrocardiograms of rats and dogs exposed to dc magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Gaffey, C.T.; Tenforde, T.S.

    1979-03-01

    An evaluation of cardiovascular performance in magnetic fields (MF) is being undertaken. Cardiovascular performance is evaluated as a function of the MF strength. Since the vector characteristics of MF may be a factor influencing cardiovascular function, the positional arrangement of animals in a MF is being tested. In practice, each test animal is inserted between the poles of a magnet in a selected orientation that locates the heart in the center of the MF. The electrocardogram (ECG) is recorded before, during, and following the application of a MF. The interval between summits of the R waves allows the average heart rate to be obtained. The average respiratory rate is measured from the baseline shifts in the ECG trace. The major change in the ECG pattern induced by a MF is an increase in the amplitude of the T wave of rats and dogs. In our rat study a 20,000 gauss field increased the T wave by about 450%; the dog's T wave was increased 750% by a 16,000 gauss field. These biomagnetic effects appear to be reversible. Out experiments with rats and dogs were designed to test for the presence of a magnetic strength threshold (MST) to evoke T wave enhancement. The MST is defined as the minimum number of gauss to product a measurable change with T wave amplitude. The MTS is 3.0 kgauss for rats and 0.9 kgauss for dogs. Augmentation of the T wave was found to be greatest when thelines of the MF were perpendicular to the long axis of the body and least when parallel. Hence, the orientation of the subject in the MF influences the ECG profile.

  8. Magnetoencephalographic accuracy profiles for the detection of auditory pathway sources.

    Science.gov (United States)

    Bauer, Martin; Trahms, Lutz; Sander, Tilmann

    2015-04-01

    The detection limits for cortical and brain stem sources associated with the auditory pathway are examined in order to analyse brain responses at the limits of the audible frequency range. The results obtained from this study are also relevant to other issues of auditory brain research. A complementary approach consisting of recordings of magnetoencephalographic (MEG) data and simulations of magnetic field distributions is presented in this work. A biomagnetic phantom consisting of a spherical volume filled with a saline solution and four current dipoles is built. The magnetic fields outside of the phantom generated by the current dipoles are then measured for a range of applied electric dipole moments with a planar multichannel SQUID magnetometer device and a helmet MEG gradiometer device. The inclusion of a magnetometer system is expected to be more sensitive to brain stem sources compared with a gradiometer system. The same electrical and geometrical configuration is simulated in a forward calculation. From both the measured and the simulated data, the dipole positions are estimated using an inverse calculation. Results are obtained for the reconstruction accuracy as a function of applied electric dipole moment and depth of the current dipole. We found that both systems can localize cortical and subcortical sources at physiological dipole strength even for brain stem sources. Further, we found that a planar magnetometer system is more suitable if the position of the brain source can be restricted in a limited region of the brain. If this is not the case, a helmet-shaped sensor system offers more accurate source estimation.

  9. A theoretical case study of type I and type II beta-turns.

    Science.gov (United States)

    Czinki, Eszter; Császár, Attila G; Perczel, András

    2003-03-03

    NMR chemical shielding anisotropy tensors have been computed by employing a medium size basis set and the GIAO-DFT(B3LYP) formalism of electronic structure theory for all of the atoms of type I and type II beta-turn models. The models contain all possible combinations of the amino acid residues Gly, Ala, Val, and Ser, with all possible side-chain orientations where applicable in a dipeptide. The several hundred structures investigated contain either constrained or optimized phi, psi, and chi dihedral angles. A statistical analysis of the resulting large database was performed and multidimensional (2D and 3D) chemical-shift/chemical-shift plots were generated. The (1)H(alpha-13)C(alpha), (13)C(alpha-1)H(alpha-13)C(beta), and (13)C(alpha-1)H(alpha-13)C' 2D and 3D plots have the notable feature that the conformers clearly cluster in distinct regions. This allows straightforward identification of the backbone and side-chain conformations of the residues forming beta-turns. Chemical shift calculations on larger For-(L-Ala)(n)-NH(2) (n=4, 6, 8) models, containing a single type I or type II beta-turn, prove that the simple models employed are adequate. A limited number of chemical shift calculations performed at the highly correlated CCSD(T) level prove the adequacy of the computational method chosen. For all nuclei, statistically averaged theoretical and experimental shifts taken from the BioMagnetic Resonance Bank (BMRB) exhibit good correlation. These results confirm and extend our previous findings that chemical shift information from selected multiple-pulse NMR experiments could be employed directly to extract folding information for polypeptides and proteins.

  10. Induction of biogenic magnetization and redox control by a component of the target of rapamycin complex 1 signaling pathway.

    Directory of Open Access Journals (Sweden)

    Keiji Nishida

    Full Text Available Most organisms are simply diamagnetic, while magnetotactic bacteria and migratory animals are among organisms that exploit magnetism. Biogenic magnetization not only is of fundamental interest, but also has industrial potential. However, the key factor(s that enable biogenic magnetization in coordination with other cellular functions and metabolism remain unknown. To address the requirements for induction and the application of synthetic bio-magnetism, we explored the creation of magnetism in a simple model organism. Cell magnetization was first observed by attraction towards a magnet when normally diamagnetic yeast Saccharomyces cerevisiae were grown with ferric citrate. The magnetization was further enhanced by genetic modification of iron homeostasis and introduction of ferritin. The acquired magnetizable properties enabled the cells to be attracted to a magnet, and be trapped by a magnetic column. Superconducting quantum interference device (SQUID magnetometry confirmed and quantitatively characterized the acquired paramagnetism. Electron microscopy and energy-dispersive X-ray spectroscopy showed electron-dense iron-containing aggregates within the magnetized cells. Magnetization-based screening of gene knockouts identified Tco89p, a component of TORC1 (Target of rapamycin complex 1, as important for magnetization; loss of TCO89 and treatment with rapamycin reduced magnetization in a TCO89-dependent manner. The TCO89 expression level positively correlated with magnetization, enabling inducible magnetization. Several carbon metabolism genes were also shown to affect magnetization. Redox mediators indicated that TCO89 alters the intracellular redox to an oxidized state in a dose-dependent manner. Taken together, we demonstrated that synthetic induction of magnetization is possible and that the key factors are local redox control through carbon metabolism and iron supply.

  11. Ultrasound-assisted fabrication of a biocompatible magnetic hydroxyapatite.

    Science.gov (United States)

    Zhou, Gang; Song, Wei; Hou, Yongzhao; Li, Qing; Deng, Xuliang; Fan, Yubo

    2014-10-01

    This work describes the fabrication and characterization of a biocompatible magnetic hydroxyapatite (HA) using an ultrasound-assisted co-precipitation method. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) were used to characterize the structure and chemical composition of the produced samples. The M-H loops of synthesized materials were traced using a vibrating sample magnetometer (VSM) and the biocompatibility was evaluated by cell culture and MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Furthermore, in vivo histopathological examinations were used to evaluate the potential toxicological effects of Fe₃O₄-HA composites on kidney of SD rats injected intraperitoneally with Fe₃O₄-HA particles. The results showed that magnetic iron oxide particles first replace OH ions of HA, which are parallel to the c axis, and then enter the HA crystal lattice which produces changes in the crystal surface of HA. Chemical bond interaction was observed between PO₄³⁻ groups of HA and iron ions of Fe₃O₄. The saturation magnetization (MS ) of Fe₃O₄-HA composites was 46.36 emu/g obtained from VSM data. Cell culture and MTT assays indicated that HA could affect the growth and proliferation of HEK-293 cells. This Fe₃O₄-HA composite produced no negative effects on cell morphology, viability, and proliferation and exhibited remarkable biocompatibility. Moreover, no inflammatory cell infiltration was observed in kidney histopathology slices. Therefore, this study succeeds to develop a Fe₃O₄-HA composite as a prospective biomagnetic material for future applications. © 2013 Wiley Periodicals, Inc.

  12. Consciousness of Unification: The Mind-Matter Phallacy Bites the Dust

    Science.gov (United States)

    Beichler, James E.

    A complete theoretical model of how consciousness arises in neural nets can be developed based on a mixed quantum/classical basis. Both mind and consciousness are multi-leveled scalar and vector electromagnetic complexity patterns, respectively, which emerge within all living organisms through the process of evolution. Like life, the mind and consciousness patterns extend throughout living organisms (bodies), but the neural nets and higher level groupings that distinguish higher levels of consciousness only exist in the brain so mind and consciousness have been traditionally associated with the brain alone. A close study of neurons and neural nets in the brain shows that the microtubules within axons are classical bio-magnetic inductors that emit and absorb electromagnetic pulses from each other. These pulses establish interference patterns that influence the quantized vector potential patterns of interstitial water molecules within the neurons as well as create the coherence within neurons and neural nets that scientists normally associate with more complex memories, thought processes and streams of thought. Memory storage and recall are guided by the microtubules and the actual memory patterns are stored as magnetic vector potential complexity patterns in the points of space at the quantum level occupied by the water molecules. This model also accounts for the plasticity of the brain and implies that mind and consciousness, like life itself, are the result of evolutionary processes. However, consciousness can evolve independent of an organism's birth genetics once it has evolved by normal bottom-up genetic processes and thus force a new type of top-down evolution on living organisms and species as a whole that can be explained by expanding the laws of thermodynamics to include orderly systems.

  13. Assessing atmospheric particulate matter distribution based on Saturation Isothermal Remanent Magnetization of herbaceous and tree leaves in a tropical urban environment.

    Science.gov (United States)

    Barima, Yao Sadaiou Sabas; Angaman, Djédoux Maxime; N'gouran, Kobenan Pierre; Koffi, N'guessan Achille; Kardel, Fatemeh; De Cannière, Charles; Samson, Roeland

    2014-02-01

    Particulate matter (PM) emissions, and the associated human health risks, are likely to continue increasing in urban environments of developing countries like Abidjan (Ivory Cost). This study evaluated the potential of leaves of several herbaceous and tree species as bioindicators of urban particulate matter pollution, and its variation over different land use classes, in a tropical area. Four species well distributed (presence frequencies >90%) over all land use classes, easy to harvest and whose leaves are wide enough to be easily scanned were selected, i.e.: Amaranthus spinosus (Amaranthaceae), Eleusine indica (Poaceae), Panicum maximum (Poaceae) and Ficus benjamina (Moraceae). Leaf sampling of these species was carried out at 3 distances from the road and at 3 height levels. Traffic density was also noted and finally biomagnetic parameters of these leaves were determined. Results showed that Saturation Isothermal Remanent Magnetization (SIRM) of leaves was at least 4 times higher (27.5×10(-6)A) in the vicinity of main roads and industrial areas than in parks and residential areas. The main potential sources of PM pollution were motor vehicles and industries. The slightly hairy leaves of the herbaceous plant A. spinosus and the waxy leaves of the tree F. benjamina showed the highest SIRM (25×10(-6)A). Leaf SIRM increased with distance to road (R(2)>0.40) and declined with sampling height (R(2)=0.17). The distance between 0 and 5m from the road seemed to be the most vulnerable in terms of PM pollution. This study has showed that leaf SIRM of herbaceous and tree species can be used to assess PM exposure in tropical urban environments. © 2013.

  14. Sonochemical synthesis of magnetic core-shell Fe{sub 3}O{sub 4}-ZrO{sub 2} nanoparticles and their application to the highly effective immobilization of myoglobin for direct electrochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Peng Huaping; Liang Ruping; Zhang Li [Department of Chemistry, Nanchang University, Nanchang 330031 (China); Qiu Jianding, E-mail: jdqiu@ncu.edu.c [Department of Chemistry, Nanchang University, Nanchang 330031 (China)

    2011-04-15

    Graphical abstract: Display Omitted Highlights: Magnetic core-shell Fe{sub 3}O{sub 4}-ZrO{sub 2} nanoparticle was synthesized by sonochemical approach. Fe{sub 3}O{sub 4}-ZrO{sub 2} NPs provided high capacity for trapping Mb on magnetic glassy carbon electrode surface. The constructed Mb/Fe{sub 3}O{sub 4}-ZrO{sub 2} film exhibited excellent electrocatalytic ability for the reduction of H{sub 2}O{sub 2}. The proposed method simplifies the immobilization methodology of proteins. - Abstract: In this study, bifunctional Fe{sub 3}O{sub 4}-ZrO{sub 2} magnetic core-shell nanoparticles (NPs), synthesized by a simple and effective sonochemical approach, were attached to the surface of a magnetic glassy carbon electrode (MGCE) and successfully applied to the immobilization/adsorption of myoglobin (Mb) for constructing a novel biosensor platform. With the advantages of the magnetism and the excellent biocompatibility of the Fe{sub 3}O{sub 4}-ZrO{sub 2} NPs, Mb could be easily immobilized on the surface of the electrode in the present of external magnetic field and well retained its bioactivity, hence dramatically facilitated direct electron transfer of Mb was demonstrated. The proposed Mb/Fe{sub 3}O{sub 4}-ZrO{sub 2} biofilm electrode exhibited excellent electrocatalytic behaviors towards the reduction of H{sub 2}O{sub 2} with a linear range from 0.64 {mu}M to 148 {mu}M. This presented system avoids the complex synthesis for protecting Fe{sub 3}O{sub 4} NPs, supplies a simple, effective and inexpensive way to immobilize protein, and is promising for construction of third-generation biosensors and other bio-magnetic induction devices.

  15. Biophysical aspects of the influence of electromagnetic fields (EMF on the human body Influencia de los campos electromagnéticos en el organismo humano: aspectos biofísicos

    Directory of Open Access Journals (Sweden)

    Napaleon Hernández

    1993-03-01

    Full Text Available

     

    Some historical aspects of biomagnetism and of the various steps that led to the development of bioelectricity and electro technique are summarized. Alterations observed in individuals working for long periods of time in contact with artificial EMF are described as well as the correlation between natural EMF and accidentality. The utilization of EMF for therapeutic purposes 15 reviewed and some considerations are given to the so called ";bioenergetic medicine"; that employs light, laser, sound, electricity and magnetism. A warning 15 made against the indiscriminate therapeutic use of EMF by practitioners without proper training; the need for solid research which may support the development of this area of medicine Is emphasized.

     

    En este artículo se resumen algunos aspectos históricos del biomagnetismo y de las etapas que condujeron al desarrollo de la bioelectricidad y la electrotécnica. Se describen las alteraciones observadas en quienes trabajan por períodos prolongados en contacto con campos electromagnéticos (CEM artificiales y la correlación entre los CEM naturales y la accidentalidad. Se revisan la utilización de los CEM con fines curativos y la escuela llamada ";bioenergética"; que utiliza terapéuticamente la luz, el láser, el sonido, la electricidad y el magnetismo. Se previene contra el uso terapéutico Indiscriminado de los CEM por personas sin adecuada formación y se hace énfasis en la necesidad de adelantar Investigaciones serias que sustenten este desarrollo de la medicina.

  16. A Role for Bioelectric Effects in the Induction of Bystander Signals by Ionizing Radiation?

    Science.gov (United States)

    Mothersill, C.; Moran, G.; McNeill, F.; Gow, M.D.; Denbeigh, J.; Prestwich, W.; Seymour, C.B.

    2007-01-01

    The induction of “bystander effects” i.e. effects in cells which have not received an ionizing radiation track, is now accepted but the mechanisms are not completely clear. Bystander effects following high and low LET radiation exposure are accepted but mechanisms are still not understood. There is some evidence for a physical component to the signal. This paper tests the hypothesis that bioelectric or biomagnetic phenomena are involved. Human immortalized skin keratinocytes and primary explants of mouse bladder and fish skin, were exposed directly to ionizing radiation or treated in a variety of bystander protocols. Exposure of cells was conducted by shielding one group of flasks using lead, to reduce the dose below the threshold of 2mGy 60Cobalt gamma rays established for the bystander effect. The endpoint for the bystander effect in the reporter system used was reduction in cloning efficiency (RCE). The magnitude of the RCE was similar in shielded and unshielded flasks. When cells were placed in a Faraday cage the magnitude of the RCE was less but not eliminated. The results suggest that liquid media or cell-cell contact transmission of bystander factors may be only part of the bystander mechanism. Bioelectric or bio magnetic fields may have a role to play. To test this further, cells were placed in a Magnetic Resonance Imaging (MRI) machine for 10min using a typical head scan protocol. This treatment also induced a bystander response. Apart from the obvious clinical relevance, the MRI results further suggest that bystander effects may be produced by non-ionizing exposures. It is concluded that bioelectric or magnetic effects may be involved in producing bystander signaling cascades commonly seen following ionizing radiation exposure. PMID:18648606

  17. Labeling of mesenchymal stem cells for MRI with single-cell sensitivity

    Directory of Open Access Journals (Sweden)

    Ariza de Schellenberger A

    2016-04-01

    Full Text Available Angela Ariza de Schellenberger,1 Harald Kratz,1 Tracy D Farr,2,3 Norbert Löwa,4 Ralf Hauptmann,1 Susanne Wagner,1 Matthias Taupitz,1 Jörg Schnorr,1 Eyk A Schellenberger1 1Department of Radiology, 2Department of Experimental Neurology, Center for Stroke Research Berlin, Charité – Universitätsmedizin Berlin, Berlin, Germany; 3School of Life Sciences, University of Nottingham, Medical School, Nottingham, UK; 4Department of Biomagnetic Signals, Physikalisch-Technische Bundesanstalt Berlin, Berlin, Germany Abstract: Sensitive cell detection by magnetic resonance imaging (MRI is an important tool for the development of cell therapies. However, clinically approved contrast agents that allow single-cell detection are currently not available. Therefore, we compared very small iron oxide nanoparticles (VSOP and new multicore carboxymethyl dextran-coated iron oxide nanoparticles (multicore particles, MCP designed by our department for magnetic particle imaging (MPI with discontinued Resovist® regarding their suitability for detection of single mesenchymal stem cells (MSC by MRI. We achieved an average intracellular nanoparticle (NP load of >10 pg Fe per cell without the use of transfection agents. NP loading did not lead to significantly different results in proliferation, colony formation, and multilineage in vitro differentiation assays in comparison to controls. MRI allowed single-cell detection using VSOP, MCP, and Resovist® in conjunction with high-resolution T2*-weighted imaging at 7 T with postprocessing of phase images in agarose cell phantoms and in vivo after delivery of 2,000 NP-labeled MSC into mouse brains via the left carotid artery. With optimized labeling conditions, a detection rate of ~45% was achieved; however, the experiments were limited by nonhomogeneous NP loading of the MSC population. Attempts should be made to achieve better cell separation for homogeneous NP loading and to thus improve NP

  18. Effects of vicarious pain on self-pain perception: investigating the role of awareness

    Directory of Open Access Journals (Sweden)

    Terrighena EL

    2017-07-01

    Full Text Available Esslin L Terrighena,1,2 Ge Lu,1 Wai Ping Yuen,1 Tatia M C Lee,1–4 Kati Keuper1,2,5 1Department of Psychology, Laboratory of Neuropsychology, The University of Hong Kong, Hong Kong; 2Laboratory of Social Cognitive Affective Neuroscience, The University of Hong Kong, Hong Kong; 3The State Key Laboratory of Brain and Cognitive Sciences, Hong Kong; 4Institute of Clinical Neuropsychology, The University of Hong Kong, Hong Kong; 5Institute for Biomagnetism and Biosignalanalysis, University of Münster, Münster, Germany Abstract: The observation of pain in others may enhance or reduce self-pain, yet the boundary conditions and factors that determine the direction of such effects are poorly understood. The current study set out to show that visual stimulus awareness plays a crucial role in ­determining whether vicarious pain primarily activates behavioral defense systems that enhance pain sensitivity and stimulate withdrawal or appetitive systems that attenuate pain sensitivity and stimulate approach. We employed a mixed factorial design with the between-subject factors exposure time (subliminal vs optimal and vicarious pain (pain vs no pain images, and the within-subject factor session (baseline vs trial to investigate how visual awareness of vicarious pain images affects subsequent self-pain in the cold-pressor test. Self-pain tolerance, intensity and unpleasantness were evaluated in a sample of 77 healthy participants. Results revealed ­significant interactions of exposure time and vicarious pain in all three dependent measures. In the presence of visual awareness (optimal condition, vicarious pain compared to no-pain elicited overall enhanced self-pain sensitivity, indexed by reduced pain tolerance and enhanced ratings of pain intensity and unpleasantness. Conversely, in the absence of visual awareness (subliminal condition, vicarious pain evoked decreased self-pain intensity and unpleasantness while pain tolerance remained unaffected. These

  19. Low-frequency noise in high-(Tc) superconductor Josephson junctions, SQUIDs, and magnetometers

    Science.gov (United States)

    Miklich, A. H.

    1994-05-01

    Design and performance of high-T(sub c) dc superconducting quantum interference devices (SQUID's), junctions that comprise them, and magnetometers made from them are described, with attention to sources of 1/f noise. Biepitaxial junctions are found to have large levels of critical current fluctuations which make them unsuitable for low-noise SQUID's; this suggests a poorly connected interface at the grain boundary junction. SQUID's from bicrystal junctions have levels of critical current noise controllable using bias current reversal techniques which leave the noise white down to frequencies of a few Hz. A SQUID with an energy resolution of 1.5 x 10(exp -30) J Hz(exp -1) at 1 Hz is reported. Magnetometers in which a (9 mm)(exp 2) pickup loop is directly coupled to a SQUID body have achieved field resolutions of 93 fT Hz(exp -1/2) down to frequencies below 1 Hz, improving to 39 fT Hz(exp -1/2) at 1 Hz with the addition of a 50mm-diameter single-turn flux transformer. Poor coupling to pickup loop makes it difficult to satisfy competing goals of high field resolution and small detector size necessary for multichannel biomagnetic imaging. Improved coupling is demonstrated by the use of multiturn-input-coil flux transformers, and a resolution of 35 fT Hz(exp -1/2) in the white noise region is reported with a (10 mm)(exp 2) pickup loop. However, additional 1/f noise from processed multilayer structures in the transformer limits the resolution at 1 Hz to 114 fT Hz(exp -1/2). High-T(sub c) SQUID's exhibit additional 1/f noise when cooled in a nonzero static magnetic field because of additional flux vortices trapped in the film, with the noise power at 1 Hz typically increasing by a factor of 10-20 in a field of 0.05mT (0.5 G). Finally, a SQUID-based voltmeter with a resolution of 9.2 pV Hz(exp -1/2) at 10 Hz (24 pV Hz(exp -1/2) at 1 Hz) is described.

  20. Low-Frequency Noise in High-T Superconductor Josephson Junctions, Squids, and Magnetometers.

    Science.gov (United States)

    Miklich, Andrew Hostetler

    The design and performance of high-T_ {rm c} dc superconducting quantum interference devices (SQUIDs), the junctions that comprise them, and magnetometers made from them are described, with special attention paid to sources of 1/f noise. Biepitaxial junctions are found to have large levels of critical current fluctuations which make them unsuitable for low-noise SQUIDs. This noise suggests a poorly connected interface at the grain boundary junction. SQUIDs from bicrystal junctions, in contrast, have levels of critical current noise that are controllable using bias current reversal techniques which leave the noise white down to frequencies of a few Hz. A SQUID with an energy resolution of 1.5times 10^{-30} J Hz^ {-1} at 1 Hz is reported. Magnetometers in which a (9 mm)^2 pickup loop is directly coupled to a SQUID body have achieved field resolutions of 93 fT Hz^{-1/2} down to frequencies below 1 Hz, improving to 39 fT Hz^{-1/2} at 1 Hz with the addition of a 50 mm-diameter single-turn flux transformer. Although the performance of these devices is sufficient for single -channel biomagnetometry or geophysical studies, their relatively poor coupling to the pickup loop makes it difficult to satisfy the competing goals of high field resolution and small detector size necessary for multichannel biomagnetic imaging. Improved coupling is demonstrated by the use of multiturn-input-coil flux transformers, and a resolution of 35 fT Hz^{-1/2} in the white noise region is reported with a (10 mm) ^2 pickup loop. However, additional 1/f noise from the processed multilayer structures in the transformer limits the resolution at 1 Hz to 114 fT Hz^ {-1/2}. High-T_{ rm c} SQUIDs are shown to exhibit additional 1/f noise when they are cooled in a nonzero static magnetic field because of the additional flux vortices trapped in the film, with the noise power at 1 Hz typically increasing by a factor of 10-20 in a field of 0.05 mT (0.5 G). Finally, a SQUID-based voltmeter with a resolution

  1. New Frontiers in Heart Rate Variability and Social Coherence Research: Techniques, Technologies, and Implications for Improving Group Dynamics and Outcomes

    Directory of Open Access Journals (Sweden)

    Rollin McCraty

    2017-10-01

    among group members. (2 Training in techniques to increase group coherence and heart rhythm synchronization will correlate with increased prosocial behaviors, such as kindness and cooperation among individuals, improved communication, and decreases in social discord and adversarial interactions. (3 Biomagnetic fields produced by the heart may be a primary mechanism in mediating HRV synchronization among group members. Data supporting each of the hypothesis is discussed.

  2. Obituary: Gordon Donaldson Obituary: Gordon Donaldson

    Science.gov (United States)

    Pegrum, Colin; Campbell, Archie; Hampshire, Damian

    2013-07-01

    Gordon Donaldson died in Glasgow on 28 November 2012 at the age of 71. He was born in Edinburgh and brought up and educated in Glasgow, which was his home city for much of his life. He was educated first at Glasgow Academy, and then with a scholarship at Christ's College Cambridge. Here he read Natural Sciences, finishing with first class honors in Physics. He then did a PhD on tunneling in superconductors in the Mond Laboratory, supervised by John Adkins. These were interesting times, since type II superconductors had only recently been identified, and the Mond was a leading player in the physics of vortices and other quantum effects. It was headed by Pippard and Shoenberg, and colleagues around that time were Brian Josephson, John Clarke, Colin Gough and John Waldram. On finishing his PhD in 1966 Gordon went straight to a lectureship at the University of Lancaster. In 1975 during a sabbatical at the University of California, Berkeley, with John Clarke's group, Gordon co-invented thin-film gradiometers with integrated DC SQUIDs. He then moved back to Glasgow, to the Department of Applied Physics at Strathclyde University, where he founded a new research group to make and use superconducting devices, especially SQUIDs and gradiometers. From modest beginnings the group grew steadily, acquiring new facilities and members, until in the 1990s it had over 20 members and a host of collaborators from elsewhere in Glasgow and abroad. With funding from the Wellcome Trust, Gordon and colleagues at Glasgow University and the Southern General Hospital in Glasgow set up a new biomagnetism facility in 1998 on the hospital campus to use SQUID gradiometers made at Strathclyde for measurements on patients and volunteers. Another of his main research interests was the use of SQUIDs for nondestructive evaluation (NDE). This started in the days before high temperature superconductors (HTS) with wire-wound gradiometers and niobium SQUIDs, soon moving on to miniature thin-film niobium

  3. PREFACE: Joint European Magnetic Symposia - JEMS 2010

    Science.gov (United States)

    Spałek, Jozef

    2011-07-01

    łekChairman of JEMS 2010 Symposia 1. Plenary, Semi-plenary, Tutorials 2. Magnetization Processes Spin Excitations and Ultrafast DynamicsCoordinator: Andrzej Maziewski (Bialystok) 3. Hard Magnetic Materials and MagnetocaloricsCoordinator: Henryk Figiel (Kraków) 4. Magnetic HydridesCoordinators: Ladislav Havela (Praha), Zbigniew Tarnawski (Kraków) 5. Interface of Magnetic Thin FilmsCoordinators: Jürgen Fassbender (Dresden), N-T H Kim-Ngan (Kraków) 6. Magnonic CrystalsCoordinators: Bahram Djafari-Rouhani (Lille), Henryk Puszkarski (Poznan) 7. Magnetism of Metals, Alloys, and IntermetallicsCoordinator: Andrzej Szytula (Kraków) 8. Molecular MagnetismCoordinators: Stephen Blundell (Oxford), Maria Balanda (Kraków) 9. Magnetooptics of NanomagnetsCoordinators: Kamil Postava (Ostrava), Marek Kisielewski (Bialystok) 10. NanomagnetismCoordinators: Marek Przybylski (Halle), Jürgen Kirschner (Halle) 11. Other topics - Biomagnetism, Domain Walls, InstrumentationCoordinator: Henryk Figiel (Kraków) 12. Magnetic Perovskites and MultiferroicsCoordinator: Henryk Szymczak (Warszawa) 13. Magnetic Semiconductors and InsulatorsCoordinators: Klaus Baerner (Göttingen), Tadeusz Gron (Katowice) 14. Magnetic Shape Memory Effects and Related PhenomenaCoordinators: Oliver Gutfleisch (Dresden), Sebastian Fähler (Dresden) 15. Soft Magnetic MaterialsCoordinators: Julian González (San Sebastian), Krzysztof Kulakowski (Kraków) 16. SpintronicsCoordinator: Maciej Sawicki (Warszawa) 17. Strongly Correlated Electron Systems, Magnetism and SuperconductivityCoordinator: Andrzej Slebarski (Katowice) The next Joint European Magnetic Symposia, JEMS 2012, will be held in Parma, Italy, 9-14 September 2012.www.jems2012.itCo-Chairs:Franca Albertini, Institute of Materials for Electronics and Magnetism (IMEM), CNR, ParmaRoberto De Renzi, Department of Physics, University of Parma

  4. The relevance of the natural magnetic environment for life

    International Nuclear Information System (INIS)

    Morariu, V. Vasile

    2001-01-01

    a common trait is that ZMF stimulate their growth and development. Also we have some evidence that ZMF is not at all good for mammals. But we do not know if long term changes of the GMF do affect the terrestrial life or whether adaptation occur. During the last several thousands years GMF decreased to at least half or more of its value. The present value of about 0.5 Gauss at mid latitude will go down to zero in about 1500 years at the present rate of change. We cannot decide whether such a decrease had an impact on terrestrial life. Also according to our present knowledge we might hypothesise that the rate of change of GMF is small enough and it allows for adaptation. However there are species who clearly depend on GMF such as magnetotactic bacteria or bees. At present the research in the field of biomagnetism is widespread into a large area of experimental conditions such as intensity, frequency and duration of the experiments. It is strongly felt the necessity to unite the efforts of various laboratories on joint projects including both on the lines a) and b) of strategies. (author)

  5. Hyperthermia treatment of tumors by mesenchymal stem cell-delivered superparamagnetic iron oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Kalber TL

    2016-05-01

    Full Text Available Tammy L Kalber,1,2,* Katherine L Ordidge,1,2,* Paul Southern,3 Michael R Loebinger,1 Panagiotis G Kyrtatos,2,3 Quentin A Pankhurst,3,* Mark F Lythgoe,2,* Sam M Janes1,* 1Lungs for Living Research Centre, UCL Respiratory, University College London, 2UCL Centre for Advanced Biomedical Imaging, Division of Medicine, University College London, 3Healthcare Biomagnetics Laboratory, University College London, London, UK *These authors contributed equally to this work Abstract: Magnetic hyperthermia – a potential cancer treatment in which superparamagnetic iron oxide nanoparticles (SPIONs are made to resonantly respond to an alternating magnetic field (AMF and thereby produce heat – is of significant current interest. We have previously shown that mesenchymal stem cells (MSCs can be labeled with SPIONs with no effect on cell proliferation or survival and that within an hour of systemic administration, they migrate to and integrate into tumors in vivo. Here, we report on some longer term (up to 3 weeks post-integration characteristics of magnetically labeled human MSCs in an immunocompromized mouse model. We initially assessed how the size and coating of SPIONs dictated the loading capacity and cellular heating of MSCs. Ferucarbotran® was the best of those tested, having the best like-for-like heating capability and being the only one to retain that capability after cell internalization. A mouse model was created by subcutaneous flank injection of a combination of 0.5 million Ferucarbotran-loaded MSCs and 1.0 million OVCAR-3 ovarian tumor cells. After 2 weeks, the tumors reached ~100 µL in volume and then entered a rapid growth phase over the third week to reach ~300 µL. In the control mice that received no AMF treatment, magnetic resonance imaging (MRI data showed that the labeled MSCs were both incorporated into and retained within the tumors over the entire 3-week period. In the AMF-treated mice, heat increases of ~4°C were observed