Bioelectric Signal Measuring System

NASA Astrophysics Data System (ADS)

Guadarrama-Santana, A.; Pólo-Parada, L.; García-Valenzuela, A.

2015-01-01

We describe a low noise measuring system based on interdigitated electrodes for sensing bioelectrical signals. The system registers differential voltage measurements in order of microvolts. The base noise during measurements was in nanovolts and thus, the sensing signals presented a very good signal to noise ratio. An excitation voltage of 1Vrms with 10 KHz frequency was applied to an interdigitated capacitive sensor without a material under test and to a mirror device simultaneously. The output signals of both devices was then subtracted in order to obtain an initial reference value near cero volts and reduce parasitic capacitances due to the electronics, wiring and system hardware as well. The response of the measuring system was characterized by monitoring temporal bioelectrical signals in real time of biological materials such as embryo chicken heart cells and bovine suprarenal gland cells.

The Relationship between Chlorophyll Fluorescence Parameter (Fv/Fm) and Frequency Component of Plant Bioelectric Potential in Spraying Chemical Herbicides

NASA Astrophysics Data System (ADS)

Shibata, Shin-Ichi; Satou, Fumitake; Kimura, Haruhiko; Oyabu, Takashi

Recently, there is a problem of the steady supply of food therefore plant factory has been establishing and takes off in world wide countries. In the plant factory, the growing environment can be controlled and the crop can also be controlled. The products are growing in an enclosed environment, therefore agricultural chemicals has no use. Secure and safe food producing system can be constructed. However, efficient production formula for the plant (for example vegetable) is not defined well. It is an effective way to control the growing environmental factors using physiology information which are directly obtained from the vegetable. The chlorophyll fluorescence is used as evaluation of plant condition. It is necessary to clarify the bioelectric potential in the growth condition of the plant. In this study, we examined the relationship between the chlorophyll fluorescence and the plant bioelectric potential in bad condition. The plant in spraying chemical herbicides was assumed as the condition. In future, plant physiological function and environmental response can be understood by directly monitoring the bioelectric potential.

Plant Bioelectric Potential of Hard-leaf Cabbage to Irradiation-light Frequency

NASA Astrophysics Data System (ADS)

Tokuda, Masaki; Shao, Lixin; Oyabu, Takashi; Nanto, Hidehito

Bioelectric potential was investigated to examine the availability of vegetable growth control. The potential is a kind of information transmitted by the vegetable and it varies markedly with one’s physiological phenomenon, light, air contaminant and insect which are external factors. Highly-efficient growth control can be made possible due to clarifying the relationship between the external factors and the potential. Vegetable can be used as a sensor in addition. A hard-leaf cabbage (Ancient specie) was adopted as a subjective plant in this study and the bioelectric potential was measured. The analysis was carried out using the summation of the potential (vm1) for one minute. The data was input every 0.1 seconds through a difference amplifier. The potential characteristic was investigated as a function of light frequency emitting from a LED panel. In addition, the potential was studied when ethyl alcohol existed and not existed as an air contaminant. As a result, it becomes obvious that the vm1 is raised when blue and red lights are irradiated. The lights mainly contribute to photosynthesis. The potential increases in the presence of ethyl alcohol which was adopted as a kind of nutrient.

Bioelectrical impedance analysis. What does it measure?

NASA Technical Reports Server (NTRS)

Schoeller, D. A.

2000-01-01

Bioelectrical impedance analysis (BIA) has been proposed for measuring fat-free mass, total body water, percent fat, body cell mass, intracellular water, and extracellular water: a veritable laboratory in a box. Although it is unlikely that BIA is quite this versatile, correlations have been demonstrated between BIA and all of these body compartments. At the same time, it is known that all of the compartments are correlated among themselves. Because of this, it is difficult to determine whether BIA is specific for any or all of these compartments. To investigate this question, we induced acute changes in total body water and its compartments over a 3-h period. Using this approach, we demonstrated that multifrequency BIA, using the Cole-Cole model to calculate the zero frequency and infinite frequency resistance, measures extracellular and intracellular water.

Electro-optic electrodes based on Lithium Niobate Mach Zhender Interferometer Modulators for wearable bioelectric activity recording

NASA Astrophysics Data System (ADS)

Fernandes, Mariana S.; Correia, José H.; Mendes, Paulo M.

2011-05-01

Wearable devices are used to record several physiological signals, providing unobtrusive and continuous monitoring. A main challenge in these systems is to develop new recording sensors, specially envisioning bioelectric activity detection. Available devices are difficult to integrate, mainly due to the amount of electrical wires and components needed. This work proposes a fiber-optic based device, which basis of operation relies on the electro-optic effect. A Lithium Niobate (LiBnO3) Mach-Zehnder Interferometer (MZI) modulator is used as the core sensing component, followed by a signal conversion and processing stage. Tests were performed in order to validate the proposed acquisition system in terms of signal amplification and quality, stability and frequency response. A light source with a wavelength operation of 1530- 1565 nm was used. The modulated intensity is amplified and converted to an output voltage with a high transimpedance gain. The filtering and electric amplification included a 50Hz notch filter, a bandpass filter with a -3 dB bandwidth from 0.50 to 35 Hz. The obtained system performance on key elements such as sensitivity, frequency content, and signal quality, have shown that the proposed acquisition system allows the development of new wearable bioelectric monitoring solutions based on optical technologies.

[The bioelectric activity of the brain in dyscirculatory encephalopathy and arterial hypertension developed in the Chernobyl nuclear disaster liquidators].

PubMed

Podsonnaia, I V; Efremushkin, G G; Zhelobetskaia, E D

2012-01-01

The long-term effects of the ionizing radiation on the bioelectric brain activity in the Chernobyl nuclear disaster liquidators with discirculatory encephalopathy and arterial hypertension were studied. We examined 195 male patients, aged from 30 to 65 years, with the clinical presentations of discirculatory encephalopathy, using electroencephalography: 105 patients were liquidators of the Chernobyl nuclear disaster (the main group) and 90 patients had no radiation anamnesis (the comparison group). It has been found that the development of discirculatory encephalopathy in liquidators of the Chernobyl nuclear disaster is mainly associated with the dysfunction of diencephalic and cortical structures. The specificity of the neurofunctional brain abnormalities in liquidators with discirculatory encephalopathy is characterized by the predominance of the low-amplitude and low-frequency alpha-activity or by the lack of alpha-rhythm and by its substitution for the high-frequency beta-rhythm with the presence of theta- and delta-activity and by the more significant flatness of the alpha-rhythm zonation. The presence of the radiation factor in the past history is correlated with the failure of the bioelectric brain activity in the alpha band (r=0.42) that increases risk of abnormal changes by a factor of 10 (p<0.001). The liquidators with arterial hypertension are characterized by the more frequent occurrence of the asymmetry of the recorded bioelectric potentials between the similar hemispheric areas, by the more significant difference in the external stimulus response of the brain (functional tests). The results indicate the more complicated and diffuse lesion of the brain in the liquidators of the Chernobyl nuclear disaster in the post-radiation period during the development of discirculatory encephalopathy and arterial hypertension.

Method of recording bioelectrical signals using a capacitive coupling

NASA Astrophysics Data System (ADS)

Simon, V. A.; Gerasimov, V. A.; Kostrin, D. K.; Selivanov, L. M.; Uhov, A. A.

2017-11-01

In this article a technique for the bioelectrical signals acquisition by means of the capacitive sensors is described. A feedback loop for the ultra-high impedance biasing of the input instrumentation amplifier, which provides receiving of the electrical cardiac signal (ECS) through a capacitive coupling, is proposed. The mains 50/60 Hz noise is suppressed by a narrow-band stop filter with an independent notch frequency and quality factor tuning. Filter output is attached to a ΣΔ analog-to-digital converter (ADC), which acquires the filtered signal with a 24-bit resolution. Signal processing board is connected through universal serial bus interface to a personal computer, where ECS in a digital form is recorded and processed.

Bioelectric fields of marine organisms: voltage and frequency contributions to detectability by electroreceptive predators.

PubMed

Bedore, Christine N; Kajiura, Stephen M

2013-01-01

Behavioral responses of elasmobranch fishes to weak electric fields have been well studied. These studies typically employ a stimulator that produces a dipole electric field intended to simulate the natural electric field of prey items. However, the characteristics of bioelectric fields have not been well described. The magnitude and frequency of the electric field produced by 11 families of marine organisms were quantified in this study. Invertebrate electric potentials ranged from 14 to 28 μV and did not differ from those of elasmobranchs, which ranged from 18 to 30 μV. Invertebrates and elasmobranchs produced electric potentials smaller than those of teleost fishes, which ranged from 39 to 319 μV. All species produced electric fields within the frequency range that is detectable by elasmobranch predators (<16 Hz), with the highest frequencies produced by the penaeids (10.3 Hz) and the gerreids (4.6 Hz). Although voltage differed by family, there was no relationship between voltage and mass or length of prey. Differences in prey voltage may be related to osmoregulatory strategies; invertebrates and elasmobranchs are osmoconformers and have less ion exchange with the surrounding seawater than teleosts species, which are hyposmotic. As predicted, voltage production was greatest at the mucous membrane-lined mouth and gills, which are sites of direct ion exchange with the environment.

Biomechanical bases of rehabilitation of children with cerebral palsy

NASA Astrophysics Data System (ADS)

Davlet'yarova, K. V.; Korshunov, S. D.; Kapilevich, L. V.

2015-11-01

Biomechanical analysis and the study results of children's with cerebral palsy (CP) muscles bioelectrical activity while walking on a flat surface are represented. Increased flexion in the hip and shoulder joints and extension in the elbow joint in children with cerebral palsy were observed, with the movement of the lower limbs had less smooth character in comparison with the control group. Herewith, the oscillation amplitude was significantly increased, and the frequency in the m. gastrocnemius and m. lateralis was decreased. It was shown, that the dynamic stereotype of walking in children with cerebral palsy was characterized by excessive involvement of m. gastrocnemius and m.latissimus dorsi in locomotion. Thus, resulting biomechanical and bioelectrical parameters of walking should be considered in the rehabilitation programs development.

Smartphone-Based Bioelectrical Impedance Analysis Devices for Daily Obesity Management

PubMed Central

Choi, Ahyoung; Kim, Justin Younghyun; Jo, Seongwook; Jee, Jae Hwan; Heymsfield, Steven B.; Bhagat, Yusuf A.; Kim, Insoo; Cho, Jaegeol

2015-01-01

Current bioelectric impedance analysis (BIA) systems are often large, cumbersome devices which require strict electrode placement on the user, thus inhibiting mobile capabilities. In this work, we developed a handheld BIA device that measures impedance from multiple frequencies (5 kHz~200 kHz) with four contact electrodes and evaluated the BIA device against standard body composition analysis systems: a dual-energy X-ray absorptiometry (DXA) system (GE Lunar Prodigy, GE Healthcare, Buckinghamshire, UK) and a whole-body BIA system (InBody S10, InBody, Co. Ltd, Seoul, Korea). In the study, 568 healthy participants, varying widely in body mass index, age, and gender, were recruited at two research centers: the Samsung Medical Center (SMC) in South Korea and the Pennington Biomedical Research Center (PBRC) in the United States. From the measured impedance data, we analyzed individual body fat and skeletal muscle mass by applying linear regression analysis against target reference data. Results indicated strong correlations of impedance measurements between the prototype pathways and corresponding InBody S10 electrical pathways (R = 0.93, p < 0.0001). Additionally, body fat estimates from DXA did not yield significant differences (p > 0.728 (paired t-test), DXA mean body fat 29.45 ± 10.77 kg, estimated body fat 29.52 ± 12.53 kg). Thus, this portable BIA system shows a promising ability to estimate an individual’s body composition that is comparable to large stationary BIA systems. PMID:26364636

Effect of Intravenous Infusion Solutions on Bioelectrical Impedance Spectroscopy.

PubMed

Yap, Jason; Rafii, Mahroukh; Azcue, Maria; Pencharz, Paul

2017-05-01

Bioelectrical impedance (BIA) is often used to measure body fluid spaces and thereby body composition. However, in acute animal studies, we found that impedance was driven by the saline content of intravenous (IV) fluids and not by the volume. The aim of the study was to investigate the effect of 3 different fluids acutely administered on the change in impedance, specifically resistance (R). Nine healthy adults participated in 3 treatment (0.9% saline, 5% dextrose, and a mixture of 0.3% saline + 3.3% dextrose) experiments on nonconsecutive days. They all received 1 L of one of the treatments intravenously over a 1-hour period. Repeated BIA measurements were performed prior to IV infusion and then every 5 minutes for the 1-hour infusion period, plus 3 more measurements up to 15 minutes after the completion of the infusion. The change in R in the 0.9% saline infusion experiment was significantly lower than that of the glucose and mixture treatment ( P < .001). Bioelectrical impedance spectroscopy and BIA measure salt rather than the volume changes over the infusion period. Hence, in patients receiving IV fluids, BIA of any kind (single frequency or multifrequency) cannot be used to measure body fluid spaces or body composition.

Tissue electrical properties measured by bioelectrical impedance analysis among healthy and sportsmen population

NASA Astrophysics Data System (ADS)

Kapica, Dominik; Warchulińska, Joanna; Jakubiak, Monika; Teter, Mariusz; Mlak, Radosław; Hałabiś, Magdalena; Wójcik, Waldemar; Małecka-Massalska, Teresa

2015-09-01

Introduction: Bioelectrical impedance analysis (BIA) is a useful tool to asses human body composition and nutrition status; multi-frequency BIA has a higher accuracy than single-frequency BIA. In our study a difference of impedance values (Z) at 5, 100 and 200 kHz and Z200/Z5 index between professional athletes and control group were determined. Methods: In this research 105 people were tested, divided into control group (72 people: 35 males and 37 females) and professional athletes (33 people: 16 males and 17 females). Impedance was measured at three frequency values - 5, 100 and 200 kHz; with received values the Z200/Z5 index was calculated. Results: In most compared subgroups impedance values showed significantly lower values in athletes than in control group (5 kHz - males: p=0.136, females: p=0.001, 100 kHz - males: p=0.039, females: p<0.0001, 200 kHz - males: p=0.047, females: p<0.0001) Z200/Z5 index also showed lower value in athletes than in control group (p=0.016 for males, p<0.0001 for females). Conclusion: Lower values of impedance and Z200/Z5 index indicates a better nutrition status and general health condition of athletes than in control group.

Bioelectrical Markers of ADHD: Enhancement of Direct EEG Analysis

ERIC Educational Resources Information Center

Martín-Brufau, Ramón; Nombela Gómez, Manuel

2017-01-01

Introduction: So far some methods to help diagnosis of ADHD grounded in EEG decomposition by the FFT method and the discovery of the relationship between different frequency bands, the most clarifying the TBR rate in the prefrontal regions, have been proposed. This procedure requires a complex gadgetry so we evaluate the advantages of a simple…

Association of phase angle on bioelectrical impedance analysis and dialysis frequency with survival of chronic hemodialysis patients

NASA Astrophysics Data System (ADS)

Muzasti, R. A.; Lubis, H. R.

2018-03-01

Phase angle, a parameter by Bioelectrical Impedance Analysis, can detect body composition changes, so it can be used as a prognostic indicator in some chronic conditions. This study was for determining the relationship between PhA and hemodiálisis frequency with the survival of chronic hemodiálisis patients. This longitudinal retrospective study involved 173 chronic hemodiálisis patients at Rasyida Renal Hospital. The Kaplan-Meier method is used to determine the survival. Cox proportional hazard analysis is used to determine which variables significantly increase mortality. During the study period, 89 patients underwent hemodiálysis 3x a week (4 hours/session), and 84 patients underwent HD 2x a week (5 hours/session). Demographic and clinical characteristics in both groups were similar. There was no difference in PhA value in groups of 3x a week and group 2x a week (4.02 ± 1.13 vs 4.25 ± 1.12). Patients with twice a week hemodiálisis had a shorter survival than the 3x week group (35.14 ± 2.76 vs 38.62 ± 3.03) although it was not statistically significant (p = 0.126).

[Effect of oxysophoridine on electric activities and its power spectrum of reticular formation in rats].

PubMed

Yu, Jianqiang; Li, Yuxiang; Zhao, Chengjun; Gong, Xin; Liu, Jianping; Wang, Feng; Jiang, Yuanxu

2010-05-01

To observe the effect of oxysophoridine (OSR) on the EEG and its power spectrum of reticulum formation in mesencephalon of anaesthetized rat. Utilizing the technique of brain stereotactic apparatus, electrodes were implanted into reticulum formation of mesencephalon. Monopolar lead and computerized FFT technique were employed to record and analyse the index of EEG, power spectrum and frequency distribution in order to study the effect of oxysophoridine on the bioelectricity change of mesencephalon reticulum formation in rats. After administrating(icy) with oxysophoridine at the dose of 2.5,5, 10 mg/rat, the EEG of mesencephalon reticulum formation mainly characterized with low amplitude and slow waves accompanied by spindle-formed sleeping waves with a significant decrease of total power of EEG (P < 0.05) while the ratio of theta, alpha waves increased in total frequency of rats (P < 0.05). Oxysophoridine possesses central inhibitory effects and its inhibitory mechanism may associate with the reduction of bioelectricity in mesencephalon reticulum formation. Mesencephalon reticulum formation may serve as one part of the structure serving as the circuit conducting the central inhibitory effect of oxysophoridine. [Key words] oxysophoridine; reticulum formation; electroencephalogram (EEG) ; rats

Imaging electric field dynamics with graphene optoelectronics.

PubMed

Horng, Jason; Balch, Halleh B; McGuire, Allister F; Tsai, Hsin-Zon; Forrester, Patrick R; Crommie, Michael F; Cui, Bianxiao; Wang, Feng

2016-12-16

The use of electric fields for signalling and control in liquids is widespread, spanning bioelectric activity in cells to electrical manipulation of microstructures in lab-on-a-chip devices. However, an appropriate tool to resolve the spatio-temporal distribution of electric fields over a large dynamic range has yet to be developed. Here we present a label-free method to image local electric fields in real time and under ambient conditions. Our technique combines the unique gate-variable optical transitions of graphene with a critically coupled planar waveguide platform that enables highly sensitive detection of local electric fields with a voltage sensitivity of a few microvolts, a spatial resolution of tens of micrometres and a frequency response over tens of kilohertz. Our imaging platform enables parallel detection of electric fields over a large field of view and can be tailored to broad applications spanning lab-on-a-chip device engineering to analysis of bioelectric phenomena.

Bioelectrical impedance analysis for bovine milk: Preliminary results

NASA Astrophysics Data System (ADS)

Bertemes-Filho, P.; Valicheski, R.; Pereira, R. M.; Paterno, A. S.

2010-04-01

This work reports the investigation and analysis of bovine milk quality by using biological impedance measurements using electrical impedance spectroscopy (EIS). The samples were distinguished by a first chemical analysis using Fourier transform midinfrared spectroscopy (FTIR) and flow citometry. A set of milk samples (100ml each) obtained from 17 different cows in lactation with and without mastitis were analyzed with the proposed technique using EIS. The samples were adulterated by adding distilled water and hydrogen peroxide in a controlled manner. FTIR spectroscopy and flow cytometry were performed, and impedance measurements were made in a frequency range from 500Hz up to 1MHz with an implemented EIS system. The system's phase shift was compensated by measuring saline solutions. It was possible to show that the results obtained with the Bioelectrical Impedance Analysis (BIA) technique may detect changes in the milk caused by mastitis and the presence of water and hydrogen peroxide in the bovine milk.

Validity and reliability of bioelectrical impedance analysis and skinfold thickness in predicting body fat in military personnel.

PubMed

Aandstad, Anders; Holtberget, Kristian; Hageberg, Rune; Holme, Ingar; Anderssen, Sigmund A

2014-02-01

Previous studies show that body composition is related to injury risk and physical performance in soldiers. Thus, valid methods for measuring body composition in military personnel are needed. The frequently used body mass index method is not a valid measure of body composition in soldiers, but reliability and validity of alternative field methods are less investigated in military personnel. Thus, we carried out test and retest of skinfold (SKF), single frequency bioelectrical impedance analysis (SF-BIA), and multifrequency bioelectrical impedance analysis measurements in 65 male and female soldiers. Several validated equations were used to predict percent body fat from these methods. Dual-energy X-ray absorptiometry was also measured, and acted as the criterion method. Results showed that SF-BIA was the most reliable method in both genders. In women, SF-BIA was also the most valid method, whereas SKF or a combination of SKF and SF-BIA produced the highest validity in men. Reliability and validity varied substantially among the equations examined. The best methods and equations produced test-retest 95% limits of agreement below ±1% points, whereas the corresponding validity figures were ±3.5% points. Each investigator and practitioner must consider whether such measurement errors are acceptable for its specific use. Reprint & Copyright © 2014 Association of Military Surgeons of the U.S.

High-resolution non-contact measurement of the electrical activity of plants in situ using optical recording

PubMed Central

Zhao, Dong-Jie; Chen, Yang; Wang, Zi-Yang; Xue, Lin; Mao, Tong-Lin; Liu, Yi-Min; Wang, Zhong-Yi; Huang, Lan

2015-01-01

The limitations of conventional extracellular recording and intracellular recording make high-resolution multisite recording of plant bioelectrical activity in situ challenging. By combining a cooled charge-coupled device camera with a voltage-sensitive dye, we recorded the action potentials in the stem of Helianthus annuus and variation potentials at multiple sites simultaneously with high spatial resolution. The method of signal processing using coherence analysis was used to determine the synchronization of the selected signals. Our results provide direct visualization of the phloem, which is the distribution region of the electrical activities in the stem and leaf of H. annuus, and verify that the phloem is the main action potential transmission route in the stems of higher plants. Finally, the method of optical recording offers a unique opportunity to map the dynamic bioelectrical activity and provides an insight into the mechanisms of long-distance electrical signal transmission in higher plants. PMID:26333536

Endogenous Bioelectric Signaling Networks: Exploiting Voltage Gradients for Control of Growth and Form.

PubMed

Levin, Michael; Pezzulo, Giovanni; Finkelstein, Joshua M

2017-06-21

Living systems exhibit remarkable abilities to self-assemble, regenerate, and remodel complex shapes. How cellular networks construct and repair specific anatomical outcomes is an open question at the heart of the next-generation science of bioengineering. Developmental bioelectricity is an exciting emerging discipline that exploits endogenous bioelectric signaling among many cell types to regulate pattern formation. We provide a brief overview of this field, review recent data in which bioelectricity is used to control patterning in a range of model systems, and describe the molecular tools being used to probe the role of bioelectrics in the dynamic control of complex anatomy. We suggest that quantitative strategies recently developed to infer semantic content and information processing from ionic activity in the brain might provide important clues to cracking the bioelectric code. Gaining control of the mechanisms by which large-scale shape is regulated in vivo will drive transformative advances in bioengineering, regenerative medicine, and synthetic morphology, and could be used to therapeutically address birth defects, traumatic injury, and cancer.

Modelling the cost-utility of bio-electric stimulation therapy compared to standard care in the treatment of elderly patients with chronic non-healing wounds in the UK.

PubMed

Clegg, John P; Guest, Julian F

2007-04-01

To estimate the cost-utility of bio-electric stimulation therapy (Posifect) compared to standard care in elderly patients with chronic, non-healing wounds of > 6 months duration, from the perspective of the National Health Service (NHS) in the UK. Clinical and resource use data from a 16 week clinical evaluation of bio-electric stimulation therapy among patients who had recalcitrant wounds were combined with utility data obtained from a standard gamble analysis to construct a 16 week Markov model. The model considers the decision by a clinician to continue with a patient's previous care plan or treat with bio-electric stimulation therapy. Unit resource costs at 2005/2006 prices were applied to the resource utilisation estimates within the model, enabling the cost-utility of bio-electric stimulation therapy compared to standard care to be estimated. The acquisition cost of Posifect had not been decided at the time of performing this study. Hence, the base case analysis used a cost of 50 pounds per dressing. 33% of all wounds are expected to heal within 16 weeks after the start of bio-electric stimulation therapy. Consequently, using bio-electric stimulation therapy is expected to lead to a 51% decrease in the number of domiciliary clinician visits, from 4.7 to 2.3 per week. The model also showed that using bio-electric stimulation therapy instead of patients' standard care is expected to reduce the NHS cost of managing them by 16% from 2287 pounds (95% CI: 1838 pounds; 2735 pounds) to 1921 pounds (95% CI: 1609 pounds; 2233 pounds) and result in a health gain of 0.023 QALYs over 16 weeks. Hence, bio-electric stimulation therapy was found to be a dominant treatment. Sensitivity analyses demonstrated that the cost-utility of using bio-electric stimulation therapy relative to standard care is very sensitive to the acquisition cost of the therapy, the acquisition cost of patients' drugs and the number of clinician visits and less sensitive to utility values and the acquisition cost of other dressings. Within the limitations of the model, bio-electric stimulation therapy is expected to afford the NHS a cost-effective dressing compared to standard care in the management of chronic non-healing wounds of > 6 months duration. Bio-electric stimulation therapy's acquisition cost is expected to be offset by a reduction in the requirement for domiciliary clinician visits, leading to a release of NHS resources for use elsewhere in the system, thereby generating an increase in NHS efficiency.

Agreement Between Bioelectrical Impedance and Dual-Energy X-Ray Absorptiometry to Track Changes in Fat-Free Mass After Resistance Training in Older Women.

PubMed

Nascimento, Matheus A; Silva, Danilo R P; Ribeiro, Alex S; Pina, Fábio L C; Gerage, Aline M; Gobbo, Luís A; Mayhew, Jerry L; Cyrino, Edilson S

2018-05-23

Nascimento, MA, Silva, DRP, Ribeiro, AS, Pina, FLC, Gerage, AM, Gobbo, LA, Mayhew, JL, and Cyrino, ES. Agreement between bioelectrical impedance and dual-energy x-ray absorptiometry to track changes in fat-free mass after resistance training in older women. J Strength Cond Res XX(X): 000-000, 2018-The aim of our study was to compare the agreement between bioelectrical impedance (BIA) and dual-energy X-ray absorptiometry (DXA) to track changes on fat-free mass (FFM) after a resistance training (RT) program in older women. Forty-three older women (65.2 ± 4.6 years, 59.5 ± 9.2 kg, 156.4 ± 6.0 cm, 24.3 ± 3.3 kg·m) participated in a RT intervention (12 weeks, 8 exercises, 2 sets, 10-15 repetitions, 3 nonconsecutive days per week). Fat-free mass changes were determined by a single-frequency BIA device (EQ1), 6 BIA prediction equations for older women (EQ2, EQ3, EQ4, EQ5, EQ6, and EQ7), and DXA. At pretraining, 3 equations overpredicted, and 3 underpredicted DXA FFM (F = 244.63, p < 0.001), although all equations had high correlations with DXA (r = 0.78-0.83). After training, 4 equations overpredicted and one underpredicted DXA FFM (F = 176.25, p < 0.001). Dual-energy X-ray absorptiometry detected significant gains in FFM (0.65 ± 0.82 kg; p < 0.05), as did EQ3 (0.55 ± 1.69 kg; p < 0.05), and EQ4 (0.61 ± 1.88 kg; p < 0.05), whereas the remaining equations did not indicate significant changes in FFM. Low correlations between FFM and equation change values suggest that single-frequency BIA-derived equations may not provide sufficient accuracy to track changes in FFM after 12 weeks of RT in older women.

Imaging electric field dynamics with graphene optoelectronics

DOE PAGES

Horng, Jason; Balch, Halleh B.; McGuire, Allister F.; ...

2016-12-16

The use of electric fields for signalling and control in liquids is widespread, spanning bioelectric activity in cells to electrical manipulation of microstructures in lab-on-a-chip devices. However, an appropriate tool to resolve the spatio-temporal distribution of electric fields over a large dynamic range has yet to be developed. Here we present a label-free method to image local electric fields in real time and under ambient conditions. Our technique combines the unique gate-variable optical transitions of graphene with a critically coupled planar waveguide platform that enables highly sensitive detection of local electric fields with a voltage sensitivity of a few microvolts,more » a spatial resolution of tens of micrometres and a frequency response over tens of kilohertz. Our imaging platform enables parallel detection of electric fields over a large field of view and can be tailored to broad applications spanning lab-on-a-chip device engineering to analysis of bioelectric phenomena.« less

Imaging electric field dynamics with graphene optoelectronics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horng, Jason; Balch, Halleh B.; McGuire, Allister F.

The use of electric fields for signalling and control in liquids is widespread, spanning bioelectric activity in cells to electrical manipulation of microstructures in lab-on-a-chip devices. However, an appropriate tool to resolve the spatio-temporal distribution of electric fields over a large dynamic range has yet to be developed. Here we present a label-free method to image local electric fields in real time and under ambient conditions. Our technique combines the unique gate-variable optical transitions of graphene with a critically coupled planar waveguide platform that enables highly sensitive detection of local electric fields with a voltage sensitivity of a few microvolts,more » a spatial resolution of tens of micrometres and a frequency response over tens of kilohertz. Our imaging platform enables parallel detection of electric fields over a large field of view and can be tailored to broad applications spanning lab-on-a-chip device engineering to analysis of bioelectric phenomena.« less

Endogenous voltage gradients as mediators of cell-cell communication: strategies for investigating bioelectrical signals during pattern formation

PubMed Central

Adams, Dany S.; Levin, Michael

2013-01-01

Alongside the well-known chemical modes of cell-cell communication, we find an important and powerful system of bioelectrical signaling: changes in the resting voltage potential (Vmem) of the plasma membrane driven by ion channels, pumps and gap junctions. Slow Vmem changes in all cells serve as a highly conserved, information-bearing pathway that regulates cell proliferation, migration and differentiation. In embryonic and regenerative pattern formation and in the disorganization of neoplasia, bioelectrical cues serve as mediators of large-scale anatomical polarity, organ identity and positional information. Recent developments have resulted in tools that enable a high-resolution analysis of these biophysical signals and their linkage with upstream and downstream canonical genetic pathways. Here, we provide an overview for the study of bioelectric signaling, focusing on state-of-the-art approaches that use molecular physiology and developmental genetics to probe the roles of bioelectric events functionally. We highlight the logic, strategies and well-developed technologies that any group of researchers can employ to identify and dissect ionic signaling components in their own work and thus to help crack the bioelectric code. The dissection of bioelectric events as instructive signals enabling the orchestration of cell behaviors into large-scale coherent patterning programs will enrich on-going work in diverse areas of biology, as biophysical factors become incorporated into our systems-level understanding of cell interactions. PMID:22350846

Ethanol or bioelectricity? Life cycle assessment of lignocellulosic bioenergy use in light-duty vehicles.

PubMed

Luk, Jason M; Pourbafrani, Mohammad; Saville, Bradley A; MacLean, Heather L

2013-09-17

Our study evaluates life cycle energy use and GHG emissions of lignocellulosic ethanol and bioelectricity use in U.S. light-duty vehicles. The well-to-pump, pump-to-wheel, and vehicle cycle stages are modeled. All ethanol (E85) and bioelectricity pathways have similar life cycle fossil energy use (~ 100 MJ/100 vehicle kilometers traveled (VKT)) and net GHG emissions (~5 kg CO2eq./100 VKT), considerably lower (65-85%) than those of reference gasoline and U.S. grid-electricity pathways. E85 use in a hybrid vehicle and bioelectricity use in a fully electric vehicle also have similar life cycle biomass and total energy use (~ 350 and ~450 MJ/100 VKT, respectively); differences in well-to-pump and pump-to-wheel efficiencies can largely offset each other. Our energy use and net GHG emissions results contrast with findings in literature, which report better performance on these metrics for bioelectricity compared to ethanol. The primary source of differences in the studies is related to our development of pathways with comparable vehicle characteristics. Ethanol or vehicle electrification can reduce petroleum use, while bioelectricity may displace nonpetroleum energy sources. Regional characteristics may create conditions under which either ethanol or bioelectricity may be the superior option; however, neither has a clear advantage in terms of GHG emissions or energy use.

Local and long-range endogenous resting potential gradients antagonistically regulate apoptosis and proliferation in the embryonic CNS.

PubMed

Pai, Vaibhav P; Lemire, Joan M; Chen, Ying; Lin, Gufa; Levin, Michael

2015-01-01

Bioelectric signals, particularly transmembrane voltage potentials (Vmem), play an important role in large-scale patterning during embryonic development. Endogenous bioelectric gradients across tissues function as instructive factors during eye, brain, and other morphogenetic processes. An important and still poorly-understood aspect is the control of cell behaviors by the voltage states of distant cell groups. Here, experimental alteration of endogenous Vmem was induced in Xenopus laevis embryos by misexpression of well-characterized ion channel mRNAs, a strategy often used to identify functional roles of Vmem gradients during embryonic development and regeneration. Immunofluorescence analysis (for activated caspase 3 and phosphor-histone H3P) on embryonic sections was used to characterize apoptosis and proliferation. Disrupting local bioelectric signals (within the developing neural tube region) increased caspase 3 and decreased H3P in the brain, resulting in brain mispatterning. Disrupting remote (ventral, non-neural region) bioelectric signals decreased caspase 3 and highly increased H3P within the brain, with normal brain patterning. Disrupting both the local and distant bioelectric signals produced antagonistic effects on caspase 3 and H3P. Thus, two components of bioelectric signals regulate apoptosis-proliferation balance within the developing brain and spinal cord: local (developing neural tube region) and distant (ventral non-neural region). Together, the local and long-range bioelectric signals create a binary control system capable of fine-tuning apoptosis and proliferation with the brain and spinal cord to achieve correct pattern and size control. Our data suggest a roadmap for utilizing bioelectric state as a diagnostic modality and convenient intervention parameter for birth defects and degenerative disease states of the CNS.

Exploring Instructive Physiological Signaling with the Bioelectric Tissue Simulation Engine

PubMed Central

Pietak, Alexis; Levin, Michael

2016-01-01

Bioelectric cell properties have been revealed as powerful targets for modulating stem cell function, regenerative response, developmental patterning, and tumor reprograming. Spatio-temporal distributions of endogenous resting potential, ion flows, and electric fields are influenced not only by the genome and external signals but also by their own intrinsic dynamics. Ion channels and electrical synapses (gap junctions) both determine, and are themselves gated by, cellular resting potential. Thus, the origin and progression of bioelectric patterns in multicellular tissues is complex, which hampers the rational control of voltage distributions for biomedical interventions. To improve understanding of these dynamics and facilitate the development of bioelectric pattern control strategies, we developed the BioElectric Tissue Simulation Engine (BETSE), a finite volume method multiphysics simulator, which predicts bioelectric patterns and their spatio-temporal dynamics by modeling ion channel and gap junction activity and tracking changes to the fundamental property of ion concentration. We validate performance of the simulator by matching experimentally obtained data on membrane permeability, ion concentration and resting potential to simulated values, and by demonstrating the expected outcomes for a range of well-known cases, such as predicting the correct transmembrane voltage changes for perturbation of single cell membrane states and environmental ion concentrations, in addition to the development of realistic transepithelial potentials and bioelectric wounding signals. In silico experiments reveal factors influencing transmembrane potential are significantly different in gap junction-networked cell clusters with tight junctions, and identify non-linear feedback mechanisms capable of generating strong, emergent, cluster-wide resting potential gradients. The BETSE platform will enable a deep understanding of local and long-range bioelectrical dynamics in tissues, and assist the development of specific interventions to achieve greater control of pattern during morphogenesis and remodeling. PMID:27458581

Ambulatory Monitoring of Congestive Heart Failure by Multiple Bioelectric Impedance Vectors

PubMed Central

Khoury, Dirar S.; Naware, Mihir; Siou, Jeff; Blomqvist, Andreas; Mathuria, Nilesh S.; Wang, Jianwen; Shih, Hue-Teh; Nagueh, Sherif F.; Panescu, Dorin

2009-01-01

Objectives To investigate properties of multiple bioelectric impedance signals recorded during congestive heart failure (CHF) by utilizing various electrode configurations of an implanted cardiac resynchronization therapy (CRT) system. Background Monitoring of CHF has relied mainly on right-heart sensors. Methods Fifteen normal dogs underwent implantation of CRT systems using standard leads. An additional left atrial (LA) pressure lead-sensor was implanted in 5 dogs. Continuous rapid right ventricular (RV) pacing was applied over several weeks. Left ventricular (LV) catheterization and echocardiography were performed biweekly. Six steady-state impedance signals, utilizing intrathorcaic and intracardiac vectors, were measured via ring (r), coil (c), and device Can electrodes. Results All animals developed CHF after 2–4 weeks of pacing. Impedance diminished gradually during CHF induction, but at varying rates for different vectors. Impedance during CHF decreased significantly in all measured vectors: LVr-Can, −17%; LVr-RVr, −15%; LVr-RAr, −11%; RVr-Can, −12%; RVc-Can, −7%; RAr-Can, −5%. The LVr-Can vector reflected both the fastest and largest change in impedance in comparison to vectors employing only right-heart electrodes, and was highly reflective of changes in LV end-diastolic volume and LA pressure. Conclusions Impedance, acquired via different lead-electrodes, have variable responses to CHF. Impedance vectors employing a LV lead are highly responsive to physiologic changes during CHF. Measuring multiple impedance signals could be useful for optimizing ambulatory monitoring in heart failure patients. PMID:19298923

[Resting metabolic rate estimated by bioelectrical impedance analysis and its determinants in maintenance hemodialysis patients].

PubMed

Da, J J; Peng, H Y; Lin, X; Shen, Y; Zhao, J Q; He, S; Zha, Y

2018-03-27

Objective: To explore the level of resting energy expenditure (REE) estimated by bioelectrical impedance analysis and the association of resting metabolic rate (RMR) with clinical related factors, and provide new ideas for improving protein energy wasting (PEW) in maintenance hemodialysis (MHD) patients. Methods: Seven hundred and sixty-five subjects receiving MHD between July 2015 and September 2016 in 11 hemodialysis centers in Guizhou province were enrolled in this cross-sectional study. Bioelectrical impedance analysis was used to measure RMR and body composition, such as lean body mass, fat mass and body cell mass (BCM). Baseline characteristics, routine blood test indexes and biochemical data of hemodialysis patients were collected. The level of RMR and body composition in hemodialysis patients was compared by gender grouping. Then the patients were divided into four groups according to the cutoff value of RMR quartile. Spearman correlation analysis and multiple linear regression analysis were used to analyze the relationships between RMR and clinical related factors. Results: The average age of MHD patients was (54.96±15.78) years and the duriation of dialysis was (42.3±9.0) months. The level of RMR in male patients (474 cases, 61.96%) was significantly higher than that in female patients [1 591(1 444, 1 764) kcal/d vs 1 226 (1 104, 1 354) kcal/d, P <0.001]. However, this significant difference of RMR between different genders disappeared after adjusting for lean body mass ( P =0.193). Multiple linear regression analysis showed that RMR was positively correlated with body surface area (β=0.817) and lactate dehydrogenase (LDH) (β=0.198), and negatively correlated with age (β=-0.141), all P <0.05. Conclusion: RMR levels in patients with maintenance hemodialysis are associated with lactate dehydrogenase level, which may become a new index to evaluate energy consumption.

Economic impacts of bio-refinery and resource cascading systems: an applied general equilibrium analysis for Poland.

PubMed

Ignaciuk, Adriana M; Sanders, Johan

2007-12-01

Due to more stringent energy and climate policies, it is expected that many traditional chemicals will be replaced by their biomass-based substitutes, bio-chemicals. These innovations, however, can influence land allocation since the demand for land dedicated to specific crops might increase. Moreover, it can have an influence on traditional agricultural production. In this paper, we use an applied general equilibrium framework, in which we include two different bio-refinery processes and incorporate so-called cascading mechanisms. The bio-refinery processes use grass, as one of the major inputs, to produce bio-nylon and propane-diol (1,3PDO) to substitute currently produced fossil fuel-based nylon and ethane-diol. We examine the impact of specific climate policies on the bioelectricity share in total electricity production, land allocation, and production quantities and prices of selected commodities. The novel technologies become competitive, with an increased stringency of climate policies. This switch, however, does not induce a higher share of bioelectricity. The cascade does stimulate the production of bioelectricity, but it induces more of a shift in inputs in the bioelectricity sector (from biomass to the cascaded bio-nylon and 1, 3PDO) than an increase in production level of bioelectricity. We conclude that dedicated biomass crops will remain the main option for bioelectricity production: the contribution of the biomass systems remains limited. Moreover, the bioelectricity sector looses a competition for land for biomass production with bio-refineries.

Prediction of fat-free body mass from bioelectrical impedance and anthropometry among 3-year-old children using DXA

PubMed Central

Ejlerskov, Katrine T.; Jensen, Signe M.; Christensen, Line B.; Ritz, Christian; Michaelsen, Kim F.; Mølgaard, Christian

2014-01-01

For 3-year-old children suitable methods to estimate body composition are sparse. We aimed to develop predictive equations for estimating fat-free mass (FFM) from bioelectrical impedance (BIA) and anthropometry using dual-energy X-ray absorptiometry (DXA) as reference method using data from 99 healthy 3-year-old Danish children. Predictive equations were derived from two multiple linear regression models, a comprehensive model (height2/resistance (RI), six anthropometric measurements) and a simple model (RI, height, weight). Their uncertainty was quantified by means of 10-fold cross-validation approach. Prediction error of FFM was 3.0% for both equations (root mean square error: 360 and 356 g, respectively). The derived equations produced BIA-based prediction of FFM and FM near DXA scan results. We suggest that the predictive equations can be applied in similar population samples aged 2–4 years. The derived equations may prove useful for studies linking body composition to early risk factors and early onset of obesity. PMID:24463487

Prediction of fat-free body mass from bioelectrical impedance and anthropometry among 3-year-old children using DXA.

PubMed

Ejlerskov, Katrine T; Jensen, Signe M; Christensen, Line B; Ritz, Christian; Michaelsen, Kim F; Mølgaard, Christian

2014-01-27

For 3-year-old children suitable methods to estimate body composition are sparse. We aimed to develop predictive equations for estimating fat-free mass (FFM) from bioelectrical impedance (BIA) and anthropometry using dual-energy X-ray absorptiometry (DXA) as reference method using data from 99 healthy 3-year-old Danish children. Predictive equations were derived from two multiple linear regression models, a comprehensive model (height(2)/resistance (RI), six anthropometric measurements) and a simple model (RI, height, weight). Their uncertainty was quantified by means of 10-fold cross-validation approach. Prediction error of FFM was 3.0% for both equations (root mean square error: 360 and 356 g, respectively). The derived equations produced BIA-based prediction of FFM and FM near DXA scan results. We suggest that the predictive equations can be applied in similar population samples aged 2-4 years. The derived equations may prove useful for studies linking body composition to early risk factors and early onset of obesity.

Investigation of the Optimum Farming Temperature for Grifola frondosa and Growth Promotion using the Bio-Electric Potential as an Index

NASA Astrophysics Data System (ADS)

Yanagibashi, Hideyuki; Hirama, Junji; Matsuda, Masato; Miyamoto, Toshio

The purpose of this study was to investigate the optimum farming conditions for mushrooms from the view point of engineering field. As the bio-electric potential of mushrooms is considered to be closely related to the activation of mushroom cells, this relationship has been used to analyze the dependence of the morphogenetic characteristics of Grifola frondosa on farming temperatures (from 16 to 22 degree C). The experimental results indicated that a maximum response was exhibited, with correspondingly favorable morphogenesis obtained at 18 degree C. Based on the experimental results, including those in a previous study, it was assumed that the larger the bio-electric potential becomes, the higher the growth yield reaches. In order to support this assumption, growth promotion was conducted by intentionally activating the bio-electric potential within the mushrooms by stimulating them with short bursts of illumination. The resulting observation of growth promotion permitted the conclusion that the bio-electric potential can, indeed, be regarded as an index of growth.

Comparison of total body water estimates from O-18 and bioelectrical response prediction equations

NASA Technical Reports Server (NTRS)

Barrows, Linda H.; Inners, L. Daniel; Stricklin, Marcella D.; Klein, Peter D.; Wong, William W.; Siconolfi, Steven F.

1993-01-01

Identification of an indirect, rapid means to measure total body water (TBW) during space flight may aid in quantifying hydration status and assist in countermeasure development. Bioelectrical response testing and hydrostatic weighing were performed on 27 subjects who ingested O-18, a naturally occurring isotope of oxygen, to measure true TBW. TBW estimates from three bioelectrical response prediction equations and fat-free mass (FFM) were compared to TBW measured from O-18. A repeated measures MANOVA with post-hoc Dunnett's Test indicated a significant (p less than 0.05) difference between TBW estimates from two of the three bioelectrical response prediction equations and O-18. TBW estimates from FFM and the Kushner & Schoeller (1986) equation yielded results that were similar to those given by O-18. Strong correlations existed between each prediction method and O-18; however, standard errors, identified through regression analyses, were higher for the bioelectrical response prediction equations compared to those derived from FFM. These findings suggest (1) the Kushner & Schoeller (1986) equation may provide a valid measure of TBW, (2) other TBW prediction equations need to be identified that have variability similar to that of FFM, and (3) bioelectrical estimates of TBW may prove valuable in quantifying hydration status during space flight.

Bioelectrical impedance vector analysis (BIVA) for measuring the hydration status in young elite synchronized swimmers

PubMed Central

Carrasco-Marginet, Marta; Castizo-Olier, Jorge; Rodríguez-Zamora, Lara; Iglesias, Xavier; Rodríguez, Ferran A.; Chaverri, Diego; Brotons, Daniel

2017-01-01

Purpose The assessment of body hydration is a complex process, and no measurement is valid for all situations. Bioelectrical impedance vector analysis (BIVA) has emerged as a relatively novel technique for assessing hydration status in sports. We applied BIVA a) to determine hydration changes evoked by an intense synchronized swimming (SS) training session; b) to characterize the sample of young elite swimmers in relation with a nonathletic reference population; and c) to generate its 50%, 75% and 95% percentiles of the bioelectrical variables. Methods Forty-nine elite SS female swimmers of two age categories, comen (Co: 13.9 ± 0.9 years, n = 34) and junior (Jr: 16.3 ± 0.6 years, n = 15), performed a long, high intensity training session. Body mass (BM) and bioelectrical variables (R, resistance; Xc, reactance; PA, phase angle; and Z, impedance module) were assessed pre- and post-training. BIVA was used to characterize 1) the distribution pattern of the bioelectrical vector (BIA vector) for both age groups, and 2) pre- to post-training BIA vector migration. Bioelectrical variables were also correlated with BM change values. Results Most swimmers were mostly located outside the 75% and some beyond the 95% percentile of the bioelectrical tolerance ellipses of the general population. The BIA vector showed statistically significant differences in both Co (T2 = 134.7, p = 0.0001) and Jr (T2 = 126.2, p < 0.001). Both groups were also bioelectrically different (T2 = 17.6, p < 0.001). After the training session, a decrease in BM (p = 0.0001) and an increase in BIA variables (p = 0.01) was observed. BIVA also showed a significant pre-post vector migration both in Co (T2 = 82.1; p < 0.001) and Jr (T2 = 41.8; p < 0.001). No correlations were observed between BM changes and bioelectrical variables. Conclusions BIVA showed specific bioelectrical characteristics in young elite SS athletes. Considering the decrease in BM and the migration of the BIA vector, we conclude that the homeostatic hydration status of these young elite female swimmers was affected by the execution of intense training sessions. From a methodological perspective, BIVA appears to be sensitive enough to detect subtle hydration changes, but further research is needed to ensure its validity and reliability. Moreover, these findings highlight the importance of ensuring adequate fluid intake during training in young SS athletes. PMID:28591135

Feasibility and acceptability of a self-measurement using a portable bioelectrical impedance analysis, by the patient with chronic heart failure, in acute decompensated heart failure.

PubMed

Huguel, Benjamin; Vaugrenard, Thibaud; Saby, Ludivine; Benhamou, Lionel; Arméro, Sébastien; Camilleri, Élise; Langar, Aida; Alitta, Quentin; Grino, Michel; Retornaz, Frédérique

2018-06-01

Chronic heart failure (CHF) is a major public health matter. Mainly affecting the elderly, it is responsible for a high rate of hospitalization due to the frequency of acute heart failure (ADHF). This represents a disabling pathology for the patient and very costly for the health care system. Our study is designed to assess a connected and portable bioelectrical impedance analysis (BIA) that could reduce these hospitalizations by preventing early ADHF. This prospective study included patients hospitalized in cardiology for ADHF. Patients achieved 3 self-measurements using the BIA during their hospitalization and answered a questionnaire evaluating the acceptability of this self-measurement. The results of these measures were compared with the clinical, biological and echocardiographic criteria of patients at the same time. Twenty-three patients were included, the self-measurement during the overall duration of the hospitalization was conducted autonomously by more than 80% of the patients. The acceptability (90%) for the use of the portable BIA was excellent. Some correlations were statistically significant, such as the total water difference to the weight difference (p=0.001). There were common trends between the variation of impedance analysis measures and other evaluation criteria. The feasibility and acceptability of a self-measurement of bioelectrical impedance analysis by the patient in AHF opens up major prospects in the management of monitoring patients in CHF. The interest of this tool is the prevention of ADHF leading to hospitalization or re-hospitalizations now requires to be presented by new studies.

Bioelectrical activity of the pelvic floor muscles during synchronous whole-body vibration--a randomized controlled study.

PubMed

Stania, Magdalena; Chmielewska, Daria; Kwaśna, Krystyna; Smykla, Agnieszka; Taradaj, Jakub; Juras, Grzegorz

2015-10-24

More and more frequently stress urinary incontinence affects young healthy women. Hence, early implementation of effective preventive strategies in nulliparous continent women is essential, including pelvic floor muscle training. An initial evaluation based on the bioelectrical activity of the pelvic floor muscles (PFM) during whole-body vibration (WBV) would help to devise the best individualized training for prevention of stress urinary incontinence in woman. We hypothesized that synchronous WBV enhances bioelectrical activity of the PFM which depends on vibration frequency and peak-to-peak vibration displacement. The sample consisted of 36 nulliparous continent women randomly allocated to three comparative groups. Group I and II subjects participated in synchronous whole-body vibrations on a vibration platform; the frequency and peak-to-peak displacement of vibration were set individually for each group. Control participants performed exercises similar to those used in the study groups but without the concurrent application of vibrations. Pelvic floor surface electromyography (sEMG) activity was recorded using a vaginal probe during three experimental trials limited to 30s, 60s and 90 s. The mean amplitude and variability of the signal were normalized to the Maximal Voluntary Contraction - MVC. Friedman's two-way ANOVA revealed a statistically significant difference in the mean normalized amplitudes (%MVC) of the sEMG signal from the PFM during 60s- and 90 s-trials between the group exposed to high-intensity WBV and control participants (p < 0.05). Longer trial duration was associated with a statistically significant decrease in the variability of sEMG signal amplitude in the study and control groups (p < 0.05). Synchronous high-intensity WBV (40 Hz, 4 mm) of long duration (60s, 90 s) significantly enhances the activation of the PFM in young continent women. Prolonged maintenance of a static position significantly decreases the variability of sEMG signal amplitude independent of whole-body vibrations. Single whole-body vibrations in nulliparous continent women does not cause pelvic floor muscle fatigue. The trial was registered in the Australian and New Zealand Clinical Trials Registry (no. ACTRN12615000966594); registration date: 15/09/2015.

Bioelectric patterning during oogenesis: stage-specific distribution of membrane potentials, intracellular pH and ion-transport mechanisms in Drosophila ovarian follicles.

PubMed

Krüger, Julia; Bohrmann, Johannes

2015-01-16

Bioelectric phenomena have been found to exert influence on various developmental and regenerative processes. Little is known about their possible functions and the cellular mechanisms by which they might act during Drosophila oogenesis. In developing follicles, characteristic extracellular current patterns and membrane-potential changes in oocyte and nurse cells have been observed that partly depend on the exchange of protons, potassium ions and sodium ions. These bioelectric properties have been supposed to be related to various processes during oogenesis, e. g. pH-regulation, osmoregulation, cell communication, cell migration, cell proliferation, cell death, vitellogenesis and follicle growth. Analysing in detail the spatial distribution and activity of the relevant ion-transport mechanisms is expected to elucidate the roles that bioelectric phenomena play during oogenesis. To obtain an overview of bioelectric patterning along the longitudinal and transversal axes of the developing follicle, the spatial distributions of membrane potentials (Vmem), intracellular pH (pHi) and various membrane-channel proteins were studied systematically using fluorescent indicators, fluorescent inhibitors and antisera. During mid-vitellogenic stages 9 to 10B, characteristic, stage-specific Vmem-patterns in the follicle-cell epithelium as well as anteroposterior pHi-gradients in follicle cells and nurse cells were observed. Corresponding distribution patterns of proton pumps (V-ATPases), voltage-dependent L-type Ca(2+)-channels, amiloride-sensitive Na(+)-channels and Na(+),H(+)-exchangers (NHE) and gap-junction proteins (innexin 3) were detected. In particular, six morphologically distinguishable follicle-cell types are characterized on the bioelectric level by differences concerning Vmem and pHi as well as specific compositions of ion channels and carriers. Striking similarities between Vmem-patterns and activity patterns of voltage-dependent Ca(2+)-channels were found, suggesting a mechanism for transducing bioelectric signals into cellular responses. Moreover, gradients of electrical potential and pH were observed within single cells. Our data suggest that spatial patterning of Vmem, pHi and specific membrane-channel proteins results in bioelectric signals that are supposed to play important roles during oogenesis, e. g. by influencing spatial coordinates, regulating migration processes or modifying the cytoskeletal organization. Characteristic stage-specific changes of bioelectric activity in specialized cell types are correlated with various developmental processes.

Comparison of two bioelectrical impedance devices and dual-energy X-ray absorptiometry to evaluate body composition in heart failure.

PubMed

Alves, F D; Souza, G C; Biolo, A; Clausell, N

2014-12-01

The utilisation of bioelectrical impedance analysis (BIA) in heart failure can be affected by many factors and its applicability remains controversial. The present study aimed to verify the adequacy of single-frequency BIA (SF-BIA) and multifrequency BIA (MF-BIA) compared to dual-energy x-ray absorptiometry (DEXA) for evaluating body composition in outpatients with heart failure. In this cross-sectional study, 55 patients with stable heart failure and left ventricle ejection fraction ≤45% were evaluated for fat mass percentage, fat mass and fat-free mass by DEXA and compared with the results obtained by SF-BIA (single frequency of 50 kHz) and MF-BIA (frequencies of 20 and 100 kHz). MF-BIA and DEXA gave similar mean values for fat mass percentage, fat mass and fat-free mass, whereas values from SF-BIA were significantly different from DEXA. Both SF-BIA and MF-BIA measures of body composition correlated strongly with DEXA (r > 0.8; P < 0.001), except for fat mass assessed by SF-BIA, which showed a moderate correlation (r = 0.760; P < 0.001). MF-BIA also showed a better agreement with DEXA by Bland-Altman analysis in all measurements. However, both types of equipment showed wide limits of agreement and a significant relationship between variance and bias (Pitmans's test P > 0.05), except MF-BIA for fat-free mass. Compared with DEXA, MF-BIA showed better accuracy than SF-BIA, although both types of equipment showed wide limits of agreement. The BIA technique should be used with caution, and regression equations might be useful for correcting the observed variations, mainly in extreme values of body composition. © 2014 The British Dietetic Association Ltd.

Interfacing with the nervous system: a review of current bioelectric technologies.

PubMed

Sahyouni, Ronald; Mahmoodi, Amin; Chen, Jefferson W; Chang, David T; Moshtaghi, Omid; Djalilian, Hamid R; Lin, Harrison W

2017-10-23

The aim of this study is to discuss the state of the art with regard to established or promising bioelectric therapies meant to alter or control neurologic function. We present recent reports on bioelectric technologies that interface with the nervous system at three potential sites-(1) the end organ, (2) the peripheral nervous system, and (3) the central nervous system-while exploring practical and clinical considerations. A literature search was executed on PubMed, IEEE, and Web of Science databases. A review of the current literature was conducted to examine functional and histomorphological effects of neuroprosthetic interfaces with a focus on end-organ, peripheral, and central nervous system interfaces. Innovations in bioelectric technologies are providing increasing selectivity in stimulating distinct nerve fiber populations in order to activate discrete muscles. Significant advances in electrode array design focus on increasing selectivity, stability, and functionality of implantable neuroprosthetics. The application of neuroprosthetics to paretic nerves or even directly stimulating or recording from the central nervous system holds great potential in advancing the field of nerve and tissue bioelectric engineering and contributing to clinical care. Although current physiotherapeutic and surgical treatments seek to restore function, structure, or comfort, they bear significant limitations in enabling cosmetic or functional recovery. Instead, the introduction of bioelectric technology may play a role in the restoration of function in patients with neurologic deficits.

The bioelectric code: An ancient computational medium for dynamic control of growth and form.

PubMed

Levin, Michael; Martyniuk, Christopher J

2018-02-01

What determines large-scale anatomy? DNA does not directly specify geometrical arrangements of tissues and organs, and a process of encoding and decoding for morphogenesis is required. Moreover, many species can regenerate and remodel their structure despite drastic injury. The ability to obtain the correct target morphology from a diversity of initial conditions reveals that the morphogenetic code implements a rich system of pattern-homeostatic processes. Here, we describe an important mechanism by which cellular networks implement pattern regulation and plasticity: bioelectricity. All cells, not only nerves and muscles, produce and sense electrical signals; in vivo, these processes form bioelectric circuits that harness individual cell behaviors toward specific anatomical endpoints. We review emerging progress in reading and re-writing anatomical information encoded in bioelectrical states, and discuss the approaches to this problem from the perspectives of information theory, dynamical systems, and computational neuroscience. Cracking the bioelectric code will enable much-improved control over biological patterning, advancing basic evolutionary developmental biology as well as enabling numerous applications in regenerative medicine and synthetic bioengineering. Copyright © 2017 Elsevier B.V. All rights reserved.

Accelerating bioelectric functional development of neural stem cells by graphene coupling: Implications for neural interfacing with conductive materials.

PubMed

Guo, Rongrong; Zhang, Shasha; Xiao, Miao; Qian, Fuping; He, Zuhong; Li, Dan; Zhang, Xiaoli; Li, Huawei; Yang, Xiaowei; Wang, Ming; Chai, Renjie; Tang, Mingliang

2016-11-01

In order to govern cell-specific behaviors in tissue engineering for neural repair and regeneration, a better understanding of material-cell interactions, especially the bioelectric functions, is extremely important. Graphene has been reported to be a potential candidate for use as a scaffold and neural interfacing material. However, the bioelectric evolvement of cell membranes on these conductive graphene substrates remains largely uninvestigated. In this study, we used a neural stem cell (NSC) model to explore the possible changes in membrane bioelectric properties - including resting membrane potentials and action potentials - and cell behaviors on graphene films under both proliferation and differentiation conditions. We used a combination of single-cell electrophysiological recordings and traditional cell biology techniques. Graphene did not affect the basic membrane electrical parameters (capacitance and input resistance), but resting membrane potentials of cells on graphene substrates were more strongly negative under both proliferation and differentiation conditions. Also, NSCs and their progeny on graphene substrates exhibited increased firing of action potentials during development compared to controls. However, graphene only slightly affected the electric characterizations of mature NSC progeny. The modulation of passive and active bioelectric properties on the graphene substrate was accompanied by enhanced NSC differentiation. Furthermore, spine density, synapse proteins expressions and synaptic activity were all increased in graphene group. Modeling of the electric field on conductive graphene substrates suggests that the electric field produced by the electronegative cell membrane is much higher on graphene substrates than that on control, and this might explain the observed changes of bioelectric development by graphene coupling. Our results indicate that graphene is able to accelerate NSC maturation during development, especially with regard to bioelectric evolvement. Our findings provide a fundamental understanding of the role of conductive materials in tuning the membrane bioelectric properties in a graphene model and pave the way for future studies on the development of methods and materials for manipulating membrane properties in a controllable way for NSC-based therapies. Copyright © 2016 Elsevier Ltd. All rights reserved.

High-quality recording of bioelectric events. Part 2. Low-noise, low-power multichannel amplifier design.

PubMed

Metting van Rijn, A C; Peper, A; Grimbergen, C A

1991-07-01

A multichannel instrumentation amplifier, developed to be used in a miniature universal eight-channel amplifier module, is described. After discussing the specific properties of a bioelectric recording, the difficulties of meeting the demanded specifications with a design based on operational amplifiers are reviewed. Because it proved impossible to achieve the demanded combination of low noise and low power consumption using commercially available operational amplifiers, an amplifier equipped with an input stage with discrete transistors was developed. A new design concept was used to expand the design to a multichannel version with an equivalent input noise voltage of 0.35 microV RMS in a bandwidth of 0.1-100 Hz and a power consumption of 0.6 mW per channel. The results of this study are applied to miniature, universal, eight-channel amplifier modules, manufactured with thick-film production techniques. The modules can be coupled to satisfy the demand for a multiple of eight channels. The low power consumption enables the modules to be used in all kinds of portable and telemetry measurement systems and simplifies the power supply in stationary measurement systems.

Endogenous Voltage Potentials and the Microenvironment: Bioelectric Signals that Reveal, Induce and Normalize Cancer

PubMed Central

Chernet, Brook; Levin, Michael

2014-01-01

Cancer may be a disease of geometry: a misregulation of the field of information that orchestrates individual cells’ activities towards normal anatomy. Recent work identified molecular mechanisms underlying a novel system of developmental control: bioelectric gradients. Endogenous spatio-temporal differences in resting potential of non-neural cells provide instructive cues for cell regulation and complex patterning during embryogenesis and regeneration. It is now appreciated that these cues are an important layer of the dysregulation of cell: cell interactions that leads to cancer. Abnormal depolarization of resting potential (Vmem) is a convenient marker for neoplasia and activates a metastatic phenotype in genetically-normal cells in vivo. Moreover, oncogene expression depolarizes cells that form tumor-like structures, but is unable to form tumors if this depolarization is artificially prevented by misexpression of hyperpolarizing ion channels. Vmem triggers metastatic behaviors at considerable distance, mediated by transcriptional and epigenetic effects of electrically-modulated flows of serotonin and butyrate. While in vivo data on voltages in carcinogenesis comes mainly from the amphibian model, unbiased genetic screens and network profiling in rodents and human tissues reveal several ion channel proteins as bona fide oncogene and promising targets for cancer drug development. However, we propose that a focus on specific channel genes is just the tip of the iceberg. Bioelectric state is determined by post-translational gating of ion channels, not only from genetically-specified complements of ion translocators. A better model is a statistical dynamics view of spatial Vmem gradients. Cancer may not originate at the single cell level, since gap junctional coupling results in multi-cellular physiological networks with multiple stable attractors in bioelectrical state space. New medical applications await a detailed understanding of the mechanisms by which organ target morphology stored in real-time patterns of ion flows is perceived or mis-perceived by cells. Mastery of somatic voltage gradients will lead to cancer normalization or rebooting strategies, such as those that occur in regenerating and embryonic organs, resulting in transformative advances in basic biology and oncology. PMID:25525610

Cell-cell bioelectrical interactions and local heterogeneities in genetic networks: a model for the stabilization of single-cell states and multicellular oscillations.

PubMed

Cervera, Javier; Manzanares, José A; Mafe, Salvador

2018-04-04

Genetic networks operate in the presence of local heterogeneities in single-cell transcription and translation rates. Bioelectrical networks and spatio-temporal maps of cell electric potentials can influence multicellular ensembles. Could cell-cell bioelectrical interactions mediated by intercellular gap junctions contribute to the stabilization of multicellular states against local genetic heterogeneities? We theoretically analyze this question on the basis of two well-established experimental facts: (i) the membrane potential is a reliable read-out of the single-cell electrical state and (ii) when the cells are coupled together, their individual cell potentials can be influenced by ensemble-averaged electrical potentials. We propose a minimal biophysical model for the coupling between genetic and bioelectrical networks that associates the local changes occurring in the transcription and translation rates of an ion channel protein with abnormally low (depolarized) cell potentials. We then analyze the conditions under which the depolarization of a small region (patch) in a multicellular ensemble can be reverted by its bioelectrical coupling with the (normally polarized) neighboring cells. We show also that the coupling between genetic and bioelectric networks of non-excitable cells, modulated by average electric potentials at the multicellular ensemble level, can produce oscillatory phenomena. The simulations show the importance of single-cell potentials characteristic of polarized and depolarized states, the relative sizes of the abnormally polarized patch and the rest of the normally polarized ensemble, and intercellular coupling.

Bioelectric modulation of wound healing in a 3D in vitro model of tissue-engineered bone.

PubMed

Sundelacruz, Sarah; Li, Chunmei; Choi, Young Jun; Levin, Michael; Kaplan, David L

2013-09-01

Long-standing interest in bioelectric regulation of bone fracture healing has primarily focused on exogenous stimulation of bone using applied electromagnetic fields. Endogenous electric signals, such as spatial gradients of resting potential among non-excitable cells in vivo, have also been shown to be important in cell proliferation, differentiation, migration, and tissue regeneration, and may therefore have as-yet unexplored therapeutic potential for regulating wound healing in bone tissue. To study this form of bioelectric regulation, there is a need for three-dimensional (3D) in vitro wound tissue models that can overcome limitations of current in vivo models. We present a 3D wound healing model in engineered bone tissue that serves as a pre-clinical experimental platform for studying electrophysiological regulation of wound healing. Using this system, we identified two electrophysiology-modulating compounds, glibenclamide and monensin, that augmented osteoblast mineralization. Of particular interest, these compounds displayed differential effects in the wound area compared to the surrounding tissue. Several hypotheses are proposed to account for these observations, including the existence of heterogeneous subpopulations of osteoblasts that respond differently to bioelectric signals, or the capacity of the wound-specific biochemical and biomechanical environment to alter cell responses to electrophysiological treatments. These data indicate that a comprehensive characterization of the cellular, biochemical, biomechanical, and bioelectrical components of in vitro wound models is needed to develop bioelectric strategies to control cell functions for improved bone regeneration. Copyright © 2013 Elsevier Ltd. All rights reserved.

[Prognostic value of chosen parameters of mechanical and bioelectrical uterine activity in prediction of threatening preterm labour].

PubMed

Zietek, Jerzy; Sikora, Jerzy; Horoba, Krzysztof; Matonia, Adam; Jezewski, Janusz; Magnucki, Jacek; Kobielska, Lucyna

2009-03-01

To record and analyse bioelectrical activity of the uterine muscle in the course of physiological pregnancy, labour and threatening premature labour; to define which parameters from the analysis of both electrohysterogram and mechanical activity signal allow us to predict threatening premature labour. Material comprised 62 pregnant women: Group I--27 patients in their first physiological pregnancy, Group II--21 patients in their first pregnancy with symptoms of threatening premature labour, and Group III--14 patients in the first labour period. The on-line analysis of the mechanical (TOCO) and electrical (EHG) contraction activity relied on determination of quantitative parameters of detected uterine contractions. The obtained statistical results demonstrated a possibility to differentiate between Group I and II through the amplitude and contraction area for EHG signal, and only the contraction amplitude for TOCO signal. Additionally, significant differentiating parameters for electrohysterogram are: contraction power and its median frequency. Analyzing Group I and III, significant differences were noted for contraction amplitude and area obtained both from EHG and TOCO signals. Similarly, the contraction power (from EHG) enables us to assign the contractions either to records from Group I or to labour type. There was no significant difference noted between Group II and III. Identification of pregnant women at risk of premature labour should lead to their inclusion in rigorous perinatal surveillance. This requires novel, more sensitive methods that are able to detect early symptoms of the uterine contraction activity increase. Electrohysterography provides complete information on principles of bioelectrical uterine activity. Quantitative parameters of EHG analysis enable the detection of records (contractions) with the symptoms of premature uterine contraction activity.

The relationship between nocturnal polyuria and the distribution of body fluid: assessment by bioelectric impedance analysis.

PubMed

Torimoto, Kazumasa; Hirayama, Akihide; Samma, Shoji; Yoshida, Katsunori; Fujimoto, Kiyohide; Hirao, Yoshihiko

2009-01-01

Increased nocturnal urinary volume is closely associated with nocturia. We investigated the relationship between nocturnal polyuria and the variation of body fluid distribution during the daytime using bioelectric impedance analysis. A total of 34 men older than 60 years were enrolled in this study. A frequency volume chart was recorded. Nocturnal polyuria was defined as a nocturnal urine volume per 24-hour production of greater than 0.35 (the nocturnal polyuria index). Bioelectric impedance analysis was performed 4 times daily at 8 and 11 a.m., and 5 and 9 p.m. using an InBody S20 body composition analyzer (BioSpace, Seoul, Korea). A significant difference was found in mean +/- SEM 24-hour urine production per fat-free mass between the groups with and without nocturnal polyuria (17.8 +/- 1.4 vs 7.7 +/- 0.9 ml/kg). The increase in fluid in the legs compared with the volume at 8 a.m. was significantly larger at 5 p.m., while there was no difference in the arms or trunk. Nocturnal urine volume significantly correlated with the difference in fluid volume in the legs (r = 0.527, p = 0.0019) and extracellular fluid volume (r = 0.3844, p = 0.0248) between the volumes at 8 a.m. and 9 p.m. Overproduction of urine per fat-free mass leads to nocturnal polyuria. Extracellular fluid accumulates as edema in the legs during the day in patients with nocturnal polyuria. The volume of accumulated extracellular fluid correlates with nocturnal urine volume. We suggest that leg edema is the source of nocturnal urine volume and decreasing edema may cure nocturnal polyuria.

Neurophysiological patterns of search and creative behavior in patients with psychoactive substance-induced disorders.

PubMed

Batukhtina, E I; Nevidimova, T I; Vetlugina, T P; Kokorina, N P; Bokhan, N A

2014-03-01

The correlation between search and creative behavior with parameters of bioelectric brain activity was observed in patients with addictive disorders. The prevalence of α- and θ-activities in the parietal-temporal-occipital areas of the cortex and increased θ-activity in the right hemisphere in addiction patients with high search and creative activities were associated with enhanced high-frequency activity in these brain areas. These changes can reflect the formation of a focus of pathologically increased excitation related to the pathogenic mechanisms of addictive disorders.

The body electric 2.0: recent advances in developmental bioelectricity for regenerative and synthetic bioengineering.

PubMed

Mathews, Juanita; Levin, Michael

2018-04-20

Breakthroughs in biomedicine and synthetic bioengineering require predictive, rational control over anatomical structure and function. Recent successes in manipulating cellular and molecular hardware have not been matched by progress in understanding the patterning software implemented during embryogenesis and regeneration. A fundamental capability gap is driving desired changes in growth and form to address birth defects and traumatic injury. Here we review new tools, results, and conceptual advances in an exciting emerging field: endogenous non-neural bioelectric signaling, which enables cellular collectives to make global decisions and implement large-scale pattern homeostasis. Spatially distributed electric circuits regulate gene expression, organ morphogenesis, and body-wide axial patterning. Developmental bioelectricity facilitates the interface to organ-level modular control points that direct patterning in vivo. Cracking the bioelectric code will enable transformative progress in bioengineering and regenerative medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Study on effects of bioelectric parameters of rats in electromagnetic radiation of HV transmission line].

PubMed

Zhang, Anying; Pang, Xiaofeng; Yuan, Ping

2007-02-01

With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.

EMG amplifier with wireless data transmission

NASA Astrophysics Data System (ADS)

Kowalski, Grzegorz; Wildner, Krzysztof

2017-08-01

Wireless medical diagnostics is a trend in modern technology used in medicine. This paper presents a concept of realization, architecture of hardware and software implementation of an elecromyography signal (EMG) amplifier with wireless data transmission. This amplifier consists of three components: analogue processing of bioelectric signal module, micro-controller circuit and an application enabling data acquisition via a personal computer. The analogue bioelectric signal processing circuit receives electromyography signals from the skin surface, followed by initial analogue processing and preparation of the signals for further digital processing. The second module is a micro-controller circuit designed to wirelessly transmit the electromyography signals from the analogue signal converter to a personal computer. Its purpose is to eliminate the need for wired connections between the patient and the data logging device. The third block is a computer application designed to display the transmitted electromyography signals, as well as data capture and analysis. Its purpose is to provide a graphical representation of the collected data. The entire device has been thoroughly tested to ensure proper functioning. In use, the device displayed the captured electromyography signal from the arm of the patient. Amplitude- frequency characteristics were set in order to investigate the bandwidth and the overall gain of the device.

Determination of saleable product in finished cattle and beef carcasses utilizing bioelectrical impedance technology.

PubMed

Marchello, M J; McLennan, J E; Dhuyvetter, D V; Slanger, W D

1999-11-01

Two experiments were performed to develop prediction equations of saleable beef and to validate the prediction equations. In Exp. 1, 50 beef cattle were finished to typical slaughter weights, and multiple linear regression equations were developed to predict kilograms of trimmed boneless, retail product of live cattle, and hot and cold carcasses. A four-terminal bioelectrical impedance analyzer (BIA) was used to measure resistance (Rs) and reactance (Xc) on each animal and processed carcass. The IMPS cuts plus trim were weighed and recorded. Distance between detector terminals (Lg) and carcass temperature (Tp) at time of BIA readings were recorded. Other variables included live weight (BW), hot carcass weight (HCW), cold carcass weight (CCW), and volume (Lg2/Rs). Regression equations for predicting kilograms of saleable product were [11.87 + (.409 x BW) - (.335 x Lg) + (.0518 x volume)] for live (R2 = .80); [-58.83 + (.589 x HCW) - (.846 x Rs) + (1.152 x Xc) + (.142 x Lg) + (2.608 x Tp)] for hot carcass (R2 = .95); and [32.15 + (.633 x CCW) + (.33 x Xc) - (.83 x Lg) + (.677 x volume)] for cold carcass (R2 = .93). In Exp. 2, 27 beef cattle were finished in a manner similar to Exp. 1, and the prediction equations from Exp. 1 were used to predict the saleable product of these animals. The Pearson correlations between actual saleable product and the predictions based on live and cold carcass data were .91 and .95, respectively. The Spearman and Kendall rank correlations were .95 and .83, respectively, for the cold carcass data. These results provide a practical application of bioelectrical impedance for market-based pricing. They complement previous studies that assessed fat-free mass.

Bioelectric characterization of epithelia from neonatal CFTR knockout ferrets.

PubMed

Fisher, John T; Tyler, Scott R; Zhang, Yulong; Lee, Ben J; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R; Engelhardt, John F

2013-11-01

Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4'-diisothiocyano-2,2'-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin-stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)-inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin-inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport.

Bioelectricity-AQA, one of the first MOOC courses in engineering.

PubMed

Barr, Roger C

2014-01-01

Bioelectricity-AQA was one of the first massively open online courses in engineering, having been given the first time via Coursera starting in September, 2012. This report provides some detail on its background, presentation, enrollment, and lessons learned.

Anisotropic bioelectrical impedance determination of subcutaneous fat thickness

NASA Astrophysics Data System (ADS)

Hernández-Becerra, P. A. I.; Delgadillo-Holtfort, I.; Balleza-Ordaz, M.; Huerta-Franco, M. R.; Vargas-Luna, M.

2014-11-01

Preliminary results have shown that bioelectrical impedance measurements performed on different parts of the human body strongly depend upon the subcutaneous fat of the considered region. In this work, a method for the determination of subcutaneous fat thickness is explored. Within this method the measurement of the bioelectrical impedance response of the fat-muscle system, both along the direction defined by the muscle fibers and along the corresponding perpendicular direction, are performed. Measurements have been carried out on human female and male subjects of ages around 25 years old at the region of the biceps. Correlation has been performed with skinfold caliper measurements.

Bioelectricity from kitchen and bamboo waste in a microbial fuel cell.

PubMed

Moqsud, M Azizul; Omine, Kiyoshi; Yasufuku, Noriyuki; Bushra, Quazi S; Hyodo, Masayuki; Nakata, Yukio

2014-02-01

This study evaluated bioelectricity generation by using kitchen garbage (KG) and bamboo waste (BW) as a solid waste management option by a microbial fuel cell (MFC) method. The nutrient content [nitrogen, phosphorus and potassium (NPK)] of the by-products of bioelectricity were also analyzed and assessed for their potential use as a soil amendment. A one-chamber MFC was used for bioelectricity generation in laboratory experiments using both KG and BW. A data-logger recorded voltage every 20 mins at a constant room temperature of 25°C over 45 days. The trend of voltage generation was different for the two organic wastes. In the case of KG, the voltage at the initial stage (0-5 days) increased rapidly and then gradually to a peak of 620 mV. In contrast, the voltage increased gradually to a peak of 540 mV in the case of BW. The by-products of bioelectricity can be used as soil conditioner as its NPK content was in the range of soil conditioner mentioned in other literature. Thus, the MFC has emerged as an efficient and eco-friendly solution for organic waste management, especially in developing and technologically less sophisticated countries, and can provide green and safe electricity from organic waste.

The Evaluation of Bioelectrical Activity of Pelvic Floor Muscles Depending on Probe Location: A Pilot Study

PubMed Central

Słupska, Lucyna

2013-01-01

Objectives. The main objective was to determine how the depth of probe placement affects functional and resting bioelectrical activity of the PFM and whether the recorded signal might be dependent on the direction in which the probe is rotated. Participants. The study comprised of healthy, nulliparous women between the ages of 21 and 25. Outcome Measures. Bioelectric activity of the PFM was recorded from four locations of the vagina by surface EMG and vaginal probe. Results. There were no statistically significant differences between the results during functional sEMG activity. During resting sEMG activity, the highest bioelectrical activity of the PFM was observed in the L1 and the lowest in the L4 and a statistically significant difference between the highest and the lowest results of resting sEMG activity was observed (P = 0.0043). Conclusion. Different electrodes placement during functional contraction of PFM does not affect the obtained results in sEMG evaluation. In order to diagnose the highest resting activity of PFM the recording plates should be placed toward the anterior vaginal wall and distally from the introitus. However, all of the PFM have similar bioelectrical activity and it seems that these muscles could be treated as a single muscle. PMID:24392449

Bioelectrical impedance analysis to define an excess of body fat: evaluation in patients with psoriasis.

PubMed

Galluzzo, M; Talamonti, M; Perino, F; Servoli, S; Giordano, D; Chimenti, S; De Simone, C; Peris, K

2017-06-01

There is strong evidence that obesity is closely associated with psoriasis. However, data on body composition are lacking in psoriasis. The purpose of this study were to investigate the body composition in psoriasis patients using bioelectrical impedance analysis and to correlate the bioelectrical impedance data with disease severity and laboratory parameters. Anthropometric measurements and bioelectrical impedance analyses were performed on patients with psoriasis, naïve to any systemic treatment, who attended the outpatient clinics of two University centers. Data of 164 adult patients were analyzed. Compared to men, women had several significantly higher bioelectrical impedance parameters including reactance, fat mass% and adipose tissue%. The values of adipose tissue were positively correlated only with patients age (p = .021) and age at disease onset (p = .0006), but not with disease severity. In addition, we observed that the use of BMI cutoffs allowed to categorize 36.7% of women and 19.2% of men as obese, while fat mass% showed that 53.3% of women and 48.1% of men were obese. In our study, psoriasis is been associated with a high fat mass%. We suggest that screening for body fat distribution in psoriatic patients might be useful to identify early obesity-related disease.

[Assessing nutritional status of severe malnutrition patients by bioelectrical impedance technique: a multicenter prospective study].

PubMed

Li, Qiang; Li, Xueni; Leng, Yuxin; Zhu, Xi; Yao, Gaiqi

2018-02-01

To assess the nutritional status of severe malnutrition patients with anorexia nervosa by multi-frequency bioelectrical impedance technique, and to provide the basis for nutritional support therapy. A prospective study was conducted. Twenty-six severe malnutrition patients with anorexia nervosa, body mass index (BMI) ≤ 16 kg/m 2 admitted to intensive care unit (ICU) of Peking University Third Hospital and general three ward of Peking University Sixth Hospital from June 1st to September 30th, 2017 were enrolled. The extracellular water (ECW), intracellular water (ICW), ECW/ICW ratio, adipose tissue mass (ATM), lean tissue mass (LTM), total body water/body weight (TBW/WT), ATM/WT, and LTM/WT were measured by multi-frequency bioelectrical impedance meter. Thirty-eighty healthy volunteers with normal nutritional status (23.0 kg/m 2 > BMI > 18.5 kg/m 2 ) matched by gender and height were enrolled as healthy control group. The predictive value of main body composition for nutritional status were analyzed by receiver operating characteristic (ROC) curve. All the patients were female. There was no significant difference in height between two groups, but WT and BMI in the severe malnutrition group were significantly higher than those in the healthy control group [WT (kg): 38.1±4.9 vs. 54.2±3.3, BMI (kg/m 2 ): 13.6±2.5 vs. 21.2±1.1, both P < 0.01]. Compared with the healthy control group, the ECW, ICW, ATM, LTM, ATM/WT and LTM/WT were significantly decreased in the severe malnutrition group [ECW (L): 9.02±0.42 vs. 10.19±0.77, ICW (L): 12.6±0.9 vs.19.1±1.3, ATM (kg): 9.3±1.1 vs. 16.6±1.9, LTM (kg): 16.5±1.5 vs. 26.1±1.7, ATM/WT: 0.26±0.02 vs. 0.30±0.02, LTM/WT: 0.22±0.02 vs. 0.26±0.01, all P < 0.01], the ECW/ICW and TBW/WT were significantly increased in the severe malnutrition group (ECW/ICW: 0.72±0.06 vs. 0.54±0.06, TBW/WT: 0.58±0.02 vs. 0.52±0.02, both P < 0.01). It was shown by ROC curve analysis that the area under ROC curve (AUC) of TBW/WT, ATM/WT, LTM/WT for evaluating severe malnutrition were 0.999, 0.919, 0.954 respectively; when the cut-off of TBW/WT, ATM/WT, LTM/WT were 0.58, 0.28, 0.24 respectively, the sensitivity were 100%, 85%, 80% respectively, and the specificity were 95%, 80%, 91% respectively. Main body composition of severe malnutrition patients with anorexia nervosa changed significantly. Bioelectrical impedance technology can be an effective assessment tool for the nutritional status of such patients.

The Performance of Five Bioelectrical Impedance Analysis Prediction Equations against Dual X-ray Absorptiometry in Estimating Appendicular Skeletal Muscle Mass in an Adult Australian Population

PubMed Central

Yu, Solomon C. Y.; Powell, Alice; Khow, Kareeann S. F.; Visvanathan, Renuka

2016-01-01

Appendicular skeletal muscle mass (ASM) is a diagnostic criterion for sarcopenia. Bioelectrical impedance analysis (BIA) offers a bedside approach to measure ASM but the performance of BIA prediction equations (PE) varies with ethnicities and body composition. We aim to validate the performance of five PEs in estimating ASM against estimation by dual-energy X-ray absorptiometry (DXA). We recruited 195 healthy adult Australians and ASM was measured using single-frequency BIA. Bland-Altman analysis was used to assess the predictive accuracy of ASM as determined by BIA against DXA. Precision (root mean square error (RMSE)) and bias (mean error (ME)) were calculated according to the method of Sheiner and Beal. Four PEs (except that by Kim) showed ASM values that correlated strongly with ASMDXA (r ranging from 0.96 to 0.97, p < 0.001). The Sergi equation performed the best with the lowest ME of −1.09 kg (CI: −0.84–−1.34, p < 0.001) and the RMSE was 2.09 kg (CI: 1.72–2.47). In men, the Kyle equation performed better with the lowest ME (−0.32 kg (CI: −0.66–0.02) and RMSE (1.54 kg (CI: 1.14–1.93)). The Sergi equation is applicable in adult Australians (Caucasian) whereas the Kyle equation can be considered in males. The need remains to validate PEs in other ethnicities and to develop equations suitable for multi-frequency BIA. PMID:27043617

The diagnostic accuracy of multi-frequency bioelectrical impedance analysis in diagnosing dehydration after stroke.

PubMed

Kafri, Mohannad W; Myint, Phyo Kway; Doherty, Danielle; Wilson, Alexander Hugh; Potter, John F; Hooper, Lee

2013-07-10

Non-invasive methods for detecting water-loss dehydration following acute stroke would be clinically useful. We evaluated the diagnostic accuracy of multi-frequency bioelectrical impedance analysis (MF-BIA) against reference standards serum osmolality and osmolarity. Patients admitted to an acute stroke unit were recruited. Blood samples for electrolytes and osmolality were taken within 20 minutes of MF-BIA. Total body water (TBW%), intracellular (ICW%) and extracellular water (ECW%), as percentages of total body weight, were calculated by MF-BIA equipment and from impedance measures using published equations for older people. These were compared to hydration status (based on serum osmolality and calculated osmolarity). The most promising Receiver Operating Characteristics curves were plotted. 27 stroke patients were recruited (mean age 71.3, SD10.7). Only a TBW% cut-off at 46% was consistent with current dehydration (serum osmolality >300 mOsm/kg) and TBW% at 47% impending dehydration (calculated osmolarity ≥295-300 mOsm/L) with sensitivity and specificity both >60%. Even here diagnostic accuracy of MF-BIA was poor, a third of those with dehydration were wrongly classified as hydrated and a third classified as dehydrated were well hydrated. Secondary analyses assessing diagnostic accuracy of TBW% for men and women separately, and using TBW as a percentage of lean body mass showed some promise, but did not provide diagnostically accurate measures across the population. MF-BIA appears ineffective at diagnosing water-loss dehydration after stroke and cannot be recommended as a test for dehydration, but separating assessment by sex, and using TBW as a percentage of lean body weight may warrant further investigation.

Making the invisible visible: bioelectrical impedance analysis demonstrates unfavourable body composition in rheumatoid arthritis patients in clinical practice.

PubMed

Konijn, N P C; van Tuyl, L H D; Bultink, I E M; Lems, W F; Earthman, C P; van Bokhorst-de van der Schueren, M A E

2014-01-01

To examine differences between the assessment of body composition by body mass index (BMI) and bioelectrical impedance analysis (BIA) in patients with rheumatoid arthritis (RA). The body composition of RA patients was assessed during their visit to the outpatient department of a Dutch academic hospital using BMI, fat-free mass index (FFMI), and fat mass index (FMI). FFMI and FMI were determined by single-frequency BIA. Sixty-five consecutive RA patients (83% women, mean age 58 years, median disease duration 7 years) with moderately active disease [mean Disease Activity Score using 28 joint counts (DAS28) = 3.40; mean Rheumatoid Arthritis Disease Activity Index (RADAI) score = 3.49] and moderate disability [mean Health Assessment Questionnaire (HAQ) score = 0.87] were included. Based on BMI, 2% of our study population were underweight, 45% had a healthy body composition, and 54% were overweight or obese. Based on BIA, 18% of the patients showed a low FFMI and 74% had a high or very high FMI. Low FFMI was found in 44% of the women with a normal BMI, and high FMI was found in 40% of the women and 75% of the men with a normal BMI. A high frequency of unfavourable body composition, predominantly reduced FFMI and elevated FMI, was found in a cohort of RA patients with moderately active disease, turning BMI into an unreliable method for assessment of body composition in RA. BIA, however, might be the preferred method to assess FFMI and FMI in RA patients in clinical practice, as it is easy to use and relatively inexpensive.

Bioelectricity-AQA, one of the first MOOC courses in Engineering

PubMed Central

Barr, Roger C.

2014-01-01

Bioelectricity-AQA was one of the first massively open online courses in engineering, having been given the first time via Coursera starting in September, 2012. This report provides some detail on its background, presentation, enrollment, and lessons learned. PMID:25570327

A Low noise, Non-contact Capacitive Cardiac Sensor*

PubMed Central

Peng, GuoChen; Bocko, Mark F.

2014-01-01

The development of sensitive, non-contact electric field sensors to measure weak bioelectric signals will be useful for the development of a number of unobtrusive health sensors. In this paper we summarize our recent work on a number of specific challenges in the development of non-contact ECG sensors. First, we considered the design of a low noise sensor preamplifier. We have adapted circuit designs that incorporate a double feedback loop to cancel the input transistor leakage current while providing stable operation, fast settling time and good low frequency response without the need for ultrahigh value resistors. The measured input referred noise of the preamplifier in the frequency band 0.05–100 Hz is 0.76 μVrms, which is several times lower than existing ECG preamplifiers. PMID:23367049

A low noise, non-contact capacitive cardiac sensor.

PubMed

Peng, GuoChen; Bocko, Mark F

2012-01-01

The development of sensitive, non-contact electric field sensors to measure weak bioelectric signals will be useful for the development of a number of unobtrusive health sensors. In this paper we summarize our recent work on a number of specific challenges in the development of non-contact ECG sensors. First, we considered the design of a low noise sensor preamplifier. We have adapted circuit designs that incorporate a double feedback loop to cancel the input transistor leakage current while providing stable operation, fast settling time and good low frequency response without the need for ultrahigh value resistors. The measured input referred noise of the preamplifier in the frequency band 0.05-100 Hz is 0.76 µV(rms), which is several times lower than existing ECG preamplifiers.

Enhanced microbial reduction of vanadium (V) in groundwater with bioelectricity from microbial fuel cells

NASA Astrophysics Data System (ADS)

Hao, Liting; Zhang, Baogang; Tian, Caixing; Liu, Ye; Shi, Chunhong; Cheng, Ming; Feng, Chuanping

2015-08-01

Bioelectricity generated from the microbial fuel cell (MFC) is applied to the bioelectrical reactor (BER) directly to enhance microbial reduction of vanadium (V) (V(V)) in groundwater. With the maximum power density of 543.4 mW m-2 from the MFC, V(V) removal is accelerated with efficiency of 93.6% during 12 h operation. Higher applied voltage can facilitate this process. V(V) removals decrease with the increase of initial V(V) concentration, while extra addition of chemical oxygen demand (COD) has little effect on performance improvement. Microbial V(V) reduction is enhanced and then suppressed with the increase of conductivity. High-throughput 16S rRNA gene pyrosequencing analysis implies the accumulated Enterobacter and Lactococcus reduce V(V) with products from fermentative microorganisms such as Macellibacteroides. The presentation of electrochemically active bacteria as Enterobacter promotes electron transfers. This study indicates that application of bioelectricity from MFCs is a promising strategy to improve the efficiency of in-situ bioremediation of V(V) polluted groundwater.

Bioelectrical Impedance and Body Composition Assessment

ERIC Educational Resources Information Center

Martino, Mike

2006-01-01

This article discusses field tests that can be used in physical education programs. The most common field tests are anthropometric measurements, which include body mass index (BMI), girth measurements, and skinfold testing. Another field test that is gaining popularity is bioelectrical impedance analysis (BIA). Each method has particular strengths…

Bioelectrical coupling in multicellular domains regulated by gap junctions: A conceptual approach.

PubMed

Cervera, Javier; Pietak, Alexis; Levin, Michael; Mafe, Salvador

2018-04-21

We review the basic concepts involved in bioelectrically-coupled multicellular domains, focusing on the role of membrane potentials (V mem ). In the first model, single-cell V mem is modulated by two generic polarizing and depolarizing ion channels, while intercellular coupling is implemented via voltage-gated gap junctions. Biochemical and bioelectrical signals are integrated via a feedback loop between V mem and the transcription and translation of a protein forming an ion channel. The effective rate constants depend on the single-cell V mem because these potentials modulate the local concentrations of signaling molecules and ions. This electrochemically-based idealization of the complex biophysical problem suggests that the spatio-temporal map of single-cell potentials can influence downstream patterning processes by means of the voltage-gated gap junction interconnectivity, much as in the case of electronic devices where the control of electric potentials and currents allows the local modulation of the circuitry to achieve full functionality. An alternative theoretical approach, the BioElectrical Tissue Simulation Engine (BETSE), is also presented. The BETSE modeling environment utilizes finite volume techniques to simulate bioelectric states from the perspective of ion concentrations and fluxes. This model has been successfully applied to make predictions and explain experimental observations in a variety of embryonic, regenerative, and oncogenic contexts. Copyright © 2018 Elsevier B.V. All rights reserved.

Multi-frequency bioelectrical impedance analysis (BIA) compared to magnetic resonance imaging (MRI) for estimation of fat-free mass in colorectal cancer patients treated with chemotherapy.

PubMed

Palle, Stine S; Møllehave, Line T; Taheri-Kadkhoda, Zahra; Johansen, Susanne; Larsen, Lisbeth; Hansen, Janne W; Jensen, Nikolaj K G; Elingaard, Anette O; Møller, Alice H; Larsen, Karen; Andersen, Jens R

2016-12-01

Changes in body composition in cancer patients during chemotherapy are associated with treatment related toxicities or mortalities. Thus, it is relevant to identify accessible, relatively inexpensive, portable and reliable tools for evaluation of body composition in cancer patients during the course of their treatments. To examine relationships between single cross-sectional thighs magnetic resonance imaging (MRI), skeletal muscle mass (SM) as reference and multi-frequency bioelectrical impedance analysis (BIA) fat free mass (FFM) in patients with colorectal cancer undergoing chemotherapy. In an observational, prospective study we examine the relationships between single cross-sectional thighs MRI (T1-weighted (1.5 T) SM compared to FFM BIA (8-electrodes multi-frequency Tanita MC780MA)) and FFM skin-fold thickness (ST) (4-points (Harpenden, Skinfold Caliper)) and SM equation for non-obese persons from Lee et al. 2000 (L2000) (based on age, height, weight, sex and race). FFM and SM (kg) were calculated based on either area (MRI) or weight. 18 CRC patients (10 males and 8 females) with mean (SD) age 67 yr (6) were measured at baseline, and 13 were available for follow-up. BIA overestimated FFM kg for all 31 measurements with mean (SD) 18.0 kg (6.0) compared to the MRI. ST overestimated FFM kg with mean 12.4 kg (6.2) and L2000 underestimated SM kg in 18 measurements and overestimated in 13 with a total mean of -4.3 kg (6.8). BIA and ST were the best alternatives to MRI as they showed constant and thereby correctable errors. The equation, L2000, carried the smallest average measurement error but it was non-constant. Copyright © 2016 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Multi-frequency bioelectrical impedance: a comparison between the Cole-Cole modelling and Hanai equations with the classical impedance index approach.

PubMed

Deurenberg, P; Andreoli, A; de Lorenzo, A

1996-01-01

Total body water and extracellular water were measured by deuterium oxide and bromide dilution respectively in 23 healthy males and 25 healthy females. In addition, total body impedance was measured at 17 frequencies, ranging from 1 kHz to 1350 kHz. Modelling programs were used to extrapolate impedance values to frequency zero (extracellular resistance) and frequency infinity (total body water resistance). Impedance indexes (height2/Zf) were computed at all 17 frequencies. The estimation errors of extracellular resistance and total body water resistance were 1% and 3%, respectively. Impedance and impedance index at low frequency were correlated with extracellular water, independent of the amount of total body water. Total body water showed the greatest correlation with impedance and impedance index at high frequencies. Extrapolated impedance values did not show a higher correlation compared to measured values. Prediction formulas from the literature applied to fixed frequencies showed the best mean and individual predictions for both extracellular water and total body water. It is concluded that, at least in healthy individuals with normal body water distribution, modelling impedance data has no advantage over impedance values measured at fixed frequencies, probably due to estimation errors in the modelled data.

Evaluation of electrical broad bandwidth impedance spectroscopy as a tool for body composition measurement in cows in comparison with body measurements and the deuterium oxide dilution method.

PubMed

Schäff, C T; Pliquett, U; Tuchscherer, A; Pfuhl, R; Görs, S; Metges, C C; Hammon, H M; Kröger-Koch, C

2017-05-01

Body fatness and degree of body fat mobilization in cows vary enormously during their reproduction cycle and influence energy partitioning and metabolic adaptation. The objective of the study was to test bioelectrical impedance spectroscopy (BIS) as a method for predicting fat depot mass (FDM), in living cows. The FDM is defined as the sum of subcutaneous, omental, mesenteric, retroperitoneal, and carcass fat mass. Bioelectrical impedance spectroscopy is compared with the prediction of FDM from the deuterium oxide (DO) dilution method and from body conformation measurements. Charolais × Holstein Friesian (HF; = 18; 30 d in milk) crossbred cows and 2 HF (lactating and nonlactating) cows were assessed by body conformation measurements, BIS, and the DO dilution method. The BCS of cows was a mean of 3.68 (SE 0.64). For the DO dilution method, a bolus of 0.23 g/kg BW DO (60 atom%) was intravenously injected and deuterium (D) enrichment was analyzed in plasma and whey by stabile isotope mass spectrometry, and total body water content was calculated. Impedance measurement was performed using a 4-electrode interface and time domain-based measurement system consisting of a voltage/current converter for applying current stimulus and an amplifier for monitoring voltage across the sensor electrodes. For the BIS, we used complex impedances over three frequency decades that delivers information on intra- and extracellular water and capacity of cell membranes. Impedance data (resistance of extra- and intracellular space, cell membrane capacity, and phase angle) were extracted 1) by simple curve fit to extract the resistance at direct current and high frequency and 2) by using an electrical equivalent circuit. Cows were slaughtered 7 d after BIS and D enrichment measurements and dissected for the measurement of FDM. Multiple linear regression analyses were performed to predict FDM based on data obtained from body conformation measurements, BIS, and D enrichment, and applied methods were evaluated by cross-validation. The FDM varied widely between cows and was correlated to D enrichment in plasma ( = 0.91, < 0.05). Prediction of FDM by body size measurements was less precise ( = 0.84), but FDM prediction was more accurate using D enrichment in plasma ( = 0.90) and BIS ( = 0.99) data. Therefore, both BIS and D enrichment analysis resulted in similarly good predictions of FDM in cows, and we conclude that BIS could have the potential to predict FDM in dairy cows from 40 to 380 kg.

Low-noise two-wired buffer electrodes for bioelectric amplifiers.

PubMed

Degen, Thomas; Torrent, Simon; Jäckel, Heinz

2007-07-01

Active buffer electrodes are known to improve the immunity of bioelectric recordings against power line interferences. A survey of published work reveals that buffer electrodes are almost exclusively designed using operational amplifiers (opamps). In this paper, we discuss the advantage of utilizing a single transistor instead. This allows for a simple electrode, which is small and requires only two wires. In addition, a single transistor adds considerably less noise when compared to an opamp with the same power consumption. We then discuss output resistance and gain as well as their respective effect on the common mode rejection ratio (CMRR). Finally, we demonstrate the use of two-wired buffer electrodes for a bioelectric amplifier.

Fabrication of self-expandable NiTi thin film devices with micro-electrode array for bioelectric sensing, stimulation and ablation.

PubMed

Bechtold, Christoph; de Miranda, Rodrigo Lima; Chluba, Christoph; Quandt, Eckhard

2016-12-01

Self-expandable medical devices provide mechanical functionality at a specific location of the human body and are viable for minimal invasive procedures. Besides radiopaque markers and drug-eluting coatings, next generation self-expandable devices can be equipped with additional functionality, such as conductive and flexible electrodes, which enables chronic recording of bioelectrical signals, stimulating or ablating tissue. This promises new therapeutic options in various medical fields, among them in particular neuromodulation (e.g. deep brain stimulation), BioMEMS, radio frequency ablation, mapping or denervation. However, the fabrication of such multi-functional devices is challenging. For this study we have realized a 35 μm thick, superelastic NiTi thin film stent structure with six isolated electrodes on the outer circumference, each electrode connected to a contact pad at the end of the stent structure, using magnetron sputtering, UV lithography and wet chemical etching. Mechanical and electrical properties of the device during typical loading conditions, i.e. crimping, simulated pulsatile and electrochemical testing, were characterized and reveal promising results. For the fabrication of future multifunctional, minimal invasive medical devices, such as electroceuticals or other intelligent implants, NiTi thin film technology is therefore a versatile alternative to conventional fabrication routes.

Validity of bioelectrical impedance measurement in predicting fat-free mass of Chinese children and adolescents.

PubMed

Wang, Lin; Hui, Stanley Sai-chuen; Wong, Stephen Heung-sang

2014-11-15

The current study aimed to examine the validity of various published bioelectrical impedance analysis (BIA) equations in estimating FFM among Chinese children and adolescents and to develop BIA equations for the estimation of fat-free mass (FFM) appropriate for Chinese children and adolescents. A total of 255 healthy Chinese children and adolescents aged 9 to 19 years old (127 males and 128 females) from Tianjin, China, participated in the BIA measurement at 50 kHz between the hand and the foot. The criterion measure of FFM was also employed using dual-energy X-ray absorptiometry (DEXA). FFM estimated from 24 published BIA equations was cross-validated against the criterion measure from DEXA. Multiple linear regression was conducted to examine alternative BIA equation for the studied population. FFM estimated from the 24 published BIA equations yielded high correlations with the directly measured FFM from DEXA. However, none of the 24 equations was statistically equivalent with the DEXA-measured FFM. Using multiple linear regression and cross-validation against DEXA measurement, an alternative prediction equation was determined as follows: FFM (kg)=1.613+0.742×height (cm)2/impedance (Ω)+0.151×body weight (kg); R2=0.95; SEE=2.45 kg; CV=6.5, 93.7% of the residuals of all the participants fell within the 95% limits of agreement. BIA was highly correlated with FFM in Chinese children and adolescents. When the new developed BIA equations are applied, BIA can provide a practical and valid measurement of body composition in Chinese children and adolescents.

Validity of Bioelectrical Impedance Measurement in Predicting Fat-Free Mass of Chinese Children and Adolescents

PubMed Central

Wang, Lin; Hui, Stanley Sai-chuen; Wong, Stephen Heung-sang

2014-01-01

Background The current study aimed to examine the validity of various published bioelectrical impedance analysis (BIA) equations in estimating FFM among Chinese children and adolescents and to develop BIA equations for the estimation of fat-free mass (FFM) appropriate for Chinese children and adolescents. Material/Methods A total of 255 healthy Chinese children and adolescents aged 9 to 19 years old (127 males and 128 females) from Tianjin, China, participated in the BIA measurement at 50 kHz between the hand and the foot. The criterion measure of FFM was also employed using dual-energy X-ray absorptiometry (DEXA). FFM estimated from 24 published BIA equations was cross-validated against the criterion measure from DEXA. Multiple linear regression was conducted to examine alternative BIA equation for the studied population. Results FFM estimated from the 24 published BIA equations yielded high correlations with the directly measured FFM from DEXA. However, none of the 24 equations was statistically equivalent with the DEXA-measured FFM. Using multiple linear regression and cross-validation against DEXA measurement, an alternative prediction equation was determined as follows: FFM (kg)=1.613+0.742×height (cm)2/impedance (Ω)+0.151×body weight (kg); R2=0.95; SEE=2.45kg; CV=6.5, 93.7% of the residuals of all the participants fell within the 95% limits of agreement. Conclusions BIA was highly correlated with FFM in Chinese children and adolescents. When the new developed BIA equations are applied, BIA can provide a practical and valid measurement of body composition in Chinese children and adolescents. PMID:25398209

Estimating body fat by using bioelectrical-impedance measurements: a preliminary assessment.

Treesearch

M.G. Raphael; H.J. Harlow; S.W. Buskirk

1991-01-01

We evaluated a technique for measuring body fat content of marten (Martes americana) by using a noninvasive bioelectrical-impedance device with four electrodes to introduce a current into the body. Instantaneous readings of resistance were significantly correlated with fat-free mass (determined from solvent extraction) of carcasses of 17 skinned (r...

Bioelectrical impedance vector distribution in the first year of life.

PubMed

Savino, Francesco; Grasso, Giulia; Cresi, Francesco; Oggero, Roberto; Silvestro, Leandra

2003-06-01

We assessed the bioelectrical impedance vector distribution in a sample of healthy infants in the first year of life, which is not available in literature. The study was conducted as a cross-sectional study in 153 healthy Caucasian infants (90 male and 63 female) younger than 1 y, born at full term, adequate for gestational age, free from chronic diseases or growth problems, and not feverish. Z scores for weight, length, cranial circumference, and body mass index for the study population were within the range of +/-1.5 standard deviations according to the Euro-Growth Study references. Concurrent anthropometrics (weight, length, and cranial circumference), body mass index, and bioelectrical impedance (resistance and reactance) measurements were made by the same operator. Whole-body (hand to foot) tetrapolar measurements were performed with a single-frequency (50 kHz), phase-sensitive impedance analyzer. The study population was subdivided into three classes of age for statistical analysis: 0 to 3.99 mo, 4 to 7.99 mo, and 8 to 11.99 mo. Using the bivariate normal distribution of resistance and reactance components standardized by the infant's length, the bivariate 95% confidence limits for the mean impedance vector separated by sex and age groups were calculated and plotted. Further, the bivariate 95%, 75%, and 50% tolerance intervals for individual vector measurements in the first year of life were plotted. Resistance and reactance values often fluctuated during the first year of life, particularly as raw measurements (without normalization by subject's length). However, 95% confidence ellipses of mean vectors from the three age groups overlapped each other, as did confidence ellipses by sex for each age class, indicating no significant vector migration during the first year of life. We obtained an estimate of mean impedance vector in a sample of healthy infants in the first year of life and calculated the bivariate values for an individual vector (95%, 75%, and 50% tolerance ellipses).

The diagnostic accuracy of multi-frequency bioelectrical impedance analysis in diagnosing dehydration after stroke

PubMed Central

Kafri, Mohannad W.; Myint, Phyo Kyaw; Doherty, Danielle; Wilson, Alexander Hugh; Potter, John F.; Hooper, Lee

2013-01-01

Background Non-invasive methods for detecting water-loss dehydration following acute stroke would be clinically useful. We evaluated the diagnostic accuracy of multi-frequency bioelectrical impedance analysis (MF-BIA) against reference standards serum osmolality and osmolarity. Material/Methods Patients admitted to an acute stroke unit were recruited. Blood samples for electrolytes and osmolality were taken within 20 minutes of MF-BIA. Total body water (TBW%), intracellular (ICW%) and extracellular water (ECW%), as percentages of total body weight, were calculated by MF-BIA equipment and from impedance measures using published equations for older people. These were compared to hydration status (based on serum osmolality and calculated osmolarity). The most promising Receiver Operating Characteristics curves were plotted. Results 27 stroke patients were recruited (mean age 71.3, SD10.7). Only a TBW% cut-off at 46% was consistent with current dehydration (serum osmolality >300 mOsm/kg) and TBW% at 47% impending dehydration (calculated osmolarity ≥295–300 mOsm/L) with sensitivity and specificity both >60%. Even here diagnostic accuracy of MF-BIA was poor, a third of those with dehydration were wrongly classified as hydrated and a third classified as dehydrated were well hydrated. Secondary analyses assessing diagnostic accuracy of TBW% for men and women separately, and using TBW as a percentage of lean body mass showed some promise, but did not provide diagnostically accurate measures across the population. Conclusions MF-BIA appears ineffective at diagnosing water-loss dehydration after stroke and cannot be recommended as a test for dehydration, but separating assessment by sex, and using TBW as a percentage of lean body weight may warrant further investigation. PMID:23839255

Bioelectric Control of a 757 Class High Fidelity Aircraft Simulation

NASA Technical Reports Server (NTRS)

Jorgensen, Charles; Wheeler, Kevin; Stepniewski, Slawomir; Norvig, Peter (Technical Monitor)

2000-01-01

This paper presents results of a recent experiment in fine grain Electromyographic (EMG) signal recognition, We demonstrate bioelectric flight control of 757 class simulation aircraft landing at San Francisco International Airport. The physical instrumentality of a pilot control stick is not used. A pilot closes a fist in empty air and performs control movements which are captured by a dry electrode array on the arm, analyzed and routed through a flight director permitting full pilot outer loop control of the simulation. A Vision Dome immersive display is used to create a VR world for the aircraft body mechanics and flight changes to pilot movements. Inner loop surfaces and differential aircraft thrust is controlled using a hybrid neural network architecture that combines a damage adaptive controller (Jorgensen 1998, Totah 1998) with a propulsion only based control system (Bull & Kaneshige 1997). Thus the 757 aircraft is not only being flown bioelectrically at the pilot level but also demonstrates damage adaptive neural network control permitting adaptation to severe changes in the physical flight characteristics of the aircraft at the inner loop level. To compensate for accident scenarios, the aircraft uses remaining control surface authority and differential thrust from the engines. To the best of our knowledge this is the first time real time bioelectric fine-grained control, differential thrust based control, and neural network damage adaptive control have been integrated into a single flight demonstration. The paper describes the EMG pattern recognition system and the bioelectric pattern recognition methodology.

Functional and Histological Effects of Chronic Neural Electrode Implantation.

PubMed

Sahyouni, Ronald; Chang, David T; Moshtaghi, Omid; Mahmoodi, Amin; Djalilian, Hamid R; Lin, Harrison W

2017-04-01

Permanent injury to the cranial nerves can often result in a substantial reduction in quality of life. Novel and innovative interventions can help restore form and function in nerve paralysis, with bioelectric interfaces among the more promising of these approaches. The foreign body response is an important consideration for any bioelectric device as it influences the function and effectiveness of the implant. The purpose of this review is to describe tissue and functional effects of chronic neural implantation among the different categories of neural implants and highlight advances in peripheral and cranial nerve stimulation. Data Sources : PubMed, IEEE, and Web of Science literature search. Review Methods : A review of the current literature was conducted to examine functional and histologic effects of bioelectric interfaces for neural implants. Bioelectric devices can be characterized as intraneural, epineural, perineural, intranuclear, or cortical depending on their placement relative to nerves and neuronal cell bodies. Such devices include nerve-specific stimulators, neuroprosthetics, brainstem implants, and deep brain stimulators. Regardless of electrode location and interface type, acute and chronic histological, macroscopic and functional changes can occur as a result of both passive and active tissue responses to the bioelectric implant. A variety of chronically implantable electrodes have been developed to treat disorders of the peripheral and cranial nerves, to varying degrees of efficacy. Consideration and mitigation of detrimental effects at the neural interface with further optimization of functional nerve stimulation will facilitate the development of these technologies and translation to the clinic. 3.

Carbon fiber enhanced bioelectricity generation in soil microbial fuel cells.

PubMed

Li, Xiaojing; Wang, Xin; Zhao, Qian; Wan, Lili; Li, Yongtao; Zhou, Qixing

2016-11-15

The soil microbial fuel cell (MFC) is a promising biotechnology for the bioelectricity recovery as well as the remediation of organics contaminated soil. However, the electricity production and the remediation efficiency of soil MFC are seriously limited by the tremendous internal resistance of soil. Conductive carbon fiber was mixed with petroleum hydrocarbons contaminated soil and significantly enhanced the performance of soil MFC. The maximum current density, the maximum power density and the accumulated charge output of MFC mixed carbon fiber (MC) were 10, 22 and 16 times as high as those of closed circuit control due to the carbon fiber productively assisted the anode to collect the electron. The internal resistance of MC reduced by 58%, 83% of which owed to the charge transfer resistance, resulting in a high efficiency of electron transfer from soil to anode. The degradation rates of total petroleum hydrocarbons enhanced by 100% and 329% compared to closed and opened circuit controls without the carbon fiber respectively. The effective range of remediation and the bioelectricity recovery was extended from 6 to 20cm with the same area of air-cathode. The mixed carbon fiber apparently enhanced the bioelectricity generation and the remediation efficiency of soil MFC by means of promoting the electron transfer rate from soil to anode. The use of conductively functional materials (e.g. carbon fiber) is very meaningful for the remediation and bioelectricity recovery in the bioelectrochemical remediation. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of vegetation type on treatment performance and bioelectric production of constructed wetland modules combined with microbial fuel cell (CW-MFC) treating synthetic wastewater.

PubMed

Saz, Çağdaş; Türe, Cengiz; Türker, Onur Can; Yakar, Anıl

2018-03-01

An operation of microcosm-constructed wetland modules combined with microbial fuel cell device (CW-MFC) was assessed for wastewater treatment and bioelectric generation. One of the crucial aims of the present experiment is also to determine effect of vegetation on wastewater treatment process and bioelectric production in wetland matrix with microbial fuel cell. Accordingly, CW-MFC modules with vegetation had higher treatment efficiency compared to unplanted wetland module, and average COD, NH 4 + , and TP removal efficiency in vegetated wetland modules were ranged from 85 to 88%, 95 to 97%, and 95 to 97%, respectively. However, the highest NO 3 - removal (63%) was achieved by unplanted control module during the experiment period. The maximum average output voltage, power density, and Coulombic efficiency were obtained in wetland module vegetated with Typha angustifolia for 1.01 ± 0.14 V, 7.47 ± 13.7 mWatt/m 2 , and 8.28 ± 10.4%, respectively. The results suggest that the presence of Typha angustifolia vegetation in the CW-MFC matrix provides the benefits for treatment efficiency and bioelectric production; thus, it increases microbial activities which are responsible for biodegradation of organic compounds and catalyzed to electron flow from anode to cathode. Consequently, we suggest that engineers can use vegetated wetland matrix with Typha angustifolia in CW-MFC module in order to maximize treatment efficiency and bioelectric production.

Bioelectric memory: modeling resting potential bistability in amphibian embryos and mammalian cells.

PubMed

Law, Robert; Levin, Michael

2015-10-15

Bioelectric gradients among all cells, not just within excitable nerve and muscle, play instructive roles in developmental and regenerative pattern formation. Plasma membrane resting potential gradients regulate cell behaviors by regulating downstream transcriptional and epigenetic events. Unlike neurons, which fire rapidly and typically return to the same polarized state, developmental bioelectric signaling involves many cell types stably maintaining various levels of resting potential during morphogenetic events. It is important to begin to quantitatively model the stability of bioelectric states in cells, to understand computation and pattern maintenance during regeneration and remodeling. To facilitate the analysis of endogenous bioelectric signaling and the exploitation of voltage-based cellular controls in synthetic bioengineering applications, we sought to understand the conditions under which somatic cells can stably maintain distinct resting potential values (a type of state memory). Using the Channelpedia ion channel database, we generated an array of amphibian oocyte and mammalian membrane models for voltage evolution. These models were analyzed and searched, by simulation, for a simple dynamical property, multistability, which forms a type of voltage memory. We find that typical mammalian models and amphibian oocyte models exhibit bistability when expressing different ion channel subsets, with either persistent sodium or inward-rectifying potassium, respectively, playing a facilitative role in bistable memory formation. We illustrate this difference using fast sodium channel dynamics for which a comprehensive theory exists, where the same model exhibits bistability under mammalian conditions but not amphibian conditions. In amphibians, potassium channels from the Kv1.x and Kv2.x families tend to disrupt this bistable memory formation. We also identify some common principles under which physiological memory emerges, which suggest specific strategies for implementing memories in bioengineering contexts. Our results reveal conditions under which cells can stably maintain one of several resting voltage potential values. These models suggest testable predictions for experiments in developmental bioelectricity, and illustrate how cells can be used as versatile physiological memory elements in synthetic biology, and unconventional computation contexts.

Greater transportation energy and GHG offsets from bioelectricity than ethanol.

PubMed

Campbell, J E; Lobell, D B; Field, C B

2009-05-22

The quantity of land available to grow biofuel crops without affecting food prices or greenhouse gas (GHG) emissions from land conversion is limited. Therefore, bioenergy should maximize land-use efficiency when addressing transportation and climate change goals. Biomass could power either internal combustion or electric vehicles, but the relative land-use efficiency of these two energy pathways is not well quantified. Here, we show that bioelectricity outperforms ethanol across a range of feedstocks, conversion technologies, and vehicle classes. Bioelectricity produces an average of 81% more transportation kilometers and 108% more emissions offsets per unit area of cropland than does cellulosic ethanol. These results suggest that alternative bioenergy pathways have large differences in how efficiently they use the available land to achieve transportation and climate goals.

Bioelectric effect and bacterial biofilms. A systematic review

PubMed Central

DEL POZO, J. L.; ROUSE, M. S.; PATEL, R.

2014-01-01

Bacteria growing in biofilms cause a wide range of human infections. Biofilm bacteria are resistant to antimicrobics at levels 500 to 5,000 times higher than those needed to kill non-biofilm bacteria. In vitro experiments have shown that electric current can enhance the activity of some antimicrobial agents against certain bacteria in biofilms; this has been termed the “bioelectric effect”. Direct electrical current has already been safely used in humans for fracture healing. Application of direct electric current with antimicrobial chemotherapy in humans could theoretically abrogate the need to remove the device in device-related infections, a procedure associated with substantial morbidity and cost. In this article, we review what has been described in the literature with regards to the bioelectric effect. PMID:18924090

Beta-Adrenergic Modulation of Tremor and Corticomuscular Coherence in Humans

PubMed Central

Baker, Mark R.; Baker, Stuart N.

2012-01-01

Coherence between the bioelectric activity of sensorimotor cortex and contralateral muscles can be observed around 20 Hz. By contrast, physiological tremor has a dominant frequency around 10 Hz. Although tremor has multiple sources, it is partly central in origin, reflecting a component of motoneuron discharge at this frequency. The motoneuron response to ∼20 Hz descending input could be altered by non-linear interactions with ∼10 Hz motoneuron firing. We investigated this further in eight healthy human subjects by testing the effects of the beta-adrenergic agents propranolol (non-selective β-antagonist) and salbutamol (β2-agonist), which are known to alter the size of physiological tremor. Corticomuscular coherence was assessed during an auxotonic precision grip task; tremor was quantified using accelerometry during index finger extension. Experiments with propranolol used a double-blind, placebo-controlled crossover design. A single oral dose of propranolol (40 mg) significantly increased beta band (15.3–32.2 Hz) corticomuscular coherence compared with placebo, but reduced tremor in the 6.2–11.9 Hz range. Salbutamol (2.5 mg) was administered by inhalation. Whilst salbutamol significantly increased tremor amplitude as expected, it did not change corticomuscular coherence. The opposite direction of the effects of propranolol on corticomuscular coherence and tremor, and the fact that salbutamol enhances tremor but does not affect coherence, implies that the magnitude of corticomuscular coherence is little influenced by non-linear interactions with 10 Hz oscillations in motoneurons or the periphery. Instead, we suggest that propranolol and salbutamol may affect both tremor and corticomuscular coherence partly via a central site of action. PMID:23185297

Preliminary bioelectrical impedance analysis (BIA) equation for body composition assessment in young females from Colombia

NASA Astrophysics Data System (ADS)

Caicedo-Eraso, J. C.; González-Correa, C. H.; González-Correa, C. A.

2013-04-01

A previous study showed that reported BIA equations for body composition are not suitable for Colombian population. The purpose of this study was to develop and validate a preliminary BIA equation for body composition assessment in young females from Colombia, using hydrodensitometry as reference method. A sample of 30 young females was evaluated. Inclusion and exclusion criteria were defined to minimize the variability of BIA. Height, weight, BIA, residual lung volume (RV) and underwater weight (UWW) were measured. A preliminary BIA equation was developed (r2 = 0.72, SEE = 2.48 kg) by stepwise multiple regression with fat-free mass (FFM) as dependent variable and weight, height and impedance measurements as independent variables. The quality of regression was evaluated and a cross-validation against 50% of sample confirmed that results obtained with the preliminary BIA equation is interchangeable with results obtained with hydrodensitometry (r2 = 0.84, SEE = 2.62 kg). The preliminary BIA equation can be used for body composition assessment in young females from Colombia until a definitive equation is developed. The next step will be increasing the sample, including a second reference method, as deuterium oxide dilution (D2O), and using multi-frequency BIA (MF-BIA). It would also be desirable to develop equations for males and other ethnic groups in Colombia.

Paradoxical Air Microembolism Induces Cerebral Bioelectrical Abnormalities and Occasionally Headache in Patent Foramen Ovale Patients With Migraine

PubMed Central

Sevgi, Eser Başak; Erdener, Sefik Evren; Demirci, Mehmet; Topcuoglu, Mehmet Akif; Dalkara, Turgay

2012-01-01

Background Although controversial, paradoxical embolism via patent foramen ovale (PFO) may account for some of the migraine attacks in a subset of migraine with aura (MA) patients. Induction of MA attacks with air bubble injection during transcranial Doppler ultrasound in MA patients with PFO supports this view. It is likely that cerebral embolism in patients with right-to-left shunt induces bioelectrical abnormalities to initiate MA under some conditions. Methods and Results We investigated changes in cerebral bioelectrical activity after intravenous microbubble injection in 10 MA patients with large PFO and right-to-left cardiac shunt. Eight PFO patients without migraine but with large right-to-left shunt and 12 MA patients without PFO served as controls. Four MA patients with PFO were reexamined with sham injections of saline without microbubbles. Bioelectrical activity was evaluated using spectral electroencephalography and, passage of microbubbles through cerebral arteries was monitored with transcranial Doppler ultrasound. Microbubble embolism caused significant electroencephalographic power increase in MA+PFO patients but not in control groups including the sham-injected MA+PFO patients. Headache developed in 2 MA with PFO patients after microbubble injection. Conclusions These findings demonstrate that air microembolism through large PFOs may cause cerebral bioelectrical disturbances and, occasionally, headache in MA patients, which may reflect an increased reactivity of their brain to transient subclinical hypoxia–ischemia, and suggest that paradoxical embolism is not a common cause of migraine but may induce headache in the presence of a large PFO and facilitating conditions. PMID:23316313

Enhancement of bioelectricity generation via heterologous expression of IrrE in Pseudomonas aeruginosa-inoculated MFCs.

PubMed

Luo, Jianmei; Wang, Tingting; Li, Xiao; Yang, Yanan; Zhou, Minghua; Li, Ming; Yan, Zhongli

2018-05-30

Low electricity power output (EPT) is still the main bottleneck limited the industrial application of microbial fuel cells (MFCs). Herein, EPT enhancement by introducing an exogenous global regulator IrrE derived from Deinococcus radiodurans into electrochemically active bacteria (EAB) was explored using Pseudomonas aeruginosa PAO1 as a model strain, achieving a power density 71% higher than that of the control strain. Moreover, IrrE-expressing strain exhibited a remarkable increase in the total amount of electron shuttles (majorly phenazines compounds) and a little decrease in internal resistance, which should underlie the enhancement in extracellular electron transfer (EET) efficiency and EPT. Strikingly, IrrE significantly affected substrate utilization profiling, improved cell growth characterization and cell tolerance to various stresses. Further quantitative RT-PCR analysis revealed that IrrE led to many differentially expressed genes, which were responsible for phenazines core biosynthesis, biofilm formation, QS systems, transcriptional regulation, glucose metabolism and general stress response. The results substantiated that targeting cellular regulatory network by the introduction of exogenous global regulators could be a facile and promising approach for the enhancement of bioelectricity generation and cell multiple phenotypes, and thus would be of great potential application in the practical MFCs. Copyright © 2018 Elsevier B.V. All rights reserved.

Ethnic Variability in Body Size, Proportions and Composition in Children Aged 5 to 11 Years: Is Ethnic-Specific Calibration of Bioelectrical Impedance Required?

PubMed Central

Lee, Simon; Bountziouka, Vassiliki; Lum, Sooky; Stocks, Janet; Bonner, Rachel; Naik, Mitesh; Fothergill, Helen; Wells, Jonathan C. K.

2014-01-01

Background Bioelectrical Impedance Analysis (BIA) has the potential to be used widely as a method of assessing body fatness and composition, both in clinical and community settings. BIA provides bioelectrical properties, such as whole-body impedance which ideally needs to be calibrated against a gold-standard method in order to provide accurate estimates of fat-free mass. UK studies in older children and adolescents have shown that, when used in multi-ethnic populations, calibration equations need to include ethnic-specific terms, but whether this holds true for younger children remains to be elucidated. The aims of this study were to examine ethnic differences in body size, proportions and composition in children aged 5 to 11 years, and to establish the extent to which such differences could influence BIA calibration. Methods In a multi-ethnic population of 2171 London primary school-children (47% boys; 34% White, 29% Black African/Caribbean, 25% South Asian, 12% Other) detailed anthropometric measurements were performed and ethnic differences in body size and proportion were assessed. Ethnic differences in fat-free mass, derived by deuterium dilution, were further evaluated in a subsample of the population (n = 698). Multiple linear regression models were used to calibrate BIA against deuterium dilution. Results In children <11 years of age, Black African/Caribbean children were significantly taller, heavier and had larger body size than children of other ethnicities. They also had larger waist and limb girths and relatively longer legs. Despite these differences, ethnic-specific terms did not contribute significantly to the BIA calibration equation (Fat-free mass = 1.12+0.71*(height2/impedance)+0.18*weight). Conclusion Although clear ethnic differences in body size, proportions and composition were evident in this population of young children aged 5 to 11 years, an ethnic-specific BIA calibration equation was not required. PMID:25478928

Ethnic variability in body size, proportions and composition in children aged 5 to 11 years: is ethnic-specific calibration of bioelectrical impedance required?

PubMed

Lee, Simon; Bountziouka, Vassiliki; Lum, Sooky; Stocks, Janet; Bonner, Rachel; Naik, Mitesh; Fothergill, Helen; Wells, Jonathan C K

2014-01-01

Bioelectrical Impedance Analysis (BIA) has the potential to be used widely as a method of assessing body fatness and composition, both in clinical and community settings. BIA provides bioelectrical properties, such as whole-body impedance which ideally needs to be calibrated against a gold-standard method in order to provide accurate estimates of fat-free mass. UK studies in older children and adolescents have shown that, when used in multi-ethnic populations, calibration equations need to include ethnic-specific terms, but whether this holds true for younger children remains to be elucidated. The aims of this study were to examine ethnic differences in body size, proportions and composition in children aged 5 to 11 years, and to establish the extent to which such differences could influence BIA calibration. In a multi-ethnic population of 2171 London primary school-children (47% boys; 34% White, 29% Black African/Caribbean, 25% South Asian, 12% Other) detailed anthropometric measurements were performed and ethnic differences in body size and proportion were assessed. Ethnic differences in fat-free mass, derived by deuterium dilution, were further evaluated in a subsample of the population (n = 698). Multiple linear regression models were used to calibrate BIA against deuterium dilution. In children < 11 years of age, Black African/Caribbean children were significantly taller, heavier and had larger body size than children of other ethnicities. They also had larger waist and limb girths and relatively longer legs. Despite these differences, ethnic-specific terms did not contribute significantly to the BIA calibration equation (Fat-free mass = 1.12+0.71*(height2/impedance)+0.18*weight). Although clear ethnic differences in body size, proportions and composition were evident in this population of young children aged 5 to 11 years, an ethnic-specific BIA calibration equation was not required.

Bioelectric Characterization of Epithelia from Neonatal CFTR Knockout Ferrets

PubMed Central

Fisher, John T.; Tyler, Scott R.; Zhang, Yulong; Lee, Ben J.; Liu, Xiaoming; Sun, Xingshen; Sui, Hongshu; Liang, Bo; Luo, Meihui; Xie, Weiliang; Yi, Yaling; Zhou, Weihong; Song, Yi; Keiser, Nicholas; Wang, Kai; de Jonge, Hugo R.

2013-01-01

Cystic fibrosis (CF) is a life-shortening, recessive, multiorgan genetic disorder caused by the loss of CF transmembrane conductance regulator (CFTR) chloride channel function found in many types of epithelia. Animal models that recapitulate the human disease phenotype are critical to understanding pathophysiology in CF and developing therapies. CFTR knockout ferrets manifest many of the phenotypes observed in the human disease, including lung infections, pancreatic disease and diabetes, liver disease, malnutrition, and meconium ileus. In the present study, we have characterized abnormalities in the bioelectric properties of the trachea, stomach, intestine, and gallbladder of newborn CF ferrets. Short-circuit current (ISC) analysis of CF and wild-type (WT) tracheas revealed the following similarities and differences: (1) amiloride-sensitive sodium currents were similar between genotypes; (2) responses to 4,4′-diisothiocyano-2,2′-stilbene disulphonic acid were 3.3-fold greater in CF animals, suggesting elevated baseline chloride transport through non-CFTR channels in a subset of CF animals; and (3) a lack of 3-isobutyl-1-methylxanthine (IBMX)/forskolin–stimulated and N-(2-Naphthalenyl)-((3,5-dibromo-2,4-dihydroxyphenyl)methylene)glycine hydrazide (GlyH-101)–inhibited currents in CF animals due to the lack of CFTR. CFTR mRNA was present throughout all levels of the WT ferret and IBMX/forskolin–inducible ISC was only observed in WT animals. However, despite the lack of CFTR function in the knockout ferret, the luminal pH of the CF ferret gallbladder, stomach, and intestines was not significantly changed relative to WT. The WT stomach and gallbladder exhibited significantly enhanced IBMX/forskolin ISC responses and inhibition by GlyH-101 relative to CF samples. These findings demonstrate that multiple organs affected by disease in the CF ferret have bioelectric abnormalities consistent with the lack of cAMP-mediated chloride transport. PMID:23782101

Body Composition Comparison: Bioelectric Impedance Analysis with Dual-Energy X-Ray Absorptiometry in Adult Athletes

ERIC Educational Resources Information Center

Company, Joe; Ball, Stephen

2010-01-01

The primary purpose of this study was to investigate the accuracy of the DF50 (ImpediMed Ltd, Eight Mile Plains, Queensland, Australia) bioelectrical impedance analysis device using dual-energy x-ray absorptiometry as the criterion in two groups: endurance athletes and power athletes. The secondary purpose was to develop accurate body fat…

Comparison of Bioelectrical Impedance and Skinfolds with Hydrodensitometry in the Assessment of Body Composition in Healthy Young Adults

ERIC Educational Resources Information Center

Rutherford, W. J.; Diemer, Gary A.; Scott, Eric D.

2011-01-01

Bioelectrical impedance analysis (BIA) is a widely used method for estimating body composition, yet issues concerning its validity persist in the literature. The purpose of this study was to validate percentage of body fat (BF) values estimated from BIA and skinfold (SF) with those obtained from hydrodensitometry (HD). Percent BF values measured…

Characterization of bioelectric potentials

NASA Technical Reports Server (NTRS)

Jorgensen, Charles C. (Inventor); Wheeler, Kevin R. (Inventor)

2004-01-01

Method and system for recognizing and characterizing bioelectric potential or electromyographic (EMG) signals associated with at least one of a coarse gesture and a fine gesture that is performed by a person, and use of the bioelectric potentials to enter data and/or commands into an electrical and/or mechanical instrument. As a gesture is performed, bioelectric signals that accompany the gesture are subjected to statistical averaging, within selected time intervals. Hidden Markov model analysis is applied to identify hidden, gesture-related states that are present. A metric is used to compare signals produced by a volitional gesture (not yet identified) with corresponding signals associated with each of a set of reference gestures, and the reference gesture that is closest to the volitional gesture is identified. Signals representing the volitional gesture are analyzed and compared with a database of reference gestures to determine if the volitional gesture is likely to be one of the reference gestures. Electronic and/or mechanical commands needed to carry out the gesture may be implemented at an interface to control an instrument. Applications include control of an aircraft, entry of data from a keyboard or other data entry device, and entry of data and commands in extreme environments that interfere with accurate entry.

Epipremnum aureum and Dracaena braunii as indoor plants for enhanced bio-electricity generation in a plant microbial fuel cell with electrochemically modified carbon fiber brush anode.

PubMed

Sarma, Pranab Jyoti; Mohanty, Kaustubha

2018-04-13

In this study, two different unexploited indoor plants, Epipremnum aureum and Dracaena braunii were used to produce clean and sustainable bio-electricity in a plant microbial fuel cell (PMFC). Acid modified carbon fiber brush electrodes as well as bare electrodes were used in both the PMFCs. A bentonite based clay membrane was successfully integrated in the PMFCs. Maximum performance of E. aureum was 620 mV which was 188 mV higher potential than D. braunii. The bio-electricity generation using modified electrode was 154 mV higher than the bare carbon fiber, probably due to the effective bacterial attachment to the carbon fiber owing to hydrogen bonding. Maximum power output of 15.38 mW/m 2 was obtained by E. aureum with an internal resistance of 200 Ω. Higher biomass yield was also obtained in case of E. aureum during 60 days of experiment, which may correlate with the higher bio-electricity generation than D. braunii. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

[Features of adaptive responses in right-handers and left-handers, and their relationship to the functional activity of the brain].

PubMed

Barkar, A A; Markina, L D

2014-01-01

In the article there is considered the relationship between adaptation state of the organism and features of bioelectric activity of the brain in right-handers and left-handers. Practically healthy persons of both genders, 23-45 years of age, with the chronic stress disorder were examined. Adaptation status was evaluated with a computer software "Anti-stress", features of bioelectric brain activity were detected by means of spectral and coherent EEG analysis, also the character of motor and sensory asymmetries was determined. The obtained data showed that the response of the organism to excitators of varying strength is a system one and manifested at different levels; adaptation status and bioelectrical activity in right-handers and left-handers have features.

Personnel Detection Technology Assessment Final Report

DTIC Science & Technology

2003-04-16

3.1.2.1 Bioelectric Activity Nerve impulses generate very weak bioelectric signals that can be detected by external probes at short ranges. The...covert detection /tracking scenarios. It was concluded that, in general , distributed sensor networks will be required to meet the scenario...personnel detection was recognized by the US Army Research Office (ARO). The Ohio State University was tasked to assess the status of sensors and signal

Effect of Exercise Intensity on Percent Body Fat Determined by Leg-to-Leg and Segmental Bioelectrical Impedance Analyses in Adults

ERIC Educational Resources Information Center

Andreacci, Joseph L.; Nagle, Trisha; Fitzgerald, Elise; Rawson, Eric S.; Dixon, Curt B.

2013-01-01

Purpose: We examined the impact that cycle ergometry exercise had on percent body fat (%BF) estimates when assessed using either leg-to-leg or segmental bioelectrical impedance analysis (LBIA; SBIA) and whether the intensity of the exercise bout impacts the %BF magnitude of change. Method: Seventy-four college-aged adults participated in this…

The Effect of an Acute After-School Exercise Bout on Percentage of Body Fat Using Leg-to-Leg Bioelectrical Impedance Analysis in Children

ERIC Educational Resources Information Center

Andreacci, Joseph L.; Dixon, Curt B.; Rompolski, Krista; VanGorden, Kelly M.

2008-01-01

Bioelectrical impedance analysis (BIA) is a fast, easy to administer, and relatively inexpensive method of evaluating body composition. Due to the ease of operation, interest in using BIA to estimate percentage of body fat (%BF) has grown, especially in settings where body composition assessments are often performed without the benefit of…

Real-Time Cameraless Measurement System Based on Bioelectrical Ventilatory Signals to Evaluate Fear and Anxiety.

PubMed

Soh, Zu; Matsuno, Motoki; Yoshida, Masayuki; Tsuji, Toshio

2018-04-01

Fear and anxiety in fish are generally evaluated by video-based behavioral analysis. However, it is difficult to distinguish the psychological state of fish exclusively through video analysis, particularly whether the fish are freezing, which represents typical fear behavior, or merely resting. We propose a system that can measure bioelectrical signals called ventilatory signals and simultaneously analyze swimming behavior in real time. Experimental results comparing the behavioral analysis of the proposed system and the camera system showed a low error level with an average absolute position error of 9.75 ± 3.12 mm (about one-third of the body length) and a correlation between swimming speeds of r = 0.93 ± 0.07 (p < 0.01). We also exposed the fish to zebrafish skin extracts containing alarm substances that induce fear and anxiety responses to evaluate their emotional changes. The results confirmed that this solution significantly changed all behavioral and ventilatory signal indices obtained by the proposed system (p < 0.01). By combining the behavioral and ventilatory signal indices, we could detect fear and anxiety with a discrimination rate of 83.3% ± 16.7%. Furthermore, we found that the decreasing fear and anxiety over time could be detected according to the peak frequency of the ventilatory signals, which cannot be measured through video analysis.

Electrical Properties Assessed by Bioelectrical Impedance Spectroscopy as Biomarkers of Age-related Loss of Skeletal Muscle Quantity and Quality.

PubMed

Yamada, Yosuke; Buehring, Bjoern; Krueger, Diane; Anderson, Rozalyn M; Schoeller, Dale A; Binkley, Neil

2017-09-01

Skeletal muscle, in addition to being comprised of a heterogeneous muscle fiber population, also includes extracellular components that do not contribute to positive tensional force production. Here we test segmental bioelectrical impedance spectroscopy (S-BIS) to assess muscle intracellular mass and composition. S-BIS can evaluate electrical properties that may be related to muscle force production. Muscle fiber membranes separate the intracellular components from the extracellular environment and consist of lipid bilayers which act as an electrical capacitor. We found that S-BIS measures accounted for ~85% of the age-related decrease in appendicular muscle power compared with only ~49% for dual-energy x-ray absorptiometry (DXA) measures. Indices of extracellular (noncontractile) and cellular (contractile) compartments in skeletal muscle tissues were determined using the Cole-Cole plot from S-BIS measures. Characteristic frequency, membrane capacitance, and phase angle determined by Cole-Cole analysis together presented a S-BIS complex model that explained ~79% of interindividual variance of leg muscle power. This finding underscores the value of S-BIS to measure muscle composition rather than lean mass as measured by DXA and suggests that S-BIS should be highly informative in skeletal muscle physiology. © The Author 2016. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Treating a pressure ulcer with bio-electric stimulation therapy.

PubMed

Hampton, Sylvie; Collins, Fiona

Mr Jones lived independently until he developed necrotic pressure ulcers over his heels and could no longer mobilize to care for himself. He was transferred to a nursing home where he lived for 18 months and where the nurses could care for his wounds. The wound had been on his right heel without changing over the 18 months and, although attempts to hydrate the eschar had been somewhat successful, the necrotic tissue proved stubborn creating large quantity of fibrous slough. Mr Jones was initially assessed by the tissue viability consultant on 14 March 2005 and agreed to the application of bio-electric stimulation therapy (POSiFEC). The wound change was immediate and was fully healed by 16 June 2005, 12 weeks after his initial assessment. This article outlines his care and the background to bio-electrical stimulation in wounds.

An equivalent body surface charge model representing three-dimensional bioelectrical activity

NASA Technical Reports Server (NTRS)

He, B.; Chernyak, Y. B.; Cohen, R. J.

1995-01-01

A new surface-source model has been developed to account for the bioelectrical potential on the body surface. A single-layer surface-charge model on the body surface has been developed to equivalently represent bioelectrical sources inside the body. The boundary conditions on the body surface are discussed in relation to the surface-charge in a half-space conductive medium. The equivalent body surface-charge is shown to be proportional to the normal component of the electric field on the body surface just outside the body. The spatial resolution of the equivalent surface-charge distribution appears intermediate between those of the body surface potential distribution and the body surface Laplacian distribution. An analytic relationship between the equivalent surface-charge and the surface Laplacian of the potential was found for a half-space conductive medium. The effects of finite spatial sampling and noise on the reconstruction of the equivalent surface-charge were evaluated by computer simulations. It was found through computer simulations that the reconstruction of the equivalent body surface-charge from the body surface Laplacian distribution is very stable against noise and finite spatial sampling. The present results suggest that the equivalent body surface-charge model may provide an additional insight to our understanding of bioelectric phenomena.

Implantable electrode for recording nerve signals in awake animals

NASA Technical Reports Server (NTRS)

Ninomiya, I.; Yonezawa, Y.; Wilson, M. F.

1976-01-01

An implantable electrode assembly consisting of collagen and metallic electrodes was constructed to measure simultaneously neural signals from the intact nerve and bioelectrical noises in awake animals. Mechanical artifacts, due to bodily movement, were negligibly small. The impedance of the collagen electrodes, measured in awake cats 6-7 days after implantation surgery, ranged from 39.8-11.5 k ohms at a frequency range of 20-5 kHz. Aortic nerve activity and renal nerve activity, measured in awake conditions using the collagen electrode, showed grouped activity synchronous with the cardiac cycle. Results indicate that most of the renal nerve activity was from postganglionic sympathetic fibers and was inhibited by the baroceptor reflex in the same cardiac cycle.

Bioelectrical activity of limb muscles during cold shivering of stimulation of the vestibular apparatus

NASA Technical Reports Server (NTRS)

Kuzmina, G. I.

1980-01-01

The effects of caloric and electric stimulation of the vestibular receptors on the EMG activity of limb muslces in anesthetized cats during cold induced shivering involved flexor muscles alone. Both types of stimulation suppressed bioelectrical activity more effectively in the ipsilateral muscles. The suppression of shivering activity seems to be due to the increased inhibitory effect of descending labyrinth pathways on the function of flexor motoneurons.

Enhanced vanadium (V) reduction and bioelectricity generation in microbial fuel cells with biocathode

NASA Astrophysics Data System (ADS)

Qiu, Rui; Zhang, Baogang; Li, Jiaxin; Lv, Qing; Wang, Song; Gu, Qian

2017-08-01

Microbial fuel cells (MFCs) represent a promising approach for remediation of toxic vanadium (V) contaminated environment. Herein, enhanced V(V) reduction and bioelectricity generation are realized in MFCs with biocathode. Synergistically electrochemical and microbial reductions result in the nearly complete removals of V(V) within 7 d operation with initial concentration of 200 mg L-1. Maximum power density of 529 ± 12 mW m-2 is obtained. Electrochemical tests reveal that biocathode promotes electron transfers and reduces charge transfer resistance. XPS analysis confirms that V(IV) is the main reduction product, which precipitates naturally under neutral conditions. High-throughput 16S rRNA gene sequencing analysis indicates that the newly appeared Dysgonomonas is responsible for V(V) reduction and Klebsiella contributes mainly to bioelectricity generation in MFCs with biocathode. This study further improves the performance of remediating V(V) contaminated environment based on MFC technology.

Noninvasive estimation of fluid shifts between body compartments by measurement of bioelectric characteristics

NASA Technical Reports Server (NTRS)

Bishop, Phillip A.

1989-01-01

Previous research has established that bioelectrical characteristics of the human body reflect fluid status to some extent. It has been previously assumed that changes in electrical resistance (R) and reactance (X) are associated with changes in total body water (TBW). The purpose of the present pilot investigation was to assess the correspondence between body R and X and changes in estimated TBW and plasma volume during a period of bedrest (simulated weightlessness). R and X were measured pre-, during, and post- a 13 day bedrest status. Although a clear relationship was not elucidated, evidence was found suggesting that R and X reflect plasma volume rather than TBW. Indirect evidence provided by previous studies which investigated other aspects of the electrical/fluid relationship, also suggests the independence of TBW and electrical properties. With further research, a bioelectrical technique for noninvasively tracking fluid changes consequent to space flight may be developed.

Conversion of Wastes to Bioelectricity, Bioethanol, and Fertilizer.

PubMed

Khan, Abdul Majeed; Hussain, Muhammad Shoukat

2017-08-01

  This research article presents production of bioelectricity, bioethanol, and fertilizer from different industrial wastewaters supplemented with waste fruit and vegetables. Bioelectricity was generated from wastewater through the development of different microbial fuel cells (MFCs). It was observed that the voltage was increased in series combination, whereas current was increased in parallel combinations. The series combination of four units of single-chamber and eight units of double-chamber MFCs produced the power output of 5.43 mW and 4.08 mW, respectively, which is sufficient to light up the light emitting diode (LED). Power output was increased by the addition of waste fruit and vegetables. The leftover filtrates of MFCs were used for the production of bioethanol using Saccharomyces cerevisiae, while residues were used as fertilizer to check the growth of okra plant. The result showed that minor amount of bioethanol is produced from different samples, which was confirmed by the preparation of ethylbenzoate derivative.

Heterogeneous silicon mesostructures for lipid-supported bioelectric interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Yuanwen; Carvalho-de-Souza, João L.; Wong, Raymond C. S.

Silicon-based materials have widespread application as biophysical tools and biomedical devices. Here we introduce a biocompatible and degradable mesostructured form of silicon with multi-scale structural and chemical heterogeneities. The material was synthesized using mesoporous silica as a template through a chemical vapour deposition process. It has an amorphous atomic structure, an ordered nanowire-based framework and random submicrometre voids, and shows an average Young’s modulus that is 2–3 orders of magnitude smaller than that of single-crystalline silicon. In addition, we used the heterogeneous silicon mesostructures to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permitsmore » non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Our findings suggest that the biomimetic expansion of silicon into heterogeneous and deformable forms can open up opportunities in extracellular biomaterial or bioelectric systems.« less

Heterogeneous silicon mesostructures for lipid-supported bioelectric interfaces

PubMed Central

Jiang, Yuanwen; Carvalho-de-Souza, João L.; Wong, Raymond C. S.; Luo, Zhiqiang; Isheim, Dieter; Zuo, Xiaobing; Nicholls, Alan W.; Jung, Il Woong; Yue, Jiping; Liu, Di-Jia; Wang, Yucai; De Andrade, Vincent; Xiao, Xianghui; Navrazhnykh, Luizetta; Weiss, Dara E.; Wu, Xiaoyang; Seidman, David N.; Bezanilla, Francisco; Tian, Bozhi

2017-01-01

Silicon-based materials have widespread application as biophysical tools and biomedical devices. Here we introduce a biocompatible and degradable mesostructured form of silicon with multiscale structural and chemical heterogeneities. The material was synthesized using mesoporous silica as a template through a chemical-vapor-deposition process. It has an amorphous atomic structure, an ordered nanowire-based framework, and random submicrometre voids, and shows an average Young’s modulus that is 2–3 orders of magnitude smaller than that of single crystalline silicon. In addition, we used the heterogeneous silicon mesostructures to design a lipid-bilayer-supported bioelectric interface that is remotely controlled and temporally transient, and that permits non-genetic and subcellular optical modulation of the electrophysiology dynamics in single dorsal root ganglia neurons. Our findings suggest that the biomimetic expansion of silicon into heterogeneous and deformable forms can open up opportunities in extracellular biomaterial or bioelectric systems. PMID:27348576

Reliability and concurrent validity of Futrex and bioelectrical impedance.

PubMed

Vehrs, P; Morrow, J R; Butte, N

1998-11-01

Thirty Caucasian males (aged 19-32yr) participated in this study designed to investigate the reliability of multiple bioelectrical impedance analysis (BIA) and near-infrared spectroscopy (Futrex, FTX) measurements and the validity of BIA and FTX estimations of hydrostatically (UW) determined percent body fat (%BF). Two BIA and two FTX instruments were used to make 6 measurements each of resistance (R) and optical density (OD) respectively over a 30 min period on two consecutive days. Repeated measures ANOVA indicated that FTX and BIA, using manufacturer's equations, significantly (p<0.01) under predicted UW by 2.4 and 3.8%BF respectively. Standard error of estimate (SEE) and total error (TE) terms provided by regression analysis for FTX (4.6 and 5.31%BF respectively) and BIA (5.65 and 6.95%BF, respectively) were high. Dependent t-tests revealed no significant differences in either FTX or BIA predictions of %BF using two machines. Intraclass reliabilities for BIA and FTX estimates of UW %BF across trials, days, and machines all exceeded 0.97. A significant random error term associated with FTX and a significant subject-by-day interaction associated with BIA was revealed using the generalizability model. Although FTX and BIA estimates of UW %BF were reliable, due to the significant underestimation of UW %BF and high SEE and TE, neither FTX nor BIA were considered valid estimates of hydrostatically determined %BF.

Increased postdialysis systolic blood pressure is associated with extracellular overhydration in hemodialysis outpatients.

PubMed

Nongnuch, Arkom; Campbell, Neil; Stern, Edward; El-Kateb, Sally; Fuentes, Laura; Davenport, Andrew

2015-02-01

Recently, intradialytic hypertension was reported to be associated with increased mortality for hemodialysis patients. To determine whether volume status plays a role in dialysis-associated hypertension, we prospectively audited 531 patients that had volume assessments measured by multiple-frequency bioelectrical impedance during their midweek dialysis session. Mean pre- and postdialysis weights were 73.2 vs 71.7 kg, and systolic blood pressures (SBPs) 140.5 vs. 130.3 mm Hg, respectively. Patients were divided into groups based on a fall in SBP of 20 mm Hg or more (32%), an increased SBP of 10 mm Hg or more (18%), and a stable group (50%). There were no differences in patient demographics, dialysis prescriptions, predialysis weight, total body (TBW), and extracellular (ECW) and intracellular water (ICW). However, the change in weight was significantly less in the increased blood pressure group (1.01 kg vs. stable 1.65, and 1.7 hypotensive). The ratio of ECW to TBW was significantly higher in the increased blood pressure group, particularly post dialysis (39.1 vs. stable 38.7% and fall in blood pressure group 38.7%). ECW overhydration was significantly greater in the increased blood pressure group post dialysis (0.7 (0.17 to 1.1) vs. stable 0.39 (-0.2 to 0.95) and fall in blood pressure group 0.38 (-0.19 to 0.86) liter). We found that patients who had increased blood pressure post dialysis had greater hydration status, particularly ECW. Thus, patients who increase their blood pressure post dialysis should have review of target weight, consideration of lowering the post-dialysis weight, and may benefit from increasing dialysis session time or frequency.

Validation of multi-frequency bioelectrical impedance analysis versus dual-energy X-ray absorptiometry to measure body fat percentage in overweight/obese Colombian adults.

PubMed

Ramírez-Vélez, Robinson; Tordecilla-Sanders, Alejandra; Correa-Bautista, Jorge Enrique; González-Ruíz, Katherine; González-Jiménez, Emilio; Triana-Reina, Hector Reynaldo; García-Hermoso, Antonio; Schmidt-RioValle, Jacqueline

2018-01-01

To verify the validity of multi-frequency bioelectrical impedance analysis (mBCA) for predicting body fat percentage (BF%) in overweight/obese adults using dual-energy X-ray absorptiometry (DXA) as the reference method. Forty-eight adults participated (54% women, mean age = 41.0 ± 7.3 years old). The Pearson's correlation coefficient was used to evaluate the correlation between BIA and BF% assessed by DXA. The concordance between BF% measured by both methods was obtained with Lin's concordance correlation coefficient and Bland-Altman difference plots. Measures of BF% were estimated as 39.0 (SD = 6.1) and 38.3 (SD = 6.5) using DXA and mBCA, respectively. The Pearson's correlation coefficient reflected a strong correlation (r =.921, P = .001). The paired t-test showed a significant mean difference between these methods for obese men BF% of -0.6 [(SD 1.95; 95% CI = -4.0 to 3.0), P =.037]. Overall, the bias of the mBCA was -0.6 [(SD 2.2; 95% CI = -5.0 to 3.7), P =.041], which indicated that the mBCA method significantly underestimated BF% in comparison to the reference method. Finally, in both genders, Lin's concordance correlation coefficient showed a strong agreement. More specifically the DXA value was ρc = 0.943 (95% CI = 0.775 to 0.950) and the mBCA value was ρc = 0.948 (95% CI = 0.778 to 0.978). Our analysis showed a strong agreement between the two methods as reflected in the range of BF%. These results show that mBCA and DXA are comparable methods for measuring body composition with higher body fat percentages. However, due to broad limits of agreement, we can only recommend mBCA for groups of populations. © 2017 Wiley Periodicals, Inc.

[Comparison BMC assessed by dual-energy X-ray absorptiometry and multi-frequency bioelectrical impedance in Chinese overweight and obesity adults].

PubMed

Wang, Zhenghe; Fu, Lianguo; Yang, Yide; Wang, Shuo; Ma, Jun

2016-05-01

To compare consistency of Body Mineral Content (BMC, kg) assessed by Multi-frequency Bioelectrical Impedance Analysis ( MF-BIA) and Dual Energy X-ray Absorptiometry (DXA) measurement, providing evidence for MF-BIA accurate application in Chinese overweight/obese adults. A total of 1323 overweight/obesity adults aged 22-55 years were recruited voluntarily. All the subjects received the measurement of BMC both using MF-BIA and DXA. To evaluate the agreement of BMC measured by MF-BIA and DXA using interclass correlation coefficients (ICC), then establish correction prediction models. The mean difference of BMC between two methods was significant different with 0, overweight male subgroup was 0.28 kg, and 0.38 kg for obesity male, 0.24 kg for overweight female and 0.36 kg for obesity female, respectively (P < 0.05). The ICC of BMC between MF-BIA and DXA measurement were statistically significant in all subgroups (P < 0.01). The ICC for overweight male subgroup was 0.787, 0.796 for obesity male, 0.741 for overweight female and 0.788 for obesity female, respectively. Correction prediction model: overweight male population: BMC (DXA method) = -0.297 + 1.005 x BMC (MF-BIA method). Obese male population: BMC (DXA method) =0.302 + 0.799 x BMC (MF-BIA method). Overweight female groups: BMC (DXA method) = 0.780 + 0.598 x BMC (MF-BIA method). Obese female group: BMC (DXA method) = 0.755 + 0.597 x BMC (MF-BIA method). Upon examination, correction prediction models were better. Co The correlation and agreement of BMC measured by BIA and DXA are weak in Chinese overweight/obese adults. Therefore, consideration should be given to BMC measured by BIA method in Chinese overweight/obese adults. It should be corrected or adjusted to reduce errors compared with DXA method.

Development of bioelectrical impedance analysis-based equations for estimation of body composition in postpartum rural Bangladeshi women.

PubMed

Shaikh, Saijuddin; Schulze, Kerry J; Kurpad, Anura; Ali, Hasmot; Shamim, Abu Ahmed; Mehra, Sucheta; Wu, Lee S-F; Rashid, Mahbubar; Labrique, Alain B; Christian, Parul; West, Keith P

2013-02-28

Equations for predicting body composition from bioelectrical impedance analysis (BIA) parameters are age-, sex- and population-specific. Currently there are no equations applicable to women of reproductive age in rural South Asia. Hence, we developed equations for estimating total body water (TBW), fat-free mass (FFM) and fat mass in rural Bangladeshi women using BIA, with ²H₂O dilution as the criterion method. Women of reproductive age, participating in a community-based placebo-controlled trial of vitamin A or β-carotene supplementation, were enrolled at 19·7 (SD 9·3) weeks postpartum in a study to measure body composition by ²H₂O dilution and impedance at 50 kHz using multi-frequency BIA (n 147), and resistance at 50 kHz using single-frequency BIA (n 82). TBW (kg) by ²H2O dilution was used to derive prediction equations for body composition from BIA measures. The prediction equation was applied to resistance measures obtained at 13 weeks postpartum in a larger population of postpartum women (n 1020). TBW, FFM and fat were 22·6 (SD 2·7), 30·9 (SD 3·7) and 10·2 (SD 3·8) kg by ²H₂O dilution. Height²/impedance or height²/resistance and weight provided the best estimate of TBW, with adjusted R² 0·78 and 0·76, and with paired absolute differences in TBW of 0·02 (SD 1·33) and 0·00 (SD 1·28) kg, respectively, between BIA and ²H₂O. In the larger sample, values for TBW, FFM and fat were 23·8, 32·5 and 10·3 kg, respectively. BIA can be an important tool for assessing body composition in women of reproductive age in rural South Asia where poor maternal nutrition is common.

Role of the Functional State of the Hypothalamus in Bioelectric Reactions of the Cerebral Cortex to Radiation,

DTIC Science & Technology

The effect of subjection of the hypothalamus to electrocoagulation in the area of the mamillary bodies on the bioelectric activity and reactivity of...the cerebral cortex exposed to radiation was studied. Rabbits were irradiated on the 10th day after electrocoagulation . Immediately after... electrocoagulation , a decline in the excitability and functional activity of cortical neurons in the posterior section of the cortex and a decrease in the

[Effects of transcranial magnetotherapy on electroencephalographic parameters in females with overactive urinary bladder].

PubMed

Neĭmark, A I; Klyzhina, E A; Neĭmark, B A; Mel'nik, M A

2007-01-01

Urodynamic parameters and bioelectric brain activity were studied in 30 females aged 24-66 years with overactive bladder (OAB) before and after transcranial magnetotherapy. It was found that OAB patients have disorders of bioelectric brain activity by two types of EEG patterns (I.A. Svyatogor classification)--thalamic and stem, Patients with thalamic type EEG benefit more from magnetotherapy higher efficacy of which manifests with regress of clinical symptoms and urodynamic improvement.

Effect of Influenza-Induced Fever on Human Bioimpedance Values

PubMed Central

Marini, Elisabetta; Buffa, Roberto; Contreras, Monica; Magris, Magda; Hidalgo, Glida; Sanchez, Wilmer; Ortiz, Vanessa; Urbaez, Maryluz; Cabras, Stefano; Blaser, Martin J.; Dominguez-Bello, Maria G.

2015-01-01

Background and Aims Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. Methods Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. Results For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). Conclusions There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states. PMID:25915945

Short-Term Effects of Kinesio Taping and Cross Taping Application in the Treatment of Latent Upper Trapezius Trigger Points: A Prospective, Single-Blind, Randomized, Sham-Controlled Trial

PubMed Central

Słupska, Lucyna; Paprocka-Borowicz, Małgorzata; Taradaj, Jakub; Bidzińska, Gabriela; Marczyński, Daniel; Cynarska, Aleksandra; Rosińczuk, Joanna

2015-01-01

Kinesio taping (KT) may be a new treatment in patients with myofascial trigger points (MTrPs). A new method available for taping practitioners is cross taping (CT). The main objective was to determine how CT, KT, and medical adhesive tape (sham group) affect the subjective assessment of resting bioelectrical activity and pain of the upper trapezius muscle (UT) in patients with MTrPs. 105 volunteers were recruited to participate. The primary outcome was resting bioelectrical activity of UT muscle as assessed by surface electromyography (sEMG) in each group and pain intensity on a visual analog scale (VAS). Assessments were collected before and after intervention and after the 24-hours follow-up. No significant differences were observed in bioelectrical activity of UT between pre-, post-, and follow-up results. In three groups patients had significantly lower pain VAS score after the intervention (CT—p < 0.001, KT—p < 0.001, and sham—p < 0.01). The Kruskal-Wallis ANOVA showed no significant differences in almost all measurements between groups. The application of all three types of tapes does not influence the resting bioelectrical activity of UT muscle and may not lead to a reduction in muscle tone in the case of MTrPs. PMID:26491458

Land-use and alternative bioenergy pathways for waste biomass.

PubMed

Campbell, J E; Block, E

2010-11-15

Rapid escalation in biofuels consumption may lead to a trade regime that favors exports of food-based biofuels from tropical developing countries to developed countries. There is growing interest in mitigating the land-use impacts of these potential biofuels exports by converting biorefinery waste streams into cellulosic ethanol, potentially reducing the amount of land needed to meet production goals. This increased land-use efficiency for ethanol production may lower the land-use greenhouse gas emissions of ethanol but would come at the expense of converting the wastes into bioelectricity which may offset fossil fuel-based electricity and could provide a vital source of domestic electricity in developing countries. Here we compare these alternative uses of wastes with respect to environmental and energy security outcomes considering a range of electricity production efficiencies, ethanol yields, land-use scenarios, and energy offset assumptions. For a given amount of waste biomass, we found that using bioelectricity production to offset natural gas achieves 58% greater greenhouse gas reductions than using cellulosic ethanol to offset gasoline but similar emissions when cellulosic ethanol is used to offset the need for more sugar cane ethanol. If bioelectricity offsets low-carbon energy sources such as nuclear power then the liquid fuels pathway is preferred. Exports of cellulosic ethanol may have a small impact on the energy security of importing nations while bioelectricity production may have relatively large impacts on the energy security in developing countries.

Functional condition of masseters muscles of patients with class ?? subdivision.

PubMed

Kuroyedova, Vera D; Makarova, Alexandra N; Chicor, Tatyana A

Main functional characteristics of masticator muscles in patients with class ?? malocclusions is activity dominance of m. temporalis in comparison with m. ?asseter. We have not found datum about functional status of the masticators in patients with class II subdivision. The purpose of our study was to investigate the functional characteristics of m. ?asseter, m. temporalis in adult patients with class II subdivision malocclusion. There have been carried out the surface electromyographic study of m. masseter, m. temporalis in 17 adult patients with class II subdivision. It was realized quantitative analysis of 271 electromyogram, it was determined the average bioelectric activity, index activity, symmetry and torsion index. It was observed predominance of the bioelectrical activity of m. temporales on m. masseter for all persons with class II subdivision. Bioelectrical activity for m. masseter was bigger on side of distal ratio and for m. temporales on side of neutral ratio. In class ?? subdivision right, the mandible was deviated to the left side and in class ?? subdivision left is deviated to the right side. Thus, rotational moment generated during compression of the jaws, causes deviation of the lower jaw to the side, with a neutral molar ratio. During voluntary chewing bioelectrical activity of m. masseter and m. temporalis was higher in the right side. In accordance with the functional condition of the masticatory muscles of class II subdivision is characterized with functional features of distal occlusion.

[A comparison of the associations of dynapenia and sarcopenia with fear of falling in elderly diabetic patients].

PubMed

Ida, Satoshi; Murata, Kazuya; Ishihara, Yuki; Imataka, Kanako; Kaneko, Ryutaro; Fujiwara, Ryoko; Takahashi, Hiroka

2017-01-01

To comparatively investigate whether dynapenia and sarcopenia, as defined by the Asian Working Group for Sarcopenia (AWGS), are associated with fear of falling in elderly patients with diabetes. The subjects were outpatients with diabetes who were at least 65 years of age when they visited our hospital. Sarcopenia was evaluated based on the AWGS definition. The cutoff values for the appendicular skeletal mass index (multi-frequency bioelectrical impedance method), grip strength, and walking speed were, respectively, 7.0 kg/m 2 for men and 5.7 kg/m 2 for women, 26 kg for men and 18 kg for women, and ≤0.8 m/s for both men and women. Those with grip strength of less than or equal to the cutoff value were considered to have dynapenia. Fear of falling was assessed by a self-administered questionnaire survey with the Fall Efficacy Scale (FES) Japanese version. A multiple regression analysis was conducted using the FES score as a dependent variable and dynapenia or sarcopenia and moderators as explanatory variables. A total of 202 patients (male, n=127; female, n=75) were analyzed in this study. The FES scores of the patients with and without sarcopenia did not differ to a statistically significant extent in either male or female patients. The multiple regression analysis revealed a statistically significant association between dynapenia and the FES score in men (P=0.028). In elderly outpatients with diabetes, no association was found between sarcopenia and the fear of falling in either men or women. In contrast, a statistically significant association was found between dynapenia and fear of falling in men. This suggests the importance paying attention to the fear of falling when examining elderly male diabetes patients with dynapenia.

[Sensitivity and specificity of abdominal adiposity with metabolic syndrome in the elderly].

PubMed

Alvero-Cruz, José Ramón; Fernández Vázquez, Rosalía; García Vega, María Del Mar; García Lavigne, Juan Antonio; Rodríguez Linares, María Victoria; Martínez Blanco, Javier

It is recognised that abdominal adiposity is associated with cardiovascular risk factors, such as intolerance to glucose, hypertension and dyslipidaemia. The objective of the present study was to assess the relationship of trunk fat and visceral fat index, obtained by anthropometric and bioelectrical impedance, with metabolic syndrome (SM) in an elderly population. The study included 208 subjects (78 men and 130 women) with a mean age of 82.5 years. Abdominal obesity was assessed by anthropometry and bioelectrical impedance. ROC curves were calculated in order to assess the ability of these variables to diagnose metabolic syndrome. There are differences between men and women in body mass index, waist to height ratio, waist circumference, and bioelectrical impedance measurements as trunk fat and visceral fat (p<.05). Also, found differences in anthropometric indices and variables and abdominal bioelectrical impedance between subjects with and without SM (p<.05) and only exist differences in blood glucose, triglycerides and HDL cholesterol (p<.05). There are significant correlations between anthropometric variables and abdominal bioelectrical impedance (p<.05). Areas under the curve (AUC) of waist to height index, waist circumference, sagittal abdominal diameter, and trunk fat were greater than 0.8 (all p<.01), and in women did not exceed values of 0.65. The cut-off points obtained for BMI were 26.81 and 23.53kg/m 2 , 102 and 91cm for waist circumference, 22.1 and 20.7cm for sagittal abdominal diameter, 34% and 43.7% for trunk fat, and 17 and 11.5 for visceral fat ratio in men and women, respectively. There are different levels of predictive ability for metabolic syndrome according to gender. Trunk fat and visceral fat index and anthropometric measures have higher predictive ability for metabolic syndrome in men than in women. Copyright © 2016 SEGG. Publicado por Elsevier España, S.L.U. All rights reserved.

Bio-isolated dc operational amplifier. [for bioelectric measurements

NASA Technical Reports Server (NTRS)

Lee, R. D. (Inventor)

1974-01-01

A bio-isolated dc operational amplifier is described for use in making bioelectrical measurements of a patient while providing isolation of the patient from electrical shocks. The circuit contains a first operational amplifier coupled to the patient with its output coupled in a forward loop through a first optic coupler to a second operational amplifier. The output of the second operational amplifier is coupled to suitable monitoring circuitry via a feedback circuit including a second optic coupler to the input of the first operational amplifier.

Gold nanoparticles produced in situ mediate bioelectricity and hydrogen production in a microbial fuel cell by quantized capacitance charging.

PubMed

Kalathil, Shafeer; Lee, Jintae; Cho, Moo Hwan

2013-02-01

Oppan quantized style: By adding a gold precursor at its cathode, a microbial fuel cell (MFC) is demonstrated to form gold nanoparticles that can be used to simultaneously produce bioelectricity and hydrogen. By exploiting the quantized capacitance charging effect, the gold nanoparticles mediate the production of hydrogen without requiring an external power supply, while the MFC produces a stable power density. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biospectral analysis of the bladder channel point in chronic low back pain patients

NASA Astrophysics Data System (ADS)

Vidal, Alberto Espinosa; Nava, Juan José Godina; Segura, Miguel Ángel Rodriguez; Bastida, Albino Villegas

2012-10-01

Chronic pain is the main cause of disability in the productive age people and is a public health problem that affects both the patient and society. On the other hand, there isn't any instrument to measure it; this is only estimated using subjective variables. The healthy cells generate a known membrane potential which is part of a network of biologically closed electric circuits still unstudied. It is proposed a biospectral analysis of a bladder channel point as a diagnosis method for chronic low back pain patients. Materials and methods: We employed a study group with chronic low back pain patients and a control group without low back pain patients. The visual analog scale (VAS) to determine the level of pain was applied. Bioelectric variables were measured for 10 seconds and the respective biostatistical analyses were made. Results: Biospectral analysis on frequency domain shows a depression in the 60-300 Hz frequency range proportional to the chronicity of low back pain compared against healthy patients.

[Topographic mapping of retinal function with a scanning laser ophthalmoscope and multifocal electroretinography using short M-sequences].

PubMed

Rudolph, G; Bechmann, M; Berninger, T; Kutschbach, E; Held, U; Tornow, R P; Kalpadakis, P; Zol'nikova, I V; Shamshinova, A M

2001-01-01

A new method of multifocal electroretinography making use of scanning laser ophthalmoscope with a wavelength of 630 nm (SLO-m-ERG), evoking short spatial visual stimuli on the retina, is proposed. Algorithm of presenting the visual stimuli and analysis of distribution of local electroretinograms on the surface of the retina is based on short m-sequences. Mathematical cross correlation analysis shows a three-dimensional distribution of bioelectrical activity of the retina in the central visual field. In normal subjects the cone bioelectrical activity is the maximum in the macular area (corresponding to the density of cone distribution) and absent in the blind spot. The method detects the slightest pathological changes in the retina under control of the site of stimulation and ophthalmoscopic picture of the fundus oculi. The site of the pathological process correlates with the topography of changes in bioelectrical activity of the examined retinal area in diseases of the macular area and pigmented retinitis detectable by ophthalmoscopy.

[Effect of angiotensin II depot administration on bioelectric functional processes of the central nervous system].

PubMed

Martin, G; Baumann, H; Grieger, F

1976-01-01

Using the average evoked potential technique, angiotensin-II depot effects (1 mg implantate = 3--4 mg/kg body weight angiotensin-II) were studied neuroelectrophysiologically in reticular, hippocampal and neocrotical structures of albino rats. A multivariate variance and discriminance analysis program revealed differentiated changes of the bioelectrical processing data of the CNS. Evidence was obtained for a varying structural sensitivity of central-nervous substructures under depot administration of angiotensin-II. In later phases of angiotensin-II action, the hippocampus was characterized by an electrographic synchronization phenomenon with high-amplitude average evoked potentials. The reticular formation, and to a lesser extent the visual cortex, showed an angiotensin-induced diminution of bioelectrical excitation. However, the intensity of the change in functional CNS patterns did not always correlate with maximal blood pressure rises. The described changes of afference processing to standardized sensory stimuli, especially in hippocampal and reticular structures of the CNS foll owing angiotensin depot action, point to a central-nervous action mechanism of angiotensin-II.

Enhanced sulfide removal and bioelectricity generation in microbial fuel cells with anodes modified by vertically oriented nanosheets.

PubMed

Yang, Meng; Zhong, Yuezhi; Zhang, Baogang; Shi, Jiaxin; Huang, Xueyang; Xing, Yi; Su, Lin; Liu, Huipeng; Borthwick, Alistair G L

2018-01-31

Anode materials and structures are of critical importance for microbial fuel cells (MFCs) recovering energy from toxic substrates. Carbon-fiber-felt anodes modified by layers of vertically oriented TiO 2 and Fe 2 O 3 nanosheets were applied in the present study. Enhanced sulfide removal efficiencies (both over 90%) were obtained after a 48-h operation, with maximum power densities improved by 1.53 and 1.36 folds compared with MFCs with raw carbon-fiber-felt anode. The modified anodes provided more active sites for microbial adhesion with increasing biomass densities. High-throughput 16S rRNA gene sequencing analysis also indicated the increase in microbial diversities. Bacteroidetes responsible for bioelectricity generation with Thiobacillus and Spirochaeta dominating sulfide removal were found in the MFCs with the modified anodes, with less anaerobic fermentative bacteria as Firmicutes appeared. This indicates that the proposed materials are competitive for applications of MFCs generating bioelectricity from toxic sulfide.

Whole-body impedance--what does it measure?

PubMed

Foster, K R; Lukaski, H C

1996-09-01

Although the bioelectrical impedance technique is widely used in human nutrition and clinical research, an integrated summary of the biophysical and bioelectrical bases of this approach is lacking. We summarize the pertinent electrical phenomena relevant to the application of the impedance technique in vivo and discuss the relations between electrical measurements and biological conductor volumes. Key terms in the derivation of bioelectrical impedance analysis are described and the relation between the electrical properties of tissues and tissue structure is discussed. The relation between the impedance of an object and its geometry, scale, and intrinsic electrical properties is also discussed. Correlations between whole-body impedance measurements and various bioconductor volumes, such as total body water and fat-free mass, are experimentally well established; however, the reason for the success of the impedence technique is much less clear. The bioengineering basis for the technique is critically presented and considerations are proposed that might help to clarify the method and potentially improve its sensitivity.

Gender differences and age-related changes in body fat mass in Tibetan children and teenagers: an analysis by the bioelectrical impedance method.

PubMed

Zhang, Hai-Long; Fu, Qiang; Li, Wen-Hui; Liu, Su-Wei; Zhong, Hua; Duoji, Bai-Ma; Zhang, Mei-Zhi; Lv, Po; Xi, Huan-Jiu

2015-01-01

We aimed to obtain the fat base value and the fat distribution characteristics of Tibetan children and teenagers by estimating their body fat content with the bioelectrical impedance method. We recruited 1427 healthy children and teenagers by a stratified cluster sampling method. By using bioelectrical impedance analysis, we obtained various values relevant to fat. We found that total body fat mass and the fat mass of various body parts increased with age in boys and girls. Yet there were no differences between age groups until 11 years. However, fat mass increased quickly between 11 and 18 years, and significant differences were seen between adolescent boys and girls; all fat indices were higher in girls than in boys (p<0.05). The characteristics of fat in Tibetan children and teenagers in Tibet is related to age and gender related hormone secretion, which reflects the physiological characteristics in different developmental stages.

Early bioelectric activities mediate redox-modulated regeneration

PubMed Central

Ferreira, Fernando; Luxardi, Guillaume; Reid, Brian

2016-01-01

Reactive oxygen species (ROS) and electric currents modulate regeneration; however, the interplay between biochemical and biophysical signals during regeneration remains poorly understood. We investigate the interactions between redox and bioelectric activities during tail regeneration in Xenopus laevis tadpoles. We show that inhibition of NADPH oxidase-mediated production of ROS, or scavenging or blocking their diffusion into cells, impairs regeneration and consistently regulates the dynamics of membrane potential, transepithelial potential (TEP) and electric current densities (JI) during regeneration. Depletion of ROS mimics the altered TEP and JI observed in the non-regenerative refractory period. Short-term application of hydrogen peroxide (H2O2) rescues (from depleted ROS) and induces (from the refractory period) regeneration, TEP increase and JI reversal. H2O2 is therefore necessary for and sufficient to induce regeneration and to regulate TEP and JI. Epistasis assays show that voltage-gated Na+ channels act downstream of H2O2 to modulate regeneration. Altogether, these results suggest a novel mechanism for regeneration via redox-bioelectric orchestration. PMID:27827821

The climate impacts of bioenergy systems depend on market and regulatory policy contexts.

PubMed

Lemoine, Derek M; Plevin, Richard J; Cohn, Avery S; Jones, Andrew D; Brandt, Adam R; Vergara, Sintana E; Kammen, Daniel M

2010-10-01

Biomass can help reduce greenhouse gas (GHG) emissions by displacing petroleum in the transportation sector, by displacing fossil-based electricity, and by sequestering atmospheric carbon. Which use mitigates the most emissions depends on market and regulatory contexts outside the scope of attributional life cycle assessments. We show that bioelectricity's advantage over liquid biofuels depends on the GHG intensity of the electricity displaced. Bioelectricity that displaces coal-fired electricity could reduce GHG emissions, but bioelectricity that displaces wind electricity could increase GHG emissions. The electricity displaced depends upon existing infrastructure and policies affecting the electric grid. These findings demonstrate how model assumptions about whether the vehicle fleet and bioenergy use are fixed or free parameters constrain the policy questions an analysis can inform. Our bioenergy life cycle assessment can inform questions about a bioenergy mandate's optimal allocation between liquid fuels and electricity generation, but questions about the optimal level of bioenergy use require analyses with different assumptions about fixed and free parameters.

Reprogramming cells and tissue patterning via bioelectrical pathways: molecular mechanisms and biomedical opportunities

PubMed Central

Levin, Michael

2013-01-01

Transformative impact in regenerative medicine requires more than the reprogramming of individual cells: advances in repair strategies for birth defects or injuries, tumor normalization, and the construction of bioengineered organs and tissues all require the ability to control large-scale anatomical shape. Much recent work has focused on the transcriptional and biochemical regulation of cell behaviour and morphogenesis. However, exciting new data reveal that bioelectrical properties of cells and their microenvironment exert a profound influence on cell differentiation, proliferation, and migration. Ion channels and pumps expressed in all cells, not just excitable nerve and muscle, establish resting potentials that vary across tissues and change with significant developmental events. Most importantly, the spatio-temporal gradients of these endogenous transmembrane voltage potentials (Vmem) serve as instructive patterning cues for large-scale anatomy, providing organ identity, positional information, and prepattern template cues for morphogenesis. New genetic and pharmacological techniques for molecular modulation of bioelectric gradients in vivo have revealed the ability to initiate complex organogenesis, change tissue identity, and trigger regeneration of whole vertebrate appendages. A large segment of the spatial information processing that orchestrates individual cells’ programs towards the anatomical needs of the host organism is electrical; this blurs the line between memory and decision-making in neural networks and morphogenesis in non-neural tissues. Advances in cracking this bioelectric code will enable the rational reprogramming of shape in whole tissues and organs, revolutionizing regenerative medicine, developmental biology, and synthetic bioengineering. PMID:23897652

Assessment of the Body Composition and the Loss of Fat-Free Mass through Bioelectric Impedance Analysis in Patients Who Underwent Open Gastric Bypass

PubMed Central

de Freitas Junior, Wilson Rodrigues; Ilias, Elias Jirjoss; Kassab, Paulo; Cordts, Roberto; Porto, Paulo Gustavo; Martins Rodrigues, Francisco Cesar; Ali Taha, Mohamed Ibrahim; Carrara, Paulo; de Carvalho Aguiar, Isabella; de Oliveira, Luis Vicente Franco; Malheiros, Carlos Alberto

2014-01-01

Background. Bariatric surgery is considered an effective option for the management of morbid obesity. The incidence of obesity has been gradually increasing all over the world reaching epidemic proportions in some regions of the world. Obesity can cause a reduction of up to 22% in the life expectancy of morbidly obese patients. Objective. The objective of this paper is to assess the weight loss associated with the first 6 months after bariatric surgery using bioelectric impedance analysis (BIA) for the evaluation of fat mass and fat-free mass. Method. A total of 36 morbidly obese patients were subjected to open gastric bypass surgery. The patients weight was monitored before and after the procedure using the bioelectric impedance analysis. Results. Bariatric surgery resulted in an average percentage of weight loss of 28.6% (40 kg) as determined 6 months after the procedure was performed. Analysis of the different components of body weight indicated an undesirable loss of fat-free mass along with the reduction of total body weight. Conclusion. Open gastric bypass induced a significant loss of total weight and loss of fat-free mass in patients six months after the surgery. The use of bioelectric impedance analysis resulted in an appropriate estimation of the total weight components in individuals subjected to bariatric surgery allowing a more real analysis of the variation of weight after the surgery. PMID:24523649

Bioelectrical impedance vector analysis detects low body cell mass and dehydration in patients with Alzheimer's disease.

PubMed

Buffa, R; Mereu, R M; Putzu, P F; Floris, G; Marini, E

2010-12-01

This paper evaluates the nutritional status in patients with mild-moderate and severe Alzheimer's disease (AD) by bioelectrical impedance vector analysis (BIVA). Cross-sectional study. Alzheimer Center, SS. Trinita Hospital, Cagliari, and "Monsignor Angioni" Nursing Home, Quartu Sant'Elena (Cagliari, Italy). 83 free-living patients with mild-moderate Alzheimer's disease (29 men, 54 women), 9 institutionalized women in the severe stage; 468 age-matched controls (202 men, 266 women). Mini Nutritional Assessment (MNA), anthropometric (height, weight, BMI), bioelectrical (R, Xc) and biochemical variables (serum albumin) were assessed. Bioelectrical characteristics were significantly different in the patients with mild-moderate AD with respect to controls, indicating low body cell mass (men, T2= 12.8; women, T2=34.9; p < 0.01). Women with severe AD showed low body cell mass and dehydration with respect to patients with mild-moderate AD (T2=17.1; p < 0.01). The phase angle, R/H and Z/H were significantly correlated (p < 0.05) with MNA (phase: r = 0.31; R/H: r =-0.37; Z/H: r =-0.37) and albumin (phase: r=0.47; R/H: r=-0.36; Z/H: r=-0.36). Alzheimer's disease is characterized by a tendency to malnutrition, present even in the mild-moderate stages, and a tendency to dehydration that appears in the severe stage. The BIVA technique is a promising tool for the screening and monitoring of nutrition and hydration status in Alzheimer's disease.

Integrating microbial fuel cells with anaerobic acidification and forward osmosis membrane for enhancing bio-electricity and water recovery from low-strength wastewater.

PubMed

Liu, Jinmeng; Wang, Xinhua; Wang, Zhiwei; Lu, Yuqin; Li, Xiufen; Ren, Yueping

2017-03-01

Microbial fuel cells (MFCs) and forward osmosis (FO) are two emerging technologies with great potential for energy-efficient wastewater treatment. In this study, anaerobic acidification and FO membrane were simultaneously integrated into an air-cathode MFC (AAFO-MFC) for enhancing bio-electricity and water recovery from low-strength wastewater. During a long-term operation of approximately 40 days, the AAFO-MFC system achieved a continuous and relatively stable power generation, and the maximum power density reached 4.38 W/m 3 . The higher bio-electricity production in the AAFO-MFC system was mainly due to the accumulation of ethanol resulted from anaerobic acidification process and the rejection of FO membrane. In addition, a proper salinity environment in the system controlled by the addition of MF membrane enhanced the electricity production. Furthermore, the AAFO-MFC system produced a high quality effluent, with the removal rates of organic matters and total phosphorus of more than 97%. However, the nitrogen removal was limited for the lower rejection of FO membrane. The combined biofouling and inorganic fouling were responsible for the lower water flux of FO membrane, and the Desulfuromonas sp. utilized the ethanol for bio-electricity production was observed in the anode. These results substantially improve the prospects for simultaneous wastewater treatment and energy recovery, and further studies are needed to optimize the system integration and operating parameters. Copyright © 2016 Elsevier Ltd. All rights reserved.

Reprogramming cells and tissue patterning via bioelectrical pathways: molecular mechanisms and biomedical opportunities.

PubMed

Levin, Michael

2013-01-01

Transformative impact in regenerative medicine requires more than the reprogramming of individual cells: advances in repair strategies for birth defects or injuries, tumor normalization, and the construction of bioengineered organs and tissues all require the ability to control large-scale anatomical shape. Much recent work has focused on the transcriptional and biochemical regulation of cell behavior and morphogenesis. However, exciting new data reveal that bioelectrical properties of cells and their microenvironment exert a profound influence on cell differentiation, proliferation, and migration. Ion channels and pumps expressed in all cells, not just excitable nerve and muscle, establish resting potentials that vary across tissues and change with significant developmental events. Most importantly, the spatiotemporal gradients of these endogenous transmembrane voltage potentials (Vmem ) serve as instructive patterning cues for large-scale anatomy, providing organ identity, positional information, and prepattern template cues for morphogenesis. New genetic and pharmacological techniques for molecular modulation of bioelectric gradients in vivo have revealed the ability to initiate complex organogenesis, change tissue identity, and trigger regeneration of whole vertebrate appendages. A large segment of the spatial information processing that orchestrates individual cells' programs toward the anatomical needs of the host organism is electrical; this blurs the line between memory and decision-making in neural networks and morphogenesis in nonneural tissues. Advances in cracking this bioelectric code will enable the rational reprogramming of shape in whole tissues and organs, revolutionizing regenerative medicine, developmental biology, and synthetic bioengineering. Copyright © 2013 Wiley Periodicals, Inc.

A synthetic microbial consortium of Shewanella and Bacillus for enhanced generation of bioelectricity.

PubMed

Liu, Ting; Yu, Yang-Yang; Chen, Tao; Chen, Wei Ning

2017-03-01

In this study, a synthetic microbial consortium containing exoelectrogen Shewanella oneidensis MR-1 and riboflavin-producing strain, Bacillus subtilis RH33, was rationally designed and successfully constructed, enabling a stable, multiple cycles of microbial fuel cells (MFCs) operation for more than 500 h. The maximum power density of MFCs with this synthetic microbial consortium was 277.4 mW/m 2 , which was 4.9 times of that with MR-1 (56.9 mW/m 2 ) and 40.2 times of RH33 (6.9 mW/m 2 ), separately. At the same time, the Coulombic efficiency of the synthetic microbial consortium (5.6%) was higher than MR-1 (4.1%) and RH33 (2.3%). Regardless the high concentration of riboflavin produced by RH33, the power density of RH33 was rather low. The low bioelectricity generation can be ascribed to the low efficiency of RH33 in utilizing riboflavin for extracellular electron transfer (EET). In the synthetic microbial consortium of MR-1 and RH33, it was found that both mediated and direct electron transfer efficiencies were enhanced. By exchanging the anolyte of MR-1 and RH33, it was confirmed that the improved MFC performance with the synthetic microbial consortium was because MR-1 could efficiently utilize the high concentration of riboflavin produced by RH33. Biotechnol. Bioeng. 2017;114: 526-532. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Cold shivering activity after unilateral destruction of the vestibular apparatus

NASA Technical Reports Server (NTRS)

Kuzmina, G. I.

1980-01-01

The bioelectric activity of muscles (flexors and extensors of the forelimbs and hindlimbs) during cold shivering after unilateral destruction of the vestibular apparatus. It was found, that unilateral delabyrinthing produces bilateral facilitation of cold shivering in the flexor extremities more pronounced on the ipsilateral side. In the extensor muscles there was an absence of bioelectric activity both before and after delabyrinthing. Enhancement of cold shivering in the flexor extremities following intervention was evidently conditioned by removal of the inhibiting effect of the vestibulary apparatus on the function of special centers.

Assessment of the emissions and air quality impacts of biomass and biogas use in California.

PubMed

Carreras-Sospedra, Marc; Williams, Robert; Dabdub, Donald

2016-02-01

It is estimated that there is sufficient in-state "technically" recoverable biomass to support nearly 4000 MW of bioelectricity generation capacity. This study assesses the emissions of greenhouse gases and air pollutants and resulting air quality impacts of new and existing bioenergy capacity throughout the state of California, focusing on feedstocks and advanced technologies utilizing biomass resources predominant in each region. The options for bioresources include the production of bioelectricity and renewable natural gas (NG). Emissions of criteria pollutants and greenhouse gases are quantified for a set of scenarios that span the emission factors for power generation and the use of renewable natural gas for vehicle fueling. Emissions are input to the Community Multiscale Air Quality (CMAQ) model to predict regional and statewide temporal air quality impacts from the biopower scenarios. With current technology and at the emission levels of current installations, maximum bioelectricity production could increase nitrogen oxide (NOx) emissions by 10% in 2020, which would cause increases in ozone and particulate matter concentrations in large areas of California. Technology upgrades would achieve the lowest criteria pollutant emissions. Conversion of biomass to compressed NG (CNG) for vehicles would achieve comparable emission reductions of criteria pollutants and minimize emissions of greenhouse gases (GHG). Air quality modeling of biomass scenarios suggest that applying technological changes and emission controls would minimize the air quality impacts of bioelectricity generation. And a shift from bioelectricity production to CNG production for vehicles would reduce air quality impacts further. From a co-benefits standpoint, CNG production for vehicles appears to provide the best benefits in terms of GHG emissions and air quality. This investigation provides a consistent analysis of air quality impacts and greenhouse gas emissions for scenarios examining increased biomass use. Further work involving economic assessment, seasonal or annual emissions and air quality modeling, and potential exposure analysis would help inform policy makers and industry with respect to further development and direction of biomass policy and bioenergy technology alternatives needed to meet energy and environmental goals in California.

Total body composition estimated by standing-posture 8-electrode bioelectrical impedance analysis in male wrestlers.

PubMed

Cheng, M-F; Chen, Y-Y; Jang, T-R; Lin, W-L; Chen, J; Hsieh, K-C

2016-12-01

Standing-posture 8-electrode bioelectrical impedance analysis is a fast and practical method for evaluating body composition in clinical settings, which can be used to estimate percentage body fat (BF%) and skeletal muscle mass in a subject's total body and body segments. In this study, dual-energy X-ray absorptiometry (DXA) was used as a reference method for validating the standing 8-electrode bioelectrical impedance analysis device BC-418 (BIA 8 , Tanita Corp., Tokyo, Japan). Forty-eight Taiwanese male wrestlers aged from 17.9 to 22.3 years volunteered to participate in this study. The lean soft tissue (LST) and BF% in the total body and body segments were measured in each subject by the BIA 8 and DXA. The correlation coefficients between total body, arm, leg segments impedance index (BI, ht 2 /Z) and lean soft tissue mass measured from DXA were r = 0.902, 0.453, 0.885, respectively (p < 0.01). In addition, the total body and segmental LST estimated by the BIA 8 were highly correlated with the DXA data (r = 0.936, 0.466, 0.886, p < 0.01). The estimation of total body and segmental BF% measured by BIA 8 and DXA also showed a significant correlation (r > 0.820, p < 0.01). The estimated LST and BF% from BIA 8 in the total body and body segments were highly correlated with the DXA results, which indicated that the standing-posture 8-electrode bioelectrical impedance analysis may be used to derive reference measures of LST and BF% in Taiwanese male wrestlers.

Total body composition estimated by standing-posture 8-electrode bioelectrical impedance analysis in male wrestlers

PubMed Central

Cheng, M-F; Chen, Y-Y; Jang, T-R; Lin, W-L; Chen, J

2015-01-01

Standing-posture 8-electrode bioelectrical impedance analysis is a fast and practical method for evaluating body composition in clinical settings, which can be used to estimate percentage body fat (BF%) and skeletal muscle mass in a subject’s total body and body segments. In this study, dual-energy X-ray absorptiometry (DXA) was used as a reference method for validating the standing 8-electrode bioelectrical impedance analysis device BC-418 (BIA8, Tanita Corp., Tokyo, Japan). Forty-eight Taiwanese male wrestlers aged from 17.9 to 22.3 years volunteered to participate in this study. The lean soft tissue (LST) and BF% in the total body and body segments were measured in each subject by the BIA8 and DXA. The correlation coefficients between total body, arm, leg segments impedance index (BI, ht2/Z) and lean soft tissue mass measured from DXA were r = 0.902, 0.453, 0.885, respectively (p < 0.01). In addition, the total body and segmental LST estimated by the BIA8 were highly correlated with the DXA data (r = 0.936, 0.466, 0.886, p < 0.01). The estimation of total body and segmental BF% measured by BIA8 and DXA also showed a significant correlation (r > 0.820, p < 0.01). The estimated LST and BF% from BIA8 in the total body and body segments were highly correlated with the DXA results, which indicated that the standing-posture 8-electrode bioelectrical impedance analysis may be used to derive reference measures of LST and BF% in Taiwanese male wrestlers. PMID:28090145

Cathodic microbial community adaptation to the removal of chlorinated herbicide in soil microbial fuel cells.

PubMed

Li, Yue; Li, Xiaojing; Sun, Yang; Zhao, Xiaodong; Li, Yongtao

2018-04-05

The microbial fuel cell (MFC) that uses a solid electrode as the inexhaustible electron acceptor is an innovative remediation technology that simultaneously generates bioelectricity. Chlorinated pollutants are better metabolized by reductive dechlorination in proximity to the cathode. Here, the removal efficiency of the herbicide metolachlor (ML) increased by 262 and 176% in soil MFCs that were spiked with 10 (C10) and 20 mg/kg (C20) of ML, respectively, relative to the non-electrode controls. The bioelectricity output of the C10 and C20 increased by over two- and eightfold, respectively, compared to that of the non-ML control, with maximum current densities of 49.6 ± 2.5 (C10) and 78.9 ± 0.6 mA/m 2 (C20). Based on correlations between ML concentrations and species abundances in the MFCs, it was inferred that Azohydromonas sp., Sphingomonas sp., and Pontibacter sp. play a major role in ML removal around the cathode, with peak removal efficiencies of 56 ± 1% (C10) and 58 ± 1% (C20). Moreover, Clostridium sp., Geobacter sp., Bacillus sp., Romboutsia sp., and Terrisporobacter sp. may be electricigens or closely related microbes due to the significant positive correlation between the bioelectricity generation levels and their abundances around the anode. This study suggests that a directional adaptation of the microbial community has taken place to increase both the removal of chlorinated herbicides around the cathode and the generation of bioelectricity around the anode in bioelectrochemical remediation systems.

EFFECTS OF FOOD AND DRINK INGESTION ON BODY COMPOSITION VARIABLES OF ABDOMINAL BIOELECTRICAL IMPEDANCE.

PubMed

Fernández Vázquez, Rosalía; Martínez Blanco, Javier; García Vega, María del Mar; Barbancho, Miguel Ángel; Alvero-Cruz, José Ramón

2015-11-01

to know the changes in trunk fat and visceral fat level determined by abdominal bioelectrical impedance (BIA) as well as other anthropometric measures related to the central or abdominal fat after the ingestion of a lunch. the experimental study was conducted to assess a longitudinal intervention descriptive study. 21 subjects (10 male and 11 female), volunteers who have access to a medical assessment, with an age of 74 ± 13.43 years. Maximal waist circumference in standing position, waist circumference at navel level in supine position and sagittal abdominal diameter (SAD). In the same position trunk fat and visceral fat level by abdominal bioelectrical impedance analysis with Tanita AB-140 (ViScan) were obtained before and after meal. anthropometric measures as waist circumference in supine position and SAD did not show significant differences (P > 0.05), after food ingestion, except for a significant increase of the maximal waist circumference in standing position (P < 0.05). In addition trunk fat and visceral fat ratio did not change (P > 0.05). The percentage changes of the measures were less than 2% for waist circumference in standing position, waist circumference by Viscan, sagittal abdominal diameter and trunk fat and 5.9% for visceral fat ratio. the effects on trunk fat and visceral fat ratio by abdominal bioelectrical impedance are minimal after the ingestion of a portion of food and drink, although it is always recommended to do it in fasting conditions. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Assessment of lamb carcass composition from live animal measurement of bioelectrical impedance or ultrasonic tissue depths.

PubMed

Berg, E P; Neary, M K; Forrest, J C; Thomas, D L; Kauffman, R G

1996-11-01

Market weight lambs, average weight 52.5 kg (+/-6.1), were used to evaluate nontraditional live animal measurements as predictors of carcass composition. The sample population (n = 106) represented U.S. market lambs and transcended geographic location, breed, carcass weight, yield grade, and production system. Realtime ultrasonic (RU) measurements and bioelectrical impedance analysis (BIA) were used for development and evaluation of prediction equations for % boneless, closely trimmed primal cuts (BCTPC), weight or % of dissected lean tissue (TDL), and chemically derived weight or % fat-free lean (FFL). Longitudinal ultrasonic images were obtained parallel to the longissimus thoracis et lumborum (LTL), positioning the last costae in the center of the transducer head. Images were saved and fat and LTL depths were derived from printed images of the ultrasonic scans. Bioelectrical impedance analysis was administered via a four-terminal impedance plethysmograph operating at 800 microA at 50 kHz. Impedance measurements of whole-body resistance and reactance were recorded. Prediction equations including common linear measurements of live weight, heart girth, hindsaddle length, and shoulder height were also evaluated. All measurements were taken just before slaughter. Bioelectrical impedance measurements (as compared to RU and linear measurements) provided equations for %BCTPC, TDL, %TDL, FFL and %FFL with the highest R2 and lowest root mean square error. Even though BIA provided the best equations of the three methodologies tested, prediction of proportional yield (%BCTPC, %TDL, and %FFL) was marginal (R2 = .296, .551, and .551, respectively). Equations combining BIA, RU, and linear measurements greatly improved equations for prediction of proportional lean yield.

Development of a Zigbee platform for bioinstrumentation.

PubMed

Cifuentes, Carlos A; Gentiletti, Gabriel G; Suarez, Marco J; Rodriguez, Luis E

2010-01-01

This paper presents the development of a network platform which allows connecting multiple individual wireless devices for transmitting bioelectrics and biomechanics signals for application in a hospital network, or continuous monitoring in a patient's diary life. The Zigbee platform development proposal was made in three stages: 1) Hardware development, including the construction of a prototype network node and the integration of sensors, (2) Evaluation, in order to define the specifications of each node and scope of communication and (3) The Zigbee Network Implementation for bioinstrumentation based on ZigBee Health Care public application profile (ZHC). Finally, this work presents the experimental results based on measurements of Lost Packets and LQI (Link Quality Indicator), and the Zigbee Platform configuration for Bioinstrumentation in operation.

Impact of eating and drinking on body composition measurements by bioelectrical impedance.

PubMed

Androutsos, O; Gerasimidis, K; Karanikolou, A; Reilly, J J; Edwards, C A

2015-04-01

Bioelectrical impedance analysis would be a more practical tool to measure body composition in clinical settings, dietetic practice and epidemiological studies if patients/subjects did not have to fast before measurements. The present study assessed whether the ingestion of food or drink had any biologically significant effect on bioimpedance measurements and body composition by the foot-to-foot method. Fifty-five healthy adults [30 males and 25 females; mean (SD) age 27.7 (7.1) years; mean (SD)body mass index 24 (3.8) kg m(-2)] were randomly assigned to a 2-day food trial (high-fat meal or high-carbohydrate meal) or a 2-day drink trial (water or high electrolyte drink). Body composition measurements were carried out in the fasting state, immediately after meal consumption and every 30 min for 2 h by the foot-to-foot single frequency bioimpedance technique. Bioimpedance increased significantly after the ingestion of food and fluid, although the changes were small. The electrolyte drink, high-fat and high-carbohydrate meals significantly increased the percentage body fat and fat mass. In all cases, the median percentage changes from baseline were approximately 1% in body fat percentage units. Although there were statistically significant changes in body composition estimates after food or drink consumption, these were small and within the imprecision of the impedance technique, and so are unlikely to be of clinical significance. The present study suggests that impedance measures of body fatness in clinical settings do not require strict adherence to fasting, and this should increase the opportunities for clinical application. © 2014 The British Dietetic Association Ltd.

The Stayhealthy bioelectrical impedance analyzer predicts body fat in children and adults.

PubMed

Erceg, David N; Dieli-Conwright, Christina M; Rossuello, Amerigo E; Jensky, Nicole E; Sun, Stephanie; Schroeder, E Todd

2010-05-01

Bioelectrical impedance analysis (BIA) is a time-efficient and cost-effective method for estimating body composition. We hypothesized that there would be no significant difference between the Stayhealthy BC1 BIA and the selected reference methods when determining body composition. Thus, the purpose of the present study was to determine the validity of estimating percent body fat (%BF) using the Stayhealthy BIA with its most recently updated algorithms compared to the reference methods of dual-energy x-ray absorptiometry for adults and hydrostatic weighing for children. We measured %BF in 245 adults aged 18 to 80 years and 115 children aged 10 to 17 years. Body fat by BIA was determined using a single 50 kHz frequency handheld impedance device and proprietary software. Agreement between BIA and reference methods was assessed by Bland and Altman plots. Bland and Altman analysis for men, women, and children revealed good agreement between the reference methods and BIA. There was no significant difference by t tests between mean %BF by BIA for men, women, or children when compared to the respective reference method. Significant correlation values between BIA, and reference methods for all men, women, and children were 0.85, 0.88, and 0.79, respectively. Reliability (test-retest) was assessed by intraclass correlation coefficient and coefficient of variation. Intraclass correlation coefficient values were greater than 0.99 (P < .001) for men, women, and children with coefficient of variation values 3.3%, 1.8%, and 1.7%, respectively. The Stayhealthy BIA device demonstrated good agreement between reference methods using Bland and Altman analyses. Copyright 2010 Elsevier Inc. All rights reserved.

Multichannel techniques for motion artifacts removal from electrocardiographic signals.

PubMed

Milanesi, M; Martini, N; Vanello, N; Positano, V; Santarelli, M F; Paradiso, R; De Rossi, D; Landini, L

2006-01-01

Electrocardiographic (ECG) signals are affected by several kinds of artifacts, that may hide vital signs of interest. Motion artifacts, due to the motion of the electrodes in relation to patient skin, are particularly frequent in bioelectrical signals acquired by wearable systems. In this paper we propose different approaches in order to get rid of motion confounds. The first approach we follow starts from measuring electrode motion provided by an accelerometer placed on the electrode and use this measurement in an adaptive filtering system to remove the noise present in the ECG. The second approach is based on independent component analysis methods applied to multichannel ECG recordings; we propose to use both instantaneous model and a frequency domain implementation of the convolutive model that accounts for different paths of the source signals to the electrodes.

The interplay between genetic and bioelectrical signaling permits a spatial regionalisation of membrane potentials in model multicellular ensembles

PubMed Central

Cervera, Javier; Meseguer, Salvador; Mafe, Salvador

2016-01-01

The single cell-centred approach emphasises ion channels as specific proteins that determine individual properties, disregarding their contribution to multicellular outcomes. We simulate the interplay between genetic and bioelectrical signals in non-excitable cells from the local single-cell level to the long range multicellular ensemble. The single-cell genetic regulation is based on mean-field kinetic equations involving the mRNA and protein concentrations. The transcription rate factor is assumed to depend on the absolute value of the cell potential, which is dictated by the voltage-gated cell ion channels and the intercellular gap junctions. The interplay between genetic and electrical signals may allow translating single-cell states into multicellular states which provide spatio-temporal information. The model results have clear implications for biological processes: (i) bioelectric signals can override slightly different genetic pre-patterns; (ii) ensembles of cells initially at the same potential can undergo an electrical regionalisation because of persistent genetic differences between adjacent spatial regions; and (iii) shifts in the normal cell electrical balance could trigger significant changes in the genetic regulation. PMID:27731412

The interplay between genetic and bioelectrical signaling permits a spatial regionalisation of membrane potentials in model multicellular ensembles.

PubMed

Cervera, Javier; Meseguer, Salvador; Mafe, Salvador

2016-10-12

The single cell-centred approach emphasises ion channels as specific proteins that determine individual properties, disregarding their contribution to multicellular outcomes. We simulate the interplay between genetic and bioelectrical signals in non-excitable cells from the local single-cell level to the long range multicellular ensemble. The single-cell genetic regulation is based on mean-field kinetic equations involving the mRNA and protein concentrations. The transcription rate factor is assumed to depend on the absolute value of the cell potential, which is dictated by the voltage-gated cell ion channels and the intercellular gap junctions. The interplay between genetic and electrical signals may allow translating single-cell states into multicellular states which provide spatio-temporal information. The model results have clear implications for biological processes: (i) bioelectric signals can override slightly different genetic pre-patterns; (ii) ensembles of cells initially at the same potential can undergo an electrical regionalisation because of persistent genetic differences between adjacent spatial regions; and (iii) shifts in the normal cell electrical balance could trigger significant changes in the genetic regulation.

MicroRNA Intercellular Transfer and Bioelectrical Regulation of Model Multicellular Ensembles by the Gap Junction Connectivity.

PubMed

Cervera, Javier; Meseguer, Salvador; Mafe, Salvador

2017-08-17

We have studied theoretically the microRNA (miRNA) intercellular transfer through voltage-gated gap junctions in terms of a biophysically grounded system of coupled differential equations. Instead of modeling a specific system, we use a general approach describing the interplay between the genetic mechanisms and the single-cell electric potentials. The dynamics of the multicellular ensemble are simulated under different conditions including spatially inhomogeneous transcription rates and local intercellular transfer of miRNAs. These processes result in spatiotemporal changes of miRNA, mRNA, and ion channel protein concentrations that eventually modify the bioelectrical states of small multicellular domains because of the ensemble average nature of the electrical potential. The simulations allow a qualitative understanding of the context-dependent nature of the effects observed when specific signaling molecules are transferred through gap junctions. The results suggest that an efficient miRNA intercellular transfer could permit the spatiotemporal control of small cellular domains by the conversion of single-cell genetic and bioelectric states into multicellular states regulated by the gap junction interconnectivity.

Evaluation of Nutritional Status in Children during Predialysis, or Treated By Peritoneal Dialysis or Hemodialysis.

PubMed

Yılmaz, Dilek; Sönmez, Ferah; Karakaş, Sacide; Yavaşcan, Önder; Aksu, Nejat; Ömürlü, İmran Kurt; Yenisey, Çiğdem

2016-06-01

Malnutrition is one of the major causes of morbidity and mortality in children with chronic kidney disease (CKD). The objective of this study was to evaluate nutritional status of children with stage 3-4 CKD and treated by peritoneal dialysis or hemodialysis using anthropometric measurements, biochemical parameters and bioelectrical impedance analysis. The study included a total of 52 patients and 46 healthy children. In anthropometric evaluation, the children with CKD had lower values for standard deviation score for weight, height, body mass index, skinfold thickness and mid-arm circumference than those of healthy children (p < 0.05). The fat mass (%) and the body cell mass (%) measurements performed by bioelectrical impedance analysis were lower compared with the control group (p < 0.05). It is considered that bioelectrical impedance analysis measurement should be used with anthropometric measurements, which are easy to perform, to achieve more accurate nutritional evaluation in children. © The Author [2016]. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Early bioelectric activities mediate redox-modulated regeneration.

PubMed

Ferreira, Fernando; Luxardi, Guillaume; Reid, Brian; Zhao, Min

2016-12-15

Reactive oxygen species (ROS) and electric currents modulate regeneration; however, the interplay between biochemical and biophysical signals during regeneration remains poorly understood. We investigate the interactions between redox and bioelectric activities during tail regeneration in Xenopus laevis tadpoles. We show that inhibition of NADPH oxidase-mediated production of ROS, or scavenging or blocking their diffusion into cells, impairs regeneration and consistently regulates the dynamics of membrane potential, transepithelial potential (TEP) and electric current densities (J I ) during regeneration. Depletion of ROS mimics the altered TEP and J I observed in the non-regenerative refractory period. Short-term application of hydrogen peroxide (H 2 O 2 ) rescues (from depleted ROS) and induces (from the refractory period) regeneration, TEP increase and J I reversal. H 2 O 2 is therefore necessary for and sufficient to induce regeneration and to regulate TEP and J I Epistasis assays show that voltage-gated Na + channels act downstream of H 2 O 2 to modulate regeneration. Altogether, these results suggest a novel mechanism for regeneration via redox-bioelectric orchestration. © 2016. Published by The Company of Biologists Ltd.

Effects of various organic carbon sources on simultaneous V(V) reduction and bioelectricity generation in single chamber microbial fuel cells.

PubMed

Hao, Liting; Zhang, Baogang; Cheng, Ming; Feng, Chuanping

2016-02-01

Four ordinary carbon sources affecting V(V) reduction and bioelectricity generation in single chamber microbial fuel cells (MFCs) were investigated. Acetate supported highest maximum power density of 589.1mW/m(2), with highest V(V) removal efficiency of 77.6% during 12h operation, compared with glucose, citrate and soluble starch. Exorbitant initial V(V) concentration led to lower V(V) removal efficiencies and power outputs. Extra addition of organics had little effect on the improvement of MFCs performance. V(V) reduction and bioelectricity generation were enhanced and then suppressed by the increase of conductivity. The larger the external resistance, the higher the V(V) removal efficiencies and voltage outputs. High-throughput 16S rRNA gene pyrosequencing analysis implied the accumulation of Enterobacter which had the capabilities of V(V) reduction, electrochemical activity and fermentation, accompanied with other functional species as Pseudomonas, Spirochaeta, Sedimentibacter and Dysgonomonas. This study steps forward to remediate V(V) contaminated environment based on MFC technology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Inhibition of Salmonella typhi growth using extremely low frequency electromagnetic (ELF-EM) waves at resonance frequency.

PubMed

Fadel, M A; Mohamed, S A; Abdelbacki, A M; El-Sharkawy, A H

2014-08-01

Typhoid is a serious disease difficult to be treated with conventional drugs. The aim of this study was to demonstrate a new method for the control of Salmonella typhi growth, through the interference with the bioelectric signals generated from the microbe during cell division by extremely low frequency electromagnetic waves (ELF-EMW-ELF-EM) at resonance frequency. Isolated Salmonella typhi was subjected to square amplitude modulated waves (QAMW) with different modulation frequencies from two generators with constant carrier frequency of 10 MHz, amplitude of 10 Vpp, modulating depth ± 2 Vpp and constant field strength of 200 V m(-1) at 37°C. Both the control and exposed samples were incubated at the same conditions during the experiment. The results showed that there was highly significant inhibition effect for Salm. typhi exposed to 0·8 Hz QAMW for a single exposure for 75 min. Dielectric relaxation, TEM and DNA results indicated highly significant changes in the molecular structure of the DNA and cellular membrane resulting from the exposure to the inhibiting EM waves. It was concluded that finding out the inhibiting resonance frequency of ELF-EM waves that deteriorates Salm. typhi growth will be promising method for the treatment of Salm. typhi infection either in vivo or in vitro. This new non-invasive technique for treatment of bacterial infections is of considerable interest for the use in medical and biotechnological applications. © 2014 The Society for Applied Microbiology.

[Age-related characteristics of the surface bioelectrical potential of human, canine and rat teeth and features of its distribution over the surface of the crown].

PubMed

Donskiĭ, G I; Pavliuchenko, O N; Palamarchuk, Iu N; Makarova, N Ia

1989-01-01

Using a digital electron voltmeter, bioelectrical potentials (BEPs) of dental crowns have been recorded in 180 patients, 36 dogs, and 93 white non-inbred rats. It has been established that the surface BEP is a marker of dental enamel maturation and does not depend on the species of mammals. On the other hand maturation processes differ in their rate on the cutting edge, equator, and neck: with advancing age algebraic difference between the magnitudes of surface BEPs decreases in humans and increases in dogs and rats.

Hydration: certain basic aspects for developing technical and scientific parameters into the nutrition knowledge

PubMed

Perales-García, Aránzazu; Estévez-Martínez, Isabel; Urrialde, Rafael

2016-07-12

Introduction: Hydration is defined as the water intake coming from food and beverages. Its study has become an area by itself, within the nutrition field. Meaning that in 2010 the European Food Safety Authority (EFSA) approved the water intake recommendations, but the study of this topic implies a rigorous methodology, which represents several issues. Objective: Showing as a glance the main methodological issues in hydration studies. Material and methods: Bibliographic revision of scientific literature. Results: The main methodological issues presented are: sample selection (investigation field and sample design), selection of the method to evaluate hydration status (dilution techniques, bioelectrical impedance, plasmatic and urinary indicators, changes in body composition, water losses and clinic symptoms) selection of the method to evaluate water intake (biomarker, questionnaires, informatics programs, smartphone use, 24-h register, dietary history and food frequency questionnaire), and the main sources of hydration. Conclusions: Hydration status should be understood as a routine model, with daily frequency, according to gender, age, physical activity and environmental conditions. Furthermore, the correct design of the methodology has a special importance in order to take into account all the aspects

Percentiles of body fat measured by bioelectrical impedance in children and adolescents from Bogotá (Colombia): the FUPRECOL study.

PubMed

Escobar-Cardozo, Germán D; Correa-Bautista, Jorge E; González-Jiménez, Emilio; Schmidt-RioValle, Jacqueline; Ramírez-Vélez, Robinson

2016-04-01

The analysis of body composition is a fundamental part of nutritional status assessment. The objective of this study was to establish body fat percentiles by bioelectrical impedance in children and adolescents from Bogotá (Colombia) who were part of the FUPRECOL study (Asociación de la Fuerza Prensil con Manifestaciones Tempranas de Riesgo Cardiovascular en Niños y Adolescentes Colombianos - Association between prehensile force and early signs of cardiovascular risk in Colombian children and adolescents). This was a cross-sectional study conducted among 5850 students aged 9-17.9 years old from Bogotá (Colombia). Body fat percentage was measured using foot-to-foot bioelectrical impedance (Tanita®, BF-689), by age and gender. Weight, height, waist circumference, and hip circumference were measured, and sexual maturity was self-staged. Percentiles (P3, P10, P25, P50, P75, P90 and P97) and centile curves were estimated using the LMS method (L [BoxCox curve], M [median curve] and S [variation coefficient curve]), by age and gender. Subjects included were 2526 children and 3324 adolescents. Body fat percentages and centile curves by age and gender were established. For most age groups, values resulted higher among girls than boys. Participants with values above P90 were considered to have a high cardiovascular risk due to excess fat (boys > 23.428.3, girls > 31.0-34.1). Body fat percentage percentiles measured using bioelectrical impedance by age and gender are presented here and may be used as reference to assess nutritional status and to predict cardiovascular risk due to excess fat at an early age. Sociedad Argentina de Pediatría.

A role for bioelectric effects in the induction of bystander signals by ionizing radiation?

PubMed

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

2007-04-03

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 (60)Cobalt 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 10 min 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.

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

PubMed Central

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

Hydration in advanced cancer: can bioelectrical impedance analysis improve the evidence base? A systematic review of the literature.

PubMed

Nwosu, Amara Callistus; Mayland, Catriona R; Mason, Stephen R; Khodabukus, Andrew F; Varro, Andrea; Ellershaw, John E

2013-09-01

Decisions surrounding the administration of clinically assisted hydration to patients dying of cancer can be challenging because of the limited understanding of hydration in advanced cancer and a lack of evidence to guide health care professionals. Bioelectrical impedance analysis (BIA) has been used to assess hydration in various patient groupings, but evidence for its use in advanced cancer is limited. To critically appraise existing methods of hydration status assessment in advanced cancer and review the potential for BIA to assess hydration in advanced cancer. Searches were carried out in four electronic databases. A hand search of selected peer-reviewed journals and conference abstracts also was conducted. Studies reporting (de)hydration assessment (physical examination, biochemical measures, symptom assessment, and BIA) in patients with advanced cancer were included. The results highlight how clinical examination and biochemical tests are standard methods of assessing hydration, but limitations exist with these methods in advanced cancer. Furthermore, there is disagreement over the evidence for some commonly associated symptoms with dehydration in cancer. Although there are limitations with using BIA alone to assess hydration in advanced cancer, analysis of BIA raw measurements through the method of bioelectrical impedance vector analysis may have a role in this population. The benefits and burdens of providing clinically assisted hydration to patients dying of cancer are unclear. Bioelectrical impedance vector analysis shows promise as a hydration assessment tool but requires further study in advanced cancer. Innovative methodologies for research are required to add to the evidence base and ultimately improve the care for the dying. Copyright © 2013 U.S. Cancer Pain Relief Committee. Published by Elsevier Inc. All rights reserved.

Accuracy of specific BIVA for the assessment of body composition in the United States population.

PubMed

Buffa, Roberto; Saragat, Bruno; Cabras, Stefano; Rinaldi, Andrea C; Marini, Elisabetta

2013-01-01

Bioelectrical impedance vector analysis (BIVA) is a technique for the assessment of hydration and nutritional status, used in the clinical practice. Specific BIVA is an analytical variant, recently proposed for the Italian elderly population, that adjusts bioelectrical values for body geometry. Evaluating the accuracy of specific BIVA in the adult U.S. population, compared to the 'classic' BIVA procedure, using DXA as the reference technique, in order to obtain an interpretative model of body composition. A cross-sectional sample of 1590 adult individuals (836 men and 754 women, 21-49 years old) derived from the NHANES 2003-2004 was considered. Classic and specific BIVA were applied. The sensitivity and specificity in recognizing individuals below the 5(th) and above the 95(th) percentiles of percent fat (FMDXA%) and extracellular/intracellular water (ECW/ICW) ratio were evaluated by receiver operating characteristic (ROC) curves. Classic and specific BIVA results were compared by a probit multiple-regression. Specific BIVA was significantly more accurate than classic BIVA in evaluating FMDXA% (ROC areas: 0.84-0.92 and 0.49-0.61 respectively; p = 0.002). The evaluation of ECW/ICW was accurate (ROC areas between 0.83 and 0.96) and similarly performed by the two procedures (p = 0.829). The accuracy of specific BIVA was similar in the two sexes (p = 0.144) and in FMDXA% and ECW/ICW (p = 0.869). Specific BIVA showed to be an accurate technique. The tolerance ellipses of specific BIVA can be used for evaluating FM% and ECW/ICW in the U.S. adult population.

Estimation of maximal oxygen uptake by bioelectrical impedance analysis.

PubMed

Stahn, Alexander; Terblanche, Elmarie; Grunert, Sven; Strobel, Günther

2006-02-01

Previous non-exercise models for the prediction of maximal oxygen uptake VO(2max) have failed to accurately discriminate cardiorespiratory fitness within large cohorts. The aim of the present study was to evaluate the feasibility of a completely indirect method for predicting VO(2max) that was based on bioelectrical impedance analysis (BIA) in 66 young, healthy fit men and women. Multiple, stepwise regression analysis was used to determine the usefulness of BIA and additional covariates to estimate VO(2max) (ml min(-1)). BIA was highly correlated to VO(2max) (r = 0.914; P < 0.001) and entered the regression equation first. The inclusion of gender and a physical activity rating further improved the model which accounted for 88% of the variance in VO(2max) and resulted in a relative standard error of the estimate (SEE) of 7.2%. Substantial agreement between the methods was confirmed by the fact that nearly all the differences were within +/-2 SD. Furthermore, in contrast to previously published non-exercise models, no trend of a reduction in prediction accuracy with increasing VO(2max) values was apparent. It was concluded that a non-exercise model based on BIA might be a rapid and useful technique to estimate VO(2max), when a direct test does not seem feasible. However, though the present results are useful to determine the viability of the method, further refinement of the BIA approach and its validation in a large, diverse population is needed before it can be applied to the clinical and epidemiological settings.

The application of biomedical engineering techniques to the diagnosis and management of tropical diseases: a review.

PubMed

Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Faisal, Tarig; Neuman, Michael

2015-03-23

This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications.

Viability of a Bioelectrical Signal Acquisition System Energized by Cellphone with NFC.

PubMed

Kay, Marcel Seiji; Iaione, Fábio

2015-01-01

Currently, smartphones are used in various systems in the medical field due to the presence of various features, notably Near Field Communication (NFC). NFC utilizes communication technology and an energy supply based on electromagnetic induction. One of the most common medical tests is the electrocardiogram (ECG), through which various heart diseases can be diagnosed. The objective of this study is to evaluate the feasibility of providing power to a bioelectrical signal acquisition module using a mobile phone with NFC. After testing it was indicated that it is possible to construct a passive module to acquire ECG signals using NFC mobile phone.

Nature's Electric Potential: A Systematic Review of the Role of Bioelectricity in Wound Healing and Regenerative Processes in Animals, Humans, and Plants.

PubMed

Tyler, Sheena E B

2017-01-01

Natural endogenous voltage gradients not only predict and correlate with growth and development but also drive wound healing and regeneration processes. This review summarizes the existing literature for the nature, sources, and transmission of information-bearing bioelectric signals involved in controlling wound healing and regeneration in animals, humans, and plants. It emerges that some bioelectric characteristics occur ubiquitously in a range of animal and plant species. However, the limits of similarities are probed to give a realistic assessment of future areas to be explored. Major gaps remain in our knowledge of the mechanistic basis for these processes, on which regenerative therapies ultimately depend. In relation to this, it is concluded that the mapping of voltage patterns and the processes generating them is a promising future research focus, to probe three aspects: the role of wound/regeneration currents in relation to morphology; the role of endogenous flux changes in driving wound healing and regeneration; and the mapping of patterns in organisms of extreme longevity, in contrast with the aberrant voltage patterns underlying impaired healing, to inform interventions aimed at restoring them.

Bioelectric modulation of macrophage polarization

NASA Astrophysics Data System (ADS)

Li, Chunmei; Levin, Michael; Kaplan, David L.

2016-02-01

Macrophages play a critical role in regulating wound healing and tissue regeneration by changing their polarization state in response to local microenvironmental stimuli. The native roles of polarized macrophages encompass biomaterials and tissue remodeling needs, yet harnessing or directing the polarization response has been largely absent as a potential strategy to exploit in regenerative medicine to date. Recent data have revealed that specific alteration of cells’ resting potential (Vmem) is a powerful tool to direct proliferation and differentiation in a number of complex tissues, such as limb regeneration, craniofacial patterning and tumorigenesis. In this study, we explored the bioelectric modulation of macrophage polarization by targeting ATP sensitive potassium channels (KATP). Glibenclamide (KATP blocker) and pinacidil (KATP opener) treatment not only affect macrophage polarization, but also influence the phenotype of prepolarized macrophages. Furthermore, modulation of cell membrane electrical properties can fine-tune macrophage plasticity. Glibenclamide decreased the secretion and gene expression of selected M1 markers, while pinacidil augmented M1 markers. More interestingly, glibencalmide promoted macrophage alternative activation by enhancing certain M2 markers during M2 polarization. These findings suggest that control of bioelectric properties of macrophages could offer a promising approach to regulate macrophage phenotype as a useful tool in regenerative medicine.

Solid phase microbial fuel cell (SMFC) for harnessing bioelectricity from composite food waste fermentation: influence of electrode assembly and buffering capacity.

PubMed

Mohan, S Venkata; Chandrasekhar, K

2011-07-01

Solid phase microbial fuel cells (SMFC; graphite electrodes; open-air cathode) were designed to evaluate the potential of bioelectricity production by stabilizing composite canteen based food waste. The performance was evaluated with three variable electrode-membrane assemblies. Experimental data depicted feasibility of bioelectricity generation from solid state fermentation of food waste. Distance between the electrodes and presence of proton exchange membrane (PEM) showed significant influence on the power yields. SMFC-B (anode placed 5 cm from cathode-PEM) depicted good power output (463 mV; 170.81 mW/m(2)) followed by SMFC-C (anode placed 5 cm from cathode; without PEM; 398 mV; 53.41 mW/m(2)). SMFC-A (PEM sandwiched between electrodes) recorded lowest performance (258 mV; 41.8 mW/m(2)). Sodium carbonate amendment documented marked improvement in power yields due to improvement in the system buffering capacity. SMFCs operation also documented good substrate degradation (COD, 76%) along with bio-ethanol production. The operation of SMFC mimicked solid-sate fermentation which might lead to sustainable solid waste management practices. Copyright © 2011 Elsevier Ltd. All rights reserved.

Nature's Electric Potential: A Systematic Review of the Role of Bioelectricity in Wound Healing and Regenerative Processes in Animals, Humans, and Plants

PubMed Central

Tyler, Sheena E. B.

2017-01-01

Natural endogenous voltage gradients not only predict and correlate with growth and development but also drive wound healing and regeneration processes. This review summarizes the existing literature for the nature, sources, and transmission of information-bearing bioelectric signals involved in controlling wound healing and regeneration in animals, humans, and plants. It emerges that some bioelectric characteristics occur ubiquitously in a range of animal and plant species. However, the limits of similarities are probed to give a realistic assessment of future areas to be explored. Major gaps remain in our knowledge of the mechanistic basis for these processes, on which regenerative therapies ultimately depend. In relation to this, it is concluded that the mapping of voltage patterns and the processes generating them is a promising future research focus, to probe three aspects: the role of wound/regeneration currents in relation to morphology; the role of endogenous flux changes in driving wound healing and regeneration; and the mapping of patterns in organisms of extreme longevity, in contrast with the aberrant voltage patterns underlying impaired healing, to inform interventions aimed at restoring them. PMID:28928669

Change with age in regression construction of fat percentage for BMI in school-age children.

PubMed

Fujii, Katsunori; Mishima, Takaaki; Watanabe, Eiji; Seki, Kazuyoshi

2011-01-01

In this study, curvilinear regression was applied to the relationship between BMI and body fat percentage, and an analysis was done to see whether there are characteristic changes in that curvilinear regression from elementary to middle school. Then, by simultaneously investigating the changes with age in BMI and body fat percentage, the essential differences in BMI and body fat percentage were demonstrated. The subjects were 789 boys and girls (469 boys, 320 girls) aged 7.5 to 14.5 years from all parts of Japan who participated in regular sports activities. Body weight, total body water (TBW), soft lean mass (SLM), body fat percentage, and fat mass were measured with a body composition analyzer (Tanita BC-521 Inner Scan), using segmental bioelectrical impedance analysis & multi-frequency bioelectrical impedance analysis. Height was measured with a digital height measurer. Body mass index (BMI) was calculated as body weight (km) divided by the square of height (m). The results for the validity of regression polynomials of body fat percentage against BMI showed that, for both boys and girls, first-order polynomials were valid in all school years. With regard to changes with age in BMI and body fat percentage, the results showed a temporary drop at 9 years in the aging distance curve in boys, followed by an increasing trend. Peaks were seen in the velocity curve at 9.7 and 11.9 years, but the MPV was presumed to be at 11.9 years. Among girls, a decreasing trend was seen in the aging distance curve, which was opposite to the changes in the aging distance curve for body fat percentage.

Validation of bioelectrical impedance analysis in Ethiopian adults with HIV.

PubMed

Hegelund, Maria H; Wells, Jonathan C; Girma, Tsinuel; Faurholt-Jepsen, Daniel; Zerfu, Dilnesaw; Christensen, Dirk L; Friis, Henrik; Olsen, Mette F

2017-01-01

Bioelectrical impedance analysis (BIA) is an inexpensive, quick and non-invasive method to determine body composition. Equations used in BIA are typically derived in healthy individuals of European descent. BIA is specific to health status and ethnicity and may therefore provide inaccurate results in populations of different ethnic origin and health status. The aim of the present study was to test the validity of BIA in Ethiopian antiretroviral-naive HIV patients. BIA was validated against the 2 H dilution technique by comparing fat-free mass (FFM) measured by the two methods using paired t tests and Bland-Altman plots. BIA was based on single frequency (50 kHz) whole-body measurements. Data were obtained at three health facilities in Jimma Zone, Oromia Region, South-West Ethiopia. Data from 281 HIV-infected participants were available. Two-thirds were female and the mean age was 32·7 (sd 8·6) years. Also, 46 % were underweight with a BMI below 18·5 kg/m 2 . There were no differences in FFM between the methods. Overall, BIA slightly underestimated FFM by 0·1 kg (-0·1, 95 % CI -0·3, 0·2 kg). The Bland-Altman plot indicated acceptable agreement with an upper limit of agreement of 4·5 kg and a lower limit of agreement of -4·6 kg, but with a small correlation between the mean difference and the average FFM. BIA slightly overestimated FFM at low values compared with the 2 H dilution technique, while it slightly underestimated FFM at high values. In conclusion, BIA proved to be valid in this population and may therefore be useful for measuring body composition in routine practice in HIV-infected African individuals.

The Application of Biomedical Engineering Techniques to the Diagnosis and Management of Tropical Diseases: A Review

PubMed Central

Ibrahim, Fatimah; Thio, Tzer Hwai Gilbert; Faisal, Tarig; Neuman, Michael

2015-01-01

This paper reviews a number of biomedical engineering approaches to help aid in the detection and treatment of tropical diseases such as dengue, malaria, cholera, schistosomiasis, lymphatic filariasis, ebola, leprosy, leishmaniasis, and American trypanosomiasis (Chagas). Many different forms of non-invasive approaches such as ultrasound, echocardiography and electrocardiography, bioelectrical impedance, optical detection, simplified and rapid serological tests such as lab-on-chip and micro-/nano-fluidic platforms and medical support systems such as artificial intelligence clinical support systems are discussed. The paper also reviewed the novel clinical diagnosis and management systems using artificial intelligence and bioelectrical impedance techniques for dengue clinical applications. PMID:25806872

Effect of Exogenous Extracellular Nicotinamide Adenine Dinucleotide (NAD⁺) on Bioelectric Activity of the Pacemaker and Conduction System of the Heart.

PubMed

Pustovit, K B; Kuz'min, V S; Sukhova, G S

2015-06-01

In rat sinoatrial node, NAD(+) (10 μM) reduced the rate of spontaneous action potentials, duration of action potentials, and the velocity of slow diastolic depolarization, but the rate of action potential front propagation increases. In passed rabbit Purkinje fibers, NAD(+) (10 μM) reduced the duration of action potentials. Under conditions of spontaneous activity of Purkinje fibers, NAD(+) reduced the fi ring rate and the rate of slow diastolic depolarization. The effects of extracellular NAD(+) on bioelectric activity of the pacemaker (sinoatrial node) and conduction system of the heart (Purkinje fibers) are probably related to activation of P1 and P2 purinoceptors.

Nutritional status among adolescent girls in children's homes: Anthropometry and dietary patterns.

PubMed

Berg, Tone; Magala-Nyago, Christine; Iversen, Per Ole

2018-06-01

Malnutrition is widespread among disadvantaged people in low-income countries like Uganda. Children and adolescents living in children's homes are considered an especially vulnerable group, and malnutrition among girls is of particular concern since it has intergenerational consequences. Virtually no information exists about the nutritional status of adolescent girls living in children's homes in Uganda. We therefore conducted a cross-sectional study to assess the nutritional status by evaluating anthropometric indicators, body composition and dietary patterns. Forty-four girls aged 10-19 years living in five children's homes participated in addition to a reference group of 27 adolescent girls from three boarding schools; both in the Ugandan capital Kampala. Height and weight were measured to assess anthropometry. Body composition data was obtained by bioelectrical impedance analysis. Dietary intake was evaluated with a food frequency questionnaire, calculation of dietary diversity score, and a 24-h dietary recall. The adolescent girls living in children's homes suffered from stunting (18.6%), overweight or obesity (18.6%), and were at risk of insufficient intakes of multiple micronutrients, especially of vitamins A, B 12 , C, D, E and calcium. They also had a low intake of essential fatty acids. Dietary diversity was low with a median score of 3 out of 9 food groups. Animal products were rarely consumed. The majority of girls in children's homes consumed a less adequate diet compared to the reference group, thus being at risk of nutrient deficiency-related disorders. Copyright © 2017 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Bioimpedance profiling of the limbs: Update

NASA Astrophysics Data System (ADS)

Ward, L. C.; Essex, T.; Bartlett, M.; Kilbreath, S.; Brookes, D.

2010-04-01

Bioelectrical impedance spectroscopy (BIS) is now commonly used to assess breast cancer-related lymphoedema. Typically, the ratio of impedances of the two arms, determined at zero frequency (Z0), is used as a quantitative index of the presence of excess lymph. Measurement uses skin electrodes spanning the whole limb. However, lymphoedema may be highly localised and may involve changes other than simple fluid accumulation, e.g. increased fat and fibrosis, that also give rise to changes in impedance-related parameters such as capacitance. We have previously reported (13th ICEBI, Graz, 2007) a prototype mobile electrode probe that replaces the distal sense electrode which, when moved proximally along the arm, provides an impedance profile. We report here the further development of this technology to incorporate real-time measurement of impedance integrated with a digital measuring wheel. This allows exact synchronisation of impedance with position on the arm. A commercial BIS instrument (ImpediMed SFB7) was modified to collect impedance (R and Xc) data every msec and the mean impedance computed for each 10-mm slice. The apparent resistivity values for arm tissue were used to calculate slice volumes. These computed volumes were compared to equivalent slice volumes from perometry and DXA. The system is being further validated by correlating slice impedance parameters with lean tissue volume determined by pQCT (StraTec XCT 3000), for multiple positions along the arm. Ultimately, it is hoped that such measurements will not only allow localised tissue volume measurement but will also provide information of tissue composition in conditions such as lymphoedema.

Single cross-sectional area of pectoralis muscle by computed tomography - correlation with bioelectrical impedance based skeletal muscle mass in healthy subjects.

PubMed

Kim, Young Saing; Kim, Eun Young; Kang, Shin Myung; Ahn, Hee Kyung; Kim, Hyung Sik

2017-09-01

Skeletal muscle depletion is an important prognostic factor in patients with chronic obstructive pulmonary disease (COPD); a recent study demonstrated significant correlations between pectoralis muscle area on an axial CT image and COPD-related traits. The purpose of this study was to evaluate the relation between pectoralis muscle areas on CT scans and total body skeletal muscle mass (SMM) in healthy subjects. For 434 subjects that underwent a low-dose chest CT and bioelectrical impedance analysis (BIA) during health screening from January to June of 2014, cross-sectional area of pectoralis muscles were measured in CT scans. Pearson's correlation and multiple linear regression analysis were used to assess the relationship between cross-sectional CT areas of pectoralis muscles and BIA-assessed SMMs. Mean age was 50 ± 10 years (78·8% were male). The mean cross-sectional area of pectoralis muscles was 24·1 cm 2  ± 6·8. A moderate correlation was observed between pectoralis muscle area and BIA-based SMM (r = 0·665, P<0.001). Multivariable analysis showed CT determined pectoralis muscle area was significantly associated with BIA-assessed SMM after adjusting for gender, weight, height and age (β = 0·14 ± 0·02, P<0·001). Cross-sectional area of the pectoralis muscles on single axial CT images shows moderate correlation with total body SMM determined by BIA in healthy subjects. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis

PubMed Central

Tint, Mya-Thway; Ward, Leigh C; Soh, Shu E; Aris, Izzuddin M; Chinnadurai, Amutha; Saw, Seang Mei; Gluckman, Peter D; Godfrey, Keith M; Chong, Yap-Seng; Kramer, Michael S; Yap, Fabian; Lingwood, Barbara; Lee, Yung Seng

2016-01-01

The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in independent Western cohort. A total of 173 neonates at birth and 140 at week-2 of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations were assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week-2 but not at birth. Compared to the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0.01kg with 2SD limits of agreement (LOA) (0.18, −0.20). Prediction explained 88.9% of variation but not beyond that of anthropometry. Applying these equations to Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared to simple anthropometry in Asian populations. There is a need for population and age appropriate FFM prediction equations. PMID:26856420

Validation of bioelectrical impedance analysis for total body water assessment against the deuterium dilution technique in Asian children.

PubMed

Liu, A; Byrne, N M; Ma, G; Nasreddine, L; Trinidad, T P; Kijboonchoo, K; Ismail, M N; Kagawa, M; Poh, B K; Hills, A P

2011-12-01

To develop and cross-validate bioelectrical impedance analysis (BIA) prediction equations of total body water (TBW) and fat-free mass (FFM) for Asian pre-pubertal children from China, Lebanon, Malaysia, Philippines and Thailand. Height, weight, age, gender, resistance and reactance measured by BIA were collected from 948 Asian children (492 boys and 456 girls) aged 8-10 years from the five countries. The deuterium dilution technique was used as the criterion method for the estimation of TBW and FFM. The BIA equations were developed using stepwise multiple regression analysis and cross-validated using the Bland-Altman approach. The BIA prediction equation for the estimation of TBW was as follows: TBW=0.231 × height(2)/resistance+0.066 × height+0.188 × weight+0.128 × age+0.500 × sex-0.316 × Thais-4.574 (R (2)=88.0%, root mean square error (RMSE)=1.3 kg), and for the estimation of FFM was as follows: FFM=0.299 × height(2)/resistance+0.086 × height+0.245 × weight+0.260 × age+0.901 × sex-0.415 × ethnicity (Thai ethnicity =1, others = 0)-6.952 (R (2)=88.3%, RMSE=1.7 kg). No significant difference between measured and predicted values for the whole cross-validation sample was found. However, the prediction equation for estimation of TBW/FFM tended to overestimate TBW/FFM at lower levels whereas underestimate at higher levels of TBW/FFM. Accuracy of the general equation for TBW and FFM was also valid at each body mass index category. Ethnicity influences the relationship between BIA and body composition in Asian pre-pubertal children. The newly developed BIA prediction equations are valid for use in Asian pre-pubertal children.

Estimation of fat-free mass in Asian neonates using bioelectrical impedance analysis.

PubMed

Tint, Mya-Thway; Ward, Leigh C; Soh, Shu E; Aris, Izzuddin M; Chinnadurai, Amutha; Saw, Seang Mei; Gluckman, Peter D; Godfrey, Keith M; Chong, Yap-Seng; Kramer, Michael S; Yap, Fabian; Lingwood, Barbara; Lee, Yung Seng

2016-03-28

The aims of this study were to develop and validate a prediction equation of fat-free mass (FFM) based on bioelectrical impedance analysis (BIA) and anthropometry using air-displacement plethysmography (ADP) as a reference in Asian neonates and to test the applicability of the prediction equations in an independent Western cohort. A total of 173 neonates at birth and 140 at two weeks of age were included. Multiple linear regression analysis was performed to develop the prediction equations in a two-third randomly selected subset and validated on the remaining one-third subset at each time point and in an independent Queensland cohort. FFM measured by ADP was the dependent variable, and anthropometric measures, sex and impedance quotient (L2/R50) were independent variables in the model. Accuracy of prediction equations was assessed using intra-class correlation and Bland-Altman analyses. L2/R50 was the significant predictor of FFM at week two but not at birth. Compared with the model using weight, sex and length, including L2/R50 slightly improved the prediction with a bias of 0·01 kg with 2 sd limits of agreement (LOA) (0·18, -0·20). Prediction explained 88·9 % of variation but not beyond that of anthropometry. Applying these equations to the Queensland cohort provided similar performance at the appropriate age. However, when the Queensland equations were applied to our cohort, the bias increased slightly but with similar LOA. BIA appears to have limited use in predicting FFM in the first few weeks of life compared with simple anthropometry in Asian populations. There is a need for population- and age-appropriate FFM prediction equations.

The investigation of the some body parameters of obese and (obese+diabetes) patients with using bioelectrical impedance analysis techniques

NASA Astrophysics Data System (ADS)

Yerlikaya, Emrah; Karageçili, Hasan; Aydin, Ruken Zeynep

2016-04-01

Obesity is a key risk for the development of hyperglycemia, hypertension, hyperlipidemia, insulin resistance and is totally referred to as the metabolic disorders. Diabetes mellitus, a metabolic disorder, is related with hyperglycemia, altered metabolism of lipids, carbohydrates and proteins. The minimum defining characteristic feature to identify diabetes mellitus is chronic and substantiated elevation of circulating glucose concentration. In this study, it is aimed to determine the body composition analyze of obese and (obese+diabetes) patients.We studied the datas taken from three independent groups with the body composition analyzer instrument. The body composition analyzer calculates body parameters, such as body fat ratio, body fat mass, fat free mass, estimated muscle mass, and base metabolic rate on the basis of data obtained by Dual Energy X-ray Absorptiometry using Bioelectrical Impedance Analysis. All patients and healthy subjects applied to Siirt University Medico and their datas were taken. The Statistical Package for Social Sciences version 21 was used for descriptive data analysis. When we compared and analyzed three groups datas, we found statistically significant difference between obese, (obese+diabetes) and control groups values. Anova test and tukey test are used to analyze the difference between groups and to do multiple comparisons. T test is also used to analyze the difference between genders. We observed the statistically significant difference in age and mineral amount p<0.00 between (diabetes+obese) and obese groups. Besides, when these patient groups and control group were analyzed, there were significant difference between most parameters. In terms of education level among the illiterate and university graduates; fat mass kg, fat percentage, internal lubrication, body mass index, water percentage, protein mass percentage, mineral percentage p<0.05, significant statistically difference were observed. This difference especially may result of a sedentary lifestyle.

An optical microfluidic platform for spatiotemporal biofilm treatment monitoring

NASA Astrophysics Data System (ADS)

Kim, Young Wook; Mosteller, Matthew P.; Subramanian, Sowmya; Meyer, Mariana T.; Bentley, William E.; Ghodssi, Reza

2016-01-01

Bacterial biofilms constitute in excess of 65% of clinical microbial infections, with the antibiotic treatment of biofilm infections posing a unique challenge due to their high antibiotic tolerance. Recent studies performed in our group have demonstrated that a bioelectric effect featuring low-intensity electric signals combined with antibiotics can significantly improve the efficacy of biofilm treatment. In this work, we demonstrate the bioelectric effect using sub-micron thick planar electrodes in a microfluidic device. This is critical in efforts to develop microsystems for clinical biofilm infection management, including both in vivo and in vitro applications. Adaptation of the method to the microscale, for example, can enable the development of localized biofilm infection treatment using microfabricated medical devices, while augmenting existing capabilities to perform biofilm management beyond the clinical realm. Furthermore, due to scale-down of the system, the voltage requirement for inducing the electric field is reduced further below the media electrolysis threshold. Enhanced biofilm treatment using the bioelectric effect in the developed microfluidic device elicited a 56% greater reduction in viable cell density and 26% further decrease in biomass growth compared to traditional antibiotic therapy. This biofilm treatment efficacy, demonstrated in a micro-scale device and utilizing biocompatible voltage ranges, encourages the use of this method for future clinical biofilm treatment applications.

Effect of artificial electric fields on plants grown under microgravity conditions

NASA Astrophysics Data System (ADS)

Nechitailo, G.; Gordeev, A.

2001-01-01

Ionic and structural hetorogeneity of cells, tissues, and organs of plants are associated with a spectrum of electric characteristics such as bioelectric potentials, electrical conductance, and bioelectric permeability. An important determinant for the plant function is electric properties of the cell membranes and organelles which maintain energy and substance exchange with the environment. Enzymes and other biologically active substances have a powerful charge at the molecular level. Finally, all molecules, including those of water, represent dipoles, and this determines their reactive capacity. A major determinant is the bioelectric polarity of a plant is genetically predetermined and cannot be modified. It is an intrinsic structural feature of the organism whose evolution advent was mediated by gravity. An illustrative presentation of polarity is the downward growth of the roots and upward growth of stems in the Earth's gravitation field. However, gravity is a critical, but not the sole determinant of the plant organism polarization. Potent polarizing effects are exerted by light, the electromagnetic field, moisture, and other factors. It is known that plant cultivation in an upturned position is associated with impairment of water and nutrient uptake, resulting in dyscoordination of physiological processes, growth and developmental retardation. These abnormalities were characteristic when early attempts were made to grow plants in weightlessness conditions.

Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics.

PubMed

Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

2016-02-04

Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level.

Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics

PubMed Central

Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

2016-01-01

Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level. PMID:26841954

Bioelectrical Signals and Ion Channels in the Modeling of Multicellular Patterns and Cancer Biophysics

NASA Astrophysics Data System (ADS)

Cervera, Javier; Alcaraz, Antonio; Mafe, Salvador

2016-02-01

Bioelectrical signals and ion channels are central to spatial patterns in cell ensembles, a problem of fundamental interest in positional information and cancer processes. We propose a model for electrically connected cells based on simple biological concepts: i) the membrane potential of a single cell characterizes its electrical state; ii) the long-range electrical coupling of the multicellular ensemble is realized by a network of gap junction channels between neighboring cells; and iii) the spatial distribution of an external biochemical agent can modify the conductances of the ion channels in a cell membrane and the multicellular electrical state. We focus on electrical effects in small multicellular ensembles, ignoring slow diffusional processes. The spatio-temporal patterns obtained for the local map of cell electric potentials illustrate the normalization of regions with abnormal cell electrical states. The effects of intercellular coupling and blocking of specific channels on the electrical patterns are described. These patterns can regulate the electrically-induced redistribution of charged nanoparticles over small regions of a model tissue. The inclusion of bioelectrical signals provides new insights for the modeling of cancer biophysics because collective multicellular states show electrical coupling mechanisms that are not readily deduced from biochemical descriptions at the individual cell level.

Compost in plant microbial fuel cell for bioelectricity generation.

PubMed

Moqsud, M A; Yoshitake, J; Bushra, Q S; Hyodo, M; Omine, K; Strik, David

2015-02-01

Recycling of organic waste is an important topic in developing countries as well as developed countries. Compost from organic waste has been used for soil conditioner. In this study, an experiment has been carried out to produce green energy (bioelectricity) by using paddy plant microbial fuel cells (PMFCs) in soil mixed with compost. A total of six buckets filled with the same soil were used with carbon fiber as the electrodes for the test. Rice plants were planted in five of the buckets, with the sixth bucket containing only soil and an external resistance of 100 ohm was used for all cases. It was observed that the cells with rice plants and compost showed higher values of voltage and power density with time. The highest value of voltage showed around 700 mV when a rice plant with 1% compost mixed soil was used, however it was more than 95% less in the case of no rice plant and without compost. Comparing cases with and without compost but with the same number of rice plants, cases with compost depicted higher voltage to as much as 2 times. The power density was also 3 times higher when the compost was used in the paddy PMFCs which indicated the influence of compost on bio-electricity generation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Uterine Junctional Zone Thickness, Cervical Length and Bioelectrical Impedance Analysis of Body Composition in Women with Endometriosis

PubMed Central

Ayas, Selçuk; Bayraktar, Mesut; Gürbüz, Ayşe; Alkan, Akif; Eren, Sadiye

2012-01-01

Objective: We aimed to evaluate uterine junctional zone thickness, cervical length and bioelectrical impedance analysis of body composition in women with endometriosis. Material and Methods: This is a prospective study conducted in a tertiary teaching hospital. A total of 73 patients were included in the study. Endometriosis was surgically diagnosed in 36 patients (study group). The control group included 37 patients. Main outcome measure(s): Bioelectrical impedance analysis was used to measure body composition. Uterine junctional zone thickness and cervical length were measured by transvaginal ultrasonography. Results: Patients’ characteristics (age, gravida, parity, live baby, age of menarche, lengths of menstrual cycle, percentage of patients with dysmenorrhea, positive family history), body mass index (BMI) (kg/m2), amount of body fat (kg), percentage of body fat were not statistically different between the two groups (p>0.05). The length of menstruation and cervical length were longer in women with endometriosis. Similarly, the inner myometrium was thicker in women with endometriosis than the control group. Conclusion: The relation between endometriosis and demographic features such as age, gravida, parity, gravida, BMI, lengths of the menstrual cycle, age of menarche are controversial. Longer cervical length and thicker inner myometrial layer may be important in the etiopathogenesis of endometriosis. PMID:25207044

Energy expenditure in caving.

PubMed

Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio; Rinaldi, Andrea C

2017-01-01

The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225-287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000-1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue.

Simultaneous wastewater treatment and bioelectricity production in microbial fuel cells using cross-linked chitosan-graphene oxide mixed-matrix membranes.

PubMed

Holder, Shima L; Lee, Ching-Hwa; Popuri, Srinivasa R

2017-05-01

Microbial fuel cells (MFCs) are emerging technology for wastewater treatment by chemical oxygen demand (COD) reduction and simultaneous bioelectricity production. Fabrication of an effective proton exchange membrane (PEM) is a vital component for MFC performance. In this work, green chitosan-based (CS) PEMs were fabricated with graphene oxide (GO) as filler material (CS-GO) and cross-linked with phosphoric acid (CS-GO-P(24)) or sulfuric acid (CS-GO-S(24)) to determine their effect on PEM properties. Interrogation of the physicochemical, thermal, and mechanical properties of the cross-linked CS-GO PEMs demonstrated that ionic cross-linking based on the incorporation of PO 4 3- groups in the CS-GO mixed-matrix composites, when compared with sulfuric acid cross-linking commonly used in proton exchange membrane fuel cell (PEMFC) studies, generated additional density of ionic cluster domains, rendered enhanced sorption properties, and augmented the thermal and mechanical stability of the composite structure. Consequently, bioelectricity performance analysis in MFC application showed that CS-GO-P(24) membrane produced 135% higher power density than the CS-GO-S(24) MFC system. Simultaneously, 89.52% COD removal of primary clarifier municipal wastewater was achieved in the MFC operated with the CS-GO-P(24) membrane.

Field comparison of body composition techniques: hydrostatic weighing, skinfold thickness, and bioelectric impedance.

PubMed

Kirkendall, D T; Grogan, J W; Bowers, R G

1991-01-01

Body composition and appropriate playing weight are frequently requested by coaches. Numerous methods for estimating these figures are available, and each has its own limitation, be it technical or biological. A comparison of three common methods was made-underwater weighting (H2O, the criterion), skinfold thicknesses (SF), and commercial bioelectrical impedance analysis (BIA). Subjects were 29 professional football players measured by each of the three methods after an overnight fast. Data was collected 10 weeks preceding the players' formal training camp. There was no difference for percentage of weight as fat between SF (15.8%) and H2O (14.2%). Bioelectrical impedance analysis significantly (p < .05) overestimated percent fat (19.2%) compared to H20. Error rates when regressing SF on H2O were favorable, whether expressed for the whole sample (3.04%) or by race (1.78% or 3.56% for whites and blacks, respectively). Regression of BIA on H2O showed an elevated, overall error rate (14.12%) and elevated error rates for whites (11.57%) and blacks (13.81%). Of the two estimates of body composition on a racially mixed sample of males, SF provided the best estimate with the least amount of error. J Orthop Sports Phys Ther 1991;13(5):235-239.

H(+)/K(+) ATPase activity is required for biomineralization in sea urchin embryos.

PubMed

Schatzberg, Daphne; Lawton, Matthew; Hadyniak, Sarah E; Ross, Erik J; Carney, Tamara; Beane, Wendy S; Levin, Michael; Bradham, Cynthia A

2015-10-15

The bioelectrical signatures associated with regeneration, wound healing, development, and cancer are changes in the polarization state of the cell that persist over long durations, and are mediated by ion channel activity. To identify physiologically relevant bioelectrical changes that occur during normal development of the sea urchin Lytechinus variegatus, we tested a range of ion channel inhibitors, and thereby identified SCH28080, a chemical inhibitor of the H(+)/K(+) ATPase (HKA), as an inhibitor of skeletogenesis. In sea urchin embryos, the primary mesodermal lineage, the PMCs, produce biomineral in response to signals from the ectoderm. However, in SCH28080-treated embryos, aside from randomization of the left-right axis, the ectoderm is normally specified and differentiated, indicating that the block to skeletogenesis observed in SCH28080-treated embryos is PMC-specific. HKA inhibition did not interfere with PMC specification, and was sufficient to block continuing biomineralization when embryos were treated with SCH28080 after the initiation of skeletogenesis, indicating that HKA activity is continuously required during biomineralization. Ion concentrations and voltage potential were abnormal in the PMCs in SCH28080-treated embryos, suggesting that these bioelectrical abnormalities prevent biomineralization. Our results indicate that this effect is due to the inhibition of amorphous calcium carbonate precipitation within PMC vesicles. Copyright © 2015 Elsevier Inc. All rights reserved.

Surface Current Density Mapping for Identification of Gastric Slow Wave Propagation

PubMed Central

Bradshaw, L. A.; Cheng, L. K.; Richards, W. O.; Pullan, A. J.

2009-01-01

The magnetogastrogram records clinically relevant parameters of the electrical slow wave of the stomach noninvasively. Besides slow wave frequency, gastric slow wave propagation velocity is a potentially useful clinical indicator of the state of health of gastric tissue, but it is a difficult parameter to determine from noninvasive bioelectric or biomagnetic measurements. We present a method for computing the surface current density (SCD) from multichannel magnetogastrogram recordings that allows computation of the propagation velocity of the gastric slow wave. A moving dipole source model with hypothetical as well as realistic biomagnetometer parameters demonstrates that while a relatively sparse array of magnetometer sensors is sufficient to compute a single average propagation velocity, more detailed information about spatial variations in propagation velocity requires higher density magnetometer arrays. Finally, the method is validated with simultaneous MGG and serosal EMG measurements in a porcine subject. PMID:19403355

[Effectiveness of magnetotherapy in optic nerve atrophy. A preliminary study].

PubMed

Zobina, L V; Orlovskaia, L S; Sokov, S L; Sabaeva, G F; Kondé, L A; Iakovlev, A A

1990-01-01

Magnetotherapy effects on visual functions (vision acuity and field), on retinal bioelectric activity, on conductive vision system, and on intraocular circulation were studied in 88 patients (160 eyes) with optic nerve atrophy. A Soviet Polyus-1 low-frequency magnetotherapy apparatus was employed with magnetic induction of about 10 mT, exposure 7-10 min, 10-15 sessions per course. Vision acuity of patients with its low (below 0.04 diopters) values improved in 50 percent of cases. The number of patients with vision acuity of 0.2 diopters has increased from 46 before treatment to 75. Magnetotherapy improved ocular hemodynamics in patients with optic nerve atrophy, it reduced the time of stimulation conduction along the vision routes and stimulated the retinal ganglia cells. The maximal effect was achieved after 10 magnetotherapy sessions. A repeated course carried out in 6-8 months promoted a stabilization of the process.

The energetics of electric organ discharge generation in gymnotiform weakly electric fish.

PubMed

Salazar, Vielka L; Krahe, Rüdiger; Lewis, John E

2013-07-01

Gymnotiform weakly electric fish produce an electric signal to sense their environment and communicate with conspecifics. Although the generation of such relatively large electric signals over an entire lifetime is expected to be energetically costly, supporting evidence to date is equivocal. In this article, we first provide a theoretical analysis of the energy budget underlying signal production. Our analysis suggests that wave-type and pulse-type species invest a similar fraction of metabolic resources into electric signal generation, supporting previous evidence of a trade-off between signal amplitude and frequency. We then consider a comparative and evolutionary framework in which to interpret and guide future studies. We suggest that species differences in signal generation and plasticity, when considered in an energetics context, will not only help to evaluate the role of energetic constraints in the evolution of signal diversity but also lead to important general insights into the energetics of bioelectric signal generation.

Assessment of adult body composition using bioelectrical impedance: comparison of researcher calculated to machine outputted values.

PubMed

Franco-Villoria, Maria; Wright, Charlotte M; McColl, John H; Sherriff, Andrea; Pearce, Mark S

2016-01-07

To explore the usefulness of Bioelectrical Impedance Analysis (BIA) for general use by identifying best-evidenced formulae to calculate lean and fat mass, comparing these to historical gold standard data and comparing these results with machine-generated output. In addition, we explored how to best to adjust lean and fat estimates for height and how these overlapped with body mass index (BMI). Cross-sectional observational study within population representative cohort study. Urban community, North East England Sample of 506 mothers of children aged 7-8 years, mean age 36.3 years. Participants were measured at a home visit using a portable height measure and leg-to-leg BIA machine (Tanita TBF-300MA). Height, weight, bioelectrical impedance (BIA). Lean and fat mass calculated using best-evidenced published formulae as well as machine-calculated lean and fat mass data. Estimates of lean mass were similar to historical results using gold standard methods. When compared with the machine-generated values, there were wide limits of agreement for fat mass and a large relative bias for lean that varied with size. Lean and fat residuals adjusted for height differed little from indices of lean (or fat)/height(2). Of 112 women with BMI >30 kg/m(2), 100 (91%) also had high fat, but of the 16 with low BMI (<19 kg/m(2)) only 5 (31%) also had low fat. Lean and fat mass calculated from BIA using published formulae produces plausible values and demonstrate good concordance between high BMI and high fat, but these differ substantially from the machine-generated values. Bioelectrical impedance can supply a robust and useful field measure of body composition, so long as the machine-generated output is not used. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Assessment of adult body composition using bioelectrical impedance: comparison of researcher calculated to machine outputted values

PubMed Central

Franco-Villoria, Maria; Wright, Charlotte M; McColl, John H; Sherriff, Andrea; Pearce, Mark S

2016-01-01

Objectives To explore the usefulness of Bioelectrical Impedance Analysis (BIA) for general use by identifying best-evidenced formulae to calculate lean and fat mass, comparing these to historical gold standard data and comparing these results with machine-generated output. In addition, we explored how to best to adjust lean and fat estimates for height and how these overlapped with body mass index (BMI). Design Cross-sectional observational study within population representative cohort study. Setting Urban community, North East England Participants Sample of 506 mothers of children aged 7–8 years, mean age 36.3 years. Methods Participants were measured at a home visit using a portable height measure and leg-to-leg BIA machine (Tanita TBF-300MA). Measures Height, weight, bioelectrical impedance (BIA). Outcome measures Lean and fat mass calculated using best-evidenced published formulae as well as machine-calculated lean and fat mass data. Results Estimates of lean mass were similar to historical results using gold standard methods. When compared with the machine-generated values, there were wide limits of agreement for fat mass and a large relative bias for lean that varied with size. Lean and fat residuals adjusted for height differed little from indices of lean (or fat)/height2. Of 112 women with BMI >30 kg/m2, 100 (91%) also had high fat, but of the 16 with low BMI (<19 kg/m2) only 5 (31%) also had low fat. Conclusions Lean and fat mass calculated from BIA using published formulae produces plausible values and demonstrate good concordance between high BMI and high fat, but these differ substantially from the machine-generated values. Bioelectrical impedance can supply a robust and useful field measure of body composition, so long as the machine-generated output is not used. PMID:26743700

Assessment of bioelectrical activity of synergistic muscles during pelvic floor muscles activation in postmenopausal women with and without stress urinary incontinence: a preliminary observational study

PubMed Central

Ptaszkowski, Kuba; Paprocka-Borowicz, Małgorzata; Słupska, Lucyna; Bartnicki, Janusz; Dymarek, Robert; Rosińczuk, Joanna; Heimrath, Jerzy; Dembowski, Janusz; Zdrojowy, Romuald

2015-01-01

Objective Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman’s ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI. Materials and methods This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity. Results Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups. Conclusion In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the mechanism of continence. PMID:26445533

Body fat measurement by bioelectrical impedance and air displacement plethysmography: a cross-validation study to design bioelectrical impedance equations in Mexican adults

PubMed Central

Macias, Nayeli; Alemán-Mateo, Heliodoro; Esparza-Romero, Julián; Valencia, Mauro E

2007-01-01

Background The study of body composition in specific populations by techniques such as bio-impedance analysis (BIA) requires validation based on standard reference methods. The aim of this study was to develop and cross-validate a predictive equation for bioelectrical impedance using air displacement plethysmography (ADP) as standard method to measure body composition in Mexican adult men and women. Methods This study included 155 male and female subjects from northern Mexico, 20–50 years of age, from low, middle, and upper income levels. Body composition was measured by ADP. Body weight (BW, kg) and height (Ht, cm) were obtained by standard anthropometric techniques. Resistance, R (ohms) and reactance, Xc (ohms) were also measured. A random-split method was used to obtain two samples: one was used to derive the equation by the "all possible regressions" procedure and was cross-validated in the other sample to test predicted versus measured values of fat-free mass (FFM). Results and Discussion The final model was: FFM (kg) = 0.7374 * (Ht2 /R) + 0.1763 * (BW) - 0.1773 * (Age) + 0.1198 * (Xc) - 2.4658. R2 was 0.97; the square root of the mean square error (SRMSE) was 1.99 kg, and the pure error (PE) was 2.96. There was no difference between FFM predicted by the new equation (48.57 ± 10.9 kg) and that measured by ADP (48.43 ± 11.3 kg). The new equation did not differ from the line of identity, had a high R2 and a low SRMSE, and showed no significant bias (0.87 ± 2.84 kg). Conclusion The new bioelectrical impedance equation based on the two-compartment model (2C) was accurate, precise, and free of bias. This equation can be used to assess body composition and nutritional status in populations similar in anthropometric and physical characteristics to this sample. PMID:17697388

Foot-to-foot bioelectrical impedance accurately tracks direction of adiposity change in overweight and obese 7- to 13-year-old children.

PubMed

Kasvis, Popi; Cohen, Tamara R; Loiselle, Sarah-Ève; Kim, Nicolas; Hazell, Tom J; Vanstone, Catherine A; Rodd, Celia; Plourde, Hugues; Weiler, Hope A

2015-03-01

Body composition measurements are valuable when evaluating pediatric obesity interventions. We hypothesized that foot-to-foot bioelectrical impedance analysis (BIA) will accurately track the direction of adiposity change, but not magnitude, in part due to differences in fat patterning. The purposes of this study were to examine the accuracy of body composition measurements of overweight and obese children over time using dual-energy x-ray absorptiometry (DXA) and BIA and to determine if BIA accuracy was affected by fat patterning. Eighty-nine overweight or obese children (48 girls, 41 boys, age 7-13 years) participating in a randomized controlled trial providing a family-centered, lifestyle intervention, underwent DXA and BIA measurements every 3 months. Bland-Altman plots showed a poor level of agreement between devices for baseline percent body fat (%BF; mean, 0.398%; +2SD, 8.685%; -2SD, -7.889%). There was overall agreement between DXA and BIA in the direction of change over time for %BF (difference between visits 3 and 1: DXA -0.8 ± 0.5%, BIA -0.7 ± 0.5%; P = 1.000) and fat mass (FM; difference between visits 3 and 1: DXA 0.7 ± 0.5 kg, BIA 0.6 ± 0.5 kg; P = 1.000). Bioelectrical impedance analysis measurements of %BF and FM at baseline were significantly different in those with android and gynoid fat (%BF: 35.9% ± 1.4%, 32.2% ± 1.4%, P < .003; FM: 20.1 ± 0.8 kg, 18.4 ± 0.8, P < .013). Bioelectrical impedance analysis accurately reports the direction of change in FM and FFM in overweight and obese children; inaccuracy in the magnitude of BIA measurements may be a result of fat patterning differences. Copyright © 2015 Elsevier Inc. All rights reserved.

Discordance between bioelectrical impedance vector analysis and the new ESPEN definition of malnutrition for the diagnosis of hospital malnutrition.

PubMed

Dehesa-López, Edgar; Martínez-Felix, Jesús Israel; Ruiz-Ramos, Arturo; Atilano-Carsi, Ximena

2017-04-01

No universally accepted diagnostic criteria for malnutrition are available to date. The aim was to assess the concordance for the diagnosis of hospital malnutrition between the bioelectrical impedance vector analysis (BIVA) and the new definition of malnutrition proposed by the European Society for Clinical Nutrition and Metabolism (ESPEN). A total of 140 adult hospitalized patients were included. The malnutrition risk was assessed by the Nutritional Risk Screening. The ESPEN malnutrition criteria (body mass index (BMI) <18.5 kg/m 2 , weight loss (WL) + low BMI, and WL + low fat free mass index (FFMI) were applied to each patient. The bioelectrical impedance of each patient was measured, and malnutrition was diagnosed using the BIVA method. Diagnostic concordance between the BIVA and the new ESPEN definition was assessed with the Kappa coefficient. The malnutrition prevalence was higher with the BIVA vs ESPEN definition (22.1% vs 13.6%) in the global population and was similar (12.8% vs 12.1%) in the population at risk of malnutrition. The diagnostic performance of the BIVA was acceptable, with higher sensitivity in patients with fluid overload (FO) and more specificity in euvolemic patients. Diagnostic concordance between the BIVA and the ESPEN definition was poor for the global population (kappa = 0.56) and the population at risk of malnutrition (kappa = 0.67) but was acceptable in patients with FO (kappa = 0.78). However, the discordant BIVA+/ESPEN- patients classified as false positives for BIVA showed clinical and body composition data (low FFMI, low phase angle) consistent with malnutrition. According to the clinical and bioelectrical characteristics of the discordant BIVA+/ESPEN- patients, the BIVA could perform better that the new ESPEN definition for the diagnosis of hospital malnutrition, which should be confirmed with other studies. Copyright © 2017 European Society for Clinical Nutrition and Metabolism. Published by Elsevier Ltd. All rights reserved.

Assessment of bioelectrical activity of synergistic muscles during pelvic floor muscles activation in postmenopausal women with and without stress urinary incontinence: a preliminary observational study.

PubMed

Ptaszkowski, Kuba; Paprocka-Borowicz, Małgorzata; Słupska, Lucyna; Bartnicki, Janusz; Dymarek, Robert; Rosińczuk, Joanna; Heimrath, Jerzy; Dembowski, Janusz; Zdrojowy, Romuald

2015-01-01

Muscles such as adductor magnus (AM), gluteus maximus (GM), rectus abdominis (RA), and abdominal external and internal oblique muscles are considered to play an important role in the treatment of stress urinary incontinence (SUI), and the relationship between contraction of these muscles and pelvic floor muscles (PFM) has been established in previous studies. Synergistic muscle activation intensifies a woman's ability to contract the PFM. In some cases, even for continent women, it is not possible to fully contract their PFM without involving the synergistic muscles. The primary aim of this study was to assess the surface electromyographic activity of synergistic muscles to PFM (SPFM) during resting and functional PFM activation in postmenopausal women with and without SUI. This study was a preliminary, prospective, cross-sectional observational study and included volunteers and patients who visited the Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Forty-two patients participated in the study and were screened for eligibility criteria. Thirty participants satisfied the criteria and were categorized into two groups: women with SUI (n=16) and continent women (n=14). The bioelectrical activity of PFM and SPFM (AM, RA, GM) was recorded with a surface electromyographic instrument in a standing position during resting and functional PFM activity. Bioelectrical activity of RA was significantly higher in the incontinent group than in the continent group. These results concern the RA activity during resting and functional PFM activity. The results for other muscles showed no significant difference in bioelectrical activity between groups. In women with SUI, during the isolated activation of PFM, an increased synergistic activity of RA muscle was observed; however, this activity was not observed in asymptomatic women. This may indicate the important accessory contribution of these muscles in the mechanism of continence.

Biohydrogen, biomethane and bioelectricity as crucial components of biorefinery of organic wastes: a review.

PubMed

Poggi-Varaldo, Héctor M; Munoz-Paez, Karla M; Escamilla-Alvarado, Carlos; Robledo-Narváez, Paula N; Ponce-Noyola, M Teresa; Calva-Calva, Graciano; Ríos-Leal, Elvira; Galíndez-Mayer, Juvencio; Estrada-Vázquez, Carlos; Ortega-Clemente, Alfredo; Rinderknecht-Seijas, Noemí F

2014-05-01

Biohydrogen is a sustainable form of energy as it can be produced from organic waste through fermentation processes involving dark fermentation and photofermentation. Very often biohydrogen is included as a part of biorefinery approaches, which reclaim organic wastes that are abundant sources of renewable and low cost substrate that can be efficiently fermented by microorganisms. The aim of this work was to critically assess selected bioenergy alternatives from organic solid waste, such as biohydrogen and bioelectricity, to evaluate their relative advantages and disadvantages in the context of biorefineries, and finally to indicate the trends for future research and development. Biorefining is the sustainable processing of biomass into a spectrum of marketable products, which means: energy, materials, chemicals, food and feed. Dark fermentation of organic wastes could be the beach-head of complete biorefineries that generate biohydrogen as a first step and could significantly influence the future of solid waste management. Series systems show a better efficiency than one-stage process regarding substrate conversion to hydrogen and bioenergy. The dark fermentation also produces fermented by-products (fatty acids and solvents), so there is an opportunity for further combining with other processes that yield more bioenergy. Photoheterotrophic fermentation is one of them: photosynthetic heterotrophs, such as non-sulfur purple bacteria, can thrive on the simple organic substances produced in dark fermentation and light, to give more H2. Effluents from photoheterotrophic fermentation and digestates can be processed in microbial fuel cells for bioelectricity production and methanogenic digestion for methane generation, thus integrating a diverse block of bioenergies. Several digestates from bioenergies could be used for bioproducts generation, such as cellulolytic enzymes and saccharification processes, leading to ethanol fermentation (another bioenergy), thus completing the inverse cascade. Finally, biohydrogen, biomethane and bioelectricity could contribute to significant improvements for solid organic waste management in agricultural regions, as well as in urban areas.

Monitoring of interaction of low-frequency electric field with biological tissues upon optical clearing with optical coherence tomography.

PubMed

Peña, Adrián F; Doronin, Alexander; Tuchin, Valery V; Meglinski, Igor

2014-08-01

The influence of a low-frequency electric field applied to soft biological tissues ex vivo at normal conditions and upon the topical application of optical clearing agents has been studied by optical coherence tomography (OCT). The electro-kinetic response of tissues has been observed and quantitatively evaluated by the double correlation OCT approach, utilizing consistent application of an adaptive Wiener filtering and Fourier domain correlation algorithm. The results show that fluctuations, induced by the electric field within the biological tissues are exponentially increased in time. We demonstrate that in comparison to impedance measurements and the mapping of the temperature profile at the surface of the tissue samples, the double correlation OCT approach is much more sensitive to the changes associated with the tissues' electro-kinetic response. We also found that topical application of the optical clearing agent reduces the tissues' electro-kinetic response and is cooling the tissue, thus reducing the temperature induced by the electric current by a few degrees. We anticipate that dcOCT approach can find a new application in bioelectrical impedance analysis and monitoring of the electric properties of biological tissues, including the resistivity of high water content tissues and its variations.

Wavelet-based study of valence-arousal model of emotions on EEG signals with LabVIEW.

PubMed

Guzel Aydin, Seda; Kaya, Turgay; Guler, Hasan

2016-06-01

This paper illustrates the wavelet-based feature extraction for emotion assessment using electroencephalogram (EEG) signal through graphical coding design. Two-dimensional (valence-arousal) emotion model was studied. Different emotions (happy, joy, melancholy, and disgust) were studied for assessment. These emotions were stimulated by video clips. EEG signals obtained from four subjects were decomposed into five frequency bands (gamma, beta, alpha, theta, and delta) using "db5" wavelet function. Relative features were calculated to obtain further information. Impact of the emotions according to valence value was observed to be optimal on power spectral density of gamma band. The main objective of this work is not only to investigate the influence of the emotions on different frequency bands but also to overcome the difficulties in the text-based program. This work offers an alternative approach for emotion evaluation through EEG processing. There are a number of methods for emotion recognition such as wavelet transform-based, Fourier transform-based, and Hilbert-Huang transform-based methods. However, the majority of these methods have been applied with the text-based programming languages. In this study, we proposed and implemented an experimental feature extraction with graphics-based language, which provides great convenience in bioelectrical signal processing.

Analysis of bioelectric records and fabrication of phototype sleep analysis equipment

NASA Technical Reports Server (NTRS)

Kellaway, P.

1972-01-01

A computer-analysis technique was used to evaluate the changes in the waking EEGs of 5 normal subjects which occurred during the oral administration of flurazepam hydrochloride (Dalmane). While the subjects were receiving the drug, there was an increase in the amount of beta (14-38 c/sec) activity in fronto-central EEG leads in all 5 subjects. This increase in beta activity was characterized by a highly consistent increase in the number of waves that occurred during an EEG recording interval of fixed duration and by a less consistent increase in average wave amplitude. There was no detectable change in mean EEG wavelength (frequency) within the beta frequency range. The EEG patterns reverted to their baseline condition during 2-3 weeks after withdrawal of the drug. Analysis of the alpha, theta and delta components of the EEG indicated no changes during or following administration of the drug. This study clearly illustrates the usefulness of specific computer-analysis techniques in the characterization and quantification of sleep-promoting drugs upon the EEG of the normal young adults in the waking state. Two preamplifiers and 150 EEG monitoring caps with electrodes were delivered to MSC.

Relationship between Body Mass Index (BMI) and body fat percentage, estimated by bioelectrical impedance, in a group of Sri Lankan adults: a cross sectional study.

PubMed

Ranasinghe, Chathuranga; Gamage, Prasanna; Katulanda, Prasad; Andraweera, Nalinda; Thilakarathne, Sithira; Tharanga, Praveen

2013-09-03

Body Mass Index (BMI) is used as a useful population-level measure of overweight and obesity. It is used as the same for both sexes and for all ages of adults. The relationship between BMI and body fat percentage (BF %) has been studied in various ethnic groups to estimate the capacity of BMI to predict adiposity. We aimed to study the BMI-BF% relationship, in a group of South Asian adults who have a different body composition compared to presently studied ethnic groups. We examined the influence of age, gender in this relationship and assessed its' linearity or curvilinearity. A cross sectional study was conducted, where adults of 18-83 years were grouped into young (18-39 years) middle aged (40-59 years) and elderly (>60 years). BF% was estimated from bioelectrical impedance analysis. Pearsons' correlation coefficient(r) was calculated to see the relationship between BMI-BF% in the different age groups. Multiple regression analysis was performed to determine the effect of age and gender in the relationship and polynomial regression was carried out to see its' linearity. The relationships between age-BMI, age-BF % were separately assessed. Out of 1114 participants, 49.1% were males. The study sample represented a wide range of BMI values (14.8-41.1 kg/m2,Mean 23.8 ± 4.2 kg/m2). A significant positive correlation was observed between BMI-BF%, in males (r =0.75, p < 0.01; SEE = 4.17) and in females (r = 0.82, p < 0.01; SEE = 3.54) of all ages. Effect of age and gender in the BMI-BF% relationship was significant (p < 0.001); with more effect from gender. Regression line found to be curvilinear in nature at higher BMI values where females (p < 0.000) having a better fit of the curve compared to males (p < 0.05). In both genders, with increase of age, BMI seemed to increase in curvilinear fashion, whereas BF% increased in a linear fashion. BMI strongly correlate with BF % estimated by bioelectrical impedance, in this sub population of South Asian adults. This relationship was curvilinear in nature and was significantly influenced by age and gender. Our findings support the importance of taking age and gender in to consideration when using BMI to predict body fat percentage/obesity, in a population.

Correlation changes in EEG, conditioned and behavioral reactions with various degrees of oxygen insufficiency

NASA Technical Reports Server (NTRS)

Agadzhanyan, N. A.; Zakharova, I. N.; Kalyuzhnyy, L. V.; Dvorzhak, I. I.; Moravek, M.; Tsmiral, Y. I.

1974-01-01

The dynamics of change in bioelectric activity of the brain during acute hypoxia are studied for the time that working capacity and active consciousness are preserved, and to establish the correlation between EEG changes and behavioral reactions under oxygen starvation. Changes in body functions and behavioral disturbances are related to the degree of oxygen saturation in the blood, to bioelectric activity of the brain, and to an increase in conditioned reflexes. The capacity for adequate reaction to external signals and for coordinated psychomotor activity after loss of consciousness returns to man after 30 seconds. Repeated effects of hypoxia produce changes in the physiological reactions of the body directed toward better adaptation to changing gaseous environments.

Anticonvulsants Teratogenic Mechanism Involves Alteration of Bioelectrically-controlled Processes in the Embryo. A hypothesis

PubMed Central

Hernández-Díaz, Sonia; Levin, Michael

2014-01-01

Maternal use of anticonvulsants during the first trimester of pregnancy has been associated with an elevated risk of major congenital malformations in the offspring. Whether the increased risk is caused by the specific pharmacological mechanisms of certain anticonvulsants, the underlying epilepsy, or common genetic or environmental risk factors shared by epilepsy and malformations is controversial. We hypothesize that anticonvulsant therapies during pregnancy that attain more successful inhibition of neurotransmission might lead to both better seizure control in the mother and stronger alteration of bioelectrically-controlled processes in the embryo that result in structural malformations. If our theory were correct, development of pharmaceuticals that do not alter cell resting transmembrane voltage levels could result in safer drugs. PMID:24815983

Psychophysiological characteristics in the ChNPP accident clean-up workers, exclusion zone evacuees and anti-terrorist operation servicemen.

PubMed

Loganovsky, K M; Gresko, M V

2017-12-01

Evaluation of interdependencies between psychometric parameters and spontaneous cerebral electric activity in the ChNPP accident clean up workers, evacuees from exclusion zone, and anti terrorist operation service men. Psychometric and neurophysiological parameters were reviewed in the study subjects retro spectively and in comparison. Study population included the ChNPP accident clean up workers (ACUW), evacuees from the 30 kilometer exclusion zone, specifically in a sample from a cohort of the NRCRM Clinical Epidemiological Register (n=316), and anti terrorist operation servicemen (n=81) undergoing rehabilitation in the NRCRM Radiation psychoneurology department. A control group of persons (n=84) was also involved in the study. Diagnostic method ology for the characteristic personality features, namely the personality test of character accentuation by G. Shmishek and K. Leonhard, and Eysenck Personality Inventory (by H. J. Eysenck) were applied. Computer EEGs were registered and analyzed on the 16 channel electroencephalograph DX 4000 (Kharkiv, Ukraine). In the aftermath of the emergency period, a personality deformation occurs in the clean up workers and survivors of the ChNPP accident, which is characterized by aggravation of such personality traits as jam (fixedness), emotiveness, pedantry, anxiety, cyclothymia, excitability and disthymia, with diminished hyperthymia and ostenta tion (demonstrability). Increased incidence of fixedness, pedantry, cyclothymia, affectability and disthymia with decreased hyperthymia were revealed in the group of ATO participants. Cerebral bioelectrical activity in the ChNPP ACUW was characterized by an increased delta activity power with decreased beta and theta activity power and dom inant frequency in comparison with all groups of survivors and control group. The ATO group was different from groups of survivors and control group with a lower power of delta, theta and beta activity, and a higher dominant frequency. Introversion featured a negative correlation with delta and theta activity index along with positive cor relation with alpha activity index. The absolute spectral power of beta, alpha and theta bands positively correlated with introversion. Increase in neuroticism featured a decrease in theta activity index and an increase in beta activ ity index along with decreased theta and delta band absolute spectral power. There is a deformation of personality in the group of ChNPP ACUW, evacuees from the 30 kilometer zone and ATO servicemen. Deformation of personality correlates with abnormal cerebral bioelectrical activity. K.M. Loganovsky, M.V. Gresko.

Microelectrode array fabrication for electrochemical detection with carbon nanotubes

NASA Astrophysics Data System (ADS)

Clark, James

Understanding how the brain works remains one of the key challenges for scientists. To further this understanding a wide variety of technologies and research methods have been developed. One such technology is conductive electrodes, used to measure the electrical signals elicited from neuronal cells and tissues. These electrodes can be fabricated as a singular electrode or as a multi-electrode array (MEA). This permits bio-electrical measurements from one particular area or simultaneous measurements from multiple areas, respectively. Studying electrical and chemical signals of individual cells in situ requires the use of electrodes with ≤20 µm diameter. However, electrodes of this size generally produce high impedance, perturbing recording of the small signals generated from individual cells. Nanomaterials, such as carbon nanotubes (CNTs), can be deposited to increase the real surface area of these electrodes, producing higher sensitivity measurements. This thesis investigates the potential for using photo-thermal chemical vapour deposition grown CNTs as the electrode material for a de novo fabricated MEA. This device aimed to measure electrochemical signals in the form of dopamine, an important mammalian neurotransmitter, as well as conventional bio-electrical signals that the device is designed for. Realising this aim began with improving CNT aqueous wetting behaviour via oxygen plasma functionalisation. This procedure demonstrated grafting of oxygen functional groups to the CNT structure, and dramatic improvements in aqueous wetting behaviour, with CNTs attached to the device. Subsequently, oxygen plasma functionalised CNT-based MEAs were fabricated and tested, allowing comparisons with a non-functionalised CNT MEA and a state-of-the-art commercial MEA. The functionalised CNT MEA demonstrated an order of magnitude improvement compared to commercial MEAs (2.75 kΩ vs. 25.6 kΩ), at the biologically relevant frequency of 1 kHz. This was followed by measurement of one of the best sensitivity density values, compared to the available literature, for the electrochemical detection of dopamine (9.48 µA µM-1 mm-2). The functionalised CNT MEA then illustrated some selectivity compared to common interferents, i.e. ascorbic acid, of a higher concentration. Nonetheless, imaging of the MEA revealed CNTs were being removed from the electrode areas due to extensive use. Therefore, the final results chapter aimed to develop a novel fabrication route for CNT-based MEAs that produced improved CNT retention on the electrodes. This next-generation functionalised CNT-based MEA displayed improved CNT retention, whilst also producing competitive electrochemical impedance values at 1 kHz (17.8 kΩ) and excellent electrochemical selectivity for dopamine vs. ascorbic acid. Overall, this thesis demonstrates the potential for using MEAs as electrochemical detectors of biological molecules, specifically when using functionalised CNTs as the electrode material.

In vitro metabolic engineering of bioelectricity generation by the complete oxidation of glucose.

PubMed

Zhu, Zhiguang; Zhang, Y-H Percival

2017-01-01

The direct generation of electricity from the most abundant renewable sugar, glucose, is an appealing alternative to the production of liquid biofuels and biohydrogen. However, enzyme-catalyzed bioelectricity generation from glucose suffers from low yields due to the incomplete oxidation of the six-carbon compound glucose via one or few enzymes. Here, we demonstrate a synthetic ATP- and CoA-free 12-enzyme pathway to implement the complete oxidation of glucose in vitro. This pathway is comprised of glucose phosphorylation via polyphosphate glucokinase, NADH generation catalyzed by glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH), electron transfer from NADH to the anode, and glucose 6-phosphate regeneration via the non-oxidative pentose phosphate pathway and gluconeogenesis. The faraday efficiency from glucose to electrons via this pathway was as high as 98.8%, suggesting the generation of nearly 24 electrons per molecule of glucose. The generated current density was greatly increased from 2.8 to 6.9mAcm -2 by replacing a low-activity G6PDH with a high-activity G6PDH and introducing a new enzyme, 6-phosphogluconolactonase, between G6PDH and 6PGDH. These results suggest the great potential of high-yield bioelectricity generation through in vitro metabolic engineering. Copyright © 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.

Evaluation of Bioelectrical Activity of Pelvic Floor Muscles and Synergistic Muscles Depending on Orientation of Pelvis in Menopausal Women with Symptoms of Stress Urinary Incontinence: A Preliminary Observational Study

PubMed Central

Halski, Tomasz; Słupska, Lucyna; Dymarek, Robert; Bartnicki, Janusz; Halska, Urszula; Król, Agata; Paprocka-Borowicz, Małgorzata; Dembowski, Janusz; Zdrojowy, Romuald

2014-01-01

Objectives. Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles (PFM) and the synergistic muscles, depending on the orientation of the pelvis, in anterior (P1) and posterior (P2) pelvic tilt. Design. Preliminary, prospective observational study. Setting. Department and Clinic of Urology, University Hospital in Wroclaw, Poland. Participants. Thirty-two menopausal and postmenopausal women with stress urinary incontinence were recruited. Based on inclusion and exclusion criteria, sixteen women aged 55 to 70 years were enrolled in the study. Primary Outcome Measures. Evaluation of resting and functional bioelectrical activity of the pelvic floor muscles by electromyography (sEMG) and vaginal probe. Secondary Outcome Measures. Evaluation of activity of the synergistic muscles by sEMG and surface electrodes. Results. No significant differences between orientations P1 and P2 were found in functional and resting sEMG activity of the PFM. During resting and functional PFM activity, higher electrical activity in P2 than in P1 has been recorded in some of the synergistic muscles. Conclusions. This preliminary study does not provide initial evidence that pelvic tilt influences PFM activation. Although different activity of synergistic muscles occurs in various orientations of the pelvic tilt, it does not have to affect the sEMG activity of the PFM. PMID:24701567

Energy expenditure in caving

PubMed Central

Antoni, Giorgia; Marini, Elisabetta; Curreli, Nicoletta; Tuveri, Valerio; Comandini, Ornella; Cabras, Stefano; Gabba, Silvia; Madeddu, Clelia; Crisafulli, Antonio

2017-01-01

The aim of this study was to determine the energy expenditure of a group of cavers of both genders and different ages and experience during a 10 hour subterranean exploration, using portable metabolimeters. The impact of caving activity on body composition and hydration were also assessed through bioelectrical impedance, and nutritional habits of cavers surveyed. During cave activity, measured total energy expenditure (TEE) was in the range 225–287 kcal/h for women-men (MET = 4.1), respectively; subjects had an energy intake from food in the range 1000–1200 kcal, thus inadequate to restore lost calories. Bayesian statistical analysis estimated the effect of predictive variables on TEE, revealing that experienced subjects had a 5% lower TEE than the less skilled ones and that women required a comparatively larger energy expenditure than men to perform the same task. BIVA (bioelectrical impedance vector analysis) showed that subjects were within the range of normal hydration before and after cave activity, but bioelectrical changes indicated a reduction of extracellular water in men, which might result in hypo-osmolal dehydration in the case of prolonged underground exercise. All these facts should be considered when planning cave explorations, preparing training programs for subjects practising caving, and optimizing a diet for cavers. Further, information gathered through this study could be of value to reduce accidents in caves related to increase in fatigue. PMID:28158208

Can Total Body Resistance Measured Using Bioelectrical Impedance Analysis Be the Index of Dehydration in Older Japanese Patients?

PubMed

Shimizu, Miyuki; Kinoshita, Kensuke; Maeno, Takami; Kobayashi, Hiroyuki; Maeno, Tetsuhiro

2017-11-01

Dehydration in older patients has long been considered a significant health problem because it implies increased morbidity and mortality. However, dehydration is detected by a combination of physical signs and blood tests. For older people dwelling at home and in nursing homes, a simple and non-invasive method for detecting dehydration by caregivers is needed. The total body resistance is measured using bioelectrical impedance analysis and is known as an indicator of dehydration. There are no data from older Japanese patients on this issue. We performed this study to examine the relationship between dehydration and total body resistance in Japan. We performed blood tests and measured bioelectrical impedance in older outpatients aged ≥ 65 years from the Internal Medicine Department at Mito Kyodo General Hospital. Patients were classified as dehydrated and non-dehydrated using the dehydration index with a blood urea nitrogen/creatinine ratio > 20, and the mean total body resistance was compared between the two groups. Eighty-one patients were recruited in the study. In the dehydrated group, the mean total body resistance was 439 Ω at 50 kHz, which was significantly higher than that in the non-dehydrated group (408 Ω, P = 0.038). The total body resistance measurements can be used for simple assessment of dehydration among older Japanese patients.

Phase angle as bioelectrical marker to identify elderly patients at risk of sarcopenia.

PubMed

Basile, Claudia; Della-Morte, David; Cacciatore, Francesco; Gargiulo, Gaetano; Galizia, Gianluigi; Roselli, Mario; Curcio, Francesco; Bonaduce, Domenico; Abete, Pasquale

2014-10-01

Several markers have been associated with sarcopenia in the elderly, including bioelectrical indices. Phase angle (PhA) is an impedance parameter and it has been suggested as an indicator of cellular death. Thus, the relationship between PhA and muscle mass and strength was investigated in 207 consecutively elderly participants (mean age 76.2±6.7years) admitted for multidimensional geriatric evaluation. Muscle strength by grip strength using a hand-held dynamometer and muscle mass was measured by bioimpedentiometer. PhA was calculated directly with its arctangent (resistance/reactance×180°/π). Linear relationship among muscular mass and strength and with clinical and biochemical parameters, including PhA at uni- and multivariate analysis were performed. Linear regression analysis demonstrated that lower level of PhA is associated with reduction in grip strength (y=3.16+0.08x; r=0.49; p<0.001), and even more, with muscle mass (y=3.04+0.25x; r=0.60; p<0001). Multivariate analysis confirms these relationships (grip strength β=0.245, p=0.031; muscular mass β=0.623, p<0.01). Thus, PhA is inversely related to muscle mass and strength in elderly subjects and it may be considered a good bioelectrical marker to identify elderly patients at risk of sarcopenia. Copyright © 2014 Elsevier Inc. All rights reserved.

Alteration of bioelectrically-controlled processes in the embryo: a teratogenic mechanism for anticonvulsants.

PubMed

Hernández-Díaz, Sonia; Levin, Michael

2014-08-01

Maternal use of anticonvulsants during the first trimester of pregnancy has been associated with an elevated risk of major congenital malformations in the offspring. Whether the increased risk is caused by the specific pharmacological mechanisms of certain anticonvulsants, the underlying epilepsy, or common genetic or environmental risk factors shared by epilepsy and malformations has been controversial. We hypothesize that anticonvulsant therapies during pregnancy that attain more successful inhibition of neurotransmission might lead to both better seizure control in the mother and stronger alteration of bioelectrically-controlled processes in the embryo that result in structural malformations. We propose that development of pharmaceuticals that do not alter cell resting transmembrane voltage levels could result in safer drugs. Copyright © 2014 Elsevier Inc. All rights reserved.

Application of bioelectrical impedance analysis in prediction of light kid carcass and muscle chemical composition.

PubMed

Silva, S R; Afonso, J; Monteiro, A; Morais, R; Cabo, A; Batista, A C; Guedes, C M; Teixeira, A

2018-06-01

Carcass data were collected from 24 kids (average live weight of 12.5±5.5 kg; range 4.5 to 22.4 kg) of Jarmelista Portuguese native breed, to evaluate bioelectrical impedance analysis (BIA) as a technique for prediction of light kid carcass and muscle chemical composition. Resistance (Rs, Ω) and reactance (Xc, Ω), were measured in the cold carcasses with a single frequency bioelectrical impedance analyzer and, together with impedance (Z, Ω), two electrical volume measurements (VolA and VolB, cm2/Ω), carcass cold weight (CCW), carcass compactness and several carcass linear measurements were fitted as independent variables to predict carcass composition by stepwise regression analysis. The amount of variation explained by VolA and VolB only reached a significant level (P<0.01 and P<0.05, respectively) for muscle weight, moisture, protein and fat-free soft tissue content, even so with low accuracy, with VolA providing the best results (0.326⩽R 2⩽0.366). Quite differently, individual BIA parameters (Rs, Xc and Z) explained a very large amount of variation in dissectible carcass fat weight (0.814⩽R 2⩽0.862; P<0.01). These individual BIA parameters also explained a large amount of variation in subcutaneous and intermuscular fat weights (respectively 0.749⩽R 2⩽0.793 and 0.718⩽R 2⩽0.760; P<0.01), and in muscle chemical fat weight (0.663⩽R 2⩽0.684; P<0.01). Still significant but much lower was the variation in muscle, moisture, protein and fat-free soft tissue weights (0.344⩽R 2⩽0.393; P<0.01) explained by BIA parameters. Still, the best models for estimation of muscle, moisture, protein and fat-free soft tissue weights included Rs in addition to CCW, and accounted for 97.1% to 99.8% (P<0.01) of the variation observed, with CCW by itself accounting for 97.0% to 99.6% (P<0.01) of that variation. Resistance was the only independent variable selected for the best model predicting subcutaneous fat weight. It was also selected for the best models predicting carcass fat weight (combined with carcass length, CL; R 2=0.943; P<0.01) and intermuscular fat weight (combined with CCW; R 2=0.945; P<0.01). The best model predicting muscle chemical fat weight combined CCW and Z, explaining 85.6% (P<0.01) of the variation observed. These results indicate BIA as a useful tool for prediction of light kids' carcass composition.

Maternal fat free mass during pregnancy is associated with birth weight.

PubMed

Wang, Yanxia; Mao, Jie; Wang, Wenling; Qiou, Jie; Yang, Lan; Chen, Simin

2017-03-28

The relationship between maternal body compositions and birth weight was not definite. Fat Mass (FM) and Fat Free Mass (FFM) can accurately reflect the maternal body fat compositions and have been considered as better predictors of birth weight. Despite its potential role, no studies have been described the maternal compositions during pregnancy in East Asian women previously. We investigated the correlation between birth weight and Maternal body composition including fat mass (FM) and fat free mass (FFM). To determine whether birth weight is associated with maternal body fat FM and FFM during pregnancy and, if so, which trimester and parameter is more critical in determining birth weight. A longitudinal prospective observational study performed, 348, 481 and 321 non-diabetics Han Chinese women with a singleton live birth attending a routine visit in their first, second and third trimesters were recruited. Maternal body composition was measured using segmental multi-frequency bioelectrical impedance analysis. Data of the pre-pregnancy body mass index (BMI), maternal BMI, the gestational weight gain (GWG), and placental and birth weight were collected. A significant correlation exists between maternal FFM in the process of pregnancy, placental weight, GWG at delivery, and birth weight (P < 0.05). On stepwise multiple linear regression analysis, material's FFM was the most important factor associated with the birth weight. After adjustment, there was significantly associated with 2.47-fold increase in risk for birth weight more than 4 kg when FFM ≥ 40.76 kg (Upper quartile of participants). The increased maternal age became a protective factor (OR = 0.69) while the increased pre-pregnancy BMI (OR = 1.50) remained predictors to birth weight more than 4 kg. The change of maternal FFM during pregnancy is independently affected the birth weight.

Maternal nutritional status in early pregnancy is associated with body water and plasma volume changes in a pregnancy cohort in rural Bangladesh.

PubMed

Gernand, Alison D; Christian, Parul; Schulze, Kerry J; Shaikh, Saijuddin; Labrique, Alain B; Shamim, Abu Ahmed; West, Keith P

2012-06-01

Plasma volume expansion has been associated with fetal growth. Our objective was to examine the associations between maternal nutritional status in early pregnancy and extracellular water (ECW), total body water (TBW), and percentage plasma volume change across pregnancy. In a subsample of 377 pregnant women participating in a cluster-randomized trial of micronutrient supplementation, hemoglobin, hematocrit, and multi-frequency bioelectrical impedance were measured at ~10, 20, and 32 wk of gestation. In early pregnancy, women were short (mean ± SD, 148.9 ± 5.3 cm) and thin (19.5 ± 2.5 kg/m(2)). In mixed-effects multiple regression models, a 1-unit higher BMI at ~10 wk was associated with higher ECW and TBW (0.27 and 0.66 kg per kg/m(2), respectively; P < 0.01) at ~10, ~20, and ~32 wk. Height was also positively associated with ECW and TBW at each time point. Early pregnancy BMI was negatively associated with gains in ECW and TBW (-0.06 and -0.14 kg per kg/m(2), respectively; P < 0.01) from 10 to 20 wk, but not with 20- to 32-wk gains after accounting for weight gain. BMI was positively associated with percentage changes in plasma volume from 20 to 32 wk (0.57% per kg/m(2); P < 0.05). Height was not associated with changes in body water or plasma volume. Women with low BMI and height in early pregnancy have lower ECW and TBW in early, mid, and late pregnancy and lower late pregnancy plasma volume expansion, potentially increasing risk of fetal growth restriction.

Comparison of the Effect of Sensory-Level and Conventional Motor-Level Neuromuscular Electrical Stimulations on Quadriceps Strength After Total Knee Arthroplasty: A Prospective Randomized Single-Blind Trial.

PubMed

Yoshida, Yosuke; Ikuno, Koki; Shomoto, Koji

2017-12-01

To compare sensory-level neuromuscular electrical stimulation (NMES) and conventional motor-level NMES in patients after total knee arthroplasty. Prospective randomized single-blind trial. Hospital total arthroplasty center: inpatients. Patients with osteoarthritis (N=66; mean age, 73.5±6.3y; 85% women) were randomized to receive either sensory-level NMES applied to the quadriceps (the sensory-level NMES group), motor-level NMES (the motor-level NMES group), or no stimulation (the control group) in addition to a standard rehabilitation program. Each type of NMES was applied in 45-minute sessions, 5d/wk, for 2 weeks. Data for the quadriceps maximum voluntary isometric contraction, the leg skeletal muscle mass determined using multiple-frequency bioelectrical impedance analysis, the timed Up and Go test, the 2-minute walk test, the visual analog scale, and the range of motion of the knee were measured preoperatively and at 2 and 4 weeks after total knee arthroplasty. The motor-level NMES (P=.001) and sensory-level NMES (P=.028) groups achieved better maximum voluntary isometric contraction results than did the control group. The motor-level NMES (P=.003) and sensory-level NMES (P=.046) groups achieved better 2-minute walk test results than did the control group. Some patients in the motor-level NMES group dropped out of the experiment because of discomfort. Motor-level NMES significantly improved muscle strength and functional performance more than did the standard program alone. Motor-level NMES was uncomfortable for some patients. Sensory-level NMES was comfortable and improved muscle strength and functional performance more than did the standard program alone. Copyright © 2017 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Visualization of bioelectric phenomena.

PubMed

Palmer, T C; Simpson, E V; Kavanagh, K M; Smith, W M

1992-01-01

Biomedical investigators are currently able to acquire and analyze physiological and anatomical data from three-dimensional structures in the body. Often, multiple kinds of data can be recorded simultaneously. The usefulness of this information, either for exploratory viewing or for presentation to others, is limited by the lack of techniques to display it in intuitive, accessible formats. Unfortunately, the complexity of scientific visualization techniques and the inflexibility of commercial packages deter investigators from using sophisticated visualization methods that could provide them added insight into the mechanisms of the phenomena under study. Also, the sheer volume of such data is a problem. High-performance computing resources are often required for storage and processing, in addition to visualization. This chapter describes a novel, language-based interface that allows scientists with basic programming skills to classify and render multivariate volumetric data with a modest investment in software training. The interface facilitates data exploration by enabling experimentation with various algorithms to compute opacity and color from volumetric data. The value of the system is demonstrated using data from cardiac mapping studies, in which multiple electrodes are placed in an on the heart to measure the cardiac electrical activity intrinsic to the heart and its response to external stimulation.

Resting potential, oncogene-induced tumorigenesis, and metastasis: the bioelectric basis of cancer in vivo

NASA Astrophysics Data System (ADS)

Lobikin, Maria; Chernet, Brook; Lobo, Daniel; Levin, Michael

2012-12-01

Cancer may result from localized failure of instructive cues that normally orchestrate cell behaviors toward the patterning needs of the organism. Steady-state gradients of transmembrane voltage (Vmem) in non-neural cells are instructive, epigenetic signals that regulate pattern formation during embryogenesis and morphostatic repair. Here, we review molecular data on the role of bioelectric cues in cancer and present new findings in the Xenopus laevis model on how the microenvironment's biophysical properties contribute to cancer in vivo. First, we investigated the melanoma-like phenotype arising from serotonergic signaling by ‘instructor’ cells—a cell population that is able to induce a metastatic phenotype in normal melanocytes. We show that when these instructor cells are depolarized, blood vessel patterning is disrupted in addition to the metastatic phenotype induced in melanocytes. Surprisingly, very few instructor cells need to be depolarized for the hyperpigmentation phenotype to occur; we present a model of antagonistic signaling by serotonin receptors that explains the unusual all-or-none nature of this effect. In addition to the body-wide depolarization-induced metastatic phenotype, we investigated the bioelectrical properties of tumor-like structures induced by canonical oncogenes and cancer-causing compounds. Exposure to carcinogen 4-nitroquinoline 1-oxide (4NQO) induces localized tumors, but has a broad (and variable) effect on the bioelectric properties of the whole body. Tumors induced by oncogenes show aberrantly high sodium content, representing a non-invasive diagnostic modality. Importantly, depolarized transmembrane potential is not only a marker of cancer but is functionally instructive: susceptibility to oncogene-induced tumorigenesis is significantly reduced by forced prior expression of hyperpolarizing ion channels. Importantly, the same effect can be achieved by pharmacological manipulation of endogenous chloride channels, suggesting a strategy for cancer suppression that does not require gene therapy. Together, these data extend our understanding of the recently demonstrated role of transmembrane potential in tumor formation and metastatic cell behavior. Vmem is an important non-genetic biophysical aspect of the microenvironment that regulates the balance between normally patterned growth and carcinogenesis.

Modified Blumlein pulse-forming networks for bioelectrical applications.

PubMed

Romeo, Stefania; Sarti, Maurizio; Scarfì, Maria Rosaria; Zeni, Luigi

2010-07-01

Intense nanosecond pulsed electric fields (nsPEFs) have been shown to induce, on intracellular structures, interesting effects dependent on electrical exposure conditions (pulse length and amplitude, repetition frequency and number of pulses), which are known in the literature as "bioelectrical effects" (Schoenbach et al., IEEE Trans Plasma Sci 30:293-300, 2002). In particular, pulses with a shorter width than the plasma membrane charging time constant (about 100 ns for mammalian cells) can penetrate the cell and trigger effects such as permeabilization of intracellular membranes, release of Ca(2+) and apoptosis induction. Moreover, the observed effects have led to exploration of medical applications, like the treatment of melanoma tumors (Nuccitelli et al., Biochem Biophys Res Commun 343:351-360, 2006). Pulsed electric fields allowing such effects usually range from several tens to a few hundred nanoseconds in duration and from a few to several tens of megavolts per meter in amplitude (Schoenbach et al., IEEE Trans Diel Elec Insul 14:1088-1109, 2007); however, the biological effects of subnanosecond pulses have been also investigated (Schoenbach et al., IEEE Trans Plasma Sci 36:414-422, 2008). The use of such a large variety of pulse parameters suggests that highly flexible pulse-generating systems, able to deliver wide ranges of pulse durations and amplitudes, are strongly required in order to explore effects and applications related to different exposure conditions. The Blumlein pulse-forming network is an often-employed circuit topology for the generation of high-voltage electric pulses with fixed pulse duration. An innovative modification to the Blumlein circuit has been recently devised which allows generation of pulses with variable amplitude, duration and polarity. Two different modified Blumlein pulse-generating systems are presented in this article, the first based on a coaxial cable configuration, matching microscopic slides as a pulse-delivery system, and the other based on microstrip transmission lines and designed to match cuvettes for the exposure of cell suspensions.

Bioelectrical impedance among rural Bangladeshi Women during pregnancy and in the postpartum period.

PubMed

Shaikh, Saijuddin; Schulze, Kerry J; Ali, Hasmot; Labrique, Alain B; Shamim, Abu Ahmed; Rashid, Mahbubur; Mehra, Sucheta; Christian, Parul; West, Keith P

2011-06-01

Properties of bioelectrical impedance analysis (BIA) reflect body-composition and may serve as stand-alone indicators of maternal health. Despite these potential roles, BIA properties during pregnancy and lactation in rural South Asian women have not been described previously, although pregnancy and infant health outcomes are often compromised. This paper reports the BIA properties among a large sample of pregnant and postpartum women of rural Bangladesh, aged 12-46 years, participating in a substudy of a community-based, placebo-controlled trial of vitamin A or beta-carotene supplementation. Anthropometry and single frequency (50 kHz) BIA were assessed in 1,435 women during the first trimester (< or =12 weeks gestation), in 1237 women during the third trimester (32-36 weeks gestation), and in 1,141 women at 12-18 weeks postpartum. Resistance and reactance were recorded, and impedance and phase angle were calculated. Data were examined cross-sectionally to maximize sample-size at each timepoint, and the factors relating to BIA properties were explored. Women were typically young, primiparous and lacking formal education (22.2 +/- 6.3 years old, 42.2% primiparous, and 39.7% unschooled among the first trimester participants). Weight (kg), resistance (omega), and reactance (omega) were 42.1 +/- 5.7, 688 +/- 77, and 73 +/- 12 in the first trimester; 47.7 +/- 5.9, 646 +/- 77, and 64 +/- 12 in the third trimester; and 42.7 +/- 5.6, 699 +/- 79, and 72 +/- 12 postpartum respectively. Resistance declined with age and increased with body mass index. Resistance was higher than that observed in other, non-Asian pregnant populations, likely reflecting considerably smaller body-volume among Bangladeshi women. Resistance and reactance decreased in advanced stage of pregnancy as the rate of gain in weight increased, returning to the first trimester values by the three months postpartum. Normative distributions of BIA properties are presented for rural Bangladeshi women across a reproductive cycle that may be related to pregnancy outcomes and ultimately be used for assessing body-composition in this population.

Sleep Apnea and Circadian Extracellular Fluid Change as Independent Factors for Nocturnal Polyuria.

PubMed

Niimi, Aya; Suzuki, Motofumi; Yamaguchi, Yasuhiro; Ishii, Masaki; Fujimura, Tetsuya; Nakagawa, Tohru; Fukuhara, Hiroshi; Kume, Haruki; Igawa, Yasuhiko; Akishita, Masahiro; Homma, Yukio

2016-10-01

We investigated the relationships among nocturnal polyuria, sleep apnea and body fluid volume to elucidate the pathophysiology of nocturia in sleep apnea syndrome. We enrolled 104 consecutive patients who underwent polysomnography for suspected sleep apnea syndrome. Self-assessed symptom questionnaires were administered to evaluate sleep disorder and lower urinary tract symptoms, including nocturia. Voiding frequency and voided volume were recorded using a 24-hour frequency-volume chart. Body fluid composition was estimated in the morning and at night using bioelectric impedance analysis. Frequency-volume chart data were analyzed in 22 patients after continuous positive airway pressure therapy. Patients with nocturnal polyuria showed a higher apnea-hypopnea index (33.9 vs 24.2, p = 0.03) and a larger circadian change in extracellular fluid adjusted to lean body mass (0.22 vs -0.19, p = 0.019) than those without nocturnal polyuria. These relations were more evident in patients 65 years old or older than in those 64 years or younger. A multivariate linear regression model showed an independent relationship of nocturnal polyuria with the apnea-hypopnea index and the circadian change in extracellular fluid adjusted to lean body mass (p = 0.0012 and 0.022, respectively). Continuous positive airway pressure therapy significantly improved nocturnal polyuria and nocturia only in patients with nocturnal polyuria. This study identified sleep apnea and the circadian change in extracellular fluid as independent factors for nocturnal polyuria. Copyright © 2016 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Neuroethology and life history adaptations of the elasmobranch electric sense.

PubMed

Sisneros, Joseph A; Tricas, Timothy C

2002-01-01

The electric sense of elasmobranch fishes (sharks and rays) is an important sensory modality known to mediate the detection of bioelectric stimuli. Although the best known function for the use of the elasmobranch electric sense is prey detection, relatively few studies have investigated other possible biological functions. Here, we review recent studies that demonstrate the elasmobranch electrosensory system functions in a wide number of behavioral contexts including social, reproductive and anti-predator behaviors. Recent work on non-electrogenic stingrays demonstrates that the electric sense is used during reproduction and courtship for conspecific detection and localization. Electrogenic skates may use their electrosensory encoding capabilities and electric organ discharges for communication during social and reproductive interactions. The electric sense may also be used to detect and avoid predators during early life history stages in many elasmobranch species. Embryonic clearnose skates demonstrate a ventilatory freeze response when a weak low-frequency electric field is imposed upon the egg capsule. Peak frequency sensitivity of the peripheral electrosensory system in embryonic skates matches the low frequencies of phasic electric stimuli produced by natural fish egg-predators. Neurophysiology experiments reveal that electrosensory tuning changes across the life history of a species and also seasonally due to steroid hormone changes during the reproductive season. We argue that the ontogenetic and seasonal variation in electrosensory tuning represent an adaptive electrosensory plasticity that may be common to many elasmobranchs to enhance an individual's fitness throughout its life history.

Electrical impedance characterization of normal and cancerous human hepatic tissue.

PubMed

Laufer, Shlomi; Ivorra, Antoni; Reuter, Victor E; Rubinsky, Boris; Solomon, Stephen B

2010-07-01

The four-electrode method was used to measure the ex vivo complex electrical impedance of tissues from 14 hepatic tumors and the surrounding normal liver from six patients. Measurements were done in the frequency range 1-400 kHz. It was found that the conductivity of the tumor tissue was much higher than that of the normal liver tissue in this frequency range (from 0.14 +/- 0.06 S m(-1) versus 0.03 +/- 0.01 S m(-1) at 1 kHz to 0.25 +/- 0.06 S m(-1) versus 0.15 +/- 0.03 S m(-1) at 400 kHz). The Cole-Cole models were estimated from the experimental data and the four parameters (rho(0), rho(infinity), alpha, f(c)) were obtained using a least-squares fit algorithm. The Cole-Cole parameters for the cancerous and normal liver are 9 +/- 4 Omega m(-1), 2.2 +/- 0.7 Omega m(-1), 0.5 +/- 0.2, 140 +/- 103 kHz and 50 +/- 28 Omega m(-1), 3.2 +/- 0.6 Omega m(-1), 0.64 +/- 0.04, 10 +/- 7 kHz, respectively. These data can contribute to developing bioelectric applications for tissue diagnostics and in tissue treatment planning with electrical fields such as radiofrequency tissue ablation, electrochemotherapy and gene therapy with reversible electroporation, nanoscale pulsing and irreversible electroporation.

Electromagnetic homeostasis and the role of low-amplitude electromagnetic fields on life organization.

PubMed

De Ninno, Antonella; Pregnolato, Massimo

2017-01-01

The appearance of endogenous electromagnetic fields in biological systems is a widely debated issue in modern science. The electrophysiological fields have very tiny intensities and it can be inferred that they are rapidly decreasing with the distance from the generating structure, vanishing at very short distances. This makes very hard their detection using standard experimental methods. However, the existence of fast-moving charged particles in the macromolecules inside both intracellular and extracellular fluids may envisage the generation of localized electric currents as well as the presence of closed loops, which implies the existence of magnetic fields. Moreover, the whole set of oscillatory frequencies of various substances, enzymes, cell membranes, nucleic acids, bioelectrical phenomena generated by the electrical rhythm of coherent groups of cells, cell-to-cell communication among population of host bacteria, forms the increasingly complex hierarchies of electromagnetic signals of different frequencies which cover the living being and represent a fundamental information network controlling the cell metabolism. From this approach emerges the concept of electromagnetic homeostasis: that is, the capability of the human body to maintain the balance of highly complex electromagnetic interactions within, in spite of the external electromagnetic noisy environment. This concept may have an important impact on the actual definitions of heal and disease.

Amplifiers for bioelectric events: a design with a minimal number of parts.

PubMed

MettingVanRijn, A C; Peper, A; Grimbergen, C A

1994-05-01

A design for an amplifier for bioelectric events is presented that has fewer parts than conventional designs. The design allows the construction of amplifiers of a high quality in terms of noise and common mode rejection, with reduced dimensions and with a lower power consumption. Gain, bandwidth and number of channels are easily adapted to a wide range of biomedical applications. An application example is given in the form of a multichannel EEG amplifier (gain is 20,000), in which each channel consists of three operational amplifiers (one single and one dual), six resistors and two capacitors. The equivalent input noise voltage and current are 0.15 microVrms and 1 pArms, respectively, in a bandwidth of 0.2-40 Hz, and a common mode rejection ratio of 136 dB is achieved without trimming.

Qualitative human body composition analysis assessed with bioelectrical impedance.

PubMed

Talluri, T

1998-12-01

Body composition is generally aiming at quantitative estimates of fat mass, inadequate to assess nutritional states that on the other hand are well defined by the intra/extra cellular masses proportion (ECM/BCM). Direct measures performed with phase sensitive bioelectrical impedance analyzers can be used to define the current distribution in normal and abnormal populations. Phase angle and reactance nomogram is directly reflecting the ECM/BCM pathways proportions and body impedance analysis (BIA) is also validated to estimate the individual content of body cell mass (BCM). A new body cell mass index (BCMI) obtained dividing the weight of BCM in kilograms by the body surface in square meters is confronted to the scatterplot distribution of phase angle and reactance values obtained from controls and patients, and proposed as a qualitative approach to identify abnormal ECM/BCM ratios and nutritional states.

Optimization of enhanced bioelectrical reactor with electricity from microbial fuel cells for groundwater nitrate removal.

PubMed

Liu, Ye; Zhang, Baogang; Tian, Caixing; Feng, Chuanping; Wang, Zhijun; Cheng, Ming; Hu, Weiwu

2016-01-01

Factors influencing the performance of a continual-flow bioelectrical reactor (BER) intensified by microbial fuel cells for groundwater nitrate removal, including nitrate load, carbon source and hydraulic retention time (HRT), were investigated and optimized by response surface methodology (RSM). With the target of maximum nitrate removal and minimum intermediates accumulation, nitrate load (for nitrogen) of 60.70 mg/L, chemical oxygen demand (COD) of 849.55 mg/L and HRT of 3.92 h for the BER were performed. COD was the dominant factor influencing performance of the system. Experimental results indicated the undistorted simulation and reliable optimized values. These demonstrate that RSM is an effective method to evaluate and optimize the nitrate-reducing performance of the present system and can guide mathematical models development to further promote its practical applications.

Body composition of collegiate football players: bioelectrical impedance and skinfolds compared to hydrostatic weighing.

PubMed

Oppliger, R A; Nielsen, D H; Shetler, A C; Crowley, E T; Albright, J P

1992-01-01

The need for simple, valid techniques of body composition assessment among athletes is a growing concern of the physical therapist. This paper reports on several common methods applied to university football players. Body composition analysis was conducted on 28 Division IA football players using three different bioelectrical impedance analysis (BIA) systems, skinfolds (SF), and hydrostatic weighing (HYDRO). Correlations for all methods with HYDRO were high (>.88), but BIA significantly overpredicted body fatness. In contrast, three SF equations showed small differences with HYDRO and reasonable measurement error. Clinicians should exercise caution when using BIA based on the existing manufacturers' equations with athletic populations. Adjustments to BIA regression equations by including modifying or anthropometric variables could enhance the predictive accuracy of these methods with lean, athletic males. J Orthop Sports Phys Ther 1992;15(4):187-192.

A wearable physiological sensor suite for unobtrusive monitoring of physiological and cognitive state.

PubMed

Matthews, Robert; McDonald, Neil J; Hervieux, Paul; Turner, Peter J; Steindorf, Martin A

2007-01-01

This paper describes an integrated Physiological Sensor Suite (PSS) based upon QUASAR's innovative non-invasive bioelectric sensor technologies that will provide, for the first time, a fully integrated, noninvasive methodology for physiological sensing. The PSS currently under development at QUASAR is a state-of-the-art multimodal array of sensors that, along with an ultra-low power personal area wireless network, form a comprehensive body-worn system for real-time monitoring of subject physiology and cognitive status. Applications of the PSS extend from monitoring of military personnel to long-term monitoring of patients diagnosed with cardiac or neurological conditions. Results for side-by-side comparisons between QUASAR's biosensor technology and conventional wet electrodes are presented. The signal fidelity for bioelectric measurements using QUASAR's biosensors is comparable to that for wet electrodes.

[Spatio-Temporal Bioelectrical Brain Activity Organization during Reading Syntagmatic and Paradigmatic Collocations by Students with Different Foreign Language Proficiency].

PubMed

Sokolova, L V; Cherkasova, A S

2015-01-01

Texts or words/pseudowords are often used as stimuli for human verbal activity research. Our study pays attention to decoding processes of grammatical constructions consisted of two-three words--collocations. Russian and English collocation sets without any narrative were presented to Russian-speaking students with different English language skill. Stimulus material had two types of collocations: paradigmatic and syntagmatic. 30 students (average age--20.4 ± 0.22) took part in the study, they were divided into two equal groups depending on their English language skill (linguists/nonlinguists). During reading brain bioelectrical activity of cortex has been registered from 12 electrodes in alfa-, beta-, theta-bands. Coherent function reflecting cooperation of different cortical areas during reading collocations has been analyzed. Increase of interhemispheric and diagonal connections while reading collocations in different languages in the group of students with low knowledge of foreign language testifies of importance of functional cooperation between the hemispheres. It has been found out that brain bioelectrical activity of students with good foreign language knowledge during reading of all collocation types in Russian and English is characterized by economization of nervous substrate resources compared to nonlinguists. Selective activation of certain cortical areas has also been observed (depending on the grammatical construction type) in nonlinguists group that is probably related to special decoding system which processes presented stimuli. Reading Russian paradigmatic constructions by nonlinguists entailed increase between left cortical areas, reading of English syntagmatic collocations--between right ones.

Generating clock signals for a cycle accurate, cycle reproducible FPGA based hardware accelerator

DOEpatents

Asaad, Sameth W.; Kapur, Mohit

2016-01-05

A method, system and computer program product are disclosed for generating clock signals for a cycle accurate FPGA based hardware accelerator used to simulate operations of a device-under-test (DUT). In one embodiment, the DUT includes multiple device clocks generating multiple device clock signals at multiple frequencies and at a defined frequency ratio; and the FPG hardware accelerator includes multiple accelerator clocks generating multiple accelerator clock signals to operate the FPGA hardware accelerator to simulate the operations of the DUT. In one embodiment, operations of the DUT are mapped to the FPGA hardware accelerator, and the accelerator clock signals are generated at multiple frequencies and at the defined frequency ratio of the frequencies of the multiple device clocks, to maintain cycle accuracy between the DUT and the FPGA hardware accelerator. In an embodiment, the FPGA hardware accelerator may be used to control the frequencies of the multiple device clocks.

Height Growth and Percentage of Body Fat in Relation to Early Menarche in Girls from Merida, Yucatan, Mexico.

PubMed

Datta Banik, Sudip; Mendez, Nina; Dickinson, Federico

2015-01-01

Early menarche (EM) (i.e., age at menarche [AAM] <12 years of age) is related to short height and higher body fatness. In a mixed-longitudinal study done in Merida, Yucatan, height, body mass index (BMI), and percentage of body fat (BF%) were recorded at a one-year interval among 258 postmenarcheal (EM = 94) girls. Anthropometric measurements were recorded of the age cohorts in 2008-09 when participants were 13-17 years of age (baseline), and in the one-year follow-up study (± 6 days) the girls were 14-18 years of age. The BF% was estimated through bioelectrical impedance analysis. Mean AAM was 10.59 years in EM girls and 12.54 years in not early menarche (NEM) girls. Height growth (cm/year) was greater in NEM girls. Mean values of BMI, BF%, and frequencies of stunting (low height-for-age) and excess weight (overweight + obesity) were higher in EM girls than in their NEM age peers.

Bioelectrical impedance analysis of bovine milk fat

NASA Astrophysics Data System (ADS)

Veiga, E. A.; Bertemes-Filho, P.

2012-12-01

Three samples of 250ml at home temperature of 20°C were obtained from whole, low fat and fat free bovine UHT milk. They were analysed by measuring both impedance spectra and dc conductivity in order to establish the relationship between samples related to fat content. An impedance measuring system was developed, which is based on digital oscilloscope, a current source and a FPGA. Data was measured by the oscilloscope in the frequency 1 kHz to 100 kHz. It was showed that there is approximately 7.9% difference in the conductivity between whole and low fat milk whereas 15.9% between low fat and free fat one. The change of fatness in the milk can be significantly sensed by both impedance spectra measurements and dc conductivity. This result might be useful for detecting fat content of milk in a very simple way and also may help the development of sensors for measuring milk quality, as for example the detection of mastitis.

Study and classification of the abdominal adiposity throughout the application of the two-dimensional predictive equation Garaulet et al., in the clinical practice.

PubMed

Piernas Sánchez, C M; Morales Falo, E M; Zamora Navarro, S; Garaulet Aza, M

2010-01-01

The excess of visceral abdominal adipose tissue is one of the major concerns in obesity and its clinical treatment. To apply the two-dimensional predictive equation proposed by Garaulet et al. to determine the abdominal fat distribution and to compare the results with the body composition obtained by multi-frequency bioelectrical impedance analysis (M-BIA). We studied 230 women, who underwent anthropometry and M-BIA. The predictive equation was applied. Multivariate lineal and partial correlation analyses were performed with control for BMI and % body fat, using SPSS 15.0 with statistical significance P < 0.05. Overall, women were considered as having subcutaneous distribution of abdominal fat. Truncal fat, regional fat and muscular mass were negatively associated with VA/SA(predicted), while the visceral index obtained by M-BIA was positively correlated with VA/SA(predicted). The predictive equation may be useful in the clinical practice to obtain an accurate, costless and safe classification of abdominal obesity.

Application of phase angle for evaluation of the nutrition status of patients with anorexia nervosa.

PubMed

Małecka-Massalska, Teresa; Popiołek, Joanna; Teter, Mariusz; Homa-Mlak, Iwona; Dec, Mariola; Makarewicz, Agata; Karakuła-Juchnowicz, Hanna

2017-12-30

The evaluation of the nutrition status of patients has been the subject of interest of many scientific disciplines. Any deviation from normal values is a serious clinical problem. There are multiple nutrition status evaluation methods used including diet history, scales and questionnaires, physical examination, anthropometric measurements, biochemical measurements, function tests, as well as bioelectric impedance analysis or adipometry. Phase angle, obtained by means of bioelectric impedance analysis, is another parameter that is being more and more frequently applied in nutrition status monitoring. It is proportional to body cell mass. Its direct correlation with the cellular nutrition status has been documented. High phase angle values signify well-being, while low phase angle values indicate poor condition of cells. The purpose of this paper was to review the current state of knowledge about the application of phase angle in evaluation and monitoring of the nutrition status of patients with anorexia nervosa on the basis of available literature. It was proven that the phase angle values in patients with anorexia nervosa are much lower compared to healthy people. Detailed observations showed phase angle value increase in the course of treatment. The relevance of the commonly used body mass index (BMI) has been questioned due to significant degree of generalization in the nutrition status evaluation. Thus, there is a need for new, objective parameters for nutrition status evaluation, which will assist in the treatment and monitoring of patients in a more meaningful and reliable way. The existing independent studies equivocally confirm the usefulness of phase angle in the evaluation of nutrition status of patients with anorexia nervosa and its broader application in clinical practice is only a matter of time. However, these are merely attempts and they have not yet found wider application in clinical practice in the treatment of anorexia nervosa.

Multiple Frequency Parametric Sonar

DTIC Science & Technology

2015-09-28

300003 1 MULTIPLE FREQUENCY PARAMETRIC SONAR STATEMENT OF GOVERNMENT INTEREST [0001] The invention described herein may be manufactured and...a method for increasing the bandwidth of a parametric sonar system by using multiple primary frequencies rather than only two primary frequencies...2) Description of Prior Art [0004] Parametric sonar generates narrow beams at low frequencies by projecting sound at two distinct primary

Bioelectrical Impedance Vector Analysis and Muscular Fitness in Healthy Men

PubMed Central

Rodríguez-Rodríguez, Fernando; Cristi-Montero, Carlos; González-Ruíz, Katherine; Correa-Bautista, Jorge Enrique; Ramírez-Vélez, Robinson

2016-01-01

Muscle strength can define the general muscular fitness (MF) measurable through hand-grip strength (HG), which is a factor that relates to the health of people of different ages. In this study we evaluated the muscle strength together with a bioimpedance electric analysis in 223 healthy Colombian adult subjects. The bioelectrical impedance vector analysis (BIVA) was conducted to determine the resistance (R), reactance (Xc) and phase angle (PhA). We classified the subjects into three groups (for tertiles), obtaining lower values of R and Xc in subjects with lower HG, plus a high correlation between PhA and HG. An increase in the level of PhA is associated with a high level of MF in a sample of healthy Latin American adult men. The BIVA’s parameters and PhA are a potentially effective preventive measure to be integrated into routine screening in the clinical setting. PMID:27384579

Anolyte recycling enhanced bioelectricity generation of the buffer-free single-chamber air-cathode microbial fuel cell.

PubMed

Ren, Yueping; Chen, Jinli; Shi, Yugang; Li, Xiufen; Yang, Na; Wang, Xinhua

2017-11-01

Anolyte acidification is an inevitable restriction for the bioelectricity generation of buffer-free microbial fuel cells (MFCs). In this work, acidification of the buffer-free KCl anolyte has been thoroughly eliminated through anolyte recycling. The accumulated HCO 3 - concentration in the recycled KCl anolyte was above 50mM, which played as natural buffer and elevated the anolyte pH to above 8. The maximum power density (P max ) increased from 322.9mWm -2 to 527.2mWm -2 , which is comparable with the phosphate buffered MFC. Besides Geobacter genus, the gradually increased anolyte pH and conductivity induced the growing of electrochemically active Geoalkalibacter genus, in the anode biofilm. Anolyte recycling is a feasible strategy to strengthen the self-buffering capacity of buffer-free MFCs, thoroughly eliminate the anolyte acidification and prominently enhance the electric power. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bioelectrical impedance analysis and anthropometry in Ecuadorian children of African ancestry.

PubMed

Vienna, A; Capucci, E; De Stefano, G F; Hauser, G

1998-12-01

In the city of Esmeraldas, north-western coast of Ecuador, height, weight, and body composition of 600 male and female schoolchildren of African ancestry in the age groups four, five and six years were investigated. All the children were apparently healthy without any obvious or reported pathologies and in accordance with data from personal information were assigned to one of two socio-economic classes. The greater values for weight and height shown by children in the higher socio-economic group than in the less well off are compatible with those for more fat and water as obtained by the BIA investigation. Additional information on nutritional, muscular and general health status was obtained from positioning and degree of dispersion of the 'Biagram' ellipses. It seems that both the anthropometric and the bioelectrical impedance methods provide useful information on the differences due to belonging to one or other of the socio-economic groups.

Simultaneous microbial and electrochemical reductions of vanadium (V) with bioelectricity generation in microbial fuel cells.

PubMed

Zhang, Baogang; Tian, Caixing; Liu, Ying; Hao, Liting; Liu, Ye; Feng, Chuanping; Liu, Yuqian; Wang, Zhongli

2015-03-01

Simultaneous microbial and electrochemical reductions of vanadium (V) with bioelectricity generation were realized in microbial fuel cells (MFCs). With initial V(V) concentrations of 75 mg/l and 150 mg/l in anolyte and catholyte, respectively, stable power output of 419±11 mW/m(2) was achieved. After 12h operation, V(V) concentration in the catholyte decreased to the value similar to that of the initial one in the anolyte, meanwhile it was nearly reduced completely in the anolyte. V(IV) was the main reduction product, which subsequently precipitated, acquiring total vanadium removal efficiencies of 76.8±2.9%. Microbial community analysis revealed the emergence of the new species of Deltaproteobacteria and Bacteroidetes as well as the enhanced Spirochaetes mainly functioned in the anode. This study opens new pathways to successful remediation of vanadium contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Microbial fuel cells and microbial electrolysis cells for the production of bioelectricity and biomaterials.

PubMed

Zhou, Minghua; Yang, Jie; Wang, Hongyu; Jin, Tao; Xu, Dake; Gu, Tingyue

2013-01-01

Today's global energy crisis requires a multifaceted solution. Bioenergy is an important part of the solution. The microbial fuel cell (MFC) technology stands out as an attractive potential technology in bioenergy. MFCs can convert energy stored in organic matter directly into bioelectricity. MFCs can also be operated in the electrolysis mode as microbial electrolysis cells to produce bioproducts such as hydrogen and ethanol. Various wastewaters containing low-grade organic carbons that are otherwise unutilized can be used as feed streams for MFCs. Despite major advances in the past decade, further improvements in MFC power output and cost reduction are needed for MFCs to be practical. This paper analysed MFC operating principles using bioenergetics and bioelectrochemistry. Several major issues were explored to improve the MFC performance. An emphasis was placed on the use of catalytic materials for MFC electrodes. Recent advances in the production of various biomaterials using MFCs were also investigated.

Prediction of beef carcass salable yield and trimmable fat using bioelectrical impedance analysis.

PubMed

Zollinger, B L; Farrow, R L; Lawrence, T E; Latman, N S

2010-03-01

Bioelectrical impedance technology (BIA) is capable of providing an objective method of beef carcass yield estimation with the rapidity of yield grading. Electrical resistance (Rs), reactance (Xc), impedance (I), hot carcass weight (HCW), fat thickness between the 12th and 13th ribs (FT), estimated percentage kidney, pelvic, and heart fat (KPH%), longissimus muscle area (LMA), length between electrodes (LGE) as well as three derived carcass values that included electrical volume (EVOL), reactive density (XcD), and resistive density (RsD) were determined for the carcasses of 41 commercially fed cattle. Carcasses were subsequently fabricated into salable beef products reflective of industry standards. Equations were developed to predict percentage salable carcass yield (SY%) and percentage trimmable fat (FT%). Resulting equations accounted for 81% and 84% of variation in SY% and FT%, respectively. These results indicate that BIA technology is an accurate predictor of beef carcass composition. Copyright 2009 Elsevier Ltd. All rights reserved.

Validation of bioelectrical-impedance analysis as a measurement of change in body composition in obesity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kushner, R.F.; Kunigk, A.; Alspaugh, M.

1990-08-01

The bioelectrical-impedance-analysis (BIA) method accurately measures body composition in weight-stable subjects. This study validates the use of BIA to measure change in body composition. Twelve obese females underwent weight loss at a mean rate of 1.16 kg/wk. Body composition was measured by deuterium oxide dilution (D2O), BIA, and skinfold anthropometry (SFA) at baseline and at 5% decrements in weight. Highly significant correlations were obtained between D2O and BIA (r = 0.971) and between D2O and SFA (r = 0.932). Overall, BIA predicted change in fat-free mass with greater accuracy (to 0.4 kg) and precision (+/- 1.28 kg) than did anthropometrymore » (to 0.8 kg and +/- 2.58 kg, respectively). We conclude that BIA is a useful clinical method for measuring change in body composition.« less

Bioelectrical impedance methods in clinical research: a follow-up to the NIH Technology Assessment Conference.

PubMed

Ellis, K J; Bell, S J; Chertow, G M; Chumlea, W C; Knox, T A; Kotler, D P; Lukaski, H C; Schoeller, D A

1999-01-01

In 1994, the National Institutes of Health (NIH) convened a Technology Assessment Conference "to provide physicians with a responsible assessment of bioelectrical impedance analysis (BIA) technology for body composition measurement." In 1997, Serono Symposia USA, Inc., organized an invited panel of scientists and clinicians, with extensive research and clinical experience with BIA, to provide an update. Panel members presented reviews based on their own work and published studies for the intervening years. Updates were provided on the single and multifrequency BIA methods and models; continued clinical research experiences; efforts toward establishing population reference norms; and the feasibility of establishing guidelines for potential diagnostic use of BIA in a clinical setting. This report provides a summary of the panel's findings including a consensus on several technical and clinical issues related to the research use of BIA, and those areas that are still in need of additional study.

A Parametric Computational Analysis into Galvanic Coupling Intrabody Communication.

PubMed

Callejon, M Amparo; Del Campo, P; Reina-Tosina, Javier; Roa, Laura M

2017-08-02

Intrabody Communication (IBC) uses the human body tissues as transmission media for electrical signals to interconnect personal health devices in wireless body area networks. The main goal of this work is to conduct a computational analysis covering some bioelectric issues that still have not been fully explained, such as the modeling of the skin-electrode impedance, the differences associated to the use of constant voltage or current excitation modes, or the influence on attenuation of the subject's anthropometrical and bioelectric properties. With this aim, a computational finite element model has been developed, allowing the IBC channel attenuation as well as the electric field and current density through arm tissues to be computed as a function of these parameters. As a conclusion, this parametric analysis has in turn permitted us to disclose some knowledge about the causes and effects of the above-mentioned issues, thus explaining and complementing previous results reported in the literature.

Lipid and moisture content modeling of amphidromous Dolly Varden using bioelectrical impedance analysis

USGS Publications Warehouse

Stolarski, J.T.; Margraf, F.J.; Carlson, J.G.; Sutton, T.M.

2014-01-01

The physiological well-being or condition of fish is most commonly estimated from aspects of individual morphology. However, these metrics may be only weakly correlated with nutritional reserves stored as lipid, the primary form of accumulated energy in fish. We constructed and evaluated bioelectrical impedance analysis (BIA) models as an alternative method of assessing condition in amphidromous Dolly Varden Salvelinus malma collected from nearshore estuarine and lotic habitats of the Alaskan Arctic. Data on electrical resistance and reactance were collected from the lateral and ventral surfaces of 192 fish, and whole-body percent lipid and moisture content were determined using standard laboratory methods. Significant inverse relationships between temperature and resistance and reactance prompted the standardization of these data to a constant temperature using corrective equations developed herein. No significant differences in resistance or reactance were detected among spawning and nonspawning females after accounting for covariates, suggesting that electrical pathways do not intersect the gonads. Best-fit BIA models incorporating electrical variables calculated from the lateral and ventral surfaces produced the strongest associations between observed and model-predicted estimates of proximate content. These models explained between 6% and 20% more of the variability in laboratory-derived estimates of proximate content than models developed from single-surface BIA data and 32% more than models containing only length and weight data. While additional research is required to address the potential effects of methodological variation, bioelectrical impedance analysis shows promise as a way to provide high-quality, minimally invasive estimates of Dolly Varden lipid or moisture content in the field with only small increases in handling time.

[ABDOMINAL BIOELECTRICAL IMPEDANCE ANALYSIS AND ANTHROPOMETRY FOR PREDICTING METABOLIC SYNDROME IN MIDDLE AGED MEN].

PubMed

Fernández-Vázquez, Rosalía; Millán Romero, Ángel; Barbancho, Miguel Ángel; Alvero-Cruz, José Ramón

2015-09-01

central obesity has a higher risk of metabolic syndrome. The present work aimed to study the relationship of trunk fat and the visceral fat index, and other anthropometric indices in relation to the metabolic syndrome in middle aged male Methods: design: transversal descriptive and correlational study. 75 male, volunteers who have access to a medical assessment, with an age range of 21 to 59 years, from different professions. Weight, height, body mass index, waist circumference, gluteal circumference, waist-to-hip ratio, waist-to-height ratio, trunk fat and visceral fat level by bioelectrical abdominal impedance analysis with Tanita AB-140 (ViScan) and biochemical markers: fasting glucose, total cholesterol, and triglycerides. Likewise, the systolic and diastolic blood pressure was measured. there are significant correlations of anthropometric measurements with trunk fat and visceral fat level and the same with biochemical variables. Receptor-operator curves (ROC curve) analysis shows that the cutoff points from which arises the metabolic syndrome are 32.7% of trunk fat and a level of visceral fat of 13 with a high sensitivity and specificity, attaining the same cut-off points for the metabolic syndrome and obesity status. trunk fat and visceral fat levels determined by bioelectrical abdominal impedance analysis, values are variables very sensitive and specific for the detection of metabolic syndrome and obesity, though not over the variables and anthropometric indices. In the condition of the overweight, trunk fat and visceral fat level are more predictive than anthropometric measures. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.

Reference Centile Curves for Body Fat Percentage, Fat-free Mass, Muscle Mass and Bone Mass Measured by Bioelectrical Impedance in Asian Indian Children and Adolescents.

PubMed

Chiplonkar, Shashi; Kajale, Neha; Ekbote, Veena; Mandlik, Rubina; Parthasarathy, Lavanya; Borade, Ashwin; Patel, Pinal; Patel, Prerna; Khadilkar, Vaman; Khadilkar, Anuradha

2017-12-15

To create gender-specific percentile curves for percent body fat (%BF) by Bio electrical Impedance Analysis (BIA) for screening adiposity and risk of hypertension in Indian children and generate reference curves for percent fat-free mass (%FFM), muscle mass (%LM) and bone mineral content (BMC) by using bioelectrical impedance. Secondary analysis of data from previous multicenter cross-sectional studies. Private schools from five regions of India. A random sample of 3850 healthy school children (2067 boys) (5-17 yr) from private schools in five major Indian cities. Anthropometry, blood pressure (BP) and body composition were measured by bioelectrical impedance. Reference curves were generated by the LMS method. %BF, %FFM, %LM, BMC and BP. Median %BF increased by 6% from 5 to 13 years of age and declined (around 2%) up to 17 years in boys. In girls, %BF increased by 8% from 5 to 14 years and thereafter declined by 3%. Based upon the risk of hypertension, the new cut-offs of 75th and 85th percentile of %BF were proposed for detecting over fatness and excess fatness in children. Median %FFM was 90% at 5 yrs and decreased till 12 years, and then showed a slight increase to 84% at 17 yrs in boys. In girls, it was 86% at 5 yrs and decreased till 15 yrs, and plateaued at 71.8% at 17 yrs. Reference curves for percent body fat for Indian children would be useful to screen children for health risk in clinical set up.

Foot-to-foot bioelectrical impedance analysis: a valuable tool for the measurement of body composition in children.

PubMed

Tyrrell, V J; Richards, G; Hofman, P; Gillies, G F; Robinson, E; Cutfield, W S

2001-02-01

To determine the accuracy of foot-to-foot bioelectrical impedance analysis (BIA) and anthropometric indices as measures of body composition in children. Comparison of foot-to-foot BIA and anthropometry to dual-energy X-ray absorptiometry (DEXA)-derived body composition in a multi-ethnic group of children. : Eighty-two European, NZ Maori and Pacific Island children aged 4.9-10.9 y. DEXA body composition, foot-to-foot bioelectrical impedance, height, weight, hip and waist measurements. Using a BIA prediction equation derived from our study population we found a high correlation between DEXA and BIA in the estimation of fat-free mass (FFM), fat mass (FM) and percentage body fat (PBF) (r=0.98, 0.98 and 0.94, respectively). BIA-FFM underestimated DEXA-FFM by a mean of 0.75 kg, BIA-FM overestimated DEXA-FM by a mean of 1.02 kg and BIA-PBF overestimated DEXA-PBF by a mean of 2.53%. The correlation between six anthropometric indices (body mass index (BMI), ponderal index, Chinn's weight-for-height index, BMI standard deviation score, weight-for-length index and Cole's weight-for-height index) and DEXA were also examined. The correlation of these indices with PBF was remarkably similar (r=0.85-0.87), more variable with FM (r=0.77-0.94) and poor with FFM (r=0.41-0.75). BIA correlated better than anthropometric indices in the estimation of FFM, FM and PBF. Foot-to-foot BIA is an accurate technique in the measurement of body composition.

Validity of segmental bioelectrical impedance analysis for estimating fat-free mass in children including overweight individuals.

PubMed

Ohta, Megumi; Midorikawa, Taishi; Hikihara, Yuki; Masuo, Yoshihisa; Sakamoto, Shizuo; Torii, Suguru; Kawakami, Yasuo; Fukunaga, Tetsuo; Kanehisa, Hiroaki

2017-02-01

This study examined the validity of segmental bioelectrical impedance (BI) analysis for predicting the fat-free masses (FFMs) of whole-body and body segments in children including overweight individuals. The FFM and impedance (Z) values of arms, trunk, legs, and whole body were determined using a dual-energy X-ray absorptiometry and segmental BI analyses, respectively, in 149 boys and girls aged 6 to 12 years, who were divided into model-development (n = 74), cross-validation (n = 35), and overweight (n = 40) groups. Simple regression analysis was applied to (length) 2 /Z (BI index) for each of the whole-body and 3 segments to develop the prediction equations of the measured FFM of the related body part. In the model-development group, the BI index of each of the 3 segments and whole body was significantly correlated to the measured FFM (R 2 = 0.867-0.932, standard error of estimation = 0.18-1.44 kg (5.9%-8.7%)). There was no significant difference between the measured and predicted FFM values without systematic error. The application of each equation derived in the model-development group to the cross-validation and overweight groups did not produce significant differences between the measured and predicted FFM values and systematic errors, with an exception that the arm FFM in the overweight group was overestimated. Segmental bioelectrical impedance analysis is useful for predicting the FFM of each of whole-body and body segments in children including overweight individuals, although the application for estimating arm FFM in overweight individuals requires a certain modification.

The use of bioelectrical impedance analysis to estimate total body water in young children with cerebral palsy.

PubMed

Bell, Kristie L; Boyd, Roslyn N; Walker, Jacqueline L; Stevenson, Richard D; Davies, Peter S W

2013-08-01

Body composition assessment is an essential component of nutritional evaluation in children with cerebral palsy. This study aimed to validate bioelectrical impedance to estimate total body water in young children with cerebral palsy and determine best electrode placement in unilateral impairment. 55 young children with cerebral palsy across all functional ability levels were included. Height/length was measured or estimated from knee height. Total body water was estimated using a Bodystat 1500MDD and three equations, and measured using the gold standard, deuterium dilution technique. Comparisons were made using Bland Altman analysis. For children with bilateral impairment, the Fjeld equation estimated total body water with the least bias (limits of agreement): 0.0 L (-1.4 L to 1.5 L); the Pencharz equation produced the greatest: 2.7 L (0.6 L-4.8 L). For children with unilateral impairment, differences between measured and estimated total body water were lowest on the unimpaired side using the Fjeld equation 0.1 L (-1.5 L to 1.6 L)) and greatest for the Pencharz equation. The ability of bioelectrical impedance to estimate total body water depends on the equation chosen. The Fjeld equation was the most accurate for the group, however, individual results varied by up to 18%. A population specific equation was developed and may enhance the accuracy of estimates. Australian New Zealand Clinical Trials Registry (ANZCTR) number: ACTRN12611000616976. Copyright © 2012 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Neuronal network imaging in acute slices using Ca2+ sensitive bioluminescent reporter.

PubMed

Tricoire, Ludovic; Lambolez, Bertrand

2014-01-01

Genetically encoded indicators are valuable tools to study intracellular signaling cascades in real time using fluorescent or bioluminescent imaging techniques. Imaging of Ca(2+) indicators is widely used to record transient intracellular Ca(2+) increases associated with bioelectrical activity. The natural bioluminescent Ca(2+) sensor aequorin has been historically the first Ca(2+) indicator used to address biological questions. Aequorin imaging offers several advantages over fluorescent reporters: it is virtually devoid of background signal; it does not require light excitation and interferes little with intracellular processes. Genetically encoded sensors such as aequorin are commonly used in dissociated cultured cells; however it becomes more challenging to express them in differentiated intact specimen such as brain tissue. Here we describe a method to express a GFP-aequorin (GA) fusion protein in pyramidal cells of neocortical acute slices using recombinant Sindbis virus. This technique allows expressing GA in several hundreds of neurons on the same slice and to perform the bioluminescence recording of Ca(2+) transients in single neurons or multiple neurons simultaneously.

Opportunistic Access in Frequency Hopping Cognitive Radio Networks

DTIC Science & Technology

2014-03-27

thresholding MA multiple access MFSK M-ary frequency shift keying MIMO multiple-input/multiple-output OFDM orthogonal frequency-division multiplexing x...adaptive BER performance as a function of ISR with orthogonal frequency-division multiplexing ( OFDM ) interference present. . . . . . . . . . 41 4.15 Non...adaptive BER performance as a function of EB/N0 with OFDM interfer- ence present

Frequency comb-based multiple-access ultrastable frequency dissemination with 7 × 10(-17) instability.

PubMed

Zhang, Shuangyou; Zhao, Jianye

2015-01-01

In this letter, we demonstrate frequency-comb-based multiple-access ultrastable frequency dissemination over a 10-km single-mode fiber link. First, we synchronize optical pulse trains from an Er-fiber frequency comb to the remote site by using a simple and robust phase-conjugate stabilization method. The fractional frequency-transfer instability at the remote site is 2.6×10(-14) and 4.9×10(-17) for averaging times of 1 and 10,000 s, respectively. Then, we reproduce the harmonic of the repetition rate from the disseminated optical pulse trains at an arbitrary point along the fiber link to test comb-based multiple-access performance, and demonstrate frequency instability of 4×10(-14) and 7×10(-17) at 1 and 10,000 s averaging time, respectively. The proposed comb-based multiple-access frequency dissemination can easily achieve highly stable wideband microwave extraction along the whole link.

Does bioelectrical impedance analysis accurately estimate the condition of threatened and endangered desert fish species?

USGS Publications Warehouse

Dibble, Kimberly L.; Yard, Micheal D.; Ward, David L.; Yackulic, Charles B.

2017-01-01

Bioelectrical impedance analysis (BIA) is a nonlethal tool with which to estimate the physiological condition of animals that has potential value in research on endangered species. However, the effectiveness of BIA varies by species, the methodology continues to be refined, and incidental mortality rates are unknown. Under laboratory conditions we tested the value of using BIA in addition to morphological measurements such as total length and wet mass to estimate proximate composition (lipid, protein, ash, water, dry mass, energy density) in the endangered Humpback Chub Gila cypha and Bonytail G. elegans and the species of concern Roundtail Chub G. robusta and conducted separate trials to estimate the mortality rates of these sensitive species. Although Humpback and Roundtail Chub exhibited no or low mortality in response to taking BIA measurements versus handling for length and wet-mass measurements, Bonytails exhibited 14% and 47% mortality in the BIA and handling experiments, respectively, indicating that survival following stress is species specific. Derived BIA measurements were included in the best models for most proximate components; however, the added value of BIA as a predictor was marginal except in the absence of accurate wet-mass data. Bioelectrical impedance analysis improved the R2 of the best percentage-based models by no more than 4% relative to models based on morphology. Simulated field conditions indicated that BIA models became increasingly better than morphometric models at estimating proximate composition as the observation error around wet-mass measurements increased. However, since the overall proportion of variance explained by percentage-based models was low and BIA was mostly a redundant predictor, we caution against the use of BIA in field applications for these sensitive fish species.

Stratification of Fat-Free Mass Index Percentiles for Body Composition Based on National Health and Nutrition Examination Survey III Bioelectric Impedance Data.

PubMed

Kudsk, Kenneth A; Munoz-Del-Rio, Alejandro; Busch, Rebecca A; Kight, Cassandra E; Schoeller, Dale A

2017-02-01

Loss of protein mass and lower fat-free mass index (FFMI) are associated with longer length of stay, postsurgical complications, and other poor outcomes in hospitalized patients. Normative data for FFMI of U.S. populations do not exist. This work aims to create a stratified FFMI percentile table for the U.S. population using the large bioelectric impedance analysis data obtained from National Health and Nutrition Examination Surveys (NHANES). Fat-free mass (FFM) was calculated from the NHANES III bioelectric impedance analysis and anthropometric data for males and females ages 12 to >90 years for 3 race/ethnicities (non-Hispanic white, non-Hispanic black, and Mexican American). FFM was normalized by subject height to create an FFMI distribution table for the U.S. Selected percentiles were obtained by age, sex, and race/ethnicity. Data were collapsed by race/ethnicity before and after removing obese and underweight participants to create an FFMI decile table for males and females 12 years and older for the healthy-weight U.S. FFMI increased during adolescent growth but stabilized in the early 20s. The FFMI deciles were similar by race/ethnicity, with age group remaining relatively stable between ages 25 and 80 years. The FFMI deciles for males and females were significantly different. After eliminating the obese and extremely thin, FFMI percentiles remain stable during adult years allowing creation of age- and race/ethnicity-independent decile tables for males and females. These tables allow stratification of individuals for nutrition intervention trials to depict changing nutrition status during medical, surgical, and nutrition interventions.

Ratio of muscle mass to fat mass assessed by bioelectrical impedance analysis is significantly correlated with liver fat accumulation in patients with type 2 diabetes mellitus.

PubMed

Kurinami, Noboru; Sugiyama, Seigo; Morita, Ayami; Yoshida, Akira; Hieshima, Kunio; Miyamoto, Fumio; Kajiwara, Keizo; Jinnouch, Katsunori; Jinnouchi, Tomio; Jinnouchi, Hideaki

2018-05-01

Obesity and ectopic fat accumulation are important conditions of type 2 diabetes mellitus (T2DM). Our aim was to determine whether bioelectrical impedance body composition analysis combined with blood test results could estimate liver ectopic fat accumulation in patients with treatment-naïve T2DM. Subjects were 119 untreated T2DM patients. Computed tomography scans were performed to calculate the liver to spleen attenuation ratio (L/S ratio) as a measure of liver fat accumulation, with excess liver fat accumulation defined as an L/S ratio <1.0. Elementary body composition was measured by bioelectrical impedance analysis using InBody770. The Nagelkerke R 2 test showed that the muscle mass/fat mass ratio (muscle/fat ratio) was the most suitable variable among anthropometric factors and body component indexes for estimating liver fat accumulation. The muscle/fat ratio was significantly correlated with the L/S ratio (ρ = 0.4386, P < 0.0001). Multivariable logistic regression analysis showed that the muscle/fat ratio (odds ratio 0.40, 95% confidence interval 0.22-0.73, P < 0.01) and alanine aminotransferase (odds ratio 1.06, 95% confidence interval 1.02-1.10, P < 0.01) were independently and significantly associated with liver fat accumulation. In receiver operating characteristic curve analysis, the cutoff value of the muscle/fat ratio for excess liver fat accumulation was 2.34. In patients with treatment-naïve T2DM, the muscle/fat ratio and ALT are useful for estimating the presence of excess liver fat accumulation in daily clinical practice. Copyright © 2018. Published by Elsevier B.V.

Bioelectrical impedance vector analysis as a useful predictor of nutritional status in patients with short bowel syndrome.

PubMed

Fassini, Priscila Giacomo; Nicoletti, Carolina Ferreira; Pfrimer, Karina; Nonino, Carla Barbosa; Marchini, Júlio Sérgio; Ferriolli, Eduardo

2017-08-01

Short bowel syndrome (SBS) represents a serious intestinal absorption disorder. Therefore, patients with SBS may have severe malnutrition and excessive mineral and fluid losses. Once the assessment of nutritional status is important in their follow-up, body composition measurements and especially total body water (TBW) must be repeatedly evaluated for the assessment of changes in hydration and nutritional care. The aim of this study was to investigate if bioelectrical impedance vector analysis (BIVA) is a useful predictor of nutritional and hydration status in SBS patients. In this observational study, 22 participants (12 women), 11 with SBS and 11 gender, age and BMI-matched controls, were evaluated using the bioelectrical impedance measurements (BIA) and BIVA to assess nutritional and hydration status. Participants age was 53 ± 8 y (mean ± SD). Body water, fat mass and lean mass as assessed by BIA did not differ between the two groups. However, BIVA showed important differences between the groups regarding hydration and amount of soft tissue (p < 0.0001 for women and p = 0.0015 for men). The results also evidenced that women's vectors were related to cachexia, while men's vectors were divided into lean and cachexia quadrants. The use of BIVA analysis also evidenced hydration disturbance and losses of soft tissue. BIVA may represent a better predictor of nutritional status for analysis and interpretation of body composition in patients with short bowel syndrome. This trial was registered at ClinicalTrials.gov as NCT02113228. Copyright © 2016 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Nutrition Status Parameters and Hydration Status by Bioelectrical Impedance Vector Analysis Were Associated With Lung Function Impairment in Children and Adolescents With Cystic Fibrosis.

PubMed

Hauschild, Daniela Barbieri; Barbosa, Eliana; Moreira, Emilia Addison Machado; Ludwig Neto, Norberto; Platt, Vanessa Borges; Piacentini Filho, Eduardo; Wazlawik, Elisabeth; Moreno, Yara Maria Franco

2016-06-01

(1) To compare nutrition and hydration status between a group of children/adolescents with cystic fibrosis (CFG; n = 46; median age, 8.5 years) and a control group without cystic fibrosis (CG). (2) To examine the association of nutrition and hydration status with lung function in the CFG. A cross-sectional study. Nutrition screening, anthropometric parameters, and bioelectrical impedance analysis (BIA) were assessed. The z scores for body mass index for age, height for age, mid upper arm circumference, triceps and subscapular skinfold thickness, mid upper arm muscle area, resistance/height, and reactance/height were calculated. Bioelectrical impedance vector analysis was conducted. Forced expiratory volume in 1 second <80% was considered lung function impairment. An adjusted logistic regression was applied (P < .05). In the CFG, lung function impairment was observed in 51.1%. All anthropometric parameters were lower, and the mean z-resistance/height and z-reactance/height were higher in the CFG (P < .05) compared with the CG. In the CFG, 43% were severely/mildly dehydrated, while none were in the CG (P = .007). In the CFG, there was an association between high nutrition risk-via nutrition screening (odds ratio [OR], 22.28; P < .05), lower values of anthropometric parameters, higher z-resistance/height (OR, 2.23; P < .05) and z-reactance/height (OR, 1.81; P < .05), and dehydration (OR, 4.94; P < .05)-and lung function impairment. The CFG exhibited a compromised nutrition status assessed by anthropometric and BIA parameters. Nutrition screening, anthropometric and BIA parameters, and hydration status were associated with lung function. © 2016 American Society for Parenteral and Enteral Nutrition.

Nutritional status and body composition by bioelectrical impedance vector analysis: A cross sectional study in mild cognitive impairment and Alzheimer's disease.

PubMed

Cova, Ilaria; Pomati, Simone; Maggiore, Laura; Forcella, Marica; Cucumo, Valentina; Ghiretti, Roberta; Grande, Giulia; Muzio, Fulvio; Mariani, Claudio

2017-01-01

Analysis of nutritional status and body composition in Alzheimer's disease (AD) and Mild Cognitive Impairment (MCI). A cross-sectional study was performed in a University-Hospital setting, recruiting 59 patients with AD, 34 subjects with MCI and 58 elderly healthy controls (HC). Nutritional status was assessed by anthropometric parameters (body mass index; calf, upper arm and waist circumferences), Mini Nutritional Assessment (MNA) and body composition by bioelectrical impedance vector analysis (BIVA). Variables were analyzed by analysis of variance and subjects were grouped by cognitive status and gender. Sociodemographic variables did not differ among the three groups (AD, MCI and HC), except for females' age, which was therefore used as covariate in a general linear multivariate model. MNA score was significantly lower in AD patients than in HC; MCI subjects achieved intermediate scores. AD patients (both sexes) had significantly (p<0.05) higher height-normalized impedance values and lower phase angles (body cell mass) compared with HC; a higher ratio of impedance to height was found in men with MCI with respect to HC. With BIVA method, MCI subjects showed a significant displacement on the RXc graph on the right side indicating lower soft tissues (Hotelling's T2 test: men = 10.6; women = 7.9;p < 0,05) just like AD patients (Hotelling's T2 test: men = 18.2; women = 16.9; p<0,001). Bioelectrical parameters significantly differ from MCI and AD to HC; MCI showed an intermediate pattern between AD and HC. Longitudinal studies are required to investigate if BIVA could reflect early AD-changes in body composition in subjects with MCI.

Estimation of total body water from bioelectrical impedance spectroscopy in oncology outpatients receiving radiotherapy and agreement with three prediction equations.

PubMed

Isenring, E; Colombo, M; Cross, G; Kellett, E; Swaney, L

2009-02-01

Bioelectrical impedance spectroscopy (BIS) may be more accurate in determining total body water (TBW) than bioelectrical impedance analysis (BIA). The present study compared the agreement between three TBW prediction equations developed using BIA and BIS-derived TBW in oncology outpatients. A cross-sectional, observational study was conducted in 37 outpatients receiving radiotherapy (27 males/10 females, aged 68.3 +/- 10.2 years). TBW was estimated by BIS (TBW(BIS)) and three BIA TBW prediction equations (TBW(ca-u): underweight cancer patients; TBW(ca-n): normal-weight cancer patients; and TBW(rad): patients receiving radiotherapy). Bland-Altman analyses determined agreement between methods. BIS-derived TBW using new resistivity constants was calculated. The mean +/- SD of TBW estimated by BIS was 39.8 +/- 8.3 L, which was significantly different from the prediction equations; TBW(rad) 35.1 +/- 7.9 L, TBW(ca-u) 33.1 +/- 7.5 L and TBW(ca-n) 32.3 +/- 7.3 L, (P < 0.001). Using new resistivity constants, TBW was 36.2 +/- 8.1 L but this still differed from the equations (P < 0.001). Bias between TBW(BIS) and that predicted by the equations was in the range 4.7-7.4 L or 1.1-3.9 L using new resistivity constants. TBW estimated by BIS cannot be directly compared with oncology-specific BIA equations, suggesting that BIS cannot be used at the group level in outpatients receiving radiotherapy. There was a reduced bias with BIS using new resistivity constants; however, further research should determine any advantage of BIS over BIA in this population.

Predictive validity of four bioelectrical impedance equations in determining percent fat mass in overweight and obese children.

PubMed

Cleary, Jane; Daniells, Suzie; Okely, Anthony D; Batterham, Marijka; Nicholls, Jessie

2008-01-01

Bioelectrical impedance equations are frequently used by food and nutrition professionals to estimate percent fat mass in overweight and obese children. However, it is not known whether they are accurate for such children, as they have been primarily developed for children of varying body weights. The aim of this cross-sectional study was to evaluate the predictive validity of four previously published prediction equations developed for the pediatric population, among a sample of overweight and obese children. Thirty overweight or obese children (mean age=7.57+/-1.28 years) underwent measurement of fat mass, percent fat mass, and fat-free mass using dual-energy x-ray absorptiometry (DEXA) and bioelectrical impedance analysis (BIA). Impedance values from the BIA were entered into the four prediction equations and Pearson correlations used to determine the significance of associations between each of the BIA prediction equations and DEXA for percent fat mass, fat mass, and fat-free mass. For percent fat mass, paired t tests were used to assess differences between the methods and the technique of Bland and Altman was used to determine bias and error. Results showed that the mean percent fat mass as determined by DEXA for this age group was 40.79%. In comparison with other BIA prediction equations, the Schaefer equation had the closest mean value of 41.98%, and was the only equation not to significantly differ from the DEXA (P=0.121). This study suggests that the Schaefer equation is the only accurate BIA prediction equation for assessing percent fat mass in this sample of overweight and obese children from primarily white backgrounds.

Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process

PubMed Central

Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M.; Sabir, Suhail; Khan, Mohammad Zain

2015-01-01

Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5–8.0, 27(±2°C and 10.6–18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery. PMID:26496083

Bioelectricity Generation and Bioremediation of an Azo-Dye in a Microbial Fuel Cell Coupled Activated Sludge Process.

PubMed

Khan, Mohammad Danish; Abdulateif, Huda; Ismail, Iqbal M; Sabir, Suhail; Khan, Mohammad Zain

2015-01-01

Simultaneous bioelectricity generation and dye degradation was achieved in the present study by using a combined anaerobic-aerobic process. The anaerobic system was a typical single chambered microbial fuel cell (SMFC) which utilizes acid navy blue r (ANB) dye along with glucose as growth substrate to generate electricity. Four different concentrations of ANB (50, 100, 200 and 400 ppm) were tested in the SMFC and the degradation products were further treated in an activated sludge post treatment process. The dye decolorization followed pseudo first order kinetics while the negative values of the thermodynamic parameter ∆G (change in Gibbs free energy) shows that the reaction proceeds with a net decrease in the free energy of the system. The coulombic efficiency (CE) and power density (PD) attained peak values at 10.36% and 2,236 mW/m2 respectively for 200 ppm of ANB. A further increase in ANB concentrations results in lowering of cell potential (and PD) values owing to microbial inhibition at higher concentrations of toxic substrates. Cyclic voltammetry studies revealed a perfect redox reaction was taking place in the SMFC. The pH, temperature and conductivity remain 7.5-8.0, 27(±2°C and 10.6-18.2 mS/cm throughout the operation. The biodegradation pathway was studied by the gas chromatography coupled with mass spectroscopy technique, suggested the preferential cleavage of the azo bond as the initial step resulting in to aromatic amines. Thus, a combined anaerobic-aerobic process using SMFC coupled with activated sludge process can be a viable option for effective degradation of complex dye substrates along with energy (bioelectricity) recovery.

Stratification of fat-free mass index percentiles for body composition based on NHANES III bioelectric impedance data

PubMed Central

Kudsk, Kenneth A.; Munoz-del-Rio, Alejandro; Busch, Rebecca A.; Kight, Cassandra E.; Schoeller, Dale A.

2015-01-01

Background Loss of protein mass and lower fat-free mass index (FFMI) are associated with longer length of stay, post-surgical complications and other poor outcomes in hospitalized patients Normative data for FFMI of U.S. populations does not exist. This work aims to create a stratified FFMI percentile table for the U.S. population using the large bioelectric impedance analysis data obtained from National Health and Nutrition Examination Surveys (NHANES). Methods Fat-free mass (FFM) was calculated from the NHANES III bioelectric impedance analysis and anthropometric data for males and females ages 12 to over 90 years for three race-ethnicities (non-Hispanic white, non-Hispanic black, and Mexican-American). FFM was normalized by subject height to create a FFMI distribution table for the U.S. population. Selected percentiles were obtained by age, sex, and race-ethnicity. Data was collapsed by race-ethnicity before and after removing obese and underweight subjects to create a FFMI decile table for males and females aged 12 and over for the healthy weight U.S. population. Results FFMI increased during adolescent growth but stabilized in the early 20s. The FFMI deciles were similar by race-ethnicity and age group remaining relatively stable between ages of 22 and 80 years. The FFMI deciles for males and females were significantly different. Conclusions After eliminating the obese and extremely thin, FFMI percentiles remain stable during adult years allowing creation of age- and race/ethnicity-independent decile tables for males and females. These tables allow stratification of individuals for nutrition intervention trials to depict changing nutrition status during medical, surgical and nutritional interventions. PMID:26092851

Validity of body composition assessment methods for older men with cardiac disease.

PubMed

Young, H; Porcari, J; Terry, L; Brice, G

1998-01-01

This study was designed to determine which of several body composition assessment methods was most accurate for patients with cardiac disease for the purpose of outcome measurement. Six body composition assessment methods were administered to each of 24 men with cardiac disease. Methods included circumference measurement, skinfold measurement, near-infrared interactance via the Futrex-5000, bioelectrical impedance via the BioAnalogics ElectroLipoGraph and Tanita TBF-150, and hydrostatic weighing, the criterion measure. A repeated measures analysis of variance indicated no significant (P > .05) difference between circumference and skinfold measurements compared to hydrostatic weighing. Near-infrared interactance presented the best standard error of estimates (3.5%) and the best correlation (r = .84) with hydrostatic weighing; however, the constant error was 3.76%. Bioelectrical impedance measured by the ElectroLipoGraph and TBF-150 instruments significantly underestimated percent body fat by 8.81% and 4.8%, respectively. In this study of middle-aged to older men with cardiac disease, the best method for determining body fat was circumferences. This technique was accurate, easy to administer, inexpensive, and had a lower error potential than the other techniques. Skinfold measurements were also closely related to hydrostatic weighing, but should be performed only by experienced practitioners because there is a greater potential for tester error in certain patients. In the future, near-infrared interactance measurements may be a viable technique for body composition assessment in patients with cardiac disease. However, algorithms specific to the population of patients with cardiac disease being tested must be developed before this technique can be routinely recommended for body composition assessment. Bioelectrical impedance assessment by either method is not recommended for patients with cardiac disease, as it consistently underestimated percent body fat when compared to hydrostatic weighing in this population.

Muscle development in healthy children evaluated by bioelectrical impedance analysis.

PubMed

Uchiyama, Tomoka; Nakayama, Takahiro; Kuru, Satoshi

2017-02-01

This study aimed to use bioelectrical impedance analysis (BIA) to generate a new muscle density index (MDI), the MDI_BIA, to evaluate muscle development, and to demonstrate the changes that occur in the BIA-based muscle cross-sectional area index (MCAI_BIA) that accompany growth. We also sought to determine the traceability of chronological changes in the MDI_BIA and MCAI_BIA. Healthy children (n=112) aged 8.68±3.16years (0.33-14.00years) underwent bioelectrical impedance (BI) measurements of their upper arms, thighs, and lower legs. The MDI_BIA and MCAI_BIA were calculated, and cross-sectional investigations were conducted into the changes in these indices that accompanied growth. Data collected after 1.10±0.08years from 45 participants determined the traceability of the chronological changes in the MDI_BIA and MCAI_BIA. The MDI_BIA and MCAI_BIA were significantly positively correlated with age and height at all locations (P<0.01). The relationships between the locations and the MDI_BIA and MCAI_BIA differed, indicating that these indices evaluated the muscles from different perspectives. Except for the upper arm MDI_BIA, both indices at all locations regardless of age, showed significant chronological increases after an average period of 1.10years. The MDI_BIA and MCAI_BIA were significantly correlated with age and height in healthy children, and they showed significant chronological increases. Hence, these indices could be used to represent muscle development and muscle mass increases. BIA is non-invasive, convenient, and economical and it may be useful in evaluating muscle development and muscle cross-sectional areas in children. Copyright © 2016 The Japanese Society of Child Neurology. Published by Elsevier B.V. All rights reserved.

Effect of epithalon on age-specific changes in the retina in rats with hereditary pigmentary dystrophy.

PubMed

Khavinson, V Kh; Razumovskii, M I; Trofimova, S V; Grigor'yan, R A; Chaban, T V; Oleinik, T L; Razumovskaya, A M

2002-01-01

The effect of peptide bioregulator Epithalon on the course of hereditary pigmentary retinal degeneration was studied in Campbell rats. Administration of epithalon starting from birth protected morphological structure, increased its bioelectrical activity, and improved its function.

Bioelectricity generation in continuously-fed microbial fuel cell: effects of anode electrode material and hydraulic retention time.

PubMed

Akman, Dilek; Cirik, Kevser; Ozdemir, Sebnem; Ozkaya, Bestamin; Cinar, Ozer

2013-12-01

The main aim of this study is to investigate the bioelectricity production in continuously-fed dual chambered microbial fuel cell (MFC). Initially, MFC was operated with different anode electrode material at constant hydraulic retention time (HRT) of 2d to evaluate the effect of electrode material on electricity production. Pt electrode yielded about 642 mW/m(2) power density, which was 4 times higher than that of the MFC with the mixed metal oxide titanium (Ti-TiO2). Further, MFC equipped with Pt electrode was operated at varying HRT (2-0.5d). The power density generation increased with decreasing HRT, corresponding to 1313 mW/m(2) which was maximum value obtained during this study. Additionally, decreasing HRT from 2 to 0.5d resulted in increasing effluent dissolved organic carbon (DOC) concentration from 1.92 g/L to 2.23 g/L, corresponding to DOC removal efficiencies of 46% and 38%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Use of infrared telemetry as part of a nonintrusive inflight data collection system to collect human factors data

NASA Technical Reports Server (NTRS)

Micocci, Angelo

1993-01-01

The objective of this paper is to present a methodology and rationale for development of a Nonintrusive Inflight Data Collection System (NIDCS) to collect Human Factors (HF) data during a space mission. These data will enable the research team to identify and resolve issues. This paper will present the background and history of the NIDCS, the methodology and techniques employed versus those in current use on Earth, initial results of the effort--including a brief description of the equipment, and, finally, a discussion of the scientific importance and possible future applications of this system elsewhere. The schema for the NIDCS includes a collection of three types of data: behavioral, physiological, and biomechanical. These will be collected using videotape of crew members' activities, bioelectric signal measurement, and measurement of kinematics and kinetics, respectively. This paper will focus on the second type of data, physiological activity as determined by changes in bioelectric potentials as crew members perform daily assignments.

Bioelectrical impedance analysis: A new tool for assessing fish condition

USGS Publications Warehouse

Hartman, Kyle J.; Margraf, F. Joseph; Hafs, Andrew W.; Cox, M. Keith

2015-01-01

Bioelectrical impedance analysis (BIA) is commonly used in human health and nutrition fields but has only recently been considered as a potential tool for assessing fish condition. Once BIA is calibrated, it estimates fat/moisture levels and energy content without the need to kill fish. Despite the promise held by BIA, published studies have been divided on whether BIA can provide accurate estimates of body composition in fish. In cases where BIA was not successful, the models lacked the range of fat levels or sample sizes we determined were needed for model success (range of dry fat levels of 29%, n = 60, yielding an R2 of 0.8). Reduced range of fat levels requires an increased sample size to achieve that benchmark; therefore, standardization of methods is needed. Here we discuss standardized methods based on a decade of research, identify sources of error, discuss where BIA is headed, and suggest areas for future research.

Self-adhesive epidermal carbon nanotube electronics for tether-free long-term continuous recording of biosignals

NASA Astrophysics Data System (ADS)

Lee, Seung Min; Byeon, Hang Jin; Lee, Joong Hoon; Baek, Dong Hyun; Lee, Kwang Ho; Hong, Joung Sook; Lee, Sang-Hoon

2014-08-01

The long-term, continuous, inconspicuous, and noiseless monitoring of bioelectrical signals is critical to the early diagnosis of disease and monitoring health and wellbeing. However, it is a major challenge to record the bioelectrical signals of patients going about their daily lives because of the difficulties of integrating skin-like conducting materials, the measuring system, and medical technologies in a single platform. In this study, we developed a thin epidermis-like electronics that is capable of repeated self-adhesion onto skin, integration with commercial electronic components through soldering, and conformal contact without serious motion artifacts. Using well-mixed carbon nanotubes and adhesive polydimethylsiloxane, we fabricated an epidermal carbon nanotube electronics which maintains excellent conformal contact even within wrinkles in skin, and can be used to record electrocardiogram signals robustly. The electrode is biocompatible and can even be operated in water, which means patients can live normal lives despite wearing a complicated recording system.

Engineering rheology of electrolytes using agar for improving the performance of bioelectrochemical systems.

PubMed

Rathinam, Navanietha Krishnaraj; Tripathi, Abhilash K; Smirnova, Alevtina; Beyenal, Haluk; Sani, Rajesh K

2018-04-24

The present study is focused on enhancing the rheological properties of the electrolyte and eliminating sedimentation of microorganisms/flocs without affecting the electron transfer kinetics for improved bioelectricity generation. Agar derived from polysaccharide agarose (0.05-0.2%, w/v) was chosen as a rheology modifying agent. Electroanalytical investigations showed that electrolytes modified with 0.15% agar display a nine-fold increase in current density (1.2 mA/cm 2 ) by a thermophilic strain (Geobacillus sp. 44C, 60 °C) when compared with the control. Sodium phosphate buffer (0.1 M, pH 7) electrolyte with riboflavin (0.1 mM) was used as the control. Electrolytes modified with 0.15% agar significantly improved chemical oxygen demand removal rates. This developed electrolyte will aid in improving bioelectricity generation in Bioelectrochemical Systems (BES). The developed strategy avoids the use of peristaltic pumps and magnetic stirrers, thereby improving the energy efficiency of the process. Copyright © 2018 Elsevier Ltd. All rights reserved.

Exploring optimal supplement strategy of medicinal herbs and tea extracts for bioelectricity generation in microbial fuel cells.

PubMed

Chen, Bor-Yann; Liao, Jia-Hui; Hsu, An-Wei; Tsai, Po-Wei; Hsueh, Chung-Chuan

2018-05-01

This first-attempt study used extracts of appropriate antioxidant abundant Camellia and non-Camellia tea and medicinal herbs as model ESs to stably intensify bioelectricity generation performance in microbial fuel cells (MFCs). As electron shuttles (ESs) could stimulate electron transport phenomena by significant reduction of electron transfer resistance, the efficiency of power generation for energy extraction in microbial fuel cells (MFCs) could be appreciably augmented. Using environmentally friendly natural bioresource as green bioresource of ESs is the most promising to sustainable practicability. As comparison of power-density profiles indicated, supplement of Camellia tea extracts would be the most appropriate, then followed non-Camellia Chrysanthemum tea and medicinal herbs. Antioxidant activities, total phenolic contents and power stimulating activities were all electrochemically associated. In particular, the extract of unfermented Camellia tea (i.e., green tea) was the most promising ESs to augment bioenergy extraction compared to other refreshing medicinal herb extracts. Copyright © 2018 Elsevier Ltd. All rights reserved.

Bacteriostatic and anti-collagenolytic dental materials through the incorporation of polyacrylic acid modified CuI nanoparticles

DOEpatents

Renne, Walter George; Mennito, Anthony Samuel; Schmidt, Michael Gerard; Vuthiganon, Jompobe; Chumanov, George

2015-05-19

Provided are antibacterial and antimicrobial surface coatings and dental materials by utilizing the antimicrobial properties of copper chalcogenide and/or copper halide (CuQ, where Q=chalcogens including oxygen, or halogens, or nothing). An antimicrobial barrier is created by incorporation of CuQ nanoparticles of an appropriate size and at a concentration necessary and sufficient to create a unique bioelectrical environment. The unique bioelectrical environment results in biocidal effectiveness through a multi-factorial mechanism comprising a combination of the intrinsic quantum flux of copper (Cu.sup.0, Cu.sup.1+, Cu.sup.2+) ions and the high surface-to-volume electron sink facilitated by the nanoparticle. The result is the constant quantum flux of copper which manifests and establishes the antimicrobial environment preventing or inhibiting the growth of bacteria. The presence of CuQ results in inhibiting or delaying bacterial destruction and endogenous enzymatic breakdown of the zone of resin inter-diffusion, the integrity of which is essential for dental restoration longevity.

Comparative efficiency and driving range of light- and heavy-duty vehicles powered with biomass energy stored in liquid fuels or batteries

PubMed Central

Laser, Mark; Lynd, Lee R.

2014-01-01

This study addresses the question, “When using cellulosic biomass for vehicular transportation, which field-to-wheels pathway is more efficient: that using biofuels or that using bioelectricity?” In considering the question, the level of assumed technological maturity significantly affects the comparison, as does the intended transportation application. Results from the analysis indicate that for light-duty vehicles, over ranges typical in the United States today (e.g., 560–820 miles), field-to-wheels performance is similar, with some scenarios showing biofuel to be more efficient, and others indicating the two pathways to be essentially the same. Over the current range of heavy-duty vehicles, the field-to-wheels efficiency is higher for biofuels than for electrically powered vehicles. Accounting for technological advances and range, there is little basis to expect mature bioelectricity-powered vehicles to have greater field-to-wheels efficiency (e.g., kilometers per gigajoule biomass or per hectare) compared with mature biofuel-powered vehicles. PMID:24550477

Extracellular NAD+ Suppresses Adrenergic Effects in the Atrial Myocardium of Rats during the Early Postnatal Ontogeny.

PubMed

Pustovit, K B; Ivanova, A D; Kuz'min, V S

2018-05-01

The effects of sympathetic cotransmitter NAD+ (10 μM) on bioelectric activity of the heart under conditions of adrenergic stimulation were studied on isolated spontaneously contracting preparations (without stimulation) of the right atrium from 2-7-day-old rats. Action potentials were recorded in the working myocardium using standard microelectrode technique. Perfusion of the right atrium with norepinephrine solution (1 μM) altered the configuration and significantly lengthened the action potentials. NAD + against the background of norepinephrine stimulation significantly decreased the duration of action potentials, in particular, at 25% repolarization. The effect of purine compounds NAD + , ATP, and adenosine on bioelectrical activity of the heart of newborn rats was studied under basal conditions (without norepinephrine stimulation). The effect of NAD + against the background of adrenergic stimulation was more pronounced than under basal conditions and was probably determined by suppression of I CaL , which can be the main mechanism of NAD + action on rat heart.

Enhanced bioelectricity generation of air-cathode buffer-free microbial fuel cells through short-term anolyte pH adjustment.

PubMed

Ren, Yueping; Chen, Jinli; Li, Xiufen; Yang, Na; Wang, Xinhua

2018-04-01

Short-term initial anolyte pH adjustment can relieve the performance deterioration of the single-chamber air-cathode buffer-free microbial fuel cell (BFMFC) caused by anolyte acidification. Adjusting the initial anolyte pH to 9 in 5 running cycles is the optimum strategy. The relative abundance of the electrochemically active Geobacter in the KCl-pH9-MFC anode biofilm increased from 59.01% to 75.13% after the short-term adjustment. The maximum power density (P max ) of the KCl-pH9-MFC was elevated from 316.4mW·m -2 to 511.6mW·m -2 , which was comparable with that of the PBS-MFC. And, after the short-term adjusting, new equilibrium between the anolyte pH and the anode biofilm electrochemical activity has been established in the BFMFC, which ensured the sustainability of the improved bioelectricity generation performance. Copyright © 2017 Elsevier B.V. All rights reserved.

Self-adhesive epidermal carbon nanotube electronics for tether-free long-term continuous recording of biosignals

PubMed Central

Lee, Seung Min; Byeon, Hang Jin; Lee, Joong Hoon; Baek, Dong Hyun; Lee, Kwang Ho; Hong, Joung Sook; Lee, Sang-Hoon

2014-01-01

The long-term, continuous, inconspicuous, and noiseless monitoring of bioelectrical signals is critical to the early diagnosis of disease and monitoring health and wellbeing. However, it is a major challenge to record the bioelectrical signals of patients going about their daily lives because of the difficulties of integrating skin-like conducting materials, the measuring system, and medical technologies in a single platform. In this study, we developed a thin epidermis-like electronics that is capable of repeated self-adhesion onto skin, integration with commercial electronic components through soldering, and conformal contact without serious motion artifacts. Using well-mixed carbon nanotubes and adhesive polydimethylsiloxane, we fabricated an epidermal carbon nanotube electronics which maintains excellent conformal contact even within wrinkles in skin, and can be used to record electrocardiogram signals robustly. The electrode is biocompatible and can even be operated in water, which means patients can live normal lives despite wearing a complicated recording system. PMID:25123356

Clinically relevant determinants of body composition, function and nutritional status as mortality predictors in lung cancer patients.

PubMed

Kovarik, Miroslav; Hronek, Miloslav; Zadak, Zdenek

2014-04-01

Lung cancer belongs to the type of tumors with a relatively high frequency of malnutrition, sarcopenia and cachexia, severe metabolic syndromes related to impairment of physical function and quality of life, resistance to therapy and short survival. Inexpensive and accessible methods of evaluating changes in body composition, physical function and nutrition status are for this reason of great importance for clinical practice to enable the early identification, monitoring, preventing and treatment of these nutritional deficiencies. This could lead to improved outcomes in the quality of life, physical performance and survival of patients with lung cancer. The aim of this article is to summarize the recent knowledge for the use of such methods, their predictability for patient outcomes and an association with other clinically relevant parameters, specifically with lung cancer patients, because such an article collectively describing their practical application in clinical practice is lacking. The interest of this article is in the use of anthropometry, handgrip dynamometry, bioelectrical impedance analysis derived phase angle and nutritional screening questionnaires in lung cancer patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Modeling for intra-body communication with bone effect.

PubMed

Pun, S H; Gao, Y M; Mak, P U; Du, M; Vai, M I

2009-01-01

Intra-body communication (IBC) is a new, different "wireless" communication technique based on the human tissue. This short range "wireless" communication technology provides an alternative solution to wearable sensors, home health system, telemedicine and implanted devices. The development of the IBC enables the possibilities of providing less complexity and convenient communication methodologies for these devices. By regarding human tissue as communication channel, IBC making use of the conductivities properties of human tissue to send electrical signal from transmitter to receiver. In this paper, the authors proposed a new mathematical model for galvanic coupling type IBC based on a human limb. Starting from the electromagnetic theory, the authors treat human tissue as volume conductor, which is in analogous with the bioelectric phenomena analysis. In order to explain the mechanism of galvanic coupling type technique of IBC, applying the quasi-static approximation, the governing equation can be reduced to Laplace Equation. Finally, the analytical model is evaluated with on-body measurement for testing its performance. The comparison result shows that the developed mathematical model can provide good approximation for galvanic coupling type IBC on human limb under low operating frequencies.

The Short Circuit Model of Reading.

ERIC Educational Resources Information Center

Lueers, Nancy M.

The name "short circuit" has been given to this model because, in many ways, it adequately describes what happens bioelectrically in the brain. The "short-circuiting" factors include linguistic, sociocultural, attitudinal and motivational, neurological, perceptual, and cognitive factors. Research is reviewed on ways in which each one affects any…

Miniature electrometer preamplifier effectively compensates for input capacitance

NASA Technical Reports Server (NTRS)

Burrous, C. N.; Deboo, G. J.

1966-01-01

Negative capacitance preamplifier using a dual MOS /Metal Oxide Silicon/ transistor in conjunction with bipolar transistors is used with intracellular microelectrodes in recording bioelectric potentials. Applications would include use as a pickup plate video amplifier in storage tube tests and for pH and ionization chamber measurements.

Demonstration of Space Optical Transmitter Development for Multiple High Frequency Bands

NASA Technical Reports Server (NTRS)

Nguyen, Hung; Simons, Rainee; Wintucky, Edwin; Freeman, Jon

2013-01-01

As the demand for multiple radio frequency carrier bands continues to grow in space communication systems, the design of a cost-effective compact optical transmitter that is capable of transmitting selective multiple RF bands is of great interest, particularly for NASA Space Communications Network Programs. This paper presents experimental results that demonstrate the feasibility of a concept based on an optical wavelength division multiplexing (WDM) technique that enables multiple microwave bands with different modulation formats and bandwidths to be combined and transmitted all in one unit, resulting in many benefits to space communication systems including reduced size, weight and complexity with corresponding savings in cost. Experimental results will be presented including the individual received RF signal power spectra for the L, C, X, Ku, Ka, and Q frequency bands, and measurements of the phase noise associated with each RF frequency. Also to be presented is a swept RF frequency power spectrum showing simultaneous multiple RF frequency bands transmission. The RF frequency bands in this experiment are among those most commonly used in NASA space environment communications.

A theoretical analysis of anatomical and functional intestinal slow wave re-entry.

PubMed

Du, Peng; O'Grady, Gregory; Cheng, Leo K

2017-07-21

Intestinal bioelectrical slow waves are a key regulator of intestinal motility. Peripheral pacemakers, ectopic initiations and sustained periods of re-entrant activities have all been experimentally observed to be important factors in setting the frequency of intestinal slow waves, but the tissue-level mechanisms underpinning these activities are unclear. This theoretical analysis aimed to define the initiation, maintenance, and termination criteria of two classes of intestinal re-entrant activities: anatomical re-entry and functional re-entry. Anatomical re-entry was modeled in a three-dimensional (3D) cylindrical model, and functional rotor was modeled in a 2D rectangle model. A single-pulse stimulus was used to invoke an anatomical re-entry and a prolonged refractory block was used to invoke the rotor. In both cases, the simulated re-entrant activities operated at frequencies above the baseline entrainment frequency. The anatomical re-entry simulation results demonstrated that a temporary functional refractory block would be required to initiate the re-entrant activity in a single direction around the cylindrical model. The rotor could be terminated by a single-pulse stimulus delivered around the core of the rotor. In conclusion, the simulation results provide the following new insights into the mechanisms of intestinal re-entry: (i) anatomical re-entry is only maintained within a specific range of velocities, outside of which the re-entrant activities become either an ectopic activity or simultaneous activations of the intestinal wall; (ii) a maintained rotor entrained slow waves faster in the antegrade direction than in the retrograde direction. Simulations are shown to be a valuable tool for achieving novel insights into the mechanisms of intestinal slow wave dysrhythmia. Copyright © 2017 Elsevier Ltd. All rights reserved.

Magnetic induction spectroscopy: non-contact measurement of the electrical conductivity spectra of biological samples

NASA Astrophysics Data System (ADS)

Barai, A.; Watson, S.; Griffiths, H.; Patz, R.

2012-08-01

Measurement of the electrical conductivity of biological tissues as a function of frequency, often termed ‘bioelectrical impedance spectroscopy (BIS)’, provides valuable information on tissue structure and composition. In implementing BIS though, there can be significant practical difficulties arising from the electrode-sample interface which have likely limited its deployment in industrial applications. In magnetic induction spectroscopy (MIS) these difficulties are eliminated through the use of fully non-contacting inductive coupling between the sensors and sample. However, inductive coupling introduces its own set of technical difficulties, primarily related to the small magnitudes of the induced currents and their proportionality with frequency. This paper describes the design of a practical MIS system incorporating new, highly-phase-stable electronics and compares its performance with that of electrode-based BIS in measurements on biological samples including yeast suspensions in saline (concentration 50-400 g l-1) and solid samples of potato, cucumber, tomato, banana and porcine liver. The shapes of the MIS spectra were in good agreement with those for electrode-based BIS, with a residual maximum discrepancy of 28%. The measurement precision of the MIS was 0.05 S m-1 at 200 kHz, improving to 0.01 S m-1 at a frequency of 20 MHz, for a sample volume of 80 ml. The data-acquisition time for each MIS measurement was 52 s. Given the value of spectroscopic conductivity information and the many advantages of obtaining these data in a non-contacting manner, even through electrically-insulating packaging materials if necessary, it is concluded that MIS is a technique with considerable potential for monitoring bio-industrial processes and product quality.

Effect of protein and energy intakes on body composition in non-diabetic maintenance-hemodialysis patients.

PubMed

Ichikawa, Yoko; Hiramatsu, Fumie; Hamada, Hisayo; Sakai, Atsuko; Hara, Keiko; Kogirima, Miho; Kawahara, Kazuhiko; Minakuchi, Jun; Kawashima, Shu; Yamamoto, Shigeru

2007-10-01

This cross sectional study was performed to find the adequate amount and combination of dietary protein and energy for maintaining better nutritional status for stable non-diabetic maintenance hemodialysis (MHD) patients. The body composition including body fat, total body water, body cell mass and body protein were measured by multi-frequency bioelectrical impedance analysis in 200 stable MHD patients without diabetes (124 men, 76 women). Dietary energy intake (DEI) and dietary protein intake (DPI) were assessed by a brief self-administered diet history questionnaire (BDHQ), the DPI value being confirmed by calculating the normalized protein equivalent of total nitrogen appearance (nPNA). The nutritional status and the body composition were compared among 4 groups of patients in each gender that were divided by the combination of DEI and DPI; high energy (HE)/high protein (HP), HE/low protein (LP), low energy (LE)/HP and LE/LP groups. The mean DPI ranged between 1.17-1.23 and 0.89-0.95 g/kg IBW/d in the HP and LP groups, respectively for both genders, and the mean DEI was 35-37 and 24-25 kcal/kg IBW/d in HE and LE groups, respectively. BMI and serum albumin concentration were not different among the 4 groups. Body cell mass index (BCMI) was maintained in the HE groups regardless of DPI, and it was significantly higher in the HE/HP group than in the LE/LP group. Multiple regression analysis also showed that the BCMI was more greatly affected by DEI than DPI. These results indicated that a DPI of 0.89-0.95 g/kg IBW/d could be sufficient for maintaining BCMI, if DEI is kept over 35 kcal/kg IBW/d in stable non-diabetic MHD patients. This DPI level is lower than the recommended DPI proposed by dietary guidelines in the US and Japan.

78 FR 34039 - Magnuson-Stevens Act Provisions; General Provisions for Domestic Fisheries; Application for...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-06

..., fecundity, bioelectrical impedance analysis (BIA), food habits, and genetic research. The yellowtail... dependent catch data and biological samples. Regulations under the Magnuson-Stevens Fishery Conservation and... Exempted Fishing Permit (EFP) on April 11, 2013, to enable data collection activities that the regulations...

Do siblings always form and evolve simultaneously? Testing the coevality of multiple protostellar systems through SEDs

NASA Astrophysics Data System (ADS)

Murillo, N. M.; van Dishoeck, E. F.; Tobin, J. J.; Fedele, D.

2016-07-01

Context. Multiplicity is common in field stars and among protostellar systems. Models suggest two paths of formation: turbulent fragmentation and protostellar disk fragmentation. Aims: We attempt to find whether or not the coevality frequency of multiple protostellar systems can help to better understand their formation mechanism. The coevality frequency is determined by constraining the relative evolutionary stages of the components in a multiple system. Methods: Spectral energy distributions (SEDs) for known multiple protostars in Perseus were constructed from literature data. Herschel PACS photometric maps were used to sample the peak of the SED for systems with separations ≥7″, a crucial aspect in determining the evolutionary stage of a protostellar system. Inclination effects and the surrounding envelope and outflows were considered to decouple source geometry from evolution. This together with the shape and derived properties from the SED was used to determine each system's coevality as accurately as possible. SED models were used to examine the frequency of non-coevality that is due to geometry. Results: We find a non-coevality frequency of 33 ± 10% from the comparison of SED shapes of resolved multiple systems. Other source parameters suggest a somewhat lower frequency of non-coevality. The frequency of apparent non-coevality that is due to random inclination angle pairings of model SEDs is 17 ± 0.5%. Observations of the outflow of resolved multiple systems do not suggest significant misalignments within multiple systems. Effects of unresolved multiples on the SED shape are also investigated. Conclusions: We find that one-third of the multiple protostellar systems sampled here are non-coeval, which is more than expected from random geometric orientations. The other two-thirds are found to be coeval. Higher order multiples show a tendency to be non-coeval. The frequency of non-coevality found here is most likely due to formation and enhanced by dynamical evolution.

Cross-mode bioelectrical impedance analysis in a standing position for estimating fat-free mass validated against dual-energy x-ray absorptiometry.

PubMed

Huang, Ai-Chun; Chen, Yu-Yawn; Chuang, Chih-Lin; Chiang, Li-Ming; Lu, Hsueh-Kuan; Lin, Hung-Chi; Chen, Kuen-Tsann; Hsiao, An-Chi; Hsieh, Kuen-Chang

2015-11-01

Bioelectrical impedance analysis (BIA) is commonly used to assess body composition. Cross-mode (left hand to right foot, Z(CR)) BIA presumably uses the longest current path in the human body, which may generate better results when estimating fat-free mass (FFM). We compared the cross-mode with the hand-to-foot mode (right hand to right foot, Z(HF)) using dual-energy x-ray absorptiometry (DXA) as the reference. We hypothesized that when comparing anthropometric parameters using stepwise regression analysis, the impedance value from the cross-mode analysis would have better prediction accuracy than that from the hand-to-foot mode analysis. We studied 264 men and 232 women (mean ages, 32.19 ± 14.95 and 34.51 ± 14.96 years, respectively; mean body mass indexes, 24.54 ± 3.74 and 23.44 ± 4.61 kg/m2, respectively). The DXA-measured FFMs in men and women were 58.85 ± 8.15 and 40.48 ± 5.64 kg, respectively. Multiple stepwise linear regression analyses were performed to construct sex-specific FFM equations. The correlations of FFM measured by DXA vs. FFM from hand-to-foot mode and estimated FFM by cross-mode were 0.85 and 0.86 in women, with standard errors of estimate of 2.96 and 2.92 kg, respectively. In men, they were 0.91 and 0.91, with standard errors of the estimates of 3.34 and 3.48 kg, respectively. Bland-Altman plots showed limits of agreement of -6.78 to 6.78 kg for FFM from hand-to-foot mode and -7.06 to 7.06 kg for estimated FFM by cross-mode for men, and -5.91 to 5.91 and -5.84 to 5.84 kg, respectively, for women. Paired t tests showed no significant differences between the 2 modes (P > .05). Hence, cross-mode BIA appears to represent a reasonable and practical application for assessing FFM in Chinese populations. Copyright © 2015 Elsevier Inc. All rights reserved.

Body composition and metabolic health of young male adults with childhood-onset multiple pituitary hormone deficiency after cessation of growth hormone treatment.

PubMed

Yang, Hongbo; Wang, Linjie; Qiu, Xiaonan; Yan, Kemin; Gong, Fengying; Zhu, Huijuan; Pan, Hui

2018-04-25

Recombinant human growth hormone (rhGH) replacement therapy is usually stopped after linear growth completion in patients with growth hormone deficiency. In patients with multiple pituitary hormone deficiency (MPHD), the long-term effects of discontinuation of rhGH replacement are unknown. In this study, the anthropometric and metabolic parameters of 24 male patients with adult growth hormone deficiency (AGHD) due to MPHD in childhood after cessation of rhGH therapy for a mean of 7.1 years were measured and compared with 35 age-matched controls. Body composition was evaluated by bioelectrical impedance analysis (BIA). In the AGHD group, body mass index (BMI) was significantly increased and 29.2% had obesity. The AGHD group had a 17.7 cm increase in waist circumference (WC). The fat free mass (FFM) was significantly lower in the AGHD group. Both the fat mass (FM) and percentage of fat mass (FM%) were significantly increased in the AGHD group. Both the systolic blood pressure (BP) and diastolic pressure were significantly lower in AGHD group. The lipid profile was generally similar in both groups, except for a decrease of high density lipoprotein-cholesterol (HDL-C) in the AGHD group. There was significant hyperuricemia in the AGHD group. Cessation of rhGH leads to a significant increase of FM in early adulthood in male patients with childhood-onset MPHD (CO-MPHD).

A fingerprint of the epileptogenic zone in human epilepsies.

PubMed

Grinenko, Olesya; Li, Jian; Mosher, John C; Wang, Irene Z; Bulacio, Juan C; Gonzalez-Martinez, Jorge; Nair, Dileep; Najm, Imad; Leahy, Richard M; Chauvel, Patrick

2018-01-01

Defining a bio-electrical marker for the brain area responsible for initiating a seizure remains an unsolved problem. Fast gamma activity has been identified as the most specific marker for seizure onset, but conflicting results have been reported. In this study, we describe an alternative marker, based on an objective description of interictal to ictal transition, with the aim of identifying a time-frequency pattern or 'fingerprint' that can differentiate the epileptogenic zone from areas of propagation. Seventeen patients who underwent stereoelectroencephalography were included in the study. Each had seizure onset characterized by sustained gamma activity and were seizure-free after tailored resection or laser ablation. We postulated that the epileptogenic zone was always located inside the resection region based on seizure freedom following surgery. To characterize the ictal frequency pattern, we applied the Morlet wavelet transform to data from each pair of adjacent intracerebral electrode contacts. Based on a visual assessment of the time-frequency plots, we hypothesized that a specific time-frequency pattern in the epileptogenic zone should include a combination of (i) sharp transients or spikes; preceding (ii) multiband fast activity concurrent; with (iii) suppression of lower frequencies. To test this hypothesis, we developed software that automatically extracted each of these features from the time-frequency data. We then used a support vector machine to classify each contact-pair as being within epileptogenic zone or not, based on these features. Our machine learning system identified this pattern in 15 of 17 patients. The total number of identified contacts across all patients was 64, with 58 localized inside the resected area. Subsequent quantitative analysis showed strong correlation between maximum frequency of fast activity and suppression inside the resection but not outside. We did not observe significant discrimination power using only the maximum frequency or the timing of fast activity to differentiate contacts either between resected and non-resected regions or between contacts identified as epileptogenic versus non-epileptogenic. Instead of identifying a single frequency or a single timing trait, we observed the more complex pattern described above that distinguishes the epileptogenic zone. This pattern encompasses interictal to ictal transition and may extend until seizure end. Its time-frequency characteristics can be explained in light of recent models emphasizing the role of fast inhibitory interneurons acting on pyramidal cells as a prominent mechanism in seizure triggering. The pattern clearly differentiates the epileptogenic zone from areas of propagation and, as such, represents an epileptogenic zone 'fingerprint'.awx306media15687076823001. © The Author (2017). Published by Oxford University Press on behalf of the Guarantors of Brain.

A fingerprint of the epileptogenic zone in human epilepsies

PubMed Central

Grinenko, Olesya; Li, Jian; Mosher, John C; Wang, Irene Z; Bulacio, Juan C; Gonzalez-Martinez, Jorge; Nair, Dileep; Najm, Imad; Leahy, Richard M; Chauvel, Patrick

2018-01-01

Abstract Defining a bio-electrical marker for the brain area responsible for initiating a seizure remains an unsolved problem. Fast gamma activity has been identified as the most specific marker for seizure onset, but conflicting results have been reported. In this study, we describe an alternative marker, based on an objective description of interictal to ictal transition, with the aim of identifying a time-frequency pattern or ‘fingerprint’ that can differentiate the epileptogenic zone from areas of propagation. Seventeen patients who underwent stereoelectroencephalography were included in the study. Each had seizure onset characterized by sustained gamma activity and were seizure-free after tailored resection or laser ablation. We postulated that the epileptogenic zone was always located inside the resection region based on seizure freedom following surgery. To characterize the ictal frequency pattern, we applied the Morlet wavelet transform to data from each pair of adjacent intracerebral electrode contacts. Based on a visual assessment of the time-frequency plots, we hypothesized that a specific time-frequency pattern in the epileptogenic zone should include a combination of (i) sharp transients or spikes; preceding (ii) multiband fast activity concurrent; with (iii) suppression of lower frequencies. To test this hypothesis, we developed software that automatically extracted each of these features from the time-frequency data. We then used a support vector machine to classify each contact-pair as being within epileptogenic zone or not, based on these features. Our machine learning system identified this pattern in 15 of 17 patients. The total number of identified contacts across all patients was 64, with 58 localized inside the resected area. Subsequent quantitative analysis showed strong correlation between maximum frequency of fast activity and suppression inside the resection but not outside. We did not observe significant discrimination power using only the maximum frequency or the timing of fast activity to differentiate contacts either between resected and non-resected regions or between contacts identified as epileptogenic versus non-epileptogenic. Instead of identifying a single frequency or a single timing trait, we observed the more complex pattern described above that distinguishes the epileptogenic zone. This pattern encompasses interictal to ictal transition and may extend until seizure end. Its time-frequency characteristics can be explained in light of recent models emphasizing the role of fast inhibitory interneurons acting on pyramidal cells as a prominent mechanism in seizure triggering. The pattern clearly differentiates the epileptogenic zone from areas of propagation and, as such, represents an epileptogenic zone ‘fingerprint’. PMID:29253102

Time delay spectrum conditioner

DOEpatents

Greiner, Norman R.

1980-01-01

A device for delaying specified frequencies of a multiple frequency laser beam. The device separates the multiple frequency beam into a series of spatially separated single frequency beams. The propagation distance of the single frequency beam is subsequently altered to provide the desired delay for each specific frequency. Focusing reflectors can be utilized to provide a simple but nonadjustable system or, flat reflectors with collimating and focusing optics can be utilized to provide an adjustable system.

Wide bandwidth phase-locked loop circuit

NASA Technical Reports Server (NTRS)

Koudelka, Robert David (Inventor)

2005-01-01

A PLL circuit uses a multiple frequency range PLL in order to phase lock input signals having a wide range of frequencies. The PLL includes a VCO capable of operating in multiple different frequency ranges and a divider bank independently configurable to divide the output of the VCO. A frequency detector detects a frequency of the input signal and a frequency selector selects an appropriate frequency range for the PLL. The frequency selector automatically switches the PLL to a different frequency range as needed in response to a change in the input signal frequency. Frequency range hysteresis is implemented to avoid operating the PLL near a frequency range boundary.

Observations of discrete magnetosonic waves off the magnetic equator

DOE PAGES

Zhima, Zeren; Chen, Lunjin; Fu, Huishan; ...

2015-11-23

Fast mode magnetosonic waves are typically confined close to the magnetic equator and exhibit harmonic structures at multiples of the local, equatorial proton cyclotron frequency. Here, we report observations of magnetosonic waves well off the equator at geomagnetic latitudes from -16.5°to -17.9° and L shell ~2.7–4.6. The observed waves exhibit discrete spectral structures with multiple frequency spacings. The predominant frequency spacings are ~6 and 9 Hz, neither of which is equal to the local proton cyclotron frequency. Backward ray tracing simulations show that the feature of multiple frequency spacings is caused by propagation from two spatially narrow equatorial source regionsmore » located at L ≈ 4.2 and 3.7. The equatorial proton cyclotron frequencies at those two locations match the two observed frequency spacings. Finally, our analysis provides the first observations of the harmonic nature of magnetosonic waves well away from the equatorial region and suggests that the propagation from multiple equatorial sources contributes to these off-equatorial magnetosonic emissions with varying frequency spacings.« less

Environmental factors and beta2-adrenergic receptor polymorphism: influence on the energy expenditure and nutritional status of obese women.

PubMed

Rosado, Eliane Lopes; Bressan, Josefina; Martínez, J Alfredo

2015-05-01

Our aim was to evaluate the influence of the Gln27Glu polymorphism of the β2-adrenergic receptor (ADRβ2) gene, fat intake and physical activity on the energy expenditure (EE) and nutritional status of obese women. Sixty obese women (30-46 years) participated in the study and were assigned to three groups depending on the genotypes: Gln27Gln, Gln27Glu and Glu27Glu. At baseline and after nutritional intervention, the anthropometric and body composition (bioelectrical impedance), dietary, EE (indirect calorimetry) and biochemical variables were measured. All women received a high-fat test meal to determine the postprandial EE (short-term) and an energy-restricted diet for 10 weeks (long term). The frequencies of Gln27Gln, Gln27Glu and Glu27Glu were 36.67, 40.0 and 23.33 %, respectively. Anthropometric and biochemical variables and EE did not differ between groups, although women who had no polymorphism demonstrated decreased carbohydrate oxidation. On the other hand, the Glu27Glu genotype showed a positive relation with EE in physical activity and fat oxidation. The environmental factors and Gln27Glu polymorphism did not influence the nutritional status and EE of obese women, but physical activity in obese women with the polymorphism in the ADRβ2 gene can promote fat oxidation. The results suggest that encouraging the practice of physical exercise is important considering the high frequency of this polymorphism in obese subjects.

The rs4285184 polymorphism of the MGAT1 gene as a risk factor for obesity in the Mexican population.

PubMed

Tapia-Rivera, José C; Baltazar-Rodríguez, Luz M; Cárdenas-Rojas, Martha I; Álvarez, Alan; Bustos-Saldaña, Rafael; Delgado-Enciso, Iván; Valdez-Velázquez, Laura L; Guzmán-Esquivel, José; Ramírez-Flores, Mario

2017-02-23

Obesity is a factor that contributes to the morbidity of certain diseases and to worldwide mortality. MGAT1 is a glycosyltransferase involved in the synthesis of protein-bound and lipid-bound oligosaccharides and its polymorphisms are possibly involved in the etiology of obesity. We investigated the association of the rs4285184 polymorphism of the MGAT1 gene with obesity in adults in the State of Colima, Mexico. A case-control study was conducted that included 244 subjects. All of them were grouped according to their percentage of body fat, determined through bioelectrical impedance, and they were genotyped for the rs4285184 polymorphism of the MGAT1 gene through PCR-RFLP. The results were analyzed for their association with the percentage of body fat. The G allele had a frequency of 49.19 and 38.75% for the cases and controls, respectively (P=.020) (OR 1.53; 95% CI 1.068-2.193). The frequency of the A/G+G/G genotype was 75% in the obese patients, which was significantly higher compared with the 57.5% of the control group (P=.004) (OR 2.217; 95% CI 1.287-3.821). The presence of the rs4285184 polymorphism of the MGAT1 gene increased the risk for developing body fat associated with obesity in the Mexican population. Copyright © 2016 Elsevier España, S.L.U. All rights reserved.

Tehran Survey of Potential Risk Factors for Multiple Births.

PubMed

Omani Samani, Reza; Almasi-Hashiani, Amir; Vesali, Samira; Shokri, Fatemeh; Cheraghi, Rezvaneh; Torkestani, Farahnaz; Sepidarkish, Mahdi

2017-10-01

The multiple pregnancy incidence is increasing worldwide. This increased incidence is concerning to the health care system. This study aims to determine the frequency of multiple pregnancy and identify factors that affect this frequency in Tehran, Iran. This cross-sectional study included 5170 mothers in labor between July 6-21, 2015 from 103 hospitals with Obstetrics and Gynecology Wards. The questionnaire used in this study consisted of five parts: demographic characteristics; information related to pregnancy; information related to the infant; information regarding the multiple pregnancy; and information associated with infertility. We recruited 103 trained midwives to collect data related to the questionnaire from eligible participants through an interview and medical records review. Frequencies and odds ratios (OR) for the association between multiple pregnancy and the selected characteristics (maternal age, economic status, history of multiple pregnancy in first-degree relatives, and reproductive history) were computed by multiple logistic regression. Stata software, version 13 (Stata Corp, College Station, TX, USA) was used for all statistical analyses. Multiple pregnancy had a prevalence of 1.48% [95% confidence interval (CI): 1.19-1.85]. After controlling for confounding variables, we observed a significant association between frequency of multiple pregnancy and mother's age (OR=1.04, 95% CI: 1.001-1.09, P=0.044), assisted reproductive technique (ART, OR=6.11, 95% CI: 1.7- 21.97, P=0.006), and history of multiple pregnancy in the mother's family (OR=5.49, 95% CI: 3.55-9.93, P=0.001). The frequency of multiple pregnancy approximated results reported in previous studies in Iran. Based on the results, we observed significantly greater frequency of multiple pregnancy in older women, those with a history of ART, and a history of multiple pregnancy in the mother's family compared to the other variables. Copyright© by Royan Institute. All rights reserved.

Adult obesity: panel study from native Amazonians.

PubMed

Zeng, Wu; Eisenberg, Dan T A; Jovel, Karla Rubio; Undurraga, Eduardo A; Nyberg, Colleen; Tanner, Susan; Reyes-García, Victoria; Leonard, William R; Castaño, Juliana; Huanca, Tomás; McDade, Thomas W; Godoy, Ricardo

2013-03-01

This paper examines three morphological indicators measuring obesity among a native Amazonian population of foragers-farmers in Bolivia (Tsimane') and estimates the associations between them and standard covariates of obesity (e.g., socioeconomic status [SES]). We collected annual data from 350 non-pregnant women and 385 men ≥20 years of age from all 311 households in 13 villages during five consecutive years (2002-2006). We used three indicators to measure obesity: body-mass index (BMI), waist circumference (WC), and body fat using bioelectrical impedance analysis (BF-BIA). We ran separate individual random-effect panel multiple regressions for women and men with wealth, acculturation, health, and household food availability as key covariates, and controlled for village and year fixed effects and village×year interaction effects. Although BMI increases by a statistically significant annual growth rate of 0.64% among women and 0.37% among men over the five years, the increase does not yield significant biological meanings. Neither do we find consistent and biologically meaningful covariates associated with adult obesity. Copyright © 2012 Elsevier B.V. All rights reserved.

Heart rate variability is differentially altered in multiple sclerosis: implications for acute, worsening and progressive disability.

PubMed

Studer, Valeria; Rocchi, Camilla; Motta, Caterina; Lauretti, Benedetta; Perugini, Jacopo; Brambilla, Laura; Pareja-Gutierrez, Lorena; Camera, Giorgia; Barbieri, Francesca Romana; Marfia, Girolama A; Centonze, Diego; Rossi, Silvia

2017-01-01

Sympathovagal imbalance has been associated with poor prognosis in chronic diseases, but there is conflicting evidence in multiple sclerosis. The objective of this study was to investigate the autonomic nervous system dysfunction correlation with inflammation and progression in multiple sclerosis. Heart rate variability was analysed in 120 multiple sclerosis patients and 60 healthy controls during supine rest and head-up tilt test; the normalised units of low frequency and high frequency power were considered to assess sympathetic and vagal components, respectively. Correlation analyses with clinical and radiological markers of disease activity and progression were performed. Sympathetic dysfunction was closely related to the progression of disability in multiple sclerosis: progressive patients showed altered heart rate variability with respect to healthy controls and relapsing-remitting patients, with higher rest low frequency power and lacking the expected low frequency power increase during the head-up tilt test. In relapsing-remitting patients, disease activity, even subclinical, was associated with lower rest low frequency power, whereas stable relapsing-remitting patients did not differ from healthy controls. Less sympathetic reactivity and higher low frequency power at rest were associated with incomplete recovery from relapse. Autonomic balance appears to be intimately linked with both the inflammatory activity of multiple sclerosis, which is featured by an overall hypoactivity of the sympathetic nervous system, and its compensatory plastic processes, which appear inefficient in case of worsening and progressive multiple sclerosis.

Non-destructive testing method and apparatus utilizing phase multiplication holography

DOEpatents

Collins, H. Dale; Prince, James M.; Davis, Thomas J.

1984-01-01

An apparatus and method for imaging of structural characteristics in test objects using radiation amenable to coherent signal processing methods. Frequency and phase multiplication of received flaw signals is used to simulate a test wavelength at least one to two orders of magnitude smaller than the actual wavelength. The apparent reduction in wavelength between the illumination and recording radiation performs a frequency translation hologram. The hologram constructed with a high synthetic frequency and flaw phase multiplication is similar to a conventional acoustic hologram construction at the high frequency.

Multiple Input Design for Real-Time Parameter Estimation in the Frequency Domain

NASA Technical Reports Server (NTRS)

Morelli, Eugene

2003-01-01

A method for designing multiple inputs for real-time dynamic system identification in the frequency domain was developed and demonstrated. The designed inputs are mutually orthogonal in both the time and frequency domains, with reduced peak factors to provide good information content for relatively small amplitude excursions. The inputs are designed for selected frequency ranges, and therefore do not require a priori models. The experiment design approach was applied to identify linear dynamic models for the F-15 ACTIVE aircraft, which has multiple control effectors.

A Novel Approach to Teach the Generation of Bioelectrical Potentials from a Descriptive and Quantitative Perspective

ERIC Educational Resources Information Center

Rodriguez-Falces, Javier

2013-01-01

In electrophysiology studies, it is becoming increasingly common to explain experimental observations using both descriptive methods and quantitative approaches. However, some electrophysiological phenomena, such as the generation of extracellular potentials that results from the propagation of the excitation source along the muscle fiber, are…

Enhancement of extracellular electron transfer and bioelectricity output by synthetic porin.

PubMed

Yong, Yang-Chun; Yu, Yang-Yang; Yang, Yun; Liu, Jing; Wang, Jing-Yuan; Song, Hao

2013-02-01

The microbial fuel cell (MFC), is a promising environmental biotechnology for harvesting electricity energy from organic wastes. However, low bacterial membrane permeability of electron shuttles is a limiting factor that restricts the electron shuttle-mediated extracellular electron transfer (EET) from bacteria to electrodes, thus the electricity power output of MFCs. To this end, we heterologously expressed a porin protein OprF from Pseudomonas aeruginosa PAO1 into Escherichia coli, which dramatically increased its membrane permeability, delivering a much higher current output in MFCs than its parental strain (BL21). We found that the oprF-expression strain showed more efficient EET than its parental strain. More strikingly, the enhanced membrane permeability also rendered the oprF-expression strain an efficient usage of riboflavin as the electron shuttle, whereas its parental strain was incapable of. Our results substantiated that membrane permeability is crucial for the efficient EET, and indicated that the expression of synthetic porins could be an efficient strategy to enhance bioelectricity generation by microorganisms (including electrogenic bacteria) in MFCs. Copyright © 2012 Wiley Periodicals, Inc.

Effect of light on the production of bioelectricity and added-value microalgae biomass in a Photosynthetic Alga Microbial Fuel Cell.

PubMed

Gouveia, Luísa; Neves, Carole; Sebastião, Diogo; Nobre, Beatriz P; Matos, Cristina T

2014-02-01

This study demonstrates the simultaneous production of bioelectricity and added-value pigments in a Photosynthetic Alga Microbial Fuel Cell (PAMFC). A PAMFC was operated using Chlorella vulgaris in the cathode compartment and a bacterial consortium in the anode. The system was studied at two different light intensities and the maximum power produced was 62.7 mW/m(2) with a light intensity of 96 μE/(m(2)s). The results showed that increasing light intensity from 26 to 96 μE/(m(2)s) leads to an increase of about 6-folds in the power produced. Additionally, the pigments produced by the microalga were analysed and the results showed that the light intensity and PAMFC operation potentiated the carotenogenesis in the cathode compartment. The demonstrated possibility of producing added-value microalgae biomass in microbial fuel cell cathodes will increase the economic feasibility of these bioelectrochemical systems, allowing the development of energy efficient systems for wastewater treatment and carbon fixation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Visualization of the membrane engineering concept: evidence for the specific orientation of electroinserted antibodies and selective binding of target analytes.

PubMed

Kokla, Anna; Blouchos, Petros; Livaniou, Evangelia; Zikos, Christos; Kakabakos, Sotiris E; Petrou, Panagiota S; Kintzios, Spyridon

2013-12-01

Membrane engineering is a generic methodology for increasing the selectivity of a cell biosensor against a target molecule, by electroinserting target-specific receptor-like molecules on the cell surface. Previous studies have elucidated the biochemical aspects of the interaction between various analytes (including viruses) and their homologous membrane-engineered cells. In the present study, purified anti-biotin antibodies from a rabbit antiserum along with in-house prepared biotinylated bovine serum albumin (BSA) were used as a model antibody-antigen pair of molecules for facilitating membrane engineering experiments. It was proven, with the aid of fluorescence microscopy, that (i) membrane-engineered cells incorporated the specific antibodies in the correct orientation and that (ii) the inserted antibodies are selectively interacting with the homologous target molecules. This is the first time the actual working concept of membrane engineering has been visualized, thus providing a final proof of the concept behind this innovative process. In addition, the fluorescence microscopy measurements were highly correlated with bioelectric measurements done with the aid of a bioelectric recognition assay. Copyright © 2013 John Wiley & Sons, Ltd.

[Abdomen specific bioelectrical impedance analysis (BIA) methods for evaluation of abdominal fat distribution].

PubMed

Ida, Midori; Hirata, Masakazu; Hosoda, Kiminori; Nakao, Kazuwa

2013-02-01

Two novel bioelectrical impedance analysis (BIA) methods have been developed recently for evaluation of intra-abdominal fat accumulation. Both methods use electrodes that are placed on abdominal wall and allow evaluation of intra-abdominal fat area (IAFA) easily without radiation exposure. Of these, "abdominal BIA" method measures impedance distribution along abdominal anterior-posterior axis, and IAFA by BIA method(BIA-IAFA) is calculated from waist circumference and the voltage occurring at the flank. Dual BIA method measures impedance of trunk and body surface at the abdominal level and calculates BIA-IAFA from transverse and antero-posterior diameters of the abdomen and the impedance of trunk and abdominal surface. BIA-IAFA by these two BIA methods correlated well with IAFA measured by abdominal CT (CT-IAFA) with correlatipn coefficient of 0.88 (n = 91, p < 0.0001) for the former, and 0.861 (n = 469, p < 0.01) for the latter. These new BIA methods are useful for evaluating abdominal adiposity in clinical study and routine clinical practice of metabolic syndrome and obesity.

The effect of algae species on the bioelectricity and biodiesel generation through open-air cathode microbial fuel cell with kitchen waste anaerobically digested effluent as substrate.

PubMed

Hou, Qingjie; Nie, Changliang; Pei, Haiyan; Hu, Wenrong; Jiang, Liqun; Yang, Zhigang

2016-10-01

Five strains algae (Golenkinia sp. SDEC-16, Chlorella vulgaris, Selenastrum capricornutum, Scenedesmus SDEC-8 and Scenedesmus SDEC-13) were screened as an effective way to promote recover electricity from MFC for kitchen waste anaerobically digested effluent (KWADE) treatment. The highest OCV, power density, biomass concentration and total lipid content were obtained with Golenkinia sp. SDEC-16 as the co-inoculum, which were 170mV, 6255mWm(-3), 325mgL(-1) and 38%, respectively. Characteristics of the organics in KWADE were analyzed, and the result showed that the hydrophilic and acidic fractions were more readily degraded, compared to the neutral fractions during the operation. Maximum COD and TN removal efficiency were 43.59% and 37.39% when inoculated with Golenkinia sp. SDEC-16, which were roughly 3.22 and 3.04 times higher than that of S. capricornutum. This study demonstrated that Golenkinia sp. SDEC-16 was a promising species for bioelectricity generation, lipid production and KWADE treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measuring body composition in dogs using multifrequency bioelectrical impedance analysis and dual energy X-ray absorptiometry.

PubMed

Rae, L S; Vankan, D M; Rand, J S; Flickinger, E A; Ward, L C

2016-06-01

Thirty-five healthy, neutered, mixed breed dogs were used to determine the ability of multifrequency bioelectrical impedance analysis (MFBIA) to predict accurately fat-free mass (FFM) in dogs using dual energy X-ray absorptiometry (DXA)-measured FFM as reference. A second aim was to compare MFBIA predictions with morphometric predictions. MFBIA-based predictors provided an accurate measure of FFM, within 1.5% when compared to DXA-derived FFM, in normal weight dogs. FFM estimates were most highly correlated with DXA-measured FFM when the prediction equation included resistance quotient, bodyweight, and body condition score. At the population level, the inclusion of impedance as a predictor variable did not add substantially to the predictive power achieved with morphometric variables alone; in individual dogs, impedance predictors were more valuable than morphometric predictors. These results indicate that, following further validation, MFBIA could provide a useful tool in clinical practice to objectively measure FFM in canine patients and help improve compliance with prevention and treatment programs for obesity in dogs. Copyright © 2016. Published by Elsevier Ltd.

Bioelectricity production from food waste leachate using microbial fuel cells: effect of NaCl and pH.

PubMed

Li, Xiao Min; Cheng, Ka Yu; Wong, Jonathan W C

2013-12-01

Microbial fuel cells are a promising technology for simultaneous treatment and energy recovery from food waste leachate. This study evaluates the effects of NaCl (0-150 mM) and pH on the treatment of food waste leachate using microbial fuel cells. The food waste leachate amended with 100mM NaCl enabled the highest maximum power density (1000 mW/m(3)) and lowest internal resistance (371Ω). Increasing the anodic pH gradually from acidic to alkaline conditions (pH 4-9) resulted in a gradual increase in maximum power density to 9956 mW/m(3) and decrease in internal cell resistance to 35.3Ω. The coulombic efficiency obtained under acidic conditions was only 17.8%, but increased significantly to 60.0% and 63.4% in the neutral and alkaline pH's MFCs, respectively. Maintaining a narrow pH window (6.3-7.6) was essential for efficient bioelectricity production and COD removal using microbial fuel cells for the treatment of food waste leachate. Copyright © 2013 Elsevier Ltd. All rights reserved.

Determining blood and plasma volumes using bioelectrical response spectroscopy

NASA Technical Reports Server (NTRS)

Siconolfi, S. F.; Nusynowitz, M. L.; Suire, S. S.; Moore, A. D. Jr; Leig, J.

1996-01-01

We hypothesized that an electric field (inductance) produced by charged blood components passing through the many branches of arteries and veins could assess total blood volume (TBV) or plasma volume (PV). Individual (N = 29) electrical circuits (inductors, two resistors, and a capacitor) were determined from bioelectrical response spectroscopy (BERS) using a Hewlett Packard 4284A Precision LCR Meter. Inductance, capacitance, and resistance from the circuits of 19 subjects modeled TBV (sum of PV and computed red cell volume) and PV (based on 125I-albumin). Each model (N = 10, cross validation group) had good validity based on 1) mean differences (-2.3 to 1.5%) between the methods that were not significant and less than the propagated errors (+/- 5.2% for TBV and PV), 2) high correlations (r > 0.92) with low SEE (< 7.7%) between dilution and BERS assessments, and 3) Bland-Altman pairwise comparisons that indicated "clinical equivalency" between the methods. Given the limitation of this study (10 validity subjects), we concluded that BERS models accurately assessed TBV and PV. Further evaluations of the models' validities are needed before they are used in clinical or research settings.

Body composition in male elite athletes, comparison of bioelectrical impedance spectroscopy with dual energy X-ray absorptiometry

PubMed Central

Svantesson, Ulla; Zander, Martina; Klingberg, Sofia; Slinde, Frode

2008-01-01

Background The aim of this study was to compare body composition results from bioelectrical spectroscopy (BIS) with results from dual energy X-ray absorptiometry (DXA) in a population of male elite athletes. Body composition was assessed using DXA (Lunar Prodigy, GE Lunar Corp., Madison, USA) and BIS (Hydra 4200, Xitron Technologies Inc, San Diego, California, USA) at the same occasion. Agreement between methods was assessed using paired t-tests and agreement-plots. Results Thirty-three male elite athletes (soccer and ice hockey) were included in the study. The results showed that BIS underestimates the proportion of fat mass by 4.6% points in the ice hockey players. In soccer players the BIS resulted in a lower mean fat mass by 1.1% points. Agreement between the methods at the individual level was highly variable. Conclusion Body composition results assessed by BIS in elite athletes should be interpreted with caution, especially in individual subjects. BIS may present values of fat mass that is either higher or lower than fat mass assessed by DXA, independent of true fat content of the individual. PMID:18211680

Comparison of hydrostatic weighing and bioelectric impedance measurements in determining body composition pre- and postdehydration.

PubMed

Pearman, P; Hunter, G; Hendricks, C; O'Sullivan, P

1989-01-01

This study investigated the effect of dehydration on measurements of body composition by hydrostatic weighing (HW) and bioelectric impedance analysis (BIA). Ten endurance-trained male athletes between the ages of 18 and 42 years performed an endurance training session consisting of running until body weight was reduced by approximately 3%. Body composition was determined prior to exercise and immediately after exercise by HW and BIA techniques. A high correlation existed between pre- and postdehydration for both HW and BIA. Validity coefficients between HW and BIA were moderate (predehydration 0.85 and postdehydration 0.82). In addition, BIA percent fat was 3.5% higher than HW percent fat. The BIA revealed a mean loss of 2.1% fat BIA and only 0.9% fat HW after approximately 45 minutes of exercise. BIA also showed an increase in percent body water (mean = 2.6%) in all 10 subjects after dehydration. There are indications that BIA, with its present equational configuration, is measuring something other than lean body weight. J Orthop Sports Phys Ther 1989;10(11):451-455.

Airway mucosal bioelectric potential difference in cystic fibrosis after lung transplantation.

PubMed

Wood, A; Higenbottam, T; Jackson, M; Scott, J; Stewart, S; Wallwork, J

1989-12-01

Bioelectrical potential difference (PD) across the respiratory mucosa is raised in cystic fibrosis (CF). We have recorded airway potentials from seven patients with CF who had undergone heart-lung transplantation and from eight patients without CF who had had transplants for cardiovascular disease; comparison of these populations controls for the effects of denervation and immunosuppressive treatment. Six patients without CF who had not had transplants formed an additional control. PD was recorded during routine fiberoptic bronchoscopy, using a Ringer's-perfused exploring bridge connected across a high impedance amplifier to an intravenous reference bridge. Bronchial lavage and sputum culture revealed no evidence of infection. Bronchial PD was similar in all three groups of patients at equivalent sites. However, nasal PD was raised in the CF group (mean value, 44 mV +/- 3.9 SE) compared with the patients who had transplants for cardiovascular disease (mean, 18 mV +/- 1.1 SE), and the control patients (mean, 15 mV +/- 1.2 SE). We conclude that the epithelial defects that result in raised airway potentials in CF do not recur in the transplanted lung.

Investigation and optimization of the novel UASB-MFC integrated system for sulfate removal and bioelectricity generation using the response surface methodology (RSM).

PubMed

Zhang, Baogang; Zhang, Jing; Yang, Qi; Feng, Chuanping; Zhu, Yuling; Ye, Zhengfang; Ni, Jinren

2012-11-01

COD/sulfate ratio and hydraulic residence time (HRT), both of which influence sulfate loadings jointly, are recognized as the most two important affecting factors for sulfate removal and bioelectricity generation in the novel up-flow anaerobic sludge blanket reactor-microbial fuel cell (UASB-MFC) integrated system. The response surface methodology (RSM) was employed for the optimization of this system and the optimum condition with COD/sulfate ratio of 2.3 and HRT of 54.3h was obtained with the target of maximizing the power output. In terms of maximizing the total sulfate removal efficiency, the obtained optimum condition was COD/sulfate ratio of 3.7 and HRT of 55.6h. Experimental results indicated the undistorted simulation and reliable optimized results. These demonstrated that RSM was effective to evaluate and optimize the UASB-MFC system for sulfate removal and energy recovery, providing a promising guide to further improvement of the system for potential applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of oxygen and carbogen therapy effect in Meniere's disease according to clinical and electroencephalographic data

NASA Technical Reports Server (NTRS)

Boronoyev, A. B.

1980-01-01

The method of constructing fields on the basis of EEG data gives a quantitative characterization of bioelectrical activity. Fields of average rates of the change of potentials in healthy people have a well defined configuration, where the greatest rates are found in the occipital zones, lower in the frontal and parietal, and least in the temporal zones. In response to functional loads the form of the field remains the same because of a synchronous change in the average rates in both hemispheres of the cerebrum to the same extent. The configuration of the fields of background bioelectric activity of the cerebrum in people with Meniere's disease is not uniform. On the basis of this investigation, a clear correlation was found between the subjective sensations of patients during oxygen and carbogen therapy and the changes in the spatial characteristics of the field of potentials of the cerebrum. This correlation makes it possible to objectively identify the nature of the vascular disturbances in Meniere's disease, develop a pathogenetic treatment plan, and evaluate its effectiveness.

Enhanced bioelectricity harvesting in microbial fuel cells treating food waste leachate produced from biohydrogen fermentation.

PubMed

Choi, Jeongdong; Ahn, Youngho

2015-05-01

Microbial fuel cells (MFCs) treating the food waste leachate produced from biohydrogen fermentation were examined to enhance power generation and energy recovery. In batch mode, the maximum voltage production was 0.56 V and the power density reached 1540 mW/m(2). The maximum Coulombic efficiency (CEmax) and energy efficiency (EE) in the batch mode were calculated to be 88.8% and 18.8%, respectively. When the organic loading rate in sequencing batch mode varied from 0.75 to 6.2 g COD/L-d (under CEmax), the maximum power density reached 769.2 mW/m(2) in OLR of 3.1 g COD/L-d, whereas higher energy recovery (CE=52.6%, 0.346 Wh/g CODrem) was achieved at 1.51 g COD/L-d. The results demonstrate that readily biodegradable substrates in biohydrogen fermentation can be effectively used for the enhanced bioelectricity harvesting of MFCs and a MFC coupled with biohydrogen fermentation is of great benefit on higher electricity generation and energy efficiency. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of Multifrequency Bioelectrical Impedance vs. Dual-Energy X-ray Absorptiometry for Assessing Body Composition Changes After Participation in a 10-Week Resistance Training Program.

PubMed

Schoenfeld, Brad J; Nickerson, Brett S; Wilborn, Colin D; Urbina, Stacie L; Hayward, Sara B; Krieger, James; Aragon, Alan A; Tinsley, Grant M

2018-06-20

Schoenfeld, BJ, Nickerson, BS, Wilborn, CD, Urbina, SL, Hayward, SB, Krieger, J, Aragon, AA, and Tinsley, G. Comparison of multifrequency bioelectrical impedance vs. dual-energy x-ray absorptiometry for assessing body composition changes after participation in a 10-week resistance training program. J Strength Cond Res XX(X): 000-000, 2018-The purpose of this study was to assess the ability of multifrequency bioelectrical impedance analysis (MF-BIA) to determine alterations in total and segmental body composition across a 10-week resistance training (RT) program in comparison with the criterion reference dual-energy X-ray absorptiometry (DXA). Twenty-one young male volunteers (mean ± SD; age = 22.9 ± 3.0 years; height = 175.5 ± 5.9 cm; body mass = 82.9 ± 13.6 kg; body mass index = 26.9 ± 3.6) performed an RT program that included exercises for all major muscle groups. Body composition was assessed using both methods before and after the intervention; change scores were determined by subtracting pre-test values from post-test values for percent body fat ([INCREMENT]%BF), fat mass ([INCREMENT]FM), and fat-free mass ([INCREMENT]FFM). Mean changes were not significantly different when comparing MF-BIA with DXA for [INCREMENT]%BF (-1.05 vs. -1.28%), [INCREMENT]FM (-1.13 vs. -1.19 kg), and FFM (0.10 vs. 0.37 kg, respectively). Both methods showed strong agreement for [INCREMENT]%BF (r = 0.75; standard error of the estimate [SEE] = 1.15%), [INCREMENT]FM (r = 0.84; SEE 1.0 kg), and [INCREMENT]FFM (r = 0.71; SEE of 1.5 kg). The 2 methods were poor predictors of each other in regards to changes in segmental measurements. Our data indicate that MF-BIA is an acceptable alternative for tracking changes in FM and FFM during a combined diet and exercise program in young, athletic men, but segmental lean mass measurements must be interpreted with circumspection.

Urinary Creatinine Excretion, Bioelectrical Impedance Analysis, and Clinical Outcomes in Patients with CKD: The CRIC Study

PubMed Central

Xie, Dawei; Anderson, Amanda H.; Leonard, Mary B.; Reese, Peter P.; Delafontaine, Patrice; Horwitz, Edward; Kallem, Radhakrishna; Navaneethan, Sankar; Ojo, Akinlolu; Porter, Anna C.; Sondheimer, James H.; Sweeney, H. Lee; Townsend, Raymond R.; Feldman, Harold I.

2014-01-01

Background and objectives Previous studies in chronic disease states have demonstrated an association between lower urinary creatinine excretion (UCr) and increased mortality, a finding presumed to reflect the effect of low muscle mass on clinical outcomes. Little is known about the relationship between UCr and other measures of body composition in terms of the ability to predict outcomes of interest. Design, setting, participants, & measurements Using data from the Chronic Renal Insufficiency Cohort (CRIC), the relationship between UCr, fat free mass (FFM) as estimated by bioelectrical impedance analysis, and (in a subpopulation) whole-body dual-energy x-ray absorptiometry assessment of appendicular lean mass were characterized. The associations of UCr and FFM with mortality and ESRD were compared using Cox proportional hazards models. Results A total of 3604 CRIC participants (91% of the full CRIC cohort) with both a baseline UCr and FFM measurement were included; of these, 232 had contemporaneous dual-energy x-ray absorptiometry measurements. Participants were recruited between July 2003 and March 2007. UCr and FFM were modestly correlated (rho=0.50; P<0.001), while FFM and appendicular lean mass were highly correlated (rho=0.91; P<0.001). Higher urinary urea nitrogen, black race, younger age, and lower serum cystatin C level were all significantly associated with higher UCr. Over a median (interquartile range) of 4.2 (3.1–5.0) years of follow-up, 336 (9.3%) participants died and 510 (14.2%) reached ESRD. Lower UCr was associated with death and ESRD even after adjustment for FFM (adjusted hazard ratio for death per 1 SD higher level of UCr, 0.63 [95% confidence interval, 0.56 to 0.72]; adjusted hazard ratio for ESRD per 1 SD higher level of UCr, 0.70 [95% confidence interval, 0.63 to 0.75]). Conclusions Among a cohort of individuals with CKD, lower UCr is associated with death and ESRD independent of FFM as assessed by bioelectrical impedance analysis. PMID:25381342

Gap Junctional Blockade Stochastically Induces Different Species-Specific Head Anatomies in Genetically Wild-Type Girardia dorotocephala Flatworms

PubMed Central

Emmons-Bell, Maya; Durant, Fallon; Hammelman, Jennifer; Bessonov, Nicholas; Volpert, Vitaly; Morokuma, Junji; Pinet, Kaylinnette; Adams, Dany S.; Pietak, Alexis; Lobo, Daniel; Levin, Michael

2015-01-01

The shape of an animal body plan is constructed from protein components encoded by the genome. However, bioelectric networks composed of many cell types have their own intrinsic dynamics, and can drive distinct morphological outcomes during embryogenesis and regeneration. Planarian flatworms are a popular system for exploring body plan patterning due to their regenerative capacity, but despite considerable molecular information regarding stem cell differentiation and basic axial patterning, very little is known about how distinct head shapes are produced. Here, we show that after decapitation in G. dorotocephala, a transient perturbation of physiological connectivity among cells (using the gap junction blocker octanol) can result in regenerated heads with quite different shapes, stochastically matching other known species of planaria (S. mediterranea, D. japonica, and P. felina). We use morphometric analysis to quantify the ability of physiological network perturbations to induce different species-specific head shapes from the same genome. Moreover, we present a computational agent-based model of cell and physical dynamics during regeneration that quantitatively reproduces the observed shape changes. Morphological alterations induced in a genomically wild-type G. dorotocephala during regeneration include not only the shape of the head but also the morphology of the brain, the characteristic distribution of adult stem cells (neoblasts), and the bioelectric gradients of resting potential within the anterior tissues. Interestingly, the shape change is not permanent; after regeneration is complete, intact animals remodel back to G. dorotocephala-appropriate head shape within several weeks in a secondary phase of remodeling following initial complete regeneration. We present a conceptual model to guide future work to delineate the molecular mechanisms by which bioelectric networks stochastically select among a small set of discrete head morphologies. Taken together, these data and analyses shed light on important physiological modifiers of morphological information in dictating species-specific shape, and reveal them to be a novel instructive input into head patterning in regenerating planaria. PMID:26610482

Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged >60 y from rural regions of Cuba, Chile and Mexico.

PubMed

Valencia, M E; Alemán-Mateo, H; Salazar, G; Hernández Triana, M

2003-07-01

In Latin American and Caribbean countries such as Chile, Mexico and Cuba, the population over 60 y has increased steadily. In this age group, there is scarce information about body composition, particularly for those living in rural areas. The purpose of this study was to determine body composition in free-living and healthy elderly subjects >60 y from rural areas of Chile, Cuba and Mexico using deuterium oxide dilution and bioelectrical impedance (BIA) and to develop and cross-validate a predictive equation for this group of subjects by BIA for future use as a field technique. The study included 133 healthy subjects (73 males and 60 females) >60 y from rural regions of Cuba, Chile and Mexico. Total body water, body weight, height and other anthropometric and BIA variables (resistance and reactance) were measured. Total body water was determined by deuterium oxide dilution, and fat-free mass (FFM)/fat mass were derived from this measurement. The total sample was used in a split-sample internal cross-validation. BIA and other anthropometric variables were integrated to multiple regression model to design the best predictive equation, which was validated in the other sample. ANOVA, multiple regression and Bland and Altman's procedure were used to analyze the data. Body weight, percentage of fat and fat-free mass were lower in the Cuban men and women compared with Chilean and Mexican men and women. The best predictive equation of the FFM was: FFM kg=(-7.71+(H(2)/R x 0.49)+(country or ethnicity x 1.12)+(body weight x 0.27)+(sex x 3.49)+(Xc x 0.13)), where H(2) is height(2) (cm); R is resistance (Omega); country: Chile=1, Mexico=2 and Cuba=3; sex: women=0 and men=1; body weight (kg) and Xc is reactance (Omega). R(2) was 0.944 and the root mean square error (RMSE) was 2.08 kg. The mean+/-s.d. of FFM prediction was 44.2+/-9.2 vs 44.6+/-10.1. The results of cross-validation showed no significant difference with the line of identity, showing that the predicted equation was accurate. The intercept (=-0.32) was not significantly different from zero (P=0.89) and the slope (=1.02) not significantly different from 1.0 (P>0.9). The R(2) was 0.86, RMSE=3.86 kg of FFM and the pure error was 3.83. The new BIA equation is accurate, precise and showed good agreement. The use of this equation could improve the estimates of body composition for the elderly population for these regions, as well as enhancing the opportunity to conduct studies in the elderly population from Latin America.

Predictors of seizure occurrence in children undergoing pre-surgical monitoring.

PubMed

Harini, Chellamani; Singh, Kanwaljit; Takeoka, Masanori; Parulkar, Isha; Bergin, Ann Marie; Loddenkemper, Tobias; Kothare, Sanjeev V

2013-10-01

Long-Term-Monitoring (LTM) is a valuable tool for seizure localization/lateralization among children with refractory-epilepsy undergoing pre-surgical-monitoring. The aim of this study was to examine the factors predicting occurrence of single/multiple seizures in children undergoing pre-surgical monitoring in the LTM unit. Chart review was done on 95 consecutive admissions on 92 children (40 females) admitted to the LTM-unit for pre-surgical workup. Relationship between occurrence of multiple (≥ 3) seizures and factors such as home seizure-frequency, demographics, MRI-lesions/seizure-type and localization/AED usage/neurological-exam/epilepsy-duration was evaluated by logistic-regression and survival-analysis. Home seizure-frequency was further categorized into low (up-to 1/month), medium (up-to 1/week) and high (>1/week) and relationship of these categories to the occurrence of multiple seizures was evaluated. Mean length of stay was 5.24 days in all 3 groups. Home seizure frequency was the only factor predicting the occurrence of single/multiple seizures in children undergoing presurgical workup. Other factors (age/sex/MRI-lesions/seizure-type and localization/AED-usage/neurological-exam/epilepsy-duration) did not affect occurrence of single/multiple seizures or time-to-occurrence of first/second seizure. Analysis of the home-seizure frequency categories revealed that 98% admissions in high-frequency, 94% in the medium, and 77% in low-frequency group had at-least 1 seizure recorded during the monitoring. Odds of first-seizure increased in high vs. low-frequency group (p=0.01). Eighty-nine percent admissions in high-frequency, 78% in medium frequency, versus 50% in low-frequency group had ≥ 3 seizures. The odds of having ≥ 3 seizures increased in high-frequency (p=0.0005) and in medium-frequency (p=0.007), compared to low-frequency group. Mean time-to-first-seizure was 2.7 days in low-frequency, 2.1 days in medium, and 2 days in high-frequency group. Time-to-first-seizure in high and medium-frequency was less than in low-frequency group (p<0.0014 and p=0.038). Majority of the admissions (92%) admitted to the LTM-unit for pre-surgical workup had at-least one seizure during a mean length of stay of 5.24 days. Home seizure-frequency was the only predictor influencing occurrence of single/multiple seizures in the LTM unit. Patients with low seizure-frequency are at risk for completing the monitoring with less than the optimum number (<3) of seizures captured. Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Unified tensor model for space-frequency spreading-multiplexing (SFSM) MIMO communication systems

NASA Astrophysics Data System (ADS)

de Almeida, André LF; Favier, Gérard

2013-12-01

This paper presents a unified tensor model for space-frequency spreading-multiplexing (SFSM) multiple-input multiple-output (MIMO) wireless communication systems that combine space- and frequency-domain spreadings, followed by a space-frequency multiplexing. Spreading across space (transmit antennas) and frequency (subcarriers) adds resilience against deep channel fades and provides space and frequency diversities, while orthogonal space-frequency multiplexing enables multi-stream transmission. We adopt a tensor-based formulation for the proposed SFSM MIMO system that incorporates space, frequency, time, and code dimensions by means of the parallel factor model. The developed SFSM tensor model unifies the tensorial formulation of some existing multiple-access/multicarrier MIMO signaling schemes as special cases, while revealing interesting tradeoffs due to combined space, frequency, and time diversities which are of practical relevance for joint symbol-channel-code estimation. The performance of the proposed SFSM MIMO system using either a zero forcing receiver or a semi-blind tensor-based receiver is illustrated by means of computer simulation results under realistic channel and system parameters.

Multiple sclerosis affects the frequency content in the vertical ground reaction forces during walking.

PubMed

Wurdeman, Shane R; Huisinga, Jessie M; Filipi, Mary; Stergiou, Nicholas

2011-02-01

Multiple sclerosis is a progressive neurological disease that results in a high incident of gait disturbance. Exploring the frequency content of the ground reaction forces generated during walking may provide additional insights to gait in patients with multiple sclerosis that could lead to specific tools for differential diagnosis. The purpose of this study was to investigate differences in the frequency content of these forces in an effort to contribute to improved clinical management of this disease. Eighteen patients and eighteen healthy controls walked across a 10 meter long walkway. The anterior-posterior and vertical ground reaction forces generated during the stance phase of gait were evaluated in the frequency domain using fast Fourier transformation. T-tests were utilized for comparison of median frequency, the 99.5% frequency, and the frequency bandwidth between patients and healthy controls and also for comparisons between patients with mild and moderate severity. Patients with multiple sclerosis had significantly lower 99.5% frequency (P=0.006) and median frequency (P<0.001) in the vertical ground reaction force. No differences were found in the anterior-posterior reaction force frequency content. There were no differences between patients with mild and moderate severity. The lower frequency content suggests lesser vertical oscillation of the center of gravity. Lack of differences between severities may suggest presence of differences prior to currently established diagnosis timelines. Analysis of the frequency content may potentially serve to provide earlier diagnostic assessment of this debilitating disease. Copyright © 2010 Elsevier Ltd. All rights reserved.

A Persistent Feature of Multiple Scattering of Waves in the Time-Domain: A Tutorial

NASA Technical Reports Server (NTRS)

Lock, James A.; Mishchenko, Michael I.

2015-01-01

The equations for frequency-domain multiple scattering are derived for a scalar or electromagnetic plane wave incident on a collection of particles at known positions, and in the time-domain for a plane wave pulse incident on the same collection of particles. The calculation is carried out for five different combinations of wave types and particle types of increasing geometrical complexity. The results are used to illustrate and discuss a number of physical and mathematical characteristics of multiple scattering in the frequency- and time-domains. We argue that frequency-domain multiple scattering is a purely mathematical construct since there is no temporal sequencing information in the frequency-domain equations and since the multi-particle path information can be dispelled by writing the equations in another mathematical form. However, multiple scattering becomes a definite physical phenomenon in the time-domain when the collection of particles is illuminated by an appropriately short localized pulse.

Methods, computer readable media, and graphical user interfaces for analysis of frequency selective surfaces

DOEpatents

Kotter, Dale K [Shelley, ID; Rohrbaugh, David T [Idaho Falls, ID

2010-09-07

A frequency selective surface (FSS) and associated methods for modeling, analyzing and designing the FSS are disclosed. The FSS includes a pattern of conductive material formed on a substrate to form an array of resonance elements. At least one aspect of the frequency selective surface is determined by defining a frequency range including multiple frequency values, determining a frequency dependent permittivity across the frequency range for the substrate, determining a frequency dependent conductivity across the frequency range for the conductive material, and analyzing the frequency selective surface using a method of moments analysis at each of the multiple frequency values for an incident electromagnetic energy impinging on the frequency selective surface. The frequency dependent permittivity and the frequency dependent conductivity are included in the method of moments analysis.

[Role of the midbrain reticular formation in hormonal supply to the body in conditions of chronic emotional stress].

PubMed

Amiragova, M G; Arakhangel'skaia, M I

1983-08-01

Chronic animal experiments were made to study the endocrine and electroencephalographic responses of the cortico-subcortical structures to stress before and after coagulation of the midbrain reticular formation. The operation entailed dramatic changes in both the bioelectrical responses and thyroid and adrenal responses, which were found to be differentiated.

Obesity and Motor Coordination Ability in Taiwanese Children with and without Developmental Coordination Disorder

ERIC Educational Resources Information Center

Zhu, Yi-Ching; Wu, Sheng K.; Cairney, John

2011-01-01

The purpose of this study was to investigate the associations between obesity and motor coordination ability in Taiwanese children with and without developmental coordination disorder (DCD). 2029 children (1078 boys, 951 girls) aged nine to ten years were chosen randomly from 14 elementary schools across Taiwan. We used bioelectrical impedance…

Utilization of eucalyptus for bioelectricity production in brazil via fast pyrolysis: a techno-economic analysis

USDA-ARS?s Scientific Manuscript database

In this study, a process model of a 2000 metric ton per day (MTPD) eucalyptus Tail Gas Reactive Pyrolysis (TGRP) and electricity generation plant was developed and simulated in SimSci Pro/II software for the purpose of evaluating its techno-economic viability in Brazil. Two scenarios were compared b...

Relationship between body fat and BMI in a U.S. Hispanic population-based cohort study: Results from HCHS/SOL

USDA-ARS?s Scientific Manuscript database

To evaluate the percentage of body fat (%BF)-BMI relationship, identify %BF levels corresponding to adult BMI cut points, and examine %BF-BMI agreement in a diverse Hispanic/Latino population. %BF by bioelectrical impedance analysis was corrected against %BF by 18O dilution in 434 participants of th...

Biomedical Interdisciplinary Curriculum Project: BIP (Biomedical Instrumentation Package) User's Manual.

ERIC Educational Resources Information Center

Biomedical Interdisciplinary Curriculum Project, Berkeley, CA.

Described is the Biomedical Instrument Package (BIP) and its use. The BIP was developed for use in understanding colorimetry, sound, electricity, and bioelectric phenomena. It can also be used in a wide range of measurements such as current, voltage, resistance, temperature, and pH. Though it was developed primarily for use in biomedical science…

Effect of Bioenergy Demands and Supply Response on Markets, Carbon, and Land Use

Treesearch

Karen L. Abt; Robert C. Abt; Christopher Galik

2012-01-01

An increase in the demand for wood for energy, including liquid fuels, bioelectricity, and pellets, has the potential to affect traditional wood users, forestland uses, management intensities, and, ultimately, carbon sequestration. Recent studies have shown that increases in bioenergy harvests could lead to displacement of traditional wood-using industries in the short...

What makes a BIA equation unique? Validity of 8-electrode multifrequency-BIA to estimate body compostion in a healthy adult population

USDA-ARS?s Scientific Manuscript database

The validity of bioelectrical impedance analysis (BIA) for body composition analysis is limited by assumptions relating to body shape. Improvement in BIA technology could overcome these limitations and reduce the population specificity of the BIA algorithm. BIA equations for the prediction of fat ...

Multiple frequency method for operating electrochemical sensors

DOEpatents

Martin, Louis P [San Ramon, CA

2012-05-15

A multiple frequency method for the operation of a sensor to measure a parameter of interest using calibration information including the steps of exciting the sensor at a first frequency providing a first sensor response, exciting the sensor at a second frequency providing a second sensor response, using the second sensor response at the second frequency and the calibration information to produce a calculated concentration of the interfering parameters, using the first sensor response at the first frequency, the calculated concentration of the interfering parameters, and the calibration information to measure the parameter of interest.

An electrical bio-chip to transfer and detect electromagnetic stimulation on the cells based on vertically aligned carbon nanotubes.

PubMed

Rafizadeh-Tafti, Saeed; Haqiqatkhah, Mohammad Hossein; Saviz, Mehrdad; Janmaleki, Mohsen; Faraji Dana, Reza; Zanganeh, Somayeh; Abdolahad, Mohammad

2017-01-01

A highly sensitive impedimetric bio-chip based on vertically aligned multiwall carbon nanotubes (VAMWCNTs), was applied in direct interaction with lung cancer cells. Our tool provided both inducing and monitoring the bioelectrical changes in the cells initiated by electromagnetic (EM) wave stimulation. EM wave of 940MHz frequency with different intensities was used. Here, wave ablation might accumulate electrical charge on the tips of nanotubes penetrated into cell's membrane. The charge might induce ionic exchanges into the cell and cause alterations in electrical states of the membrane. Transmembrane electrostatic/dynamic states would be strongly affected due to such exchanges. Our novel modality was that, the cells' vitality changes caused by charge inductions were electrically detected with the same nanotubes in the architecture of electrodes for impedance measurement. The responses of the sensor were confirmed by electron and florescent microscopy images as well as biological assays. In summation, our method provided an effective biochip for enhancing and detecting external EM stimulation on the cells useful for future diagnostic and therapeutic applications, such as wave-guided drug-resistance breakage. Copyright © 2016 Elsevier B.V. All rights reserved.

Endogenous electric fields as guiding cue for cell migration

PubMed Central

Funk, Richard H. W.

2015-01-01

This review covers two topics: (1) “membrane potential of low magnitude and related electric fields (bioelectricity)” and (2) “cell migration under the guiding cue of electric fields (EF).”Membrane potentials for this “bioelectricity” arise from the segregation of charges by special molecular machines (pumps, transporters, ion channels) situated within the plasma membrane of each cell type (including eukaryotic non-neural animal cells). The arising patterns of ion gradients direct many cell- and molecular biological processes such as embryogenesis, wound healing, regeneration. Furthermore, EF are important as guiding cues for cell migration and are often overriding chemical or topographic cues. In osteoblasts, for instance, the directional information of EF is captured by charged transporters on the cell membrane and transferred into signaling mechanisms that modulate the cytoskeleton and motor proteins. This results in a persistent directional migration along an EF guiding cue. As an outlook, we discuss questions concerning the fluctuation of EF and the frequencies and mapping of the “electric” interior of the cell. Another exciting topic for further research is the modeling of field concepts for such distant, non-chemical cellular interactions. PMID:26029113

Muscle performance, body fat, pain and function in the elderly with arthritis.

PubMed

Dos Santos, Wagner Teixeira; Rodrigues, Erika de Carvalho; Mainenti, Míriam Raquel Meira

2014-01-01

To correlate muscule performance, body composition, pain and joint function in elderly people with gonarthrosis. 21 elderly patients were submitted to bioelectrical impedance analysis, dynamometry associated with electromyographic (EMG) evaluation of isometric knee extension, in addition to pain assessment by the Numeric Pain Intensity Scale and function assessment, by the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis (OA) questionnaire. Correlations were checked by the Pearson's correlation coefficient. The sample characteristics were mean age 67.36 ± 4.21 years old, body fat percentage 40.57±6.15%, total WOMAC score 43.27 ± 16.32%, and maximum strength 19.95 ± 6.99 kgF. Pain during movement showed a statistical association with WOMAC physical activity domain (r = 0.47) and its general score (r = 0.51); pain intensity at night presented association with WOMAC stiffness domain (r = 0.55), in addition to the negative correlation with the slope values of the Medium Frequency of the EMG signal (r = - 0.57). pain intensity is correlated to functional incapacity in elderly people with knee OA and to a greater expression of fatigue in EMG signal. Levels of Evidence III, Study of non consecutive patients.

Diet, growth, and obesity development throughout childhood in the Avon Longitudinal Study of Parents and Children

PubMed Central

Jones, Louise R.

2015-01-01

Publications from the Avon Longitudinal Study of Parents and Children covering diet, growth, and obesity development during childhood are reviewed. Diet was assessed by food frequency questionnaires and food records. Growth data were collected by routine measurements, and in standardized clinics, body fatness was assessed by bioelectrical impedance and DXA (dual-energy X-ray absorptiometry) scans. Diets changed dramatically during the preschool period with an increase in the intake of free (added) sugars (12.3% rising to 16.4% of energy) that remained similar until adolescence. This was due to increased intake of energy-dense, nutrient-poor foods. Two periods of rapid growth were identified; infancy and mid-childhood (ages 7–11 y) and both were associated with obesity development. Diets with high energy density were associated with increasing fat mass from mid-childhood until adolescence. Genetic and dietary factors showed independent associations with increasing adiposity. At all ages studied, there were dietary inequalities related to maternal educational attainment that may influence inequalities found in obesity development. The Avon Longitudinal Study of Parents and Children has provided valuable insights into how disparities in diet and growth may affect the development of ill health in adulthood. PMID:26395342

Smart Phase Tuning in Microwave Photonic Integrated Circuits Toward Automated Frequency Multiplication by Design

NASA Astrophysics Data System (ADS)

Nabavi, N.

2018-07-01

The author investigates the monitoring methods for fine adjustment of the previously proposed on-chip architecture for frequency multiplication and translation of harmonics by design. Digital signal processing (DSP) algorithms are utilized to create an optimized microwave photonic integrated circuit functionality toward automated frequency multiplication. The implemented DSP algorithms are formed on discrete Fourier transform and optimization-based algorithms (Greedy and gradient-based algorithms), which are analytically derived and numerically compared based on the accuracy and speed of convergence criteria.

Hybrid spread spectrum radio system

DOEpatents

Smith, Stephen F [London, TN; Dress, William B [Camas, WA

2010-02-09

Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

Phase discriminating capacitive array sensor system

NASA Technical Reports Server (NTRS)

Vranish, John M. (Inventor); Rahim, Wadi (Inventor)

1993-01-01

A phase discriminating capacitive sensor array system which provides multiple sensor elements which are maintained at a phase and amplitude based on a frequency reference provided by a single frequency stabilized oscillator. Sensor signals provided by the multiple sensor elements are controlled by multiple phase control units, which correspond to the multiple sensor elements, to adjust the sensor signals from the multiple sensor elements based on the frequency reference. The adjustment made to the sensor signals is indicated by output signals which indicate the proximity of the object. The output signals may also indicate the closing speed of the object based on the rate of change of the adjustment made, and the edges of the object based on a sudden decrease in the adjustment made.

Sarcopenia is associated with an increased risk of advanced colorectal neoplasia.

PubMed

Park, Youn Su; Kim, Ji Won; Kim, Byeong Gwan; Lee, Kook Lae; Lee, Jae Kyung; Kim, Joo Sung; Koh, Seong-Joon

2017-04-01

Although sarcopenia is associated with an increased risk for mortality after the curative resection of colorectal cancer, its influence on the development of advanced colonic neoplasia remains unclear. This study included 1270 subjects aged 40 years or older evaluated with first-time screening colonoscopy at Seoul National University Boramae Health Care Center from January 2010 to February 2015. Skeletal muscle mass was measured with a body composition analyzer (direct segmental multifrequency bioelectrical impedance analysis method). Multiple logistic regression analysis was performed to determine whether sarcopenia is associated with advanced colorectal neoplasia. Of 1270 subjects, 139 (10.9%) were categorized into the sarcopenia group and 1131 (89.1%) into the non-sarcopenia group. In the non-sarcopenia group, 55 subjects (4.9%) had advanced colorectal neoplasia. However, in the sarcopenia group, 19 subjects (13.7%) had advanced colorectal neoplasia, including 1 subject with invasive colorectal cancer (0.7%). In addition, subjects with sarcopenia had a higher prevalence of advanced adenoma (P < 0.001) than those without sarcopenia. According to the multiple logistic regression analysis adjusted for variable confounders, age (odds ratio 1.062, 95% confidence interval 1.032-1.093; P < 0.001), male sex (odds ratio 1.749, 95% confidence interval 1.008-3.036; P = 0.047), and sarcopenia (odds ratio 2.347, 95% confidence interval 1.311-4.202; P = 0.004) were associated with an advanced colorectal neoplasia. Sarcopenia is associated with an increased risk of advanced colorectal neoplasia.

Millimeter-wave monolithic diode-grid frequency multiplier

NASA Technical Reports Server (NTRS)

Maserjian, Joseph (Inventor)

1990-01-01

A semiconductor diode structure useful for harmonic generation of millimeter or submillimeter wave radiation from a fundamental input wave is fabricated on a GaAs substrate. A heavily doped layer of n(sup ++) GaAs is produced on the substrate and then a layer of intrinsic GaAs on said heavily doped layer on top of which a sheet of heavy doping (++) is produced. A thin layer of intrinsic GaAs grown over the sheet is capped with two metal contacts separated by a gap to produce two diodes connected back to back through the n(sup ++) layer for multiplication of frequency by an odd multiple. If only one metal contact caps the thin layer of intrinsic GaAs, the second diode contact is produced to connect to the n(sup ++) layer for multiplication of frequency by an even number. The odd or even frequency multiple is selected by a filter. A phased array of diodes in a grid will increase the power of the higher frequency generated.

How-To-Do-It: Multiple Allelic Frequencies in Populations at Equilibrium: Algorithms and Applications.

ERIC Educational Resources Information Center

Nussbaum, Francis, Jr.

1988-01-01

Presents an algorithm for solving problems related to multiple allelic frequencies in populations at equilibrium. Considers sample problems and provides their solution using this tabular algorithm. (CW)

Tunable optical frequency comb enabled scalable and cost-effective multiuser orthogonal frequency-division multiple access passive optical network with source-free optical network units.

PubMed

Chen, Chen; Zhang, Chongfu; Liu, Deming; Qiu, Kun; Liu, Shuang

2012-10-01

We propose and experimentally demonstrate a multiuser orthogonal frequency-division multiple access passive optical network (OFDMA-PON) with source-free optical network units (ONUs), enabled by tunable optical frequency comb generation technology. By cascading a phase modulator (PM) and an intensity modulator and dynamically controlling the peak-to-peak voltage of a PM driven signal, a tunable optical frequency comb source can be generated. It is utilized to assist the configuration of a multiple source-free ONUs enhanced OFDMA-PON where simultaneous and interference-free multiuser upstream transmission over a single wavelength can be efficiently supported. The proposed multiuser OFDMA-PON is scalable and cost effective, and its feasibility is successfully verified by experiment.

Corti's organ physiology-based cochlear model: a microelectronic prosthetic implant

NASA Astrophysics Data System (ADS)

Rios, Francisco; Fernandez-Ramos, Raquel; Romero-Sanchez, Jorge; Martin, Jose Francisco

2003-04-01

Corti"s Organ is an Electro-Mechanical transducer that allows the energy coupling between acoustical stimuli and auditory nerve. Although the structure and funtionality of this organ are complex, state of the art models have been currently developed and tested. Cochlea model presented in this paper is based on the theories of Bekesy and others and concerns on the behaviour of auditory system on frequency-place domain and mechanisms of lateral inhibition. At the same time, present state of technology will permit us developing a microsystem that reproduce this phenomena applied to hearing aid prosthesis. Corti"s Organ is composed of more than 20.000 cilia excited by mean of travelling waves. These waves produce relative pressures distributed along the cochlea, exciting an specific number of cilia in a local way. Nonlinear mechanisms of local adaptation to the intensity (external cilia cells) and lateral inhibition (internal cilia cells) allow the selection of very few elements excited. These transmit a very precise intensity and frequency information. These signals are the only ones coupled to the auditory nerve. Distribution of pressure waves matches a quasilogaritmic law due to Cochlea morphology. Microsystem presented in this paper takes Bark"s law as an approximation to this behaviour consisting on grouped arbitrary elements composed of a set of selective coupled exciters (bank of filters according to Patterson"s model).These sets apply the intensity adaptation principles and lateral inhibition. Elements excited during the process generate a bioelectric signal in the same way than cilia cell. A microelectronic solution is presented for the development of an implantable prosthesis device.

Multiple Frequency Contrast Source Inversion Method for Vertical Electromagnetic Profiling: 2D Simulation Results and Analyses

NASA Astrophysics Data System (ADS)

Li, Jinghe; Song, Linping; Liu, Qing Huo

2016-02-01

A simultaneous multiple frequency contrast source inversion (CSI) method is applied to reconstructing hydrocarbon reservoir targets in a complex multilayered medium in two dimensions. It simulates the effects of a salt dome sedimentary formation in the context of reservoir monitoring. In this method, the stabilized biconjugate-gradient fast Fourier transform (BCGS-FFT) algorithm is applied as a fast solver for the 2D volume integral equation for the forward computation. The inversion technique with CSI combines the efficient FFT algorithm to speed up the matrix-vector multiplication and the stable convergence of the simultaneous multiple frequency CSI in the iteration process. As a result, this method is capable of making quantitative conductivity image reconstruction effectively for large-scale electromagnetic oil exploration problems, including the vertical electromagnetic profiling (VEP) survey investigated here. A number of numerical examples have been demonstrated to validate the effectiveness and capacity of the simultaneous multiple frequency CSI method for a limited array view in VEP.

Suppressing multiples using an adaptive multichannel filter based on L1-norm

NASA Astrophysics Data System (ADS)

Shi, Ying; Jing, Hongliang; Zhang, Wenwu; Ning, Dezhi

2017-08-01

Adaptive subtraction is an important link for removing surface-related multiples in the wave equation-based method. In this paper, we propose an adaptive multichannel subtraction method based on the L1-norm. We achieve enhanced compensation for the mismatch between the input seismogram and the predicted multiples in terms of the amplitude, phase, frequency band, and travel time. Unlike the conventional L2-norm, the proposed method does not rely on the assumption that the primary and the multiples are orthogonal, and also takes advantage of the fact that the L1-norm is more robust when dealing with outliers. In addition, we propose a frequency band extension via modulation to reconstruct the high frequencies to compensate for the frequency misalignment. We present a parallel computing scheme to accelerate the subtraction algorithm on graphic processing units (GPUs), which significantly reduces the computational cost. The synthetic and field seismic data tests show that the proposed method effectively suppresses the multiples.

JPRS Report, Science & Technology, USSR: Life Sciences.

DTIC Science & Technology

1987-08-12

between the structure and effect of hallucinogens is beyond the scope of this article. It should be noted though that in the phenylethylamine series...The majority of derivatives of alpha-methyl- phenylethylamine (amphetamine) surpass mescaline with respect to their hallucinogenic effect . Thus...Metlitskiy (deceased), Yu. T. Dyakov, et al. ZHURNAL OBSHCHEY BIOLOGII, No 6, Nov-Dec 86) Effect of Dehydration and Heating on Bioelectrical

Electroreception in the ratfish (Hydrolagus colliei).

PubMed

Fields, R D; Lange, G D

1980-02-01

Behavioral and neurophysiological experiments and anatomical work indicate that the ampullar structures on the head of fish of the subclass Holocephali are sense organs responsive to weak electric fields and are functionally and structurally homologous to the ampullae of Lorenzini in elasmobranchs. It is concluded that, as in elasmobranchs, these organs are used to detect bioelectric and other natural electric phenomena in the environment.

Relationships among dual-energy X-ray absorptiometry (DXA), bioelectrical impedance (BIA), and ultrasound measurements of body composition of swine

USDA-ARS?s Scientific Manuscript database

In three separate studies (156 pigs total), DXA, BIA, and ultrasound were compared as methods for measuring live body composition of pigs at 60 and 100-110 kg BWt. DXA measured total body fat and lean content, BIA measurements of resistance (Rs) and reactance (Xc) were used to calculate total body l...

Fossilized bioelectric wire - the trace fossil Trichichnus

NASA Astrophysics Data System (ADS)

Kędzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

2014-12-01

The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the interface oxic - anoxic zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that produced by modern large, mat-forming, sulphide-oxidizing bacteria, belonging mostly to Trichichnus-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized "electric wire".

Fossilized bioelectric wire - the trace fossil Trichichnus

NASA Astrophysics Data System (ADS)

Kędzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

2015-04-01

The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the oxic-anoxic interface zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus, formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that it is produced by modern large, mat-forming, sulfide-oxidizing bacteria, belonging mostly to Thioploca-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized "electric wire".

Enhanced bioelectricity generation and azo dye treatment in a reversible photo-bioelectrochemical cell by using novel anthraquinone-2,6-disulfonate (AQDS)/MnOx-doped polypyrrole film electrodes.

PubMed

Sun, Jian; Cai, Bihai; Xu, Wenjing; Huang, Yu; Zhang, Yaping; Peng, Yenping; Chang, Kenlin; Kuo, Jiahong; Chen, Kufan; Ning, Xunan; Liu, Guoguang; Wang, Yujie; Yang, Zuoyi; Liu, Jingyong

2017-02-01

A novel anthraquinone-2,6-disulfonate/MnO x -doped polypyrrole film (AQDS/Mn/PPy) electrode was prepared by one-step electropolymerization method and was used to improve performance of a reversible photo-bioelectrochemical cell (RPBEC). The RPBEC was operated in polarity reversion depended on dark/light reaction of alga Chlorella vulgaris by which sequential decolorization of azo dye and mineralization of decolorization products coupled with bioelectricity generation can be achieved. The results showed that formation of uniform AQDS/Mn/PPy film significantly enhanced electroactive surface area and electrocatalytic activity of carbon electrode. The RPBEC with AQDS/Mn/PPy electrodes demonstrated 77% increases in maximum power and 73% increases in Congo red decolorization rate before polarity reversion, and 198% increases in maximum power and 138% increases in decolorization products mineralization rate after polarity reversion, respectively, compared to the RPBEC with bare electrode. This was resulted from simultaneous dynamics improvement in half-reaction rate of anode and photo-biocathode due to enhanced electron transfer and algal-bacterial biofilm formation. Copyright © 2016 Elsevier Ltd. All rights reserved.

A programmable laboratory testbed in support of evaluation of functional brain activation and connectivity.

PubMed

Barbour, Randall L; Graber, Harry L; Xu, Yong; Pei, Yaling; Schmitz, Christoph H; Pfeil, Douglas S; Tyagi, Anandita; Andronica, Randy; Lee, Daniel C; Barbour, San-Lian S; Nichols, J David; Pflieger, Mark E

2012-03-01

An important determinant of the value of quantitative neuroimaging studies is the reliability of the derived information, which is a function of the data collection conditions. Near infrared spectroscopy (NIRS) and electroencelphalography are independent sensing domains that are well suited to explore principal elements of the brain's response to neuroactivation, and whose integration supports development of compact, even wearable, systems suitable for use in open environments. In an effort to maximize the translatability and utility of such resources, we have established an experimental laboratory testbed that supports measures and analysis of simulated macroscopic bioelectric and hemodynamic responses of the brain. Principal elements of the testbed include 1) a programmable anthropomorphic head phantom containing a multisignal source array embedded within a matrix that approximates the background optical and bioelectric properties of the brain, 2) integrated translatable headgear that support multimodal studies, and 3) an integrated data analysis environment that supports anatomically based mapping of experiment-derived measures that are directly and not directly observable. Here, we present a description of system components and fabrication, an overview of the analysis environment, and findings from a representative study that document the ability to experimentally validate effective connectivity models based on NIRS tomography.

Enhanced Shewanella biofilm promotes bioelectricity generation.

PubMed

Liu, Ting; Yu, Yang-Yang; Deng, Xiao-Peng; Ng, Chun Kiat; Cao, Bin; Wang, Jing-Yuan; Rice, Scott A; Kjelleberg, Staffan; Song, Hao

2015-10-01

Electroactive biofilms play essential roles in determining the power output of microbial fuel cells (MFCs). To engineer the electroactive biofilm formation of Shewanella oneidensis MR-1, a model exoelectrogen, we herein heterologously overexpressed a c-di-GMP biosynthesis gene ydeH in S. oneidensis MR-1, constructing a mutant strain in which the expression of ydeH is under the control of IPTG-inducible promoter, and a strain in which ydeH is under the control of a constitutive promoter. Such engineered Shewanella strains had significantly enhanced biofilm formation and bioelectricity generation. The MFCs inoculated with these engineered strains accomplished a maximum power density of 167.6 ± 3.6 mW/m(2) , which was ∼ 2.8 times of that achieved by the wild-type MR-1 (61.0 ± 1.9 mW/m(2) ). In addition, the engineered strains in the bioelectrochemical system at poised potential of 0.2 V vs. saturated calomel electrode (SCE) generated a stable current density of 1100 mA/m(2) , ∼ 3.4 times of that by wild-type MR-1 (320 mA/m(2) ). © 2015 Wiley Periodicals, Inc.

Dark fermentation, anaerobic digestion and microbial fuel cells: An integrated system to valorize swine manure and rice bran.

PubMed

Schievano, Andrea; Sciarria, Tommy Pepè; Gao, Yong Chang; Scaglia, Barbara; Salati, Silvia; Zanardo, Marina; Quiao, Wei; Dong, Renjie; Adani, Fabrizio

2016-10-01

This work describes how dark fermentation (DF), anaerobic digestion (AD) and microbial fuel cells (MFC) and solid-liquid separation can be integrated to co-produce valuable biochemicals (hydrogen and methane), bioelectricity and biofertilizers. Two integrated systems (System 1: AD+MFC, and System 2: DF+AD+MFC) are described and compared to a traditional one-stage AD system in converting a mixture (COD=124±8.1gO2kg(-1)Fresh Matter) of swine manure and rice bran. System 1 gave a biomethane yield of 182 LCH4kg(-1)COD-added, while System 2 gave L yields of bio-hydrogen and bio-methane of 27.3±7.2LH2kg(-1)COD-added and 154±14LCH4kg(-1)COD-added, respectively. A solid-liquid separation (SLS) step was applied to the digested slurry, giving solid and liquid fractions. The liquid fraction was treated via the MFC-steps, showing power densities of 12-13Wm(-3) (500Ω) and average bioelectricity yields of 39.8Whkg(-1)COD to 54.2Whkg(-1)COD. Copyright © 2016 Elsevier Ltd. All rights reserved.

Body composition of adult cystic fibrosis patients and control subjects as determined by densitometry, bioelectrical impedance, total-body electrical conductivity, skinfold measurements, and deuterium oxide dilution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Newby, M.J.; Keim, N.L.; Brown, D.L.

1990-08-01

This study contrasts body compositions (by six methods) of eight cystic fibrosis (CF) subjects with those of eight control subjects matched for age, height, and sex. CF subjects weighed 84% as much as control subjects. Densitometry and two bioelectrical impedance-analysis methods suggested that reduced CF weights were due to less lean tissue (10.7, 9.5, and 10.4 kg). Total-body electrical conductivity (TOBEC) and skinfold-thickness measurements indicated that CF subjects were leaner than control subjects and had less fat (5.4 and 3.6 kg) and less lean (5.2 and 7 kg) tissue. D2O dilution showed a pattern similar to TOBEC (8.3 kg lessmore » lean, 2.7 kg less fat tissue). Densitometry estimates of fat (mass and percent) were not correlated (r less than 0.74, p greater than 0.05) with any other method for CF subjects but were correlated with all other methods for control subjects. CF subjects contained less fat and lean tissue than did control subjects. Densitometry by underwater weighing is unsuitable for assessing body composition of CF patients.« less

Nutritional support and growth in thalassaemia major

PubMed Central

Fuchs, G; Tienboon, P; Khaled, M; Nimsakul, S; Linpisarn, S; Faruque, A; Yutrabootr, Y; Dewier, M; Suskind, R

1997-01-01

Accepted 30 January 1997
 Twelve thalassaemic children under 3 years of age received intensive nutritional support for one month and were discharged on a prescribed diet of locally available foods. Anthropometry, bioelectrical impedance analysis and dietary intake were longitudinally assessed. Mean energy intake was 20% greater than the recommended daily allowance during nutritional supplementation as compared with below the recommended daily allowance before and after the period of nutritional support. Weight, but not height, significantly increased during the support period and was due to increases in both fat free mass and fat mass. Body weight, fat free mass and fat mass declined in line with the reduced intake upon return home; however, height velocity accelerated and exceeded normal through the fourth month before resuming a below normal rate. It can be concluded that (1) nutritional stunting as the result of reduced nutrient intake is an important cause of growth failure in young children with thalassaemia and is responsive to nutritional support, (2) the deficit in height velocity was due to retarded truncal height growth, and (3) the bioelectrical impedance analysis method is suitable for body composition analysis of thalassaemic children.

 PMID:9245848

Assessment of fat-free mass from bioelectrical impedance analysis in obese women with Prader-Willi syndrome.

PubMed

Bedogni, Giorgio; Grugni, Graziano; Tringali, Gabriella; Agosti, Fiorenza; Sartorio, Alessandro

2015-01-01

Fat-free mass (FFM) is lower in obese subjects with Prader-Willi syndrome (PWS) than in obese subjects without PWS. FFM prediction equations developed in non-PWS subjects may, thus, not work in PWS subjects. To test whether the estimation of FFM from bioelectrical impedance analysis (BIA) in PWS subjects requires population-specific equations. Using dual-energy X-ray absorptiometry, this study measured FFM in 27 PWS and 56 non-PWS obese women and evaluated its association with the impedance index at 50 kHz (ZI50), i.e. the ratio between squared height and whole-body impedance at 50 kHz. At the same level of ZI50, PWS women had a lower FFM than non-PWS women. However, when PWS-specific equations were used, FFM was accurately estimated at the population level. An equation employing a dummy variable coding for PWS status was able to explain 85% of the variance of FFM with a root mean squared error of 3.3 kg in the pooled sample (n = 83). Population-specific equations are needed to estimate FFM from BIA in obese PWS women.

Effects of redox and sulfhydryl reagents on the bioelectric properties of the giant axon of the squid.

PubMed

Huneeus-Cox, F; Fernandez, H L; Smith, B H

1966-09-01

The effects of internally and externally applied sulfhydryl reagents on the bioelectric properties of the giant axon of the squid Loligo pealeii and Dosidicus gigas were studied. Cysteine-HCl (400 mM, pH 7.3) was used to remove axoplasm from the perfusion channel. Oxidizing agents (1 to 60 mM) tended to increase the duration of the action potential and had a slow, irreversible blocking effect when perfused internally; the membrane potential was little affected. Reducing agents applied internally caused a decrease in the spike duration without affecting its height or the membrane potential, although at high concentrations there was reversible deterioration of the action potential. Both external and internal perfusion of mercaptide-forming reagents caused deterioration in the action and membrane potentials with conduction block occurring in 5 to 45 min. 2-mercaptoethanol reversed the effects. Thiol alkylating reagents, iodoacetate and iodoacetamide, were without effect. N-ethylmaleimide did, however, block. Tests with chelating agents for nonheme iron in the membrane brought about no change in the electrical parameters. The implications of the present findings with regard to the macromolecular mechanism of excitation are discussed.

Effects of Redox and Sulfhydryl Reagents on the Bioelectric Properties of the Giant Axon of the Squid

PubMed Central

Huneeus-Cox, F.; Fernandez, H. L.; Smith, B. H.

1966-01-01

The effects of internally and externally applied sulfhydryl reagents on the bioelectric properties of the giant axon of the squid Loligo pealeii and Dosidicus gigas were studied. Cysteine-HCl (400 mM, pH 7.3) was used to remove axoplasm from the perfusion channel. Oxidizing agents (1 to 60 mM) tended to increase the duration of the action potential and had a slow, irreversible blocking effect when perfused internally; the membrane potential was little affected. Reducing agents applied internally caused a decrease in the spike duration without affecting its height or the membrane potential, although at high concentrations there was reversible deterioration of the action potential. Both external and internal perfusion of mercaptide-forming reagents caused deterioration in the action and membrane potentials with conduction block occurring in 5 to 45 min. 2-mercaptoethanol reversed the effects. Thiol alkylating reagents, iodoacetate and iodoacetamide, were without effect. N-ethylmaleimide did, however, block. Tests with chelating agents for nonheme iron in the membrane brought about no change in the electrical parameters. The implications of the present findings with regard to the macromolecular mechanism of excitation are discussed. ImagesFigure 1 PMID:5970570

Some changes of the heart bioelectric activity at the cosmonauts under the influence of LBNP in the long duration flights.

PubMed

Shelepnevich, S O; Alferova, I V; Golybchicova, Z A

2004-07-01

There was selected the group of the cosmonauts, who carry out long duration flights on the orbital complex "Mir", in which the tolerance of LBNP test was evaluated as poor (by hemodynamic indices--heart rate, arterial pressure, rheoencephalographic indices). The in-depth analysis of the electrocardiogram (in DS leads) indices was carry oiled on possible disturbances of conductivity and dynamics of temporary or amplitude characteristics. Furthermore is carry oiled the comparative estimation of these indices with the results of ECG analysis at the cosmonauts, who tolerance test good. Studies showed that the most informative ECG indices are the R, T-amplitudes and QT-interval. Under the influence of LBNP, especially during rarefactions on 45 and 50 mm Hg was noted reduction in the R, T-amplitude and the relative extension of QT-interval. The directivity of changes in these indices are identical for the cosmonauts with good and poor tolerance of the test; however in flight manifestation of the changes is more significant for the cosmonauts with poor tolerance of LBNP test. Thus, in the formation of orthostatic stability together with the hemodynamic influences take part the bioelectric processes, which are formed in the myocardium.

EEG-Based Detection of Braking Intention Under Different Car Driving Conditions

PubMed Central

Hernández, Luis G.; Mozos, Oscar Martinez; Ferrández, José M.; Antelis, Javier M.

2018-01-01

The anticipatory recognition of braking is essential to prevent traffic accidents. For instance, driving assistance systems can be useful to properly respond to emergency braking situations. Moreover, the response time to emergency braking situations can be affected and even increased by different driver's cognitive states caused by stress, fatigue, and extra workload. This work investigates the detection of emergency braking from driver's electroencephalographic (EEG) signals that precede the brake pedal actuation. Bioelectrical signals were recorded while participants were driving in a car simulator while avoiding potential collisions by performing emergency braking. In addition, participants were subjected to stress, workload, and fatigue. EEG signals were classified using support vector machines (SVM) and convolutional neural networks (CNN) in order to discriminate between braking intention and normal driving. Results showed significant recognition of emergency braking intention which was on average 71.1% for SVM and 71.8% CNN. In addition, the classification accuracy for the best participant was 80.1 and 88.1% for SVM and CNN, respectively. These results show the feasibility of incorporating recognizable driver's bioelectrical responses into advanced driver-assistance systems to carry out early detection of emergency braking situations which could be useful to reduce car accidents. PMID:29910722

Influence of the operational parameters on bioelectricity generation in continuous microbial fuel cell, experimental and computational fluid dynamics modelling

NASA Astrophysics Data System (ADS)

Sobieszuk, Paweł; Zamojska-Jaroszewicz, Anna; Makowski, Łukasz

2017-12-01

The influence of the organic loading rate (also known as active anodic chamber volume) on bioelectricity generation in a continuous, two-chamber microbial fuel cell for the treatment of synthetic wastewater, with glucose as the only carbon source, was examined. Ten sets of experiments with different combinations of hydraulic retention times (0.24-1.14 d) and influent chemical oxygen demand concentrations were performed to verify the impact of organic loading rate on the voltage generation capacity of a simple dual-chamber microbial fuel cell working in continuous mode. We found that there is an optimal hydraulic retention time value at which the maximum voltage is generated: 0.41 d. However, there were no similar effects, in terms of voltage generation, when a constant hydraulic retention time with different influent chemical oxygen demand of wastewater was used. The obtained maximal voltage value (600 mV) has also been compared to literature data. Computational fluid dynamics (CFD) was used to calculate the fluid flow and the exit age distribution of fluid elements in the reactor to explain the obtained experimental results and identify the crucial parameters for the design of bioreactors on an industrial scale.

Body composition by bioelectrical-impedance analysis compared with deuterium dilution and skinfold anthropometry in patients with chronic obstructive pulmonary disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schols, A.M.; Wouters, E.F.; Soeters, P.B.

1991-02-01

Body composition is an important measure of nutritional status in patients with chronic obstructive pulmonary disease (COPD). We generated a regression model for bioelectrical impedance (BI) by using deuterium dilution (2H2O) as a reference method in 32 COPD patients, aged 63 +/- 9 y (mean +/- SD), in stable pulmonary and cardiac condition. Height squared divided by resistance (Ht2/Res) correlated well with total body water (TBW) as measured by 2H2O (r = 0.93, P less than 0.001, SEE = 1.9 L). The best-fitting regression equation to predict TBW comprised Ht2/Res and body weight (r2 = 0.89, SEE = 1.8 L,more » P less than 0.001). BI-predicted TBW was used to estimate BI-fat-free mass (FFM) that was compared with skinfold-thickness-based FFM predictions (Anthr-FFM). Relative to BI-FFM a significant overestimation of 4.4 +/- 0.8 kg was found by Anthr-FFM. Our results suggest that BI is a useful measure of body composition in patients with severe COPD.« less

Improvement of Human Keratinocyte Migration by a Redox Active Bioelectric Dressing

PubMed Central

Banerjee, Jaideep; Das Ghatak, Piya; Roy, Sashwati; Khanna, Savita; Sequin, Emily K.; Bellman, Karen; Dickinson, Bryan C.; Suri, Prerna; Subramaniam, Vish V.; Chang, Christopher J.; Sen, Chandan K.

2014-01-01

Exogenous application of an electric field can direct cell migration and improve wound healing; however clinical application of the therapy remains elusive due to lack of a suitable device and hence, limitations in understanding the molecular mechanisms. Here we report on a novel FDA approved redox-active Ag/Zn bioelectric dressing (BED) which generates electric fields. To develop a mechanistic understanding of how the BED may potentially influence wound re-epithelialization, we direct emphasis on understanding the influence of BED on human keratinocyte cell migration. Mapping of the electrical field generated by BED led to the observation that BED increases keratinocyte migration by three mechanisms: (i) generating hydrogen peroxide, known to be a potent driver of redox signaling, (ii) phosphorylation of redox-sensitive IGF1R directly implicated in cell migration, and (iii) reduction of protein thiols and increase in integrinαv expression, both of which are known to be drivers of cell migration. BED also increased keratinocyte mitochondrial membrane potential consistent with its ability to fuel an energy demanding migration process. Electric fields generated by a Ag/Zn BED can cross-talk with keratinocytes via redox-dependent processes improving keratinocyte migration, a critical event in wound re-epithelialization. PMID:24595050

Validity of Bioelectrical Impedance Analysis to Estimation Fat-Free Mass in the Army Cadets.

PubMed

Langer, Raquel D; Borges, Juliano H; Pascoa, Mauro A; Cirolini, Vagner X; Guerra-Júnior, Gil; Gonçalves, Ezequiel M

2016-03-11

Bioelectrical Impedance Analysis (BIA) is a fast, practical, non-invasive, and frequently used method for fat-free mass (FFM) estimation. The aims of this study were to validate predictive equations of BIA to FFM estimation in Army cadets and to develop and validate a specific BIA equation for this population. A total of 396 males, Brazilian Army cadets, aged 17-24 years were included. The study used eight published predictive BIA equations, a specific equation in FFM estimation, and dual-energy X-ray absorptiometry (DXA) as a reference method. Student's t-test (for paired sample), linear regression analysis, and Bland-Altman method were used to test the validity of the BIA equations. Predictive BIA equations showed significant differences in FFM compared to DXA (p < 0.05) and large limits of agreement by Bland-Altman. Predictive BIA equations explained 68% to 88% of FFM variance. Specific BIA equations showed no significant differences in FFM, compared to DXA values. Published BIA predictive equations showed poor accuracy in this sample. The specific BIA equations, developed in this study, demonstrated validity for this sample, although should be used with caution in samples with a large range of FFM.

Fossilized bioelectric wire – the trace fossil Trichichnus

PubMed Central

Kędzierski, M.; Uchman, A.; Sawlowicz, Z.; Briguglio, A.

2015-01-01

The trace fossil Trichichnus is proposed as an indicator of fossil bioelectric bacterial activity at the oxic–anoxic interface zone of marine sediments. This fulfils the idea that such processes, commonly found in the modern realm, should be also present in the geological past. Trichichnus is an exceptional trace fossil due to its very thin diameter (mostly less than 1 mm) and common pyritic filling. It is ubiquitous in some fine-grained sediments, where it has been interpreted as a burrow formed deeper than any other trace fossils, below the redox boundary. Trichichnus, formerly referred to as deeply burrowed invertebrates, has been found as remnant of a fossilized intrasediment bacterial mat that is pyritized. As visualized in 3-D by means of X-ray computed microtomography scanner, Trichichnus forms dense filamentous fabric, which reflects that it is produced by modern large, mat-forming, sulfide-oxidizing bacteria, belonging mostly to Thioploca-related taxa, which are able to house a complex bacterial consortium. Several stages of Trichichnus formation, including filamentous, bacterial mat and its pyritization, are proposed to explain an electron exchange between oxic and suboxic/anoxic layers in the sediment. Therefore, Trichichnus can be considered a fossilized “electric wire”. PMID:26290671

Biophoton signal transmission and processing in the brain.

PubMed

Tang, Rendong; Dai, Jiapei

2014-10-05

The transmission and processing of neural information in the nervous system plays a key role in neural functions. It is well accepted that neural communication is mediated by bioelectricity and chemical molecules via the processes called bioelectrical and chemical transmission, respectively. Indeed, the traditional theories seem to give valuable explanations for the basic functions of the nervous system, but difficult to construct general accepted concepts or principles to provide reasonable explanations of higher brain functions and mental activities, such as perception, learning and memory, emotion and consciousness. Therefore, many unanswered questions and debates over the neural encoding and mechanisms of neuronal networks remain. Cell to cell communication by biophotons, also called ultra-weak photon emissions, has been demonstrated in several plants, bacteria and certain animal cells. Recently, both experimental evidence and theoretical speculation have suggested that biophotons may play a potential role in neural signal transmission and processing, contributing to the understanding of the high functions of nervous system. In this paper, we review the relevant experimental findings and discuss the possible underlying mechanisms of biophoton signal transmission and processing in the nervous system. Copyright © 2014 Elsevier B.V. All rights reserved.

Visceral fat estimation method by bioelectrical impedance analysis and causal analysis

NASA Astrophysics Data System (ADS)

Nakajima, Hiroshi; Tasaki, Hiroshi; Tsuchiya, Naoki; Hamaguchi, Takehiro; Shiga, Toshikazu

2011-06-01

It has been clarified that abdominal visceral fat accumulation is closely associated to the lifestyle disease and metabolic syndrome. The gold standard in medical fields is visceral fat area measured by an X-ray computer tomography (CT) scan or magnetic resonance imaging. However, their measurements are high invasive and high cost; especially a CT scan causes X-ray exposure. They are the reasons why medical fields need an instrument for viscera fat measurement with low invasive, ease of use, and low cost. The article proposes a simple and practical method of visceral fat estimation by employing bioelectrical impedance analysis and causal analysis. In the method, abdominal shape and dual impedances of abdominal surface and body total are measured to estimate a visceral fat area based on the cause-effect structure. The structure is designed according to the nature of abdominal body composition to be fine-tuned by statistical analysis. The experiments were conducted to investigate the proposed model. 180 subjects were hired to be measured by both a CT scan and the proposed method. The acquired model explained the measurement principle well and the correlation coefficient is 0.88 with the CT scan measurements.

Frequent Shifts in Aspergillus flavus Populations Associated with Maize Production in Sonora, Mexico.

PubMed

Ortega-Beltran, A; Cotty, P J

2018-03-01

Aspergillus flavus frequently contaminates maize, a critical staple for billions of people, with aflatoxins. Diversity among A. flavus L morphotype populations associated with maize in Sonora, Mexico was assessed and, in total, 869 isolates from 83 fields were placed into 136 vegetative compatibility groups (VCGs) using nitrate-nonutilizing mutants. VCG diversity indices did not differ in four agroecosystems (AES) but diversity significantly differed among years. Frequencies of certain VCGs changed manyfold over single years in both multiple fields and multiple AES. Certain VCGs were highly frequent (>1%) in 2006 but frequencies declined repeatedly in each of the two subsequent years. Other VCGs that had low frequencies in 2006 increased in 2007 and subsequently declined. None of the VCGs were consistently associated with any AES. Fourteen VCGs were considered dominant in at least a single year. However, frequencies often varied significantly among years. Only 9% of VCGs were detected all 3 years whereas 66% were detected in only 1 year. Results suggest that the most realistic measurements of both genetic diversity and the frequency of A. flavus VCGs are obtained by sampling multiple locations in multiple years. Single-season sampling in many locations should not be substituted for sampling over multiple years.

Robust multiple frequency multiple power localization schemes in the presence of multiple jamming attacks

PubMed Central

2017-01-01

Localization of the wireless sensor network is a vital area acquiring an impressive research concern and called upon to expand more with the rising of its applications. As localization is gaining prominence in wireless sensor network, it is vulnerable to jamming attacks. Jamming attacks disrupt communication opportunity among the sender and receiver and deeply impact the localization process, leading to a huge error of the estimated sensor node position. Therefore, detection and elimination of jamming influence are absolutely indispensable. Range-based techniques especially Received Signal Strength (RSS) is facing severe impact of these attacks. This paper proposes algorithms based on Combination Multiple Frequency Multiple Power Localization (C-MFMPL) and Step Function Multiple Frequency Multiple Power Localization (SF-MFMPL). The algorithms have been tested in the presence of multiple types of jamming attacks including capture and replay, random and constant jammers over a log normal shadow fading propagation model. In order to overcome the impact of random and constant jammers, the proposed method uses two sets of frequencies shared by the implemented anchor nodes to obtain the averaged RSS readings all over the transmitted frequencies successfully. In addition, three stages of filters have been used to cope with the replayed beacons caused by the capture and replay jammers. In this paper the localization performance of the proposed algorithms for the ideal case which is defined by without the existence of the jamming attack are compared with the case of jamming attacks. The main contribution of this paper is to achieve robust localization performance in the presence of multiple jamming attacks under log normal shadow fading environment with a different simulation conditions and scenarios. PMID:28493977

ASSESSMENT OF BODY FAT IN OBESE PATIENTS PREOPERATIVELY FOR BARIATRIC SURGERY.

PubMed

Fernandez, Mônica; Toimil, Rosana Farah; Rasslan, Zied; Ilias, Elias Jirjoss; Gradinar, Ana Lúcia Torloni; Malheiros, Carlos Alberto

The study of body composition in patient candidates for bariatric surgery is directly related to the increase and distribution of body fat in the development of cardiovascular disease. To correlate anthropometric indicators and bioelectrical impedance in the assessment of body fat in female candidates for bariatric surgery. Cross-sectional, observational study of 88 women. The weight, height, body mass index and waist circumference data were evaluated in the anthropometric analysis. The body fat was determinate by bioelectrical impedance conducted according to the manufacturer´s recommended technique with a specific severe obesity formula. The patients were divided into two subgroups according to the average waist circumference and body mass index for better analysis of the results. The group had a mean age of 39.7 years (±7.2), average weight of 125.6 kg (±16.2), mean body mass index of 48.7 kg/m2 (±6.4) and the mean waist circumference 137.6 cm (±12.4). Negative and significant relationship between BMI values waist circumference and resistance obtained by bioelectrical impedance ​​were found. By analyzing the two groups the mean BMI and waist circumference, a significant relationship was observed, ie, the higher the degree of obesity less resistance was obtained by bioelectrical impedance. The higher is the obesity the lower is value found for resistance. The increase of anthropometric indicators (BMI and waist circumference) determined reduction in resistance and reactance obtained by bioelectrical impedance analysis in obese women candidates to bariatric surgery. O estudo da composição corporal em pacientes candidatas à cirurgia bariátrica tem relação direta com o aumento e distribuição da gordura corporal e no desenvolvimento de doenças cardiovasculares. Estudar a correlação entre indicadores antropométricos e da bioimpedância elétrica na avaliação da gordura corporal em mulheres candidatas à cirurgia bariátrica. Estudo transversal, observacional com 88 pacientes. Na análise antropométrica foram avaliados os dados de peso, altura, IMC e circunferência da cintura. Para bioimpedância elétrica utilizou-se a técnica recomendada pelo fabricante do aparelho e fórmula específica para obeso grave na determinação da gordura corporal. Para melhor análise dos resultados as pacientes foram divididas em dois subgrupos de acordo com a média de circunferência da cintura e IMC. O grupo apresentou média de idade 39,7 anos (±7,2), média de peso 125,6 kg (±16,2), média de IMC 48,7 kg/m2 (±6,4) e média de circunferência da cintura 137,6 cm (±12,4). Foram encontradas relações negativas e significativas entre os valores de IMC, circunferência da cintura e a resistência obtida através da bioimpedância elétrica. Ao analisar os dois subgrupos de valores médios de IMC e circunferência da cintura, observou-se relação significativa, ou seja, quanto maior o grau de obesidade menor é a resistência obtida através da bioimpedância elétrica. O aumento dos indicadores antropométricos (IMC e circunferência da cintura) determinaram redução nas variáveis resistência e reatância obtidas pela bioimpedância elétrica em mulheres candidatas à cirurgia bariátrica.

Frequency of multiple blood meals taken in a single gonotrophic cycle by Anopheles arabiensis mosquitoes in Macha, Zambia.

PubMed

Norris, Laura C; Fornadel, Christen M; Hung, Wei-Chien; Pineda, Fernando J; Norris, Douglas E

2010-07-01

Anopheles arabiensis is a major vector of Plasmodium falciparum in southern Zambia. This study aimed to determine the rate of multiple human blood meals taken by An. arabiensis to more accurately estimate entomologic inoculation rates (EIRs). Mosquitoes were collected in four village areas over two seasons. DNA from human blood meals was extracted and amplified at four microsatellite loci. Using the three-allele method, which counts > or = 3 alleles at any microsatellite locus as a multiple blood meal, we determined that the overall frequency of multiple blood meals was 18.9%, which was higher than rates reported for An. gambiae in Kenya and An. funestus in Tanzania. Computer simulations showed that the three-allele method underestimates the true multiple blood meal proportion by 3-5%. Although P. falciparum infection status was not shown to influence the frequency of multiple blood feeding, the high multiple feeding rate found in this study increased predicted malaria risk by increasing EIR.

Fat-free mass prediction equations for bioelectric impedance analysis compared to dual energy X-ray absorptiometry in obese adolescents: a validation study.

PubMed

Hofsteenge, Geesje H; Chinapaw, Mai J M; Weijs, Peter J M

2015-10-15

In clinical practice, patient friendly methods to assess body composition in obese adolescents are needed. Therefore, the bioelectrical impedance analysis (BIA) related fat-free mass (FFM) prediction equations (FFM-BIA) were evaluated in obese adolescents (age 11-18 years) compared to FFM measured by dual-energy x-ray absorptiometry (FFM-DXA) and a new population specific FFM-BIA equation is developed. After an overnight fast, the subjects attended the outpatient clinic. After measuring height and weight, a full body scan by dual-energy x-ray absorptiometry (DXA) and a BIA measurement was performed. Thirteen predictive FFM-BIA equations based on weight, height, age, resistance, reactance and/or impedance were systematically selected and compared to FFM-DXA. Accuracy of FFM-BIA equations was evaluated by the percentage adolescents predicted within 5% of FFM-DXA measured, the mean percentage difference between predicted and measured values (bias) and the Root Mean Squared prediction Error (RMSE). Multiple linear regression was conducted to develop a new BIA equation. Validation was based on 103 adolescents (60% girls), age 14.5 (sd1.7) years, weight 94.1 (sd15.6) kg and FFM-DXA of 56.1 (sd9.8) kg. The percentage accurate estimations varied between equations from 0 to 68%; bias ranged from -29.3 to +36.3% and RMSE ranged from 2.8 to 12.4 kg. An alternative prediction equation was developed: FFM = 0.527 * H(cm)(2)/Imp + 0.306 * weight - 1.862 (R(2) = 0.92, SEE = 2.85 kg). Percentage accurate prediction was 76%. Compared to DXA, the Gray equation underestimated the FFM with 0.4 kg (55.7 ± 8.3), had an RMSE of 3.2 kg, 63% accurate prediction and the smallest bias of (-0.1%). When split by sex, the Gray equation had the narrowest range in accurate predictions, bias, and RMSE. For the assessment of FFM with BIA, the Gray-FFM equation appears to be the most accurate, but 63% is still not at an acceptable accuracy level for obese adolescents. The new equation appears to be appropriate but await further validation. DXA measurement remains the method of choice for FFM in obese adolescents. Netherlands Trial Register ( ISRCTN27626398).

Comparison of bipolar vs. tripolar concentric ring electrode Laplacian estimates.

PubMed

Besio, W; Aakula, R; Dai, W

2004-01-01

Potentials on the body surface from the heart are of a spatial and temporal function. The 12-lead electrocardiogram (ECG) provides useful global temporal assessment, but it yields limited spatial information due to the smoothing effect caused by the volume conductor. The smoothing complicates identification of multiple simultaneous bioelectrical events. In an attempt to circumvent the smoothing problem, some researchers used a five-point method (FPM) to numerically estimate the analytical solution of the Laplacian with an array of monopolar electrodes. The FPM is generalized to develop a bi-polar concentric ring electrode system. We have developed a new Laplacian ECG sensor, a trielectrode sensor, based on a nine-point method (NPM) numerical approximation of the analytical Laplacian. For a comparison, the NPM, FPM and compact NPM were calculated over a 400 x 400 mesh with 1/400 spacing. Tri and bi-electrode sensors were also simulated and their Laplacian estimates were compared against the analytical Laplacian. We found that tri-electrode sensors have a much-improved accuracy with significantly less relative and maximum errors in estimating the Laplacian operator. Apart from the higher accuracy, our new electrode configuration will allow better localization of the electrical activity of the heart than bi-electrode configurations.

The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

PubMed

Sage, Cindy

2015-01-01

The 'informational content' of Earth's electromagnetic signaling is like a set of operating instructions for human life. These environmental cues are dynamic and involve exquisitely low inputs (intensities) of critical frequencies with which all life on Earth evolved. Circadian and other temporal biological rhythms depend on these fluctuating electromagnetic inputs to direct gene expression, cell communication and metabolism, neural development, brainwave activity, neural synchrony, a diversity of immune functions, sleep and wake cycles, behavior and cognition. Oscillation is also a universal phenomenon, and biological systems of the heart, brain and gut are dependent on the cooperative actions of cells that function according to principles of non-linear, coupled biological oscillations for their synchrony. They are dependent on exquisitely timed cues from the environment at vanishingly small levels. Altered 'informational content' of environmental cues can swamp natural electromagnetic cues and result in dysregulation of normal biological rhythms that direct growth, development, metabolism and repair mechanisms. Pulsed electromagnetic fields (PEMF) and radiofrequency radiation (RFR) can have the devastating biological effects of disrupting homeostasis and desynchronizing normal biological rhythms that maintain health. Non-linear, weak field biological oscillations govern body electrophysiology, organize cell and tissue functions and maintain organ systems. Artificial bioelectrical interference can give false information (disruptive signaling) sufficient to affect critical pacemaker cells (of the heart, gut and brain) and desynchronize functions of these important cells that orchestrate function and maintain health. Chronic physiological stress undermines homeostasis whether it is chemically induced or electromagnetically induced (or both exposures are simultaneous contributors). This can eventually break down adaptive biological responses critical to health maintenance; and resilience can be compromised. Electrohypersensitivity can be caused by successive assaults on human bioelectrochemical dynamics from exogenous electromagnetic fields (EMF) and RFR or a single acute exposure. Once sensitized, further exposures are widely reported to cause reactivity to lower and lower intensities of EMF/RFR, at which point thousand-fold lower levels can cause adverse health impacts to the electrosensitive person. Electrohypersensitivity (EHS) can be a precursor to, or linked with, multiple chemical sensitivity (MCS) based on reports of individuals who first develop one condition, then rapidly develop the other. Similarity of chemical biomarkers is seen in both conditions [histamines, markers of oxidative stress, auto-antibodies, heat shock protein (HSP), melatonin markers and leakage of the blood-brain barrier]. Low intensity pulsed microwave activation of voltage-gated calcium channels (VGCCs) is postulated as a mechanism of action for non-thermal health effects.

Red blood cells aggregability measurement of coagulating blood in extracorporeal circulation system with multiple-frequency electrical impedance spectroscopy.

PubMed

Li, Jianping; Sapkota, Achyut; Kikuchi, Daisuke; Sakota, Daisuke; Maruyama, Osamu; Takei, Masahiro

2018-07-30

Red blood cells (RBCs) aggregability A G of coagulating blood in extracorporeal circulation system has been investigated under the condition of pulsatile flow. Relaxation frequency f c from the multiple-frequency electrical impedance spectroscopy is utilized to obtain RBCs aggregability A G . Compared with other methods, the proposed multiple-frequency electrical impedance method is much easier to obtain non-invasive measurement with high speed and good penetrability performance in biology tissues. Experimental results show that, RBCs aggregability A G in coagulating blood falls down with the thrombus formation while that in non-coagulation blood almost keeps the same value, which has a great agreement with the activated clotting time (ACT) fibrinogen concertation (F bg ) tests. Modified Hanai formula is proposed to quantitatively analyze the influence of RBCs aggregation on multiple-frequency electrical impedance measurement. The reduction of RBCs aggregability A G is associated with blood coagulation reaction, which indicates the feasibility of the high speed, compact and cheap on-line thrombus measurement biosensors in extracorporeal circulation systems. Copyright © 2018 Elsevier B.V. All rights reserved.

Assessing Body Composition of Children and Adolescents Using Dual-Energy X-Ray Absorptiometry, Skinfolds, and Electrical Impedance

ERIC Educational Resources Information Center

Mooney, Angela; Kelsey, Laurel; Fellingham, Gilbert W.; George, James D.; Hager, Ron L.; Myrer, J. William; Vehrs, Pat R.

2011-01-01

To determine the validity and reliability of percent body fat estimates in 177 boys and 154 girls between 12-17 years of age, percent body fat was assessed once using dual-energy X-ray absorptiometry and twice using the sum of two skinfolds and three bioelectrical impedance analysis devices. The assessments were repeated on 79 participants on a…

The space flight of the Soviet-Indian crew

NASA Technical Reports Server (NTRS)

Nikitin, S. A.

1985-01-01

After a brief discussion of the Indian space program, the paper examines the flight of the Soyuz T-11, which included an Indian crew member. Particular attention is given to experiments conducted aboard Soyuz T-11, including the Optokinez vestibular experiment, the Vektor cardiac bioelectricity experiment, the yoga experiment for the counteraction of the negative effects of weightlessness, a supercooling experiment, and the Terra remote sensing experiment.

[Detection of constitutional types of EEG using the orthogonal decomposition method].

PubMed

Kuznetsova, S M; Kudritskaia, O V

1987-01-01

The authors present an algorithm of investigation into the processes of brain bioelectrical activity with the help of an orthogonal decomposition device intended for the identification of constitutional types of EEGs. The method has helped to effectively solve the task of the diagnosis of constitutional types of EEGs, which are determined by a variable degree of hereditary predisposition for longevity or cerebral stroke.

Relationship between lower limb position and pelvic floor muscle surface electromyography activity in menopausal women: a prospective observational study

PubMed Central

Halski, Tomasz; Ptaszkowski, Kuba; Słupska, Lucyna; Dymarek, Robert; Paprocka-Borowicz, Małgorzata

2017-01-01

Objectives In physiotherapeutic practice, special attention is being given to the reciprocal anatomical, physiological, and biomechanical relationship of the pelvis and the structures connected to it. However, the scientific literature shows mainly the theoretical information about their mutual connections. The lack of information about these relations from a practical aspect coupled with the paucity of scientific papers on the impact of posture changes on the pelvic floor led the authors to conduct this study. The primary aim of this study was to compare the resting and functional bioelectrical activities of pelvic floor muscles (PFMs) depending on three different positions of the lower limbs (positions A, B, and C) in the supine position. Materials and methods This was a prospective observational study evaluating resting and functional activities of the PFM depending on the position of the lower limbs. The study was carried out at the Department and Clinic of Urology, University Hospital in Wroclaw, Poland and the target group were women in the menopausal period. Bioelectrical activity of PFM was recorded using a surface electromyographic instrument in the supine position. Results of the values obtained in A, B, and C positions were compared using a one-way analysis of variance. Results In position A, the average resting surface electromyography (sEMG) activity of PFM was 6.9±2.6 µV; in position B, the result was 6.9±2.5 µV and in position C, the resting sEMG activity was 5.7±1.8 µV (P=0.0102). The results of the functional bioelectrical activity of PFM were as follows: position A – 20.3±11.8 µV, position B – 19.9±10.6 µV, and position C – 25.3±10.9 µV (P=0.0104). Conclusion The results showed that in the supine position, the PFM achieved the lowest resting activity and the highest functional activity. Therefore, the supine position can be recommended for the diagnosis and therapy of weakened PFM. PMID:28115836

Effect of electrical energy on the efficacy of biofilm treatment using the bioelectric effect

PubMed Central

Kim, Young Wook; Subramanian, Sowmya; Gerasopoulos, Konstantinos; Ben-Yoav, Hadar; Wu, Hsuan-Chen; Quan, David; Carter, Karen; Meyer, Mariana T; Bentley, William E; Ghodssi, Reza

2015-01-01

Background/Objectives: The use of electric fields in combination with small doses of antibiotics for enhanced treatment of biofilms is termed the ‘bioelectric effect’ (BE). Different mechanisms of action for the AC and DC fields have been reported in the literature over the last two decades. In this work, we conduct the first study on the correlation between the electrical energy and the treatment efficacy of the bioelectric effect on Escherichia coli K-12 W3110 biofilms. Methods: A thorough study was performed through the application of alternating (AC), direct (DC) and superimposed (SP) potentials of different amplitudes on mature E. coli biofilms. The electric fields were applied in combination with the antibiotic gentamicin (10 μg/ml) over a course of 24 h, after the biofilms had matured for 24 h. The biofilms were analysed using the crystal violet assay, the colony-forming unit method and fluorescence microscopy. Results: Results show that there is no statistical difference in treatment efficacy between the DC-, AC- and SP-based BE treatment of equivalent energies (analysis of variance (ANOVA) P>0.05) for voltages <1 V. We also demonstrate that the efficacy of the BE treatment as measured by the crystal violet staining method and colony-forming unit assay is proportional to the electrical energy applied (ANOVA P<0.05). We further verify that the treatment efficacy varies linearly with the energy of the BE treatment (r2 =0.984). Our results thus suggest that the energy of the electrical signal is the primary factor in determining the efficacy of the BE treatment, at potentials less than the media electrolysis voltage. Conclusions: Our results demonstrate that the energy of the electrical signal, and not the type of electrical signal (AC or DC or SP), is the key to determine the efficacy of the BE treatment. We anticipate that this observation will pave the way for further understanding of the mechanism of action of the BE treatment method and may open new doors to the use of electric fields in the treatment of bacterial biofilms. PMID:28721233

Repetition rate multiplication of frequency comb using all-pass fiber resonator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Lijun; Yang, Honglei; Zhang, Hongyuan

2016-09-15

We propose a stable method for repetition rate multiplication of a 250-MHz Er-fiber frequency comb by a phase-locked all-pass fiber ring resonator, whose phase-locking configuration is simple. The optical path length of the fiber ring resonator is automatically controlled to be accurately an odd multiple of half of the original cavity length using an electronical phase-locking unit with an optical delay line. As for shorter cavity length of the comb, high-order odd multiple is preferable. Because the power loss depends only on the net-attenuation of the fiber ring resonator, the energetic efficiency of the proposed method is high. The inputmore » and output optical spectrums show that the spectral width of the frequency comb is clearly preserved. Besides, experimental results show less pulse intensity fluctuation and 35 dB suppression ratio of side-modes while providing a good long-term and short-term frequency stability. Higher-order repetition rate multiplication to several GHz can be obtained by using several fiber ring resonators in cascade configuration.« less

Frequency-domain method for measuring spectral properties in multiple-scattering media: methemoglobin absorption spectrum in a tissuelike phantom

NASA Astrophysics Data System (ADS)

Fishkin, Joshua B.; So, Peter T. C.; Cerussi, Albert E.; Gratton, Enrico; Fantini, Sergio; Franceschini, Maria Angela

1995-03-01

We have measured the optical absorption and scattering coefficient spectra of a multiple-scattering medium (i.e., a biological tissue-simulating phantom comprising a lipid colloid) containing methemoglobin by using frequency-domain techniques. The methemoglobin absorption spectrum determined in the multiple-scattering medium is in excellent agreement with a corrected methemoglobin absorption spectrum obtained from a steady-state spectrophotometer measurement of the optical density of a minimally scattering medium. The determination of the corrected methemoglobin absorption spectrum takes into account the scattering from impurities in the methemoglobin solution containing no lipid colloid. Frequency-domain techniques allow for the separation of the absorbing from the scattering properties of multiple-scattering media, and these techniques thus provide an absolute

Improved MIMO radar GMTI via cyclic-shift transmission of orthogonal frequency division signals

NASA Astrophysics Data System (ADS)

Li, Fuyou; He, Feng; Dong, Zhen; Wu, Manqing

2018-05-01

Minimum detectable velocity (MDV) and maximum detectable velocity are both important in ground moving target indication (GMTI) systems. Smaller MDV can be achieved by longer baseline via multiple-input multiple-output (MIMO) radar. Maximum detectable velocity is decided by blind velocities associated with carrier frequencies, and blind velocities can be mitigated by orthogonal frequency division signals. However, the scattering echoes from different carrier frequencies are independent, which is not good for improving MDV performance. An improved cyclic-shift transmission is applied in MIMO GMTI system in this paper. MDV performance is improved due to the longer baseline, and maximum detectable velocity performance is improved due to the mitigation of blind velocities via multiple carrier frequencies. The signal model for this mode is established, the principle of mitigating blind velocities with orthogonal frequency division signals is presented; the performance of different MIMO GMTI waveforms is analysed; and the performance of different array configurations is analysed. Simulation results by space-time-frequency adaptive processing proves that our proposed method is a valid way to improve GMTI performance.

Automated Method of Frequency Determination in Software Metric Data Through the Use of the Multiple Signal Classification (MUSIC) Algorithm

DTIC Science & Technology

1998-06-26

METHOD OF FREQUENCY DETERMINATION 4 IN SOFTWARE METRIC DATA THROUGH THE USE OF THE 5 MULTIPLE SIGNAL CLASSIFICATION ( MUSIC ) ALGORITHM 6 7 STATEMENT OF...graph showing the estimated power spectral 12 density (PSD) generated by the multiple signal classification 13 ( MUSIC ) algorithm from the data set used...implemented in this module; however, it is preferred to use 1 the Multiple Signal Classification ( MUSIC ) algorithm. The MUSIC 2 algorithm is

Quasi-distributed fiber sensor using active mode locking laser cavity with multiple FBG reflections

NASA Astrophysics Data System (ADS)

Park, Chang Hyun; Kim, Gyeong Hun; Kim, Chang-Seok; Lee, Hwi Don; Chung, Youngjoo

2017-04-01

We have demonstrated a quasi-distributed sensor using an active mode-locking (AML) laser with multiple fiber Bragg grating (FBG) reflections of the same center wavelength. We found that variations in the multiple cavity segment lengths between FBGs can be measured by simply sweeping the modulation frequency, because the modulation frequency of the AML laser is proportionally affected by cavity length.

Frequency Hopping, Multiple Frequency-Shift Keying, Coding, and Optimal Partial-Band Jamming.

DTIC Science & Technology

1982-08-01

receivers appropriate for these two strategies. Each receiver is noncoherent (a coherent receiver is generally impractical) and implements hard...Advances in Coding and Modulation for Noncoherent Channels Affected by Fading, Partial Band, and Multiple- . Access Interference, in A. J. Viterbi...Modulation for Noncoherent Channels Affected by Fading, Partial Band, and Multiple-Access interference, in A. J. Viterbi, ed., Advances in Coumunication

Linear and nonlinear frequency- and time-domain spectroscopy with multiple frequency combs.

PubMed

Bennett, Kochise; Rouxel, Jeremy R; Mukamel, Shaul

2017-09-07

Two techniques that employ equally spaced trains of optical pulses to map an optical high frequency into a low frequency modulation of the signal that can be detected in real time are compared. The development of phase-stable optical frequency combs has opened up new avenues to metrology and spectroscopy. The ability to generate a series of frequency spikes with precisely controlled separation permits a fast, highly accurate sampling of the material response. Recently, pairs of frequency combs with slightly different repetition rates have been utilized to down-convert material susceptibilities from the optical to microwave regime where they can be recorded in real time. We show how this one-dimensional dual comb technique can be extended to multiple dimensions by using several combs. We demonstrate how nonlinear susceptibilities can be quickly acquired using this technique. In a second class of techniques, sequences of ultrafast mode locked laser pulses are used to recover pathways of interactions contributing to nonlinear susceptibilities by using a photo-acoustic modulation varying along the sequences. We show that these techniques can be viewed as a time-domain analog of the multiple frequency comb scheme.

An asymptotic preserving unified gas kinetic scheme for frequency-dependent radiative transfer equations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Wenjun, E-mail: sun_wenjun@iapcm.ac.cn; Jiang, Song, E-mail: jiang@iapcm.ac.cn; Xu, Kun, E-mail: makxu@ust.hk

This paper presents an extension of previous work (Sun et al., 2015 [22]) of the unified gas kinetic scheme (UGKS) for the gray radiative transfer equations to the frequency-dependent (multi-group) radiative transfer system. Different from the gray radiative transfer equations, where the optical opacity is only a function of local material temperature, the simulation of frequency-dependent radiative transfer is associated with additional difficulties from the frequency-dependent opacity. For the multiple frequency radiation, the opacity depends on both the spatial location and the frequency. For example, the opacity is typically a decreasing function of frequency. At the same spatial region themore » transport physics can be optically thick for the low frequency photons, and optically thin for high frequency ones. Therefore, the optical thickness is not a simple function of space location. In this paper, the UGKS for frequency-dependent radiative system is developed. The UGKS is a finite volume method and the transport physics is modeled according to the ratio of the cell size to the photon's frequency-dependent mean free path. When the cell size is much larger than the photon's mean free path, a diffusion solution for such a frequency radiation will be obtained. On the other hand, when the cell size is much smaller than the photon's mean free path, a free transport mechanism will be recovered. In the regime between the above two limits, with the variation of the ratio between the local cell size and photon's mean free path, the UGKS provides a smooth transition in the physical and frequency space to capture the corresponding transport physics accurately. The seemingly straightforward extension of the UGKS from the gray to multiple frequency radiation system is due to its intrinsic consistent multiple scale transport modeling, but it still involves lots of work to properly discretize the multiple groups in order to design an asymptotic preserving (AP) scheme in all regimes. The current scheme is tested in a few frequency-dependent radiation problems, and the results are compared with the solutions from the well-defined implicit Monte Carlo (IMC) method. The UGKS is much more efficient than IMC, and the computational times of both schemes for all test cases are listed. The UGKS seems to be the first discrete ordinate method (DOM) for the accurate capturing of multiple frequency radiative transport physics from ballistic particle motion to the diffusive wave propagation.« less

Simulation-Based Validation for Four-Dimensional Multi-Channel Ultrasound Current Source Density Imaging

PubMed Central

Wang, Zhaohui; Witte, Russell S.

2015-01-01

Ultrasound current source density imaging (UCSDI), which has application to the heart and brain, exploits the acoustoelectric (AE) effect and Ohm's law to detect and map an electrical current distribution. In this study, we describe 4-D UCSDI simulations of a dipole field for comparison and validation with bench-top experiments. The simulations consider the properties of the ultrasound pulse as it passes through a conductive medium, the electric field of the injected dipole, and the lead field of the detectors. In the simulation, the lead fields of detectors and electric field of the dipole were calculated by the finite element (FE) method, and the convolution and correlation in the computation of the detected AE voltage signal were accelerated using 3-D fast Fourier transforms. In the bench-top experiment, an electric dipole was produced in a bath of 0.9% NaCl solution containing two electrodes, which injected an ac pulse (200 Hz, 3 cycles) ranging from 0 to 140 mA. Stimulating and recording electrodes were placed in a custom electrode chamber made on a rapid prototype printer. Each electrode could be positioned anywhere on an x-y grid (5 mm spacing) and individually adjusted in the depth direction for precise control of the geometry of the current sources and detecting electrodes. A 1-MHz ultrasound beam was pulsed and focused through a plastic film to modulate the current distribution inside the saline-filled tank. AE signals were simultaneously detected at a sampling frequency of 15 MHz on multiple recording electrodes. A single recording electrode is sufficient to form volume images of the current flow and electric potentials. The AE potential is sensitive to the distance from the dipole, but is less sensitive to the angle between the detector and the dipole. Multi-channel UCSDI potentially improves 4-D mapping of bioelectric sources in the body at high spatial resolution, which is especially important for diagnosing and guiding treatment of cardiac and neurologic disorders, including arrhythmia and epilepsy. PMID:24569247

Optical Tunable-Based Transmitter for Multiple Radio Frequency Bands

NASA Technical Reports Server (NTRS)

Nguyen, Hung (Inventor); Simons, Rainee N. (Inventor); Wintucky, Edwin G. (Inventor); Freeman, Jon C. (Inventor)

2016-01-01

An optical tunable transmitter is used to transmit multiple radio frequency bands on a single beam. More specifically, a tunable laser is configured to generate a plurality of optical wavelengths, and an optical tunable transmitter is configured to modulate each of the plurality of optical wavelengths with a corresponding radio frequency band. The optical tunable transmitter is also configured to encode each of the plurality of modulated optical wavelengths onto a single laser beam for transmission of a plurality of radio frequency bands using the single laser beam.

Serum osteocalcin is significantly related to indices of obesity and lipid profile in Malaysian men.

PubMed

Chin, Kok-Yong; Ima-Nirwana, Soelaiman; Mohamed, Isa Naina; Ahmad, Fairus; Ramli, Elvy Suhana Mohd; Aminuddin, Amilia; Ngah, Wan Zurinah Wan

2014-01-01

Recent studies revealed a possible reciprocal relationship between the skeletal system and obesity and lipid metabolism, mediated by osteocalcin, an osteoblast-specific protein. This study aimed to validate the relationship between serum osteocalcin and indices of obesity and lipid parameters in a group of Malaysian men. A total of 373 men from the Malaysian Aging Male Study were included in the analysis. Data on subjects' demography, body mass index (BMI), body fat (BF) mass, waist circumference (WC), serum osteocalcin and fasting lipid levels were collected. Bioelectrical impendence (BIA) method was used to estimate BF. Multiple linear and binary logistic regression analyses were performed to analyze the association between serum osteocalcin and the aforementioned variables, with adjustment for age, ethnicity and BMI. Multiple regression results indicated that weight, BMI, BF mass, BF %, WC were significantly and negatively associated with serum osteocalcin (p < 0.001). There was a significant positive association between serum osteocalcin and high density lipoprotein (HDL) cholesterol (p = 0.032). Binary logistic results indicated that subjects with low serum osteocalcin level were more likely to be associated with high BMI (obese and overweight), high BF%, high WC and low HDL cholesterol (p < 0.05). Subjects with high osteocalcin level also demonstrated high total cholesterol level (p < 0.05) but this association was probably driven by high HDL level. These variables were not associated with serum C-terminal of telopeptide crosslinks in the subjects (p > 0.05). Serum osteocalcin is associated with indices of obesity and HDL level in men. These relationships should be validated by a longitudinal study, with comprehensive hormone profile testing.

An increase in visceral fat is associated with a decrease in the taste and olfactory capacity

PubMed Central

Fernandez-Garcia, Jose Carlos; Alcaide, Juan; Santiago-Fernandez, Concepcion; Roca-Rodriguez, MM.; Aguera, Zaida; Baños, Rosa; Botella, Cristina; de la Torre, Rafael; Fernandez-Real, Jose M.; Fruhbeck, Gema; Gomez-Ambrosi, Javier; Jimenez-Murcia, Susana; Menchon, Jose M.; Casanueva, Felipe F.; Fernandez-Aranda, Fernando; Tinahones, Francisco J.; Garrido-Sanchez, Lourdes

2017-01-01

Introduction Sensory factors may play an important role in the determination of appetite and food choices. Also, some adipokines may alter or predict the perception and pleasantness of specific odors. We aimed to analyze differences in smell–taste capacity between females with different weights and relate them with fat and fat-free mass, visceral fat, and several adipokines. Materials and methods 179 females with different weights (from low weight to morbid obesity) were studied. We analyzed the relation between fat, fat-free mass, visceral fat (indirectly estimated by bioelectrical impedance analysis with visceral fat rating (VFR)), leptin, adiponectin and visfatin. The smell and taste assessments were performed through the "Sniffin’ Sticks" and "Taste Strips" respectively. Results We found a lower score in the measurement of smell (TDI-score (Threshold, Discrimination and Identification)) in obese subjects. All the olfactory functions measured, such as threshold, discrimination, identification and the TDI-score, correlated negatively with age, body mass index (BMI), leptin, fat mass, fat-free mass and VFR. In a multiple linear regression model, VFR mainly predicted the TDI-score. With regard to the taste function measurements, the normal weight subjects showed a higher score of taste functions. However a tendency to decrease was observed in the groups with greater or lesser BMI. In a multiple linear regression model VFR and age mainly predicted the total taste scores. Discussion We show for the first time that a reverse relationship exists between visceral fat and sensory signals, such as smell and taste, across a population with different body weight conditions. PMID:28158237

Development of a solenoid actuated planar valveless micropump with single and multiple inlet-outlet arrangements

NASA Astrophysics Data System (ADS)

Kumar, N.; George, D.; Sajeesh, P.; Manivannan, P. V.; Sen, A. K.

2016-07-01

We report a planar solenoid actuated valveless micropump with multiple inlet-outlet configurations. The self-priming characteristics of the multiple inlet-multiple outlet micropump are studied. The filling dynamics of the micropump chamber during start-up and the effects of fluid viscosity, voltage and frequency on the dynamics are investigated. Numerical simulations for multiple inlet-multiple outlet micropumps are carried out using fluid structure algorithm. With DI water and at 5.0 Vp-p, 20 Hz frequency, the two inlet-two outlet micropump provides a maximum flow rate of 336 μl min-1 and maximum back pressure of 441 Pa. Performance characteristics of the two inlet-two outlet micropump are studied for aqueous fluids of different viscosity. Transport of biological cell lines and diluted blood samples are demonstrated; the flow rate-frequency characteristics are studied. Viability of cells during pumping with multiple inlet multiple outlet configuration is also studied in this work, which shows 100% of cells are viable. Application of the proposed micropump for simultaneous pumping, mixing and distribution of fluids is demonstrated. The proposed integrated, standalone and portable micropump is suitable for drug delivery, lab-on-chip and micro-total-analysis applications.

Multiple access techniques and spectrum utilization of the GLOBALSTAR mobile satellite system

NASA Astrophysics Data System (ADS)

Louie, Ming; Cohen, Michel; Rouffet, Denis; Gilhousen, Klein S.

The GLOBALSTAR System is a Low Earth Orbit (LEO) satellite-based mobile communications system that is interoperable with the current and future Public Land Mobile Network (PLMN). The GLOBALSTAR System concept is based upon technological advancement in two key areas: (1) the advancement in LEO satellite technology; (2) the advancement in cellular telephone technology, including the commercial applications of Code Division Multiple Access (CDMA) technologies, and of the most recent progress in Time Division Multiple Access technologies. The GLOBALSTAR System uses elements of CDMA, Frequency Division Multiple Access (FDMA), and Time Division Multiple Access (TDMA) technology, combining with satellite Multiple Beam Antenna (MBA) technology, to arrive at one of the most efficient modulation and multiple access system ever proposed for a satellite communications system. The technology used in GLOBALSTAR exploits the following techniques in obtaining high spectral efficiency and affordable cost per channel, with minimum coordination among different systems: power control, in open and closed loops, voice activation, spot beam satellite antenna for frequency reuse, weighted satellite antenna gain, multiple satellite coverage, and handoff between satellites. The GLOBALSTAR system design will use the following frequency bands: 1610-1626.5 MHz for up-link and 2483.5-2500 MHz for down-link.

A Neurophysiological Perspective on a Preventive Treatment against Schizophrenia Using Transcranial Electric Stimulation of the Corticothalamic Pathway

PubMed Central

Pinault, Didier

2017-01-01

Schizophrenia patients are waiting for a treatment free of detrimental effects. Psychotic disorders are devastating mental illnesses associated with dysfunctional brain networks. Ongoing brain network gamma frequency (30–80 Hz) oscillations, naturally implicated in integrative function, are excessively amplified during hallucinations, in at-risk mental states for psychosis and first-episode psychosis. So, gamma oscillations represent a bioelectrical marker for cerebral network disorders with prognostic and therapeutic potential. They accompany sensorimotor and cognitive deficits already present in prodromal schizophrenia. Abnormally amplified gamma oscillations are reproduced in the corticothalamic systems of healthy humans and rodents after a single systemic administration, at a psychotomimetic dose, of the glutamate N-methyl-d-aspartate receptor antagonist ketamine. These translational ketamine models of prodromal schizophrenia are thus promising to work out a preventive noninvasive treatment against first-episode psychosis and chronic schizophrenia. In the present essay, transcranial electric stimulation (TES) is considered an appropriate preventive therapeutic modality because it can influence cognitive performance and neural oscillations. Here, I highlight clinical and experimental findings showing that, together, the corticothalamic pathway, the thalamus, and the glutamatergic synaptic transmission form an etiopathophysiological backbone for schizophrenia and represent a potential therapeutic target for preventive TES of dysfunctional brain networks in at-risk mental state patients against psychotic disorders. PMID:28350371

A Neurophysiological Perspective on a Preventive Treatment against Schizophrenia Using Transcranial Electric Stimulation of the Corticothalamic Pathway.

PubMed

Pinault, Didier

2017-03-28

Schizophrenia patients are waiting for a treatment free of detrimental effects. Psychotic disorders are devastating mental illnesses associated with dysfunctional brain networks. Ongoing brain network gamma frequency (30-80 Hz) oscillations, naturally implicated in integrative function, are excessively amplified during hallucinations, in at-risk mental states for psychosis and first-episode psychosis. So, gamma oscillations represent a bioelectrical marker for cerebral network disorders with prognostic and therapeutic potential. They accompany sensorimotor and cognitive deficits already present in prodromal schizophrenia. Abnormally amplified gamma oscillations are reproduced in the corticothalamic systems of healthy humans and rodents after a single systemic administration, at a psychotomimetic dose, of the glutamate N - methyl -d-aspartate receptor antagonist ketamine. These translational ketamine models of prodromal schizophrenia are thus promising to work out a preventive noninvasive treatment against first-episode psychosis and chronic schizophrenia. In the present essay, transcranial electric stimulation (TES) is considered an appropriate preventive therapeutic modality because it can influence cognitive performance and neural oscillations. Here, I highlight clinical and experimental findings showing that, together, the corticothalamic pathway, the thalamus, and the glutamatergic synaptic transmission form an etiopathophysiological backbone for schizophrenia and represent a potential therapeutic target for preventive TES of dysfunctional brain networks in at-risk mental state patients against psychotic disorders.

The insulation performance of reactive parylene films in implantable electronic devices

PubMed Central

Seymour, John P.; Elkasabi, Yaseen; Chen, Hsien-yeh; Lahann, Joerg; Kipke, Daryl R.

2009-01-01

Parylene-C (poly-chloro-p-xylylene) is an appropriate material for use in an implantable, microfabricated device. It is hydrophobic, conformally deposited, has a low dielectric constant, and superb biocompatibility. Yet for many bioelectrical applications, its poor wet adhesion may be an impassable shortcoming. This research contrasts parylene-C and poly(p-xylylene) functionalized with reactive group X (PPX-X) layers using long-term electrical soak and adhesion tests. The reactive parylene was made of complementary derivatives having aldehyde and aminomethyl side groups (PPX-CHO and PPX-CH2NH2 respectively). These functional groups have previously been shown to covalently react together after heating. Electrical testing was conducted in saline at 37°C on interdigitated electrodes with either parylene-C or reactive parylene as the metal layer interface. Results showed that reactive parylene devices maintained the highest impedance. Heat-treated PPX-X device impedance was 800% greater at 10 kHz and 70% greater at 1Hz relative to heated parylene-C controls after 60 days. Heat treatment proved to be critical for maintaining high impedance of both parylene-C and the reactive parylene. Adhesion measurements showed improved wet metal adhesion for PPX-X, which corresponds well with its excellent high frequency performance. PMID:19703712

Ultrafast traveling wave dominates the electric organ discharge of Apteronotus leptorhynchus: an inverse modelling study.

PubMed

Shifman, Aaron R; Longtin, André; Lewis, John E

2015-10-30

Identifying and understanding the current sources that give rise to bioelectric fields is a fundamental problem in the biological sciences. It is very difficult, for example, to attribute the time-varying features of an electroencephalogram recorded from the head surface to the neural activity of specific brain areas; model systems can provide important insight into such problems. Some species of fish actively generate an oscillating (c. 1000 Hz) quasi-dipole electric field to communicate and sense their environment in the dark. A specialized electric organ comprises neuron-like cells whose collective signal underlies this electric field. As a step towards understanding the detailed biophysics of signal generation in these fish, we use an anatomically-detailed finite-element modelling approach to reverse-engineer the electric organ signal over one oscillation cycle. We find that the spatiotemporal profile of current along the electric organ constitutes a travelling wave that is well-described by two spatial Fourier components varying in time. The conduction velocity of this wave is faster than action potential conduction in any known neuronal axon (>200 m/s), suggesting that the spatiotemporal features of high-frequency electric organ discharges are not constrained by the conduction velocities of spinal neuron pathways.

Association between chocolate consumption and fatness in European adolescents.

PubMed

Cuenca-García, Magdalena; Ruiz, Jonatan R; Ortega, Francisco B; Castillo, Manuel J

2014-02-01

There is a substantial interest in the potential role of chocolate in the prevention of cardiovascular diseases. It has been recently reported that a higher frequency of chocolate intake is linked to lower body mass index (BMI) in adults. The aim of the present study was to determine if higher chocolate consumption also is associated with lower BMI, as well as other markers of total and central body fat, in adolescents. This study comprised 1458 adolescents (ages 12.5-17.5 y) participating in HELENA-CSS (Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study). Dietary intake was self-registered using a computer-based tool for 24-h dietary recall on 2 non-consecutive days. Weight and height were measured, and BMI was calculated. Adiposity was estimated using skinfolds (Slaughter's equation) and bioelectrical impedance analysis (BIA). Waist circumference was measured. Sexual maturation also was recorded. Physical activity was measured by accelerometry. Higher chocolate consumption was associated with lower levels of total and central fatness, as estimated by BMI, body fat estimated from skinfolds and BIA, and waist circumference, regardless of potential confounders (P ≤ 0.01). Our results demonstrate that a higher chocolate consumption was associated with lower total and central fatness in European adolescents. Copyright © 2014 Elsevier Inc. All rights reserved.

Accuracy of Body Mass Index Versus Lean Mass Index for Prediction of Sarcopenia in Older Women.

PubMed

Benton, M J; Silva-Smith, A L

2018-01-01

We compared accuracy of body mass index (BMI) versus lean mass index (LMI) to predict sarcopenia in 58 community-dwelling women (74.1±0.9 years). Lean mass was measured with multi-frequency bioelectrical impedance analysis, and strength was measured with Arm Curl test, Chair Stand test, and handgrip dynamometry. Sarcopenia was defined as low LMI. When categorized by BMI, normal women had less absolute lean mass (37.6±1.0 vs. 42.6±0.9 kg; P<0.001) and less relative lean mass (14.1±0.2 vs. 16.1±0.2 kg/m2; P<0.001) compared to overweight/obese women, but no differences in strength. When categorized by LMI, normal women had more absolute lean mass (44.0±0.7 vs. 35.7±0.7 kg; P<0.001), more relative lean mass (16.2±0.2 vs. 13.8±0.2 kg/m2; P<0.001), and greater upper body strength (16.7±0.9 vs. 14.2±0.6 arm curls; P<0.05) compared to women with low LMI. BMI failed to accurately predict low values of lean mass and strength. For clinical assessment, calculation of LMI rather than BMI is appropriate.

Individual neurophysiological profile in external effects investigation

NASA Astrophysics Data System (ADS)

Schastlivtseva, Daria; Tatiana Kotrovskaya, D..

Cortex biopotentials are the significant elements in human psychophysiological individuality. Considered that cortical biopotentials are diverse and individually stable, therefore there is the existence of certain dependence between the basic properties of higher nervous activity and cerebral bioelectric activity. The main purpose of the study was to reveal the individual neurophysiological profile and CNS initial functional state manifestation in human electroencephalogram (EEG) under effect of inert gases (argon, xenon, helium), hypoxia, pressure changes (0.02 and 0.2 MPa). We obtained 5-minute eyes closed background EEG on 19 scalp positions using Ag/AgCl electrodes mounted in an electrode cap. All EEG signals were re-referenced to average earlobes; Fast Furies Transformation analysis was used to calculate the relative power spectrum of delta-, theta-, alpha- and beta frequency band in artifact-free EEG. The study involved 26 healthy men who provided written informed consent, aged 20 to 35 years. Data obtained depend as individual EEG type and initial central nervous functional state as intensity, duration and mix of factors. Pronounced alpha rhythm in the raw EEG correlated with their adaptive capacity under studied factor exposure. Representation change and zonal distribution perversion of EEG alpha rhythm were accompanied by emotional instability, increased anxiety and difficulty adapting subjects. High power factor or combination factor with psychological and emotional or physical exertion minimizes individual EEG pattern.

Feasibility of controlled micturition through electric stimulation.

PubMed

Schmidt, R A; Tanagho, E A

1979-01-01

Historically, man has been aware of bioelectric phenomena for some 4,000 years. Yet it has only been during the last 20 years that technology has advanced to the stage where controlled bladder emptying has become feasible. A great deal of interest followed the introduction of transistor and bladder stimulation via the principle of radio frequency induction. Spinal cord, sacral, and pelvic nerve and direct bladder stimulation have all been attempted. Only direct bladder stimulation in lower motor neuron situations has shown any promise. The many difficulties associated with bladder stimulation include simultaneous sphincter contraction, pain, electrode and insulation difficulties, and fibroplasia due to movement of electrodes placed in pliable tissues. In addition, the role of the prostate, increased urethral length, and erection responses in the male have received little investigation. These problems are outlined and experimental observations of attempts to achieve controlled micturition in canines areresented. These studies were carried out over a 3-year period, and emphasize responses to stimulation of the spinal cord and sacral roots. It was concluded that the most efficient manner by which to effect simulated micturition is via stimulation of the ventral sacral root dominant for bladder responsiveness, and combine this with selective division of somatic fibers of only the root being stimulated.

Ultrafast traveling wave dominates the electric organ discharge of Apteronotus leptorhynchus: an inverse modelling study

PubMed Central

Shifman, Aaron R.; Longtin, André; Lewis, John E.

2015-01-01

Identifying and understanding the current sources that give rise to bioelectric fields is a fundamental problem in the biological sciences. It is very difficult, for example, to attribute the time-varying features of an electroencephalogram recorded from the head surface to the neural activity of specific brain areas; model systems can provide important insight into such problems. Some species of fish actively generate an oscillating (c. 1000 Hz) quasi-dipole electric field to communicate and sense their environment in the dark. A specialized electric organ comprises neuron-like cells whose collective signal underlies this electric field. As a step towards understanding the detailed biophysics of signal generation in these fish, we use an anatomically-detailed finite-element modelling approach to reverse-engineer the electric organ signal over one oscillation cycle. We find that the spatiotemporal profile of current along the electric organ constitutes a travelling wave that is well-described by two spatial Fourier components varying in time. The conduction velocity of this wave is faster than action potential conduction in any known neuronal axon (>200 m/s), suggesting that the spatiotemporal features of high-frequency electric organ discharges are not constrained by the conduction velocities of spinal neuron pathways. PMID:26514932

Diet, growth, and obesity development throughout childhood in the Avon Longitudinal Study of Parents and Children.

PubMed

Emmett, Pauline M; Jones, Louise R

2015-10-01

Publications from the Avon Longitudinal Study of Parents and Children covering diet, growth, and obesity development during childhood are reviewed. Diet was assessed by food frequency questionnaires and food records. Growth data were collected by routine measurements, and in standardized clinics, body fatness was assessed by bioelectrical impedance and DXA (dual-energy X-ray absorptiometry) scans. Diets changed dramatically during the preschool period with an increase in the intake of free (added) sugars (12.3% rising to 16.4% of energy) that remained similar until adolescence. This was due to increased intake of energy-dense, nutrient-poor foods. Two periods of rapid growth were identified; infancy and mid-childhood (ages 7-11 y) and both were associated with obesity development. Diets with high energy density were associated with increasing fat mass from mid-childhood until adolescence. Genetic and dietary factors showed independent associations with increasing adiposity. At all ages studied, there were dietary inequalities related to maternal educational attainment that may influence inequalities found in obesity development. The Avon Longitudinal Study of Parents and Children has provided valuable insights into how disparities in diet and growth may affect the development of ill health in adulthood. © The Author(s) 2015. Published by Oxford University Press on behalf of the International Life Sciences Institute.

Repletion of Zinc and Iron Deficiencies Improve Cognition of Premenopausal Women

DTIC Science & Technology

1998-10-01

bioelectrical Impedance, taste acuity and other indices related to Zn status ~d 30 Measure baseline neuropsychological outcomes on day 8-12 of... taste buds. A circular, 5mm in diameter, stainless steel electrode was used. Subject were comfortably sitting and familiar with the difference between...determined by increasing the stimulation current starting from zero. Taste acuity was measured before and after treatment. Taste acuity was also measured

Sensitivity field distributions for segmental bioelectrical impedance analysis based on real human anatomy

NASA Astrophysics Data System (ADS)

Danilov, A. A.; Kramarenko, V. K.; Nikolaev, D. V.; Rudnev, S. G.; Salamatova, V. Yu; Smirnov, A. V.; Vassilevski, Yu V.

2013-04-01

In this work, an adaptive unstructured tetrahedral mesh generation technology is applied for simulation of segmental bioimpedance measurements using high-resolution whole-body model of the Visible Human Project man. Sensitivity field distributions for a conventional tetrapolar, as well as eight- and ten-electrode measurement configurations are obtained. Based on the ten-electrode configuration, we suggest an algorithm for monitoring changes in the upper lung area.

Agreement between Omron 306 and Biospace InBody 720 Bioelectrical Impedance Analyzers (BIA) in Children and Adolescents

ERIC Educational Resources Information Center

Finn, Kevin J.; Saint-Maurice, Pedro F.; Karsai, István; Ihász, Ferenc; Csányi, Tamás

2015-01-01

Purpose: The purpose of this study was to test the convergent validity of Omron 306 using Biospace InBody 720. Method: A total of 267 participants (145 boys; aged 10.4-17.9 years) completed testing during a single session. Each measure provided percent body fat (%BF), while the InBody 720 included fat-free mass (FFM). The validity was examined…

Agreement in Body Fat Estimates between a Hand-Held Bioelectrical Impedance Analyzer and Skinfold Thicknesses in African American and Caucasian Adolescents

ERIC Educational Resources Information Center

Hannon, James C.; Ratliffe, Thomas; Williams, Daniel P.

2006-01-01

The body mass index (BMI), or the ratio of weight in kilograms to the square of height in meters, is widely used to determine the presence or absence of overweight and obesity in adults. Although many consider BMI an acceptable clinical surrogate of body fatness, it does not differentiate between fat and fat-free tissues. Thus, children and…

Modulating endogenous electric currents in human corneal wounds--a novel approach of bioelectric stimulation without electrodes.

PubMed

Reid, Brian; Graue-Hernandez, Enrique O; Mannis, Mark J; Zhao, Min

2011-03-01

To measure electric current in human corneal wounds and test the feasibility of pharmacologically enhancing the current to promote corneal wound healing. Using a noninvasive vibrating probe, corneal electric current was measured before and after wounding of the epithelium of donated postmortem human corneas. The effects of drug aminophylline and chloride-free solution on wound current were also tested. Unwounded cornea had small outward currents (0.07 μA/cm²). Wounding increased the current more than 5 fold (0.41 μA/cm²). Monitoring the wound current over time showed that it seemed to be actively regulated and maintained above normal unwounded levels for at least 6 hours. The time course was similar to that previously measured in rat cornea. Drug treatment or chloride-free solution more than doubled the size of wound currents. Electric current at human corneal wounds can be significantly increased with aminophylline or chloride-free solution. Because corneal wound current directly correlates with wound healing rate, our results suggest a role for chloride-free and/or aminophylline eyedrops to enhance healing of damaged cornea in patients with reduced wound healing such as the elderly or diabetic patient. This novel approach offers bioelectric stimulation without electrodes and can be readily tested in patients.

Self-sustaining, solar-driven bioelectricity generation in micro-sized microbial fuel cell using co-culture of heterotrophic and photosynthetic bacteria

NASA Astrophysics Data System (ADS)

Liu, Lin; Choi, Seokheun

2017-04-01

Among many energy harvesting techniques with great potential, microbial fuel cell (MFC) technology is arguably the most underdeveloped. Even so, excitement is building, as microorganisms can harvest electrical power from any biodegradable organic source (e.g. wastewater) that is readily available in resource-limited settings. Nevertheless, the requirement for endless introduction of organic matter imposes a limiting factor to this technology, demanding an active feeding system and additional power. Here, we demonstrated self-sustaining bioelectricity generation from a microliter-scale microbial fuel cell (MFC) by using the syntrophic interaction between heterotrophic exoelectrogenic bacteria and phototrophs. The MFC continuously generated light-responsive electricity from the heterotrophic bacterial metabolic respiration with the organic substrates produced by photosynthetic bacteria. Without additional organic fuel, the mixed culture in a 90-μL-chamber MFC generated self-sustained current for more than 13 days, while the heterotrophic culture produced current that decreased dramatically within a few hours. The current from the mixed culture was about 70 times greater than that of the device with only photosynthetic bacteria. The miniaturization provided a short start-up time, a well-controlled environment, and small internal resistance. Those advantages will become the general design platform for micropower generation.

Unveiling characteristics of a bioelectrochemical system with polarity reversion for simultaneous azo dye treatment and bioelectricity generation.

PubMed

Sun, Jian; Zhang, Yaping; Liu, Guoguang; Ning, Xunan; Wang, Yujie; Liu, Jingyong

2015-09-01

A novel bioelectrochemical system (BES) operated with polarity reversion was explored for simultaneous anaerobic/aerobic treatment of azo dye and production of bioelectricity under extremely low buffer. The Congo red was first decolorized in anode, with completed color removal in 35 h. The resultant decolorization intermediates were then mineralized after the anode reversed to aerobic biocathode, evidenced by 55 % chemical oxygen demand (COD) removal in 200 h. The mineralization efficiency was further increased to 70 % when the period of the half-cycle was prolonged to 375 h. Meanwhile, the BES produced a continuous stable positive/negative alternate voltage output under 5 mM phosphate buffer because of the self-neutralization of the accumulated protons and hydroxyl ions in electrolyte. The electrode performance was significantly improved, which was indicated by alleviated electrode polarization, due to in situ use of accumulated protons and hydroxyl ions and enhanced electron transfer in the presence of Congo red and its degradation intermediates, which resulted in 1.05-fold increases in maximum power density (67.5 vs. 32.9 mW/m(2)). An analysis of the microbial diversity in the biofilm revealed that the biofilm was dominated by facultative bacteria with functional roles in contaminant degradation and electricity generation.

Methanobrevibacter attenuation via probiotic intervention reduces flatulence in adult human: A non-randomised paired-design clinical trial of efficacy.

PubMed

Seo, Minseok; Heo, Jaeyoung; Yoon, Joon; Kim, Se-Young; Kang, Yoon-Mo; Yu, Jihyun; Cho, Seoae; Kim, Heebal

2017-01-01

The aim of this study was to investigate which of the gut microbes respond to probiotic intervention, as well as study whether they are associated with gastrointestinal symptoms in a healthy adult human. For the experimental purpose, twenty-one healthy adults were recruited and received probiotic mixture, which is composed of five Lactobacilli strains and two Bifidobacteria strains, once a day for 60 days. Defecation survey and Bioelectrical Impedance Analysis were conducted pre- and post-administration to measure phenotypic differences. Stool samples of the subjects were collected twice. The statistical analysis was performed for pair designed metagenome data with 11 phenotypic records of the bioelectrical impedance body composition analyzer and 6 responses of the questionnaires about gastrointestinal symptom. Furthemore, correlation-based network analysis was conducted for exploring complex relationships among microbiome communities. The abundances of Citrobacter, Klebsiella, and Methanobrevibacter were significantly reduced, which are strong candidates to be highly affected by the probiotic administration. In addition, interaction effects were observed between flatulence symptom attenuation and decreasing patterns of the Methanobrevibacter abundance. These results reveal that probiotic intervention modulated the composition of gut microbiota and reduced the abundance of potential pathogens (i.e. Citrobacter and Klebsiella). In addition, methanogens (i.e. Methanobrevibacter) associated with the gastrointestinal symptom in an adult human.

Efferent influences on the bioelectrical activity of the retina in primates.

PubMed

Ortiz, Gonzalo; Odom, J Vernon; Passaglia, Christopher L; Tzekov, Radouil T

2017-02-01

The existence of retinopetal (sometimes referred to as "efferent" or "centrifugal") axons in the mammalian optic nerve is a topic of long-standing debate. Opposition is fading as efferent innervation of the retina has now been widely documented in rodents and other animals. The existence and function of an efferent system in humans and non-human primates has not, though, been definitively established. Such a feedback pathway could have important functional, clinical, and experimental significance to the field of vision science and ophthalmology. Following a comprehensive literature review (PubMed and Google Scholar, until July 2016), we present evidence regarding a system that can influence the bioelectrical activity of the retina in primates. Anatomical and physiological evidences are presented separately. Improvements in histological staining and the advent of retrograde nerve fiber tracers have allowed for more confidence in the identification of efferent optic nerve fibers, including back to their point of origin. Even with the accumulation of more modern anatomical and physiological evidence, some limitations and uncertainties about crucial details regarding the origins and role of a top-down, efferent system still exist. However, the summary of the evidence from earlier and more modern studies makes a compelling case in support of such a system in humans and non-human primates.

Surfactants selectively reallocated the bacterial distribution in soil bioelectrochemical remediation of petroleum hydrocarbons.

PubMed

Li, Xiaojing; Zhao, Qian; Wang, Xin; Li, Yongtao; Zhou, Qixing

2018-02-15

Soil contaminated by aged petroleum hydrocarbons is faced with scarcity of electron acceptors, low activity of functional microbes and inefficient electron transfer, which hinder the bioremediation application. The soil microbial fuel cell (MFC) simultaneously solves these problems with bioelectricity production. In this study, five types of surfactants were introduced to enhance the bioavailability of aged petroleum hydrocarbon in soils. The ampholytic surfactant (lecithos) was optimal due to the highest bioelectricity generation (0.321Cd -1 g -1 ) and promoted hydrocarbon degradation (328%), while the nonionic (glyceryl monostearate) and cationic (cetyltrimethylammonium bromide) surfactants were inefficient. The surfactants induced a special microbial enrichment affiliated with Proteobacteria, Firmicutes, Bacteroidetes, Actinobacteria, Chloroflexi, Planctomycetes and Acidobacteria (93%-99% of total) in soil MFCs. The anionic surfactant (sodium dodecyl sulfate) exhibited the strongest selectivity, and α-proteobacteria and γ-proteobacteria abundances decreased while Clostridia increased, much like the result obtained with the biosurfactant β-cyclodextrin. Furthermore, Bacillus abundance was increased in connected soil MFCs, except addition of lecithos in which Clostridium increased to 14.88% from 3.61% in the control. The high correlations among Bacillus, Phenylobacterium, Solibacillus (0.9162-0.9577) and among Alcaligenes, Dysgonomonas, Sedimentibacter (0.9538-0.9966) indicated a metabolic network of microorganisms in the soil bioelectrochemical remediation system. Copyright © 2017 Elsevier B.V. All rights reserved.

Phase Angle of Bioelectrical Impedance Analysis as Prognostic Factor in Palliative Care Patients at the National Cancer Institute in Mexico.

PubMed

Pérez Camargo, Dana A; Allende Pérez, Silvia R; Rivera Franco, Mónica M; Álvarez Licona, Nelson E; Urbalejo Ceniceros, Víctor I; Figueroa Baldenegro, Lilian E

2017-01-01

Patients with advanced cancer often experience symptoms of disease and treatment that contribute to distress such as weight loss, which is present in up to 85% of cancer patients. Palliative care in these patients focuses on care aimed at improving quality of life. Phase angle (PA) is obtained by bioelectric impedance analysis (BIA) and is associated with cellular function. It is considered a reliable marker of malnutrition. A low PA may suggest deterioration of the cell membrane, which in palliative patients may result in a short-term survival. The aim of this study was to associate PA and survival in palliative patients of the National Cancer Institute of Mexico. We included 452 patients (women, 56.4%); the average PA was 4.0°. The most frequent disease was gastric cancer (39.2%). Mean body mass index (BMI) was 22.84. The average survival of patients with PA ≤ 4° was 86 days, while in the group with PA > 4°, it was 163 days (P > 0.0001). PA showed significant positive correlation with survival time and BMI. Our results corroborate the reliability of PA in Mexican population, as an indicator of survival in palliative care patients compared to the reported literature in other countries.

Validation of bioelectrical impedance analysis to hydrostatic weighing in male body builders.

PubMed

Volpe, Stella Lucia; Melanson, Edward L; Kline, Gregory

2010-03-01

The purpose of this study was to compare bioelectrical impedance analysis (BIA) to hydrostatic weighing (HW) in male weight lifters and body builders. Twenty-two male body builders and weight lifters, 23 +/- 3 years of age (mean +/- SD), were studied to determine the efficacy of BIA to HW in this population. Subjects were measured on two separate occasions, 6 weeks apart, for test-retest reliability purposes. Participants recorded 3-day dietary intakes and average work-out times and regimens between the two testing periods. Subjects were, on average, 75 +/- 8 kg of body weight and 175 +/- 7 cm tall. Validation results were as follows: constant error for HW-BIA = 0.128 +/- 3.7%, r for HW versus BIA = -0.294. Standard error of the estimate for BIA = 2.32% and the total error for BIA = 3.6%. Percent body fat was 7.8 +/- 1% from BIA and 8.5 +/- 2% from HW (P > 0.05). Subjects consumed 3,217 +/- 1,027 kcals; 1,848 +/- 768 kcals from carbohydrates; 604 +/- 300 kcals from protein; and 783 +/- 369 kcals from fat. Although work-outs differed among one another, within subject training did not vary. These results suggest that measurement of percent body fat in male body builders and weight trainers is equally as accurate using BIA or HW.

A novel approach to teach the generation of bioelectrical potentials from a descriptive and quantitative perspective.

PubMed

Rodriguez-Falces, Javier

2013-12-01

In electrophysiology studies, it is becoming increasingly common to explain experimental observations using both descriptive methods and quantitative approaches. However, some electrophysiological phenomena, such as the generation of extracellular potentials that results from the propagation of the excitation source along the muscle fiber, are difficult to describe and conceptualize. In addition, most traditional approaches aimed at describing extracellular potentials consist of complex mathematical machinery that gives no chance for physical interpretation. The aim of the present study is to present a new method to teach the formation of extracellular potentials around a muscle fiber from both a descriptive and quantitative perspective. The implementation of this method was tested through a written exam and a satisfaction survey. The new method enhanced the ability of students to visualize the generation of bioelectrical potentials. In addition, the new approach improved students' understanding of how changes in the fiber-to-electrode distance and in the shape of the excitation source are translated into changes in the extracellular potential. The survey results show that combining general principles of electrical fields with accurate graphic imagery gives students an intuitive, yet quantitative, feel for electrophysiological signals and enhances their motivation to continue their studies in the biomedical engineering field.

Bioelectricity-assisted partial degradation of linear polyacrylamide in a bioelectrochemical system.

PubMed

Cui, Yu-Zhi; Zhang, Jian; Sun, Min; Zhai, Lin-Feng

2015-01-01

The wide application of water-soluble linear polyacrylamides (PAMs) can cause serious environmental pollution. Biological treatment of PAMs receives very limited efficiency due to their recalcitrance to the microbial degradation. Here, we show the bioelectrochemical system (BES) can be used as an effective strategy to improve the biodegradation efficiency of PAMs. A linear PAM with viscosity-average molecular weight of 5 × 10(6) was treated in the anodic chamber of BES reactor, and the change of PAM structure during the degradation process was investigated. The anodic bacteria in the BES demonstrated abilities to utilize the PAM as the sole carbon and nitrogen source to generate electricity. Both the anode-attached and planktonic bacteria contributed to the electricity generation, while the anode-attached community exhibited stronger electron transfer ability than the planktonic one. The closed-circuit and open-circuit operations of the BES reactor obtained chemical oxygen demand (COD) removal efficiencies of 32.5 and 7.4 %, respectively, implying the generation of bioelectricity could enhance the biodegradation of PAM. Structure analysis suggested the carbon chain of PAM was partially degraded in the BES, producing polymeric products with lower molecular weight. The microbial cleavage of the carbon chain was proposed to start from the "head-to-head" linkages and end with the formation of ether bonds.

Impact of hemodialysis on dual X-ray absorptiometry, bioelectrical impedance measurements, and anthropometry.

PubMed

Abrahamsen, B; Hansen, T B; Høgsberg, I M; Pedersen, F B; Beck-Nielsen, H

1996-01-01

Dual X-ray absorptiometry (DXA) performs noninvasive assessment of bone and soft tissue with high precision. However, soft tissue algorithms assume that 73.2% of the lean body mass is water, a potential source of error in fluid retention. We evaluated DXA (model QDR-2000; Hologic Inc, Waltham, MA), bioelectrical impedance analysis (BIA), and simple anthropometry in 19 patients (9 women and 10 men, mean age 46 y) before and after hemodialysis, removing 0.9-4.3 L (x: 2.8L) of ultrafiltrate. The reduction in fat-free mass (FFM) measured by DXA was highly correlated with the ultrafiltrate, as determined by the reduction in gravimetric weight (r = 0.975, P < 0.0001; SEE: 233 g), whereas BIA was considerably less accurate in assessing FFM reductions (r = 0.66, P < 0.01; SEE: 757 g). Lumbar bone mineral density (BMD) was unaffected by dialysis, as were whole-body fat and BMD. Whole-body bone mineral content, however, was estimated to be 0.6% lower after dialysis. None of the simple anthropometric measurements correlated significantly with the reduction in FFM. In an unmodified clinical setting, DXA appears to be superior to other simple noninvasive methods for determining body composition, particularly when the emphasis is on repeated measurements.

High-power free-electron maser with frequency multiplication operating in a shortwave part of the millimeter wave range

NASA Astrophysics Data System (ADS)

Bandurkin, I. V.; Kaminsky, A. K.; Perelstein, E. A.; Peskov, N. Yu.; Savilov, A. V.; Sedykh, S. N.

2012-08-01

The possibility of using frequency multiplication in order to obtain high-power short-wavelength radiation from a free-electron maser (FEM) with a Bragg resonator has been studied. Preliminary experiments with an LIU-3000 (JINR) linear induction accelerator demonstrate the operation of a frequency-multiplying FEM at megawatt power in the 6- and 4-mm wave bands on the second and third harmonic, respectively.

A self-powered glucose biosensing system.

PubMed

Slaughter, Gymama; Kulkarni, Tanmay

2016-04-15

A self-powered glucose biosensor (SPGS) system is fabricated and in vitro characterization of the power generation and charging frequency characteristics in glucose analyte are described. The bioelectrodes consist of compressed network of three-dimensional multi-walled carbon nanotubes with redox enzymes, pyroquinoline quinone glucose dehydrogenase (PQQ-GDH) and laccase functioning as the anodic and cathodic catalyst, respectively. When operated in 45 mM glucose, the biofuel cell exhibited an open circuit voltage and power density of 681.8 mV and 67.86 µW/cm(2) at 335 mV, respectively, with a current density of 202.2 µA/cm(2). Moreover, at physiological glucose concentration (5mM), the biofuel cell exhibits open circuit voltage and power density of 302.1 mV and 15.98 µW/cm(2) at 166.3 mV, respectively, with a current density of 100 µA/cm(2). The biofuel cell assembly produced a linear dynamic range of 0.5-45 mM glucose. These findings show that glucose biofuel cells can be further investigated in the development of a self-powered glucose biosensor by using a capacitor as the transducer element. By monitoring the capacitor charging frequencies, which are influenced by the concentration of the glucose analyte, a linear dynamic range of 0.5-35 mM glucose is observed. The operational stability of SPGS is monitored over a period of 63 days and is found to be stable with 15.38% and 11.76% drop in power density under continuous discharge in 10mM and 20mM glucose, respectively. These results demonstrate that SPGSs can simultaneously generate bioelectricity to power ultra-low powered devices and sense glucose. Copyright © 2015 Elsevier B.V. All rights reserved.

Scaling and the frequency dependence of Nyquist plot maxima of the electrical impedance of the human thigh.

PubMed

Shiffman, Carl

2017-11-30

To define and elucidate the properties of reduced-variable Nyquist plots. Non-invasive measurements of the electrical impedance of the human thigh. A retrospective analysis of the electrical impedances of 154 normal subjects measured over the past decade shows that 'scaling' of the Nyquist plots for human thigh muscles is a property shared by healthy thigh musculature, irrespective of subject and the length of muscle segment. Here the term scaling signifies the near and sometimes 'perfect' coalescence of the separate X versus R plots into one 'reduced' Nyquist plot by the simple expedient of dividing R and X by X m , the value of X at the reactance maximum. To the extent allowed by noise levels one can say that there is one 'universal' reduced Nyquist plot for the thigh musculature of healthy subjects. There is one feature of the Nyquist curves which is not 'universal', however, namely the frequency f m at which the maximum in X is observed. That is found to vary from 10 to 100 kHz. depending on subject and segment length. Analysis shows, however, that the mean value of 1/f m is an accurately linear function of segment length, though there is a small subject-to-subject random element as well. Also, following the recovery of an otherwise healthy victim of ankle fracture demonstrates the clear superiority of measurements above about 800 kHz, where scaling is not observed, in contrast to measurements below about 400 kHz, where scaling is accurately obeyed. The ubiquity of 'scaling' casts new light on the interpretation of impedance results as they are used in electrical impedance myography and bioelectric impedance analysis.

Stochastic and superharmonic stochastic resonances of a confined overdamped harmonic oscillator

NASA Astrophysics Data System (ADS)

Zhang, Lu; Lai, Li; Peng, Hao; Tu, Zhe; Zhong, Suchuan

2018-01-01

The dynamics of many soft condensed matter and biological systems is affected by space limitations, which produce some peculiar effects on the systems' stochastic resonance (SR) behavior. In this study, we propose a model where SR can be observed: a confined overdamped harmonic oscillator that is subjected to a sinusoidal driving force and is under the influence of a multiplicative white noise. The output response of the system is a periodic signal with harmonic frequencies that are odd multiples of the driving frequency. We verify the amplitude resonances at the driving frequencies and superharmonic frequencies that are equal to three, five, and seven times the driving frequency, using a numerical method based on the stochastic Taylor expansion. The synergistic effect of the multiplicative white noise, constant boundaries, and periodic driving force that can induce a SR in the output amplitude at the driving and superharmonic frequencies is found. The SR phenomenon found in this paper is sensitive to the driving amplitude and frequency, inherent potential parameter, and boundary width, thus leading to various resonance conditions. Therefore, the mechanism found could be beneficial for the characterization of these confined systems and could constitute an important tool for controlling their basic properties.

Obtaining eigensolutions for multiple frequency ranges in a single NASTRAN execution

NASA Technical Reports Server (NTRS)

Pamidi, P. R.; Brown, W. K.

1990-01-01

A novel and general procedure for obtaining eigenvalues and eigenvectors for multiple frequency ranges in a single NASTRAN execution is presented. The scheme is applicable to normal modes analyzes employing the FEER and Inverse Power methods of eigenvalue extraction. The procedure is illustrated by examples.

Multiple stable states of a periodically driven electron spin in a quantum dot using circularly polarized light

NASA Astrophysics Data System (ADS)

Korenev, V. L.

2011-06-01

The periodical modulation of circularly polarized light with a frequency close to the electron spin resonance frequency induces a sharp change of the single electron spin orientation. Hyperfine interaction provides a feedback, thus fixing the precession frequency of the electron spin in the external and the Overhauser field near the modulation frequency. The nuclear polarization is bidirectional and the electron-nuclear spin system (ENSS) possesses a few stable states. The same physics underlie the frequency-locking effect for two-color and mode-locked excitations. However, the pulsed excitation with mode-locked laser brings about the multitudes of stable states in ENSS in a quantum dot. The resulting precession frequencies of the electron spin differ in these states by the multiple of the modulation frequency. Under such conditions ENSS represents a digital frequency converter with more than 100 stable channels.

Orthogonal Multi-Carrier DS-CDMA with Frequency-Domain Equalization

NASA Astrophysics Data System (ADS)

Tanaka, Ken; Tomeba, Hiromichi; Adachi, Fumiyuki

Orthogonal multi-carrier direct sequence code division multiple access (orthogonal MC DS-CDMA) is a combination of orthogonal frequency division multiplexing (OFDM) and time-domain spreading, while multi-carrier code division multiple access (MC-CDMA) is a combination of OFDM and frequency-domain spreading. In MC-CDMA, a good bit error rate (BER) performance can be achieved by using frequency-domain equalization (FDE), since the frequency diversity gain is obtained. On the other hand, the conventional orthogonal MC DS-CDMA fails to achieve any frequency diversity gain. In this paper, we propose a new orthogonal MC DS-CDMA that can obtain the frequency diversity gain by applying FDE. The conditional BER analysis is presented. The theoretical average BER performance in a frequency-selective Rayleigh fading channel is evaluated by the Monte-Carlo numerical computation method using the derived conditional BER and is confirmed by computer simulation of the orthogonal MC DS-CDMA signal transmission.

Comprehensive molecular profiling of 718 Multiple Myelomas reveals significant differences in mutation frequencies between African and European descent cases

PubMed Central

Christofferson, Austin; Aldrich, Jessica; Jewell, Scott; Kittles, Rick A.; Derome, Mary; Craig, David Wesley; Carpten, John D.

2017-01-01

Multiple Myeloma (MM) is a plasma cell malignancy with significantly greater incidence and mortality rates among African Americans (AA) compared to Caucasians (CA). The overall goal of this study is to elucidate differences in molecular alterations in MM as a function of self-reported race and genetic ancestry. Our study utilized somatic whole exome, RNA-sequencing, and correlated clinical data from 718 MM patients from the Multiple Myeloma Research Foundation CoMMpass study Interim Analysis 9. Somatic mutational analyses based upon self-reported race corrected for ancestry revealed significant differences in mutation frequency between groups. Of interest, BCL7A, BRWD3, and AUTS2 demonstrate significantly higher mutation frequencies among AA cases. These genes are all involved in translocations in B-cell malignancies. Moreover, we detected a significant difference in mutation frequency of TP53 and IRF4 with frequencies higher among CA cases. Our study provides rationale for interrogating diverse tumor cohorts to best understand tumor genomics across populations. PMID:29166413

A multi-reference filtered-x-Newton narrowband algorithm for active isolation of vibration and experimental investigations

NASA Astrophysics Data System (ADS)

Wang, Chun-yu; He, Lin; Li, Yan; Shuai, Chang-geng

2018-01-01

In engineering applications, ship machinery vibration may be induced by multiple rotational machines sharing a common vibration isolation platform and operating at the same time, and multiple sinusoidal components may be excited. These components may be located at frequencies with large differences or at very close frequencies. A multi-reference filtered-x Newton narrowband (MRFx-Newton) algorithm is proposed to control these multiple sinusoidal components in an MIMO (multiple input and multiple output) system, especially for those located at very close frequencies. The proposed MRFx-Newton algorithm can decouple and suppress multiple sinusoidal components located in the same narrow frequency band even though such components cannot be separated from each other by a narrowband-pass filter. Like the Fx-Newton algorithm, good real-time performance is also achieved by the faster convergence speed brought by the 2nd-order inverse secondary-path filter in the time domain. Experiments are also conducted to verify the feasibility and test the performance of the proposed algorithm installed in an active-passive vibration isolation system in suppressing the vibration excited by an artificial source and air compressor/s. The results show that the proposed algorithm not only has comparable convergence rate as the Fx-Newton algorithm but also has better real-time performance and robustness than the Fx-Newton algorithm in active control of the vibration induced by multiple sound sources/rotational machines working on a shared platform.

A frequency domain global parameter estimation method for multiple reference frequency response measurements

NASA Astrophysics Data System (ADS)

Shih, C. Y.; Tsuei, Y. G.; Allemang, R. J.; Brown, D. L.

1988-10-01

A method of using the matrix Auto-Regressive Moving Average (ARMA) model in the Laplace domain for multiple-reference global parameter identification is presented. This method is particularly applicable to the area of modal analysis where high modal density exists. The method is also applicable when multiple reference frequency response functions are used to characterise linear systems. In order to facilitate the mathematical solution, the Forsythe orthogonal polynomial is used to reduce the ill-conditioning of the formulated equations and to decouple the normal matrix into two reduced matrix blocks. A Complex Mode Indicator Function (CMIF) is introduced, which can be used to determine the proper order of the rational polynomials.

Changes in Nutritional Status after Deep Brain Stimulation of the Nucleus Basalis of Meynert in Alzheimer's Disease--Results of a Phase I Study.

PubMed

Noreik, M; Kuhn, J; Hardenacke, K; Lenartz, D; Bauer, A; Bührle, C P; Häussermann, P; Hellmich, M; Klosterkötter, J; Wiltfang, J; Maarouf, M; Freund, H-J; Visser-Vandewalle, V; Sturm, V; Schulz, R-J

2015-10-01

The progression of Alzheimer's disease (AD) is associated with impaired nutritional status. New methods, such as deep brain stimulation (DBS), are currently being tested to decrease the progression of AD. DBS is an approved method in the treatment of Parkinson's disease, and its suitability for the treatment of AD patients is currently under experimental investigation. To evaluate the advantages and disadvantages of this new treatment, it is important to assess potential side effects of DBS regarding the nucleus basalis of Meynert; this new treatment is thought to positively affect cognition and might counteract the deterioration of nutritional status and progressive weight loss observed in AD. This study aims to assess the nutritional status of patients with AD before receiving DBS of the nucleus basalis of Meynert and after 1 year, and to analyze potential associations between changes in cognition and nutritional status. A 1-year phase I proof-of-concept study. The Department of Psychiatry and Psychotherapy at the University of Cologne. We assessed a consecutive sample of patients with mild to moderate AD (n=6) who fulfilled the inclusion criteria and provided written informed consent. Bilateral low-frequency DBS of the nucleus basalis of Meynert. Nutritional status was assessed using a modified Mini Nutritional Assessment, bioelectrical impedance analysis, a completed 3-day food diary, and analysis of serum levels of vitamin B12 and folate. With a normal body mass index (BMI) at baseline (mean 23.75 kg/m²) and after 1 year (mean 24.59 kg/m²), all but one patient gained body weight during the period of the pilot study (mean 2.38 kg, 3.81% of body weight). This was reflected in a mainly stable or improved body composition, assessed by bioelectrical impedance analysis, in five of the six patients. Mean energy intake increased from 1534 kcal/day (min 1037, max 2370) at baseline to 1736 kcal/day (min 1010, max 2663) after 1 year, leading to the improved fulfillment of energy needs in four patients. The only nutritional factors that were associated with changes in cognition were vitamin B12 level at baseline (Spearman's rho = 0.943, p = 0.005) and changes in vitamin B12 level (Spearman's rho = -0.829, p = 0.042). Patients with AD that received DBS of the nucleus basalis of Meynert demonstrated a mainly stable nutritional status within a 1-year period. Whether DBS is causative regarding these observations must be investigated in additional studies.

Magnetic-Field Hazards Bibliography.

DTIC Science & Technology

1985-09-01

Field Hazards Bibliography 15. Bianchi, A.; Capraro, V., and Gualtierotti, T., "Decrease of the sodium transport across frog skin in a steady magnetic...Effects of static magnetic field on some lipid and protein metabolic processes of rabbit, J. Transport . Med. 34:376 (1980). 56. Nakhil ’Nitskaya, Z. N... Brain ," Elsevier Pub. Co., New York. 3. Aleksandrovskaya, M. M.; Kholodov, Yu. A., "The potential role of neruaglia in the onset of a bioelectrical

[Wearable Automatic External Defibrillators].

PubMed

Luo, Huajie; Luo, Zhangyuan; Jin, Xun; Zhang, Leilei; Wang, Changjin; Zhang, Wenzan; Tu, Quan

2015-11-01

Defibrillation is the most effective method of treating ventricular fibrillation(VF), this paper introduces wearable automatic external defibrillators based on embedded system which includes EGG measurements, bioelectrical impedance measurement, discharge defibrillation module, which can automatic identify VF signal, biphasic exponential waveform defibrillation discharge. After verified by animal tests, the device can realize EGG acquisition and automatic identification. After identifying the ventricular fibrillation signal, it can automatic defibrillate to abort ventricular fibrillation and to realize the cardiac electrical cardioversion.

Incredibly Versatile Microbial Fuel Cells Innovative Ideas at HES-SO Valais-Wallis for Solving Topical Problems.

PubMed

Heinzelmann, Elsbeth

2016-01-01

At HES-SO Valais-Wallis, Prof. Fabian Fischer is specialized in microbial fuel cells for novel applications that meet the challenge of producing renewable energies. He and his team possess a unique expertise in bioelectric energy vector generation, phosphate extraction (CHIMIA 2015, 69, 296) and the testing of antimicrobial surfaces. Let's take a look behind the scenes of the Institute of Life Technologies in Sion.

Overview of multi-input frequency domain modal testing methods with an emphasis on sine testing

NASA Technical Reports Server (NTRS)

Rost, Robert W.; Brown, David L.

1988-01-01

An overview of the current state of the art multiple-input, multiple-output modal testing technology is discussed. A very brief review of the current time domain methods is given. A detailed review of frequency and spatial domain methods is presented with an emphasis on sine testing.

Roles of Frequency, Attitudes, and Multiple Intelligence Modality Surrounding Electricity Content-Based Reader's Theatre

ERIC Educational Resources Information Center

Hosier, Julie Winchester

2009-01-01

Integration of subjects is something elementary teachers must do to insure required objectives are covered. Science-based Reader's Theatre is one way to weave reading into science. This study examined the roles of frequency, attitudes, and Multiple Intelligence modalities surrounding Electricity Content-Based Reader's Theatre. This study used…

Universal filtered multi-carrier system for asynchronous uplink transmission in optical access network

NASA Astrophysics Data System (ADS)

Kang, Soo-Min; Kim, Chang-Hun; Han, Sang-Kook

2016-02-01

In passive optical network (PON), orthogonal frequency division multiplexing (OFDM) has been studied actively due to its advantages such as high spectra efficiency (SE), dynamic resource allocation in time or frequency domain, and dispersion robustness. However, orthogonal frequency division multiple access (OFDMA)-PON requires tight synchronization among multiple access signals. If not, frequency orthogonality could not be maintained. Also its sidelobe causes inter-channel interference (ICI) to adjacent channel. To prevent ICI caused by high sidelobes, guard band (GB) is usually used which degrades SE. Thus, OFDMA-PON is not suitable for asynchronous uplink transmission in optical access network. In this paper, we propose intensity modulation/direct detection (IM/DD) based universal filtered multi-carrier (UFMC) PON for asynchronous multiple access. The UFMC uses subband filtering to subsets of subcarriers. Since it reduces sidelobe of each subband by applying subband filtering, it could achieve better performance compared to OFDM. For the experimental demonstration, different sample delay was applied to subbands to implement asynchronous transmission condition. As a result, time synchronization robustness of UFMC was verified in asynchronous multiple access system.

Electromagnetic Ion Cyclotron Waves in the Helium Branch Induced by Multiple Electromagnetic Ion Cyclotron Triggered Emissions

NASA Astrophysics Data System (ADS)

Shoji, M.; Omura, Y.; Grison, B.; Pickett, J. S.; Dandouras, I. S.; Engebretson, M. J.

2011-12-01

Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the multiple EMIC triggered emissions. We performed a self-consistent hybrid simulation with a one-dimensional cylindrical magnetic flux model approximating the dipole magnetic field of the Earth's inner magnetosphere. In the presence of energetic protons with a sufficient density and temperature anisotropy, multiple EMIC triggered emissions are reproduced due to the nonlinear wave growth mechanism of rising-tone chorus emissions, and a constant frequency wave in the He+ EMIC branch is subsequently generated. Through interaction with the multiple EMIC rising-tone emissions, the velocity distribution function of the energetic protons is strongly modified. Because of the pitch angle scattering of the protons, the gradient of the distribution in velocity phase space is enhanced along the diffusion curve of the He+ branch wave, resulting in the linear growth of the EMIC wave in the He+ branch.

Electromagnetic ion cyclotron waves in the helium branch induced by multiple electromagnetic ion cyclotron triggered emissions

NASA Astrophysics Data System (ADS)

Shoji, Masafumi; Omura, Yoshiharu; Grison, Benjamin; Pickett, Jolene; Dandouras, Iannis; Engebretson, Mark

2011-09-01

Electromagnetic ion cyclotron (EMIC) triggered emissions with rising tones between the H+ and He+ cyclotron frequencies were found in the inner magnetosphere by the recent Cluster observations. Another type of EMIC wave with a constant frequency is occasionally observed below the He+ cyclotron frequency after the multiple EMIC triggered emissions. We performed a self-consistent hybrid simulation with a one-dimensional cylindrical magnetic flux model approximating the dipole magnetic field of the Earth's inner magnetosphere. In the presence of energetic protons with a sufficient density and temperature anisotropy, multiple EMIC triggered emissions are reproduced due to the nonlinear wave growth mechanism of rising-tone chorus emissions, and a constant frequency wave in the He+ EMIC branch is subsequently generated. Through interaction with the multiple EMIC rising-tone emissions, the velocity distribution function of the energetic protons is strongly modified. Because of the pitch angle scattering of the protons, the gradient of the distribution in velocity phase space is enhanced along the diffusion curve of the He+ branch wave, resulting in the linear growth of the EMIC wave in the He+ branch.

Advanced multiple access concepts in mobile satellite systems

NASA Technical Reports Server (NTRS)

Ananasso, Fulvio

1990-01-01

Some multiple access strategies for Mobile Satellite Systems (MSS) are discussed. These strategies were investigated in the context of three separate studies conducted for the International Maritime Satellite Organization (INMARSAT) and the European Space Agency (ESA). Satellite-Switched Frequency Division Multiple Access (SS-FDMA), Code Division Multiple Access (CDMA), and Frequency-Addressable Beam architectures are addressed, discussing both system and technology aspects and outlining advantages and drawbacks of either solution with associated relevant hardware issues. An attempt is made to compare the considered option from the standpoint of user terminal/space segment complexity, synchronization requirements, spectral efficiency, and interference rejection.

FAST TRACK PAPER: A construct of internal multiples from surface data only: the concept of virtual seismic events

NASA Astrophysics Data System (ADS)

Ikelle, Luc T.

2006-02-01

We here describe one way of constructing internal multiples from surface seismic data only. The key feature of our construct of internal multiples is the introduction of the concept of virtual seismic events. Virtual events here are events, which are not directly recorded in standard seismic data acquisition, but their existence allows us to construct internal multiples with scattering points at the sea surface; the standard construct of internal multiples does not include any scattering points at the sea surface. The mathematical and computational operations invoked in our construction of virtual events and internal multiples are similar to those encountered in the construction of free-surface multiples based on the Kirchhoff or Born scattering theory. For instance, our construct operates on one temporal frequency at a time, just like free-surface demultiple algorithms; other internal multiple constructs tend to require all frequencies for the computation of an internal multiple at a given frequency. It does not require any knowledge of the subsurface nor an explicit knowledge of specific interfaces that are responsible for the generation of internal multiples in seismic data. However, our construct requires that the data be divided into two, three or four windows to avoid generating primaries. This segmentation of the data also allows us to select a range of periods of internal multiples that one wishes to construct because, in the context of the attenuation of internal multiples, it is important to avoid generating short-period internal multiples that may constructively average to form primaries at the seismic scale.

Optical frequency upconversion technique for transmission of wireless MIMO-type signals over optical fiber.

PubMed

Shaddad, R Q; Mohammad, A B; Al-Gailani, S A; Al-Hetar, A M

2014-01-01

The optical fiber is well adapted to pass multiple wireless signals having different carrier frequencies by using radio-over-fiber (ROF) technique. However, multiple wireless signals which have the same carrier frequency cannot propagate over a single optical fiber, such as wireless multi-input multi-output (MIMO) signals feeding multiple antennas in the fiber wireless (FiWi) system. A novel optical frequency upconversion (OFU) technique is proposed to solve this problem. In this paper, the novel OFU approach is used to transmit three wireless MIMO signals over a 20 km standard single mode fiber (SMF). The OFU technique exploits one optical source to produce multiple wavelengths by delivering it to a LiNbO3 external optical modulator. The wireless MIMO signals are then modulated by LiNbO3 optical intensity modulators separately using the generated optical carriers from the OFU process. These modulators use the optical single-sideband with carrier (OSSB+C) modulation scheme to optimize the system performance against the fiber dispersion effect. Each wireless MIMO signal is with a 2.4 GHz or 5 GHz carrier frequency, 1 Gb/s data rate, and 16-quadrature amplitude modulation (QAM). The crosstalk between the wireless MIMO signals is highly suppressed, since each wireless MIMO signal is carried on a specific optical wavelength.

Full duplex dense-wavelength-division-multiplexing radio-over-fiber system transmission of 75-GHz W-band frequency multiple-input multiple-output orthogonal-frequency-division-multiplexing signals with 3×12 Gbps downstream and 6 Gbps upstream

NASA Astrophysics Data System (ADS)

Fang, Wei Jin; Huang, Xu Guang; Yang, Kai; Zhang, Xiao Min

2012-09-01

We propose and demonstrate a full duplex dense-wavelength-division-multiplexing radio-over-fiber (DWDM-ROF) system for transmitting 75-GHz W-band frequency multiple-input multiple-output orthogonal-frequency-division-multiplexing (MIMO-OFDM) signals with 12 Gbps downstream and 6 Gbps upstream. The downstream transmitting terminal is based on a three-channels sextupling-frequency scheme using an external modulation of a distributed feedback laser diode (DFB-LD) and dual drive Mach-Zehnder modulator (DD-MZM) for carrying downstream signals. MIMO-OFDM algorithms effectively compensate for impairments in the wireless link. Without using costly W-band components in the transmitter, a 12 Gbps downstream transmission system operation at 75 GHz is experimentally validated. For the downstream transmission, a power penalty of less than 3 dB was observed after a 50 km single mode fiber (SMF) and 4 m wireless transmission at a bit error rate (BER) of 3.8×10-3. For the upstream transmission, we use a commercially available 1.5 GHz bandwidth reflective semiconductor optical amplifier (RSOA) to achieve 6 Gbps upstream traffic for 16 QAM-OFDM signals. A power penalty of 3 dB was observed after a 50 km SMF transmission at a BER of 3.8×10-3. The frequency of the local oscillator is reduced due to the frequency sextupling scheme. The cost of the proposed system is largely reduced.

Temporal Interactions between Cortical Rhythms

PubMed Central

Roopun, Anita K.; Kramer, Mark A.; Carracedo, Lucy M.; Kaiser, Marcus; Davies, Ceri H.; Traub, Roger D.; Kopell, Nancy J.; Whittington, Miles A.

2008-01-01

Multiple local neuronal circuits support different, discrete frequencies of network rhythm in neocortex. Relationships between different frequencies correspond to mechanisms designed to minimise interference, couple activity via stable phase interactions, and control the amplitude of one frequency relative to the phase of another. These mechanisms are proposed to form a framework for spectral information processing. Individual local circuits can also transform their frequency through changes in intrinsic neuronal properties and interactions with other oscillating microcircuits. Here we discuss a frequency transformation in which activity in two co-active local circuits may combine sequentially to generate a third frequency whose period is the concatenation sum of the original two. With such an interaction, the intrinsic periodicity in each component local circuit is preserved – alternate, single periods of each original rhythm form one period of a new frequency – suggesting a robust mechanism for combining information processed on multiple concurrent spatiotemporal scales. PMID:19225587

Multi-pixel high-resolution three-dimensional imaging radar

NASA Technical Reports Server (NTRS)

Cooper, Ken B. (Inventor); Dengler, Robert J. (Inventor); Siegel, Peter H. (Inventor); Chattopadhyay, Goutam (Inventor); Ward, John S. (Inventor); Juan, Nuria Llombart (Inventor); Bryllert, Tomas E. (Inventor); Mehdi, Imran (Inventor); Tarsala, Jan A. (Inventor)

2012-01-01

A three-dimensional imaging radar operating at high frequency e.g., 670 GHz radar using low phase-noise synthesizers and a fast chirper to generate a frequency-modulated continuous-wave (FMCW) waveform, is disclosed that operates with a multiplexed beam to obtain range information simultaneously on multiple pixels of a target. A source transmit beam may be divided by a hybrid coupler into multiple transmit beams multiplexed together and directed to be reflected off a target and return as a single receive beam which is demultiplexed and processed to reveal range information of separate pixels of the target associated with each transmit beam simultaneously. The multiple transmit beams may be developed with appropriate optics to be temporally and spatially differentiated before being directed to the target. Temporal differentiation corresponds to a different intermediate frequencies separating the range information of the multiple pixels. Collinear transmit beams having differentiated polarizations may also be implemented.

THE DYNAMICS OF A NEUROMUSCULAR SYSTEM FUNCTIONAL CONDITION DURING THE PREPARATION FOR IMPORTANT CONTESTS

PubMed Central

Titov, G.

1973-01-01

The aim of this research was to determine a conjugation of the functional condition dynamics of the neuromuscular organs, visual analyser, latent period of the motorial activity and supporting kinosthetic functions at different stages of preparation of the sportsmen for important contests. The following research methods were used to achieve this aim: a functional mobility of the neuromuscular organs was determined with the help of an electrostimulation method (excitability thresholds, frequency range of optimum and maximum rhythm, data on the changes of a bioelectric potential in relation to electrical stimuli); a functional condition of the visual analyser was determined with the use of an electrostimulation method (excitability thresholds, frequency range of phosefan in the reaction to a threshold irritant); a grey matter neurodynamics was determined with the help of a chronoreflexometry using an audio irritant of a different power with the preliminary strain of motor centres or without it; supporting kinosthetic functions were determined with the help of seismotremography and stabilography (frequency and amplitude of tremor, deviations of the gravity centre of the body in different positions of the Romberg test). All the research on the systems mentioned was carried out within the preparatory, main and contest periods during the preparation for the important contests. Gymnasts, boxers and fencers were under observation. In all there were carried out 570 observations of 54 sportsmen of a high sporting qualification. The functional condition of the visual analyser at a satisfactory level of training was characterised by relatively low excitability thresholds and high frequency limits of phosefan. The functional mobility of the neuromuscular organs was reduced during this period. The supporting kinosthetic functions became apparent in the instability of frequency and amplitude tremor characteristics and general gravity centre deviations. The latent period of the motor movement reaction was the longest without the preliminary strain of the motor centres. The performance of intense training efforts was accompanied by distinct symptoms of the nervous system excitement against a background of the reduced functional mobility of the neuromuscular organs. Just before the main contests, when the sportsmen were in good training condition, the excitability thresholds of the visual analyser were slightly increasing; frequency limits of phosefan were falling; functional mobility of the neuromuscular organs achieved the highest value; supporting kinosthetic functions were characterised by stable values of the tremor frequency and amplitude and of the deviations of the general gravity centre of the body; minimum latent period of the motor movement reaction was dependent upon the preliminary strain of the motor centres. The data obtained gave us the opportunity to assume that the functional condition dynamics of the systems under consideration might characterise the level of an operative rest, as A. A. Ukhtomsky saw it, as a combatant readiness for physical activity.

Active Vibration Control for Helicopter Interior Noise Reduction Using Power Minimization

NASA Technical Reports Server (NTRS)

Mendoza, J.; Chevva, K.; Sun, F.; Blanc, A.; Kim, S. B.

2014-01-01

This report describes work performed by United Technologies Research Center (UTRC) for NASA Langley Research Center (LaRC) under Contract NNL11AA06C. The objective of this program is to develop technology to reduce helicopter interior noise resulting from multiple gear meshing frequencies. A novel active vibration control approach called Minimum Actuation Power (MAP) is developed. MAP is an optimal control strategy that minimizes the total input power into a structure by monitoring and varying the input power of controlling sources. MAP control was implemented without explicit knowledge of the phasing and magnitude of the excitation sources by driving the real part of the input power from the controlling sources to zero. It is shown that this occurs when the total mechanical input power from the excitation and controlling sources is a minimum. MAP theory is developed for multiple excitation sources with arbitrary relative phasing for single or multiple discrete frequencies and controlled by a single or multiple controlling sources. Simulations and experimental results demonstrate the feasibility of MAP for structural vibration reduction of a realistic rotorcraft interior structure. MAP control resulted in significant average global vibration reduction of a single frequency and multiple frequency excitations with one controlling actuator. Simulations also demonstrate the potential effectiveness of the observed vibration reductions on interior radiated noise.

MFAM: Multiple Frequency Adaptive Model-Based Indoor Localization Method.

PubMed

Tuta, Jure; Juric, Matjaz B

2018-03-24

This paper presents MFAM (Multiple Frequency Adaptive Model-based localization method), a novel model-based indoor localization method that is capable of using multiple wireless signal frequencies simultaneously. It utilizes indoor architectural model and physical properties of wireless signal propagation through objects and space. The motivation for developing multiple frequency localization method lies in the future Wi-Fi standards (e.g., 802.11ah) and the growing number of various wireless signals present in the buildings (e.g., Wi-Fi, Bluetooth, ZigBee, etc.). Current indoor localization methods mostly rely on a single wireless signal type and often require many devices to achieve the necessary accuracy. MFAM utilizes multiple wireless signal types and improves the localization accuracy over the usage of a single frequency. It continuously monitors signal propagation through space and adapts the model according to the changes indoors. Using multiple signal sources lowers the required number of access points for a specific signal type while utilizing signals, already present in the indoors. Due to the unavailability of the 802.11ah hardware, we have evaluated proposed method with similar signals; we have used 2.4 GHz Wi-Fi and 868 MHz HomeMatic home automation signals. We have performed the evaluation in a modern two-bedroom apartment and measured mean localization error 2.0 to 2.3 m and median error of 2.0 to 2.2 m. Based on our evaluation results, using two different signals improves the localization accuracy by 18% in comparison to 2.4 GHz Wi-Fi-only approach. Additional signals would improve the accuracy even further. We have shown that MFAM provides better accuracy than competing methods, while having several advantages for real-world usage.

MFAM: Multiple Frequency Adaptive Model-Based Indoor Localization Method

PubMed Central

Juric, Matjaz B.

2018-01-01

This paper presents MFAM (Multiple Frequency Adaptive Model-based localization method), a novel model-based indoor localization method that is capable of using multiple wireless signal frequencies simultaneously. It utilizes indoor architectural model and physical properties of wireless signal propagation through objects and space. The motivation for developing multiple frequency localization method lies in the future Wi-Fi standards (e.g., 802.11ah) and the growing number of various wireless signals present in the buildings (e.g., Wi-Fi, Bluetooth, ZigBee, etc.). Current indoor localization methods mostly rely on a single wireless signal type and often require many devices to achieve the necessary accuracy. MFAM utilizes multiple wireless signal types and improves the localization accuracy over the usage of a single frequency. It continuously monitors signal propagation through space and adapts the model according to the changes indoors. Using multiple signal sources lowers the required number of access points for a specific signal type while utilizing signals, already present in the indoors. Due to the unavailability of the 802.11ah hardware, we have evaluated proposed method with similar signals; we have used 2.4 GHz Wi-Fi and 868 MHz HomeMatic home automation signals. We have performed the evaluation in a modern two-bedroom apartment and measured mean localization error 2.0 to 2.3 m and median error of 2.0 to 2.2 m. Based on our evaluation results, using two different signals improves the localization accuracy by 18% in comparison to 2.4 GHz Wi-Fi-only approach. Additional signals would improve the accuracy even further. We have shown that MFAM provides better accuracy than competing methods, while having several advantages for real-world usage. PMID:29587352

Acoustical Detection Of Leakage In A Combustor

NASA Technical Reports Server (NTRS)

Puster, Richard L.; Petty, Jeffrey L.

1993-01-01

Abnormal combustion excites characteristic standing wave. Acoustical leak-detection system gives early warning of failure, enabling operating personnel to stop combustion process and repair spray bar before leak grows large enough to cause damage. Applicable to engines, gas turbines, furnaces, and other machines in which acoustic emissions at known frequencies signify onset of damage. Bearings in rotating machines monitored for emergence of characteristic frequencies shown in previous tests associated with incipient failure. Also possible to monitor for signs of trouble at multiple frequencies by feeding output of transducer simultaneously to multiple band-pass filters and associated circuitry, including separate trigger circuit set to appropriate level for each frequency.

Improved assessment of body cell mass by segmental bioimpedance analysis in malnourished subjects and acromegaly.

PubMed

Pirlich, M; Schütz, T; Ockenga, J; Biering, H; Gerl, H; Schmidt, B; Ertl, S; Plauth, M; Lochs, H

2003-04-01

Estimation of body cell mass (BCM) has been regarded valuable for the assessment of malnutrition. To investigate the value of segmental bioelectrical impedance analysis (BIA) for BCM estimation in malnourished subjects and acromegaly. Nineteen controls and 63 patients with either reduced (liver cirrhosis without and with ascites, Cushing's disease) or increased BCM (acromegaly) were included. Whole-body and segmental BIA (separately measuring arm, trunk, leg) at 50 kHz was compared with BCM measured by total-body potassium. Multiple regression analysis was used to develop specific equations for BCM in each subgroup. Compared to whole-body BIA equations, the inclusion of arm resistance improved the specific equation in cirrhotic patients without ascites and in Cushing's disease resulting in excellent prediction of BCM (R(2) = 0.93 and 0.92, respectively; both P<0.001). In acromegaly, inclusion of resistance and reactance of the trunk best described BCM (R(2) = 0.94, P<0.001). In controls and in cirrhotic patients with ascites, segmental impedance parameters did not improve BCM prediction (best values obtained by whole-body measurements: R(2)=0.88 and 0.60; P<0.001 and <0.003, respectively). Segmental BIA improves the assessment of BCM in malnourished patients and acromegaly, but not in patients with severe fluid overload. Copyright 2003 Elsevier Science Ltd.

A critical examination of the numerology of antigen-binding cells: evidence for multiple receptor specificities on single cells.

PubMed

Miller, A

1977-01-01

The data available from other laboratories as well as our own on the frequency of cells recognizing major histocompatibility antigens or conventional protein and hapten antigens is critically evaluated. The frequency of specific binding for a large number of antigens is sufficiently high to support the idea that at least part of the antigen-binding cell population must have multiple specificities. Our results suggest that these multiple specific cells result from single cells synthesizing and displaying as many as 50-100 species of receptor, each at a frequency of 10(4) per cell. A model involving gene expansion of constant-region genes is suggested and some auxilliary evidence consistent with such C-gene expansion is presented.

Could bioelectric impedance spectroscopy (BIS) measured appendicular intracellular water serve as a lean mass measurement in sarcopenia definitions? A pilot study.

PubMed

Siglinsky, E; Buehring, B; Krueger, D; Binkley, N; Yamada, Y

2018-03-25

DXA lean mass measurement for sarcopenia diagnosis is not always possible. Bioelectric impedance spectroscopy (BIS), a portable technology, is a potential alternative to DXA-measured lean mass. This pilot study explores the possibility and proposes an arbitrarily chosen potential cut-point for appendicular intracellular water corrected by height (aICW/ht 2 ). Sarcopenia definitions often include DXA lean mass measurement. However, DXA is not always available. We explored the potential of a less-expensive mobile method, bioelectric impedance spectroscopy (BIS), to assess lean mass for sarcopenia determination. We hypothesized that BIS-measured appendicular intracellular water (aICW/ht 2 ) would correlate with DXA-measured appendicular lean mass (ALM)/ht 2 and with functional parameters. If so, establishing an aICW/ht 2 cut-point in sarcopenia definitions may be feasible. Sixty-one community-dwelling women, mean age 79.9, had BIS and DXA lean mass, grip strength, gait speed, and jumping mechanography assessments. BIS aICW was calculated using limb length and intracellular water resistance. aICW/ht 2 was compared to DXA-measured ALM/ht 2 by linear regression. The European Working Group ALM/ht 2 and an exploratory aICW/ht 2 cut-point were utilized. In this cohort, ALM/ht 2 and aICW/ht 2 were moderately correlated, R 2  = 0.55, p < 0.0001. Lean mass was low in 7 and normal in 44 by BIS and DXA. Those with low aICW/ht 2 had lower grip strength (p = 0.04) and jump power (p = 0.0002) than those with normal aICW/ht 2 and ALM/ht 2 . Subjects with low ALM/ht 2 had lower jump power (p = 0.0006) but were not different in gait speed or grip strength. BIS aICW is correlated with DXA-measured ALM directly, and when height adjusted. An aICW/ht 2 cut-point of 6.5 L/m 2 identified 70% of women with low ALM/ht 2 . Women with low lean mass by DXA and BIS had poorer function measured by jump power. These pilot data support further evaluation of BIS measurement inclusion into sarcopenia definitions.

Total and Segmental Body Composition Examination in Collegiate Football Players Using Multifrequency Bioelectrical Impedance Analysis and Dual X-ray Absorptiometry.

PubMed

Raymond, Christiana J; Dengel, Donald R; Bosch, Tyler A

2018-03-01

Raymond, CJ, Dengel, DR, and Bosch, TA. Total and segmental body composition examination in collegiate football players using multifrequency bioelectrical impedance analysis and dual X-ray absorptiometry. J Strength Cond Res 32(3): 772-782, 2018-The current study examined the influence of player position on the agreement between multifrequency bioelectrical impedance analysis (MfBIA) and dual X-ray absorptiometry (DXA) when assessing total and segmental percent body fat (BF%), fat mass (FM), and fat-free mass (FFM) in National Collegiate Athletic Association Division I collegiate football athletes. Forty-four male collegiate athletes (age = 19 ± 1 year; height = 1.9 ± 1.0 m; and body mass = 106.4 ± 18.8 kg) participated. Player positions included: offensive linemen (OL; n = 7), tight ends (TE; n = 4), wide receivers (WR; n = 9), defensive linemen (DL; n = 6), defensive backs (DB; n = 8), linebackers (LB; n = 6), and running backs (RB; n = 4). Total and segmental body composition measured using MfBIA were compared with values obtained using DXA. Compared with DXA, MfBIA underestimated BF% (3.0 ± 3.8%), total FM (2.5 ± 4.3 kg), arm FM (0.4 ± 0.8 kg), arm FFM (1.4 ± 0.9 kg), leg FM (2.8 ± 2.0 kg), and leg FFM (5.4 ± 2.4 kg) (all p < 0.001; arm FM p = 0.002) and overestimated total FFM (-2.4 ± 4.5 kg) (p < 0.001). Limits of agreement (LOAs) were: ±7.39% (BF%), ±8.50 kg (total FM), ±1.50 kg (arm FM), ±1.83 kg (arm FFM), ±3.83 kg (leg FM), ±4.62 kg (leg FFM), and ±8.83 kg (total FFM). No significant differences were observed between devices for trunk FM (-0.3 ± 3.0 kg; p = 0.565) and trunk FFM (0.4 ± 2.4 kg; p = 0.278), with LOAs of ±5.92 and ±4.69 kg, respectively. Player position significantly affected all between-device mean body composition measurement differences (adjusted p ≤ 0.05), with OL demonstrating the greatest effect on each variable. Therefore, MfBIA does not seem accurate in examining between-player body composition in college football players.

77 FR 43259 - Takes of Marine Mammals Incidental to Specified Activities; Pile Driving for Honolulu Seawater...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-24

...-frequency, and high-frequency. Bryde's whale, humpback whale, and minke whale are considered low-frequency... to 160 kHz. Dwarf sperm whale and pygmy sperm whale are considered high-frequency cetaceans and their... field versus laboratory conditions. While multiple controlled studies of high-frequency cetaceans to...

Nonlinear convergence active vibration absorber for single and multiple frequency vibration control

NASA Astrophysics Data System (ADS)

Wang, Xi; Yang, Bintang; Guo, Shufeng; Zhao, Wenqiang

2017-12-01

This paper presents a nonlinear convergence algorithm for active dynamic undamped vibration absorber (ADUVA). The damping of absorber is ignored in this algorithm to strengthen the vibration suppressing effect and simplify the algorithm at the same time. The simulation and experimental results indicate that this nonlinear convergence ADUVA can help significantly suppress vibration caused by excitation of both single and multiple frequency. The proposed nonlinear algorithm is composed of equivalent dynamic modeling equations and frequency estimator. Both the single and multiple frequency ADUVA are mathematically imitated by the same mechanical structure with a mass body and a voice coil motor (VCM). The nonlinear convergence estimator is applied to simultaneously satisfy the requirements of fast convergence rate and small steady state frequency error, which are incompatible for linear convergence estimator. The convergence of the nonlinear algorithm is mathematically proofed, and its non-divergent characteristic is theoretically guaranteed. The vibration suppressing experiments demonstrate that the nonlinear ADUVA can accelerate the convergence rate of vibration suppressing and achieve more decrement of oscillation attenuation than the linear ADUVA.

The dependence of frequency distributions on multiple meanings of words, codes and signs

NASA Astrophysics Data System (ADS)

Yan, Xiaoyong; Minnhagen, Petter

2018-01-01

The dependence of the frequency distributions due to multiple meanings of words in a text is investigated by deleting letters. By coding the words with fewer letters the number of meanings per coded word increases. This increase is measured and used as an input in a predictive theory. For a text written in English, the word-frequency distribution is broad and fat-tailed, whereas if the words are only represented by their first letter the distribution becomes exponential. Both distribution are well predicted by the theory, as is the whole sequence obtained by consecutively representing the words by the first L = 6 , 5 , 4 , 3 , 2 , 1 letters. Comparisons of texts written by Chinese characters and the same texts written by letter-codes are made and the similarity of the corresponding frequency-distributions are interpreted as a consequence of the multiple meanings of Chinese characters. This further implies that the difference of the shape for word-frequencies for an English text written by letters and a Chinese text written by Chinese characters is due to the coding and not to the language per se.

Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences

DOEpatents

Vail, W.B. III.

1991-12-24

Methods of operation are described for an apparatus having at least two pairs of voltage measurement electrodes vertically disposed in a cased well to measure the resistivity of adjacent geological formations from inside the cased well. During stationary measurements with the apparatus at a fixed vertical depth within the cased well, the invention herein discloses methods of operation which include a measurement step and subsequent first and second compensation steps respectively resulting in improved accuracy of measurement. The invention also discloses multiple frequency methods of operation resulting in improved accuracy of measurement while the apparatus is simultaneously moved vertically in the cased well. The multiple frequency methods of operation disclose a first A.C. current having a first frequency that is conducted from the casing into formation and a second A.C. current having a second frequency that is conducted along the casing. The multiple frequency methods of operation simultaneously provide the measurement step and two compensation steps necessary to acquire accurate results while the apparatus is moved vertically in the cased well. 6 figures.

Electronic measurement apparatus movable in a cased borehole and compensating for casing resistance differences

DOEpatents

Vail, III, William B.

1991-01-01

Methods of operation of an apparatus having at least two pairs of voltage measurement electrodes vertically disposed in a cased well to measure the resistivity of adjacent geological formations from inside the cased well. During stationary measurements with the apparatus at a fixed vertical depth within the cased well, the invention herein discloses methods of operation which include a measurement step and subsequent first and second compensation steps respectively resulting in improved accuracy of measurement. The invention also discloses multiple frequency methods of operation resulting in improved accuracy of measurement while the apparatus is simultaneously moved vertically in the cased well. The multiple frequency methods of operation disclose a first A.C. current having a first frequency that is conducted from the casing into formation and a second A.C. current having a second frequency that is conducted along the casing. The multiple frequency methods of operation simultaneously provide the measurement step and two compensation steps necessary to acquire accurate results while the apparatus is moved vertically in the cased well.

Embedding multiple watermarks in the DFT domain using low- and high-frequency bands

NASA Astrophysics Data System (ADS)

Ganic, Emir; Dexter, Scott D.; Eskicioglu, Ahmet M.

2005-03-01

Although semi-blind and blind watermarking schemes based on Discrete Cosine Transform (DCT) or Discrete Wavelet Transform (DWT) are robust to a number of attacks, they fail in the presence of geometric attacks such as rotation, scaling, and translation. The Discrete Fourier Transform (DFT) of a real image is conjugate symmetric, resulting in a symmetric DFT spectrum. Because of this property, the popularity of DFT-based watermarking has increased in the last few years. In a recent paper, we generalized a circular watermarking idea to embed multiple watermarks in lower and higher frequencies. Nevertheless, a circular watermark is visible in the DFT domain, providing a potential hacker with valuable information about the location of the watermark. In this paper, our focus is on embedding multiple watermarks that are not visible in the DFT domain. Using several frequency bands increases the overall robustness of the proposed watermarking scheme. Specifically, our experiments show that the watermark embedded in lower frequencies is robust to one set of attacks, and the watermark embedded in higher frequencies is robust to a different set of attacks.

Single-transducer dual-frequency ultrasound generation to enhance acoustic cavitation.

PubMed

Liu, Hao-Li; Hsieh, Chao-Ming

2009-03-01

Dual- or multiple-frequency ultrasound stimulation is capable of effectively enhancing the acoustic cavitation effect over single-frequency ultrasound. Potential application of this sonoreactor design has been widely proposed such as on sonoluminescence, sonochemistry enhancement, and transdermal drug release enhancement. All currently available sonoreactor designs employed multiple piezoelectric transducers for generating single-frequency ultrasonic waves separately and then these waves were mixed and interfered in solutions. The purpose of this research is to propose a novel design of generating dual-frequency ultrasonic waves with single piezoelectric elements, thereby enhancing acoustic cavitation. Macroscopic bubbles were detected optically, and they were quantified at either a single-frequency or for different frequency combinations for determining their efficiency for enhancing acoustic cavitation. Visible bubbles were optically detected and hydrogen peroxide was measured to quantify acoustic cavitation. Test water samples with different gas concentrations and different power levels were used to determine the efficacy of enhancing acoustic cavitation of this design. The spectrum obtained from the backscattered signals was also recorded and examined to confirm the occurrence of stable cavitation. The results confirmed that single-element dual-frequency ultrasound stimulation can enhance acoustic cavitation. Under certain testing conditions, the generation of bubbles can be enhanced up to a level of five times higher than the generation of bubbles in single-frequency stimulation, and can increase the hydrogen peroxide production up to an increase of one fold. This design may serve as a useful alternative for future sonoreactor design owing to its simplicity to produce dual- or multiple-frequency ultrasound.

Animal electricity from Bologna to Boston.

PubMed

Goldensohn, E S

1998-02-01

This is an appreciation of 3 scientists who made historic contributions toward understanding bio-electrical activity. The discoveries of Galvani and Volta, who were contemporaries two hundred years ago, continue as basic supports in advancing the strength and health of all mankind. They, nevertheless, had political and scientific disagreements that still linger. The third scientist was our contemporary, Alexander Forbes who, throughout most of the 20th century, continued to increase our understanding of electrical activity in the nervous system.

RF-powered BIONs for stimulation and sensing.

PubMed

Loeb, G E; Richmond, F J R; Singh, J; Peck, R A; Tan, W; Zou, Q; Sachs, N

2004-01-01

Virtually all bodily functions are controlled by electrical signals in nerves and muscles. Electrical stimulation can restore missing signals but this has been difficult to achieve practically because of limitations in the bioelectric interfaces. Wireless, injectable microdevices are versatile, robust and relatively inexpensive to implant in a variety of sites and applications. Several variants are now in clinical use or under development to perform stimulation and/or sensing functions and to operate autonomously or with continuous coordination and feedback control.

Development of bioelectrical impedance-derived indices of fat and fat-free mass for assessment of nutritional status in childhood.

PubMed

Wright, C M; Sherriff, A; Ward, S C G; McColl, J H; Reilly, J J; Ness, A R

2008-02-01

(1) To develop a method of manipulating bioelectrical impedance (BIA) that gives indices of lean and fat adjusted for body size, using a large normative cohort of children. (2) To assess the discriminant validity of the method in a group of children likely to have abnormal body composition. Two prospective cohort studies. Normative data: Avon Longitudinal Study of Parents and Children (ALSPAC), population based cohort; proof of concept study: tertiary feeding clinic and special needs schools. Normative data: 7576 children measured aged between 7.25 and 8.25 (mean 7.5) (s.d.=0.2) years; proof of concept study: 29 children with either major neurodisability or receiving artificial feeding, or both, mean age 7.6 (s.d.=2) years. Leg-to-leg (Z (T)) and arm-to-leg (Z (B)) BIA, weight and height. Total body water (TBW) was estimated from the resistance index (RI=height(2)/Z), and fat-free mass was linearly related to TBW. Fat mass was obtained by subtracting fat-free mass from total weight. Fat-free mass was log-transformed and the reciprocal transform was taken for fat mass to satisfy parametric model assumptions. Lean and fat mass were then adjusted for height and age using multiple linear regression models. The resulting standardized residuals gave the lean index and fat index, respectively. In the normative cohort, the lean index was higher and fat index lower in boys. The lean index rose steeply to the middle of the normal range of body mass index (BMI) and then slowly for higher BMI values, whereas the fat index rose linearly through and above the normal range. In the proof of concept study, the children as a group had low lean indices (mean (s.d.) -1.5 (1.7)) with average fat indices (+0.21 (2.0)) despite relatively low BMI standard deviation scores (-0.60 (2.3)), but for any given BMI, individual children had extremely wide ranges of fat indices. The lean index proved more stable and repeatable than BMI. This clinical method of handling BIA reveals important variations in nutritional status that would not be detected using anthropometry alone. BIA used in this way would allow more accurate assessment of energy sufficiency in children with neurodisability and may provide a more valid identification of children at risk of underweight or obesity in field and clinical settings.

A Fast Framework for Abrupt Change Detection Based on Binary Search Trees and Kolmogorov Statistic

PubMed Central

Qi, Jin-Peng; Qi, Jie; Zhang, Qing

2016-01-01

Change-Point (CP) detection has attracted considerable attention in the fields of data mining and statistics; it is very meaningful to discuss how to quickly and efficiently detect abrupt change from large-scale bioelectric signals. Currently, most of the existing methods, like Kolmogorov-Smirnov (KS) statistic and so forth, are time-consuming, especially for large-scale datasets. In this paper, we propose a fast framework for abrupt change detection based on binary search trees (BSTs) and a modified KS statistic, named BSTKS (binary search trees and Kolmogorov statistic). In this method, first, two binary search trees, termed as BSTcA and BSTcD, are constructed by multilevel Haar Wavelet Transform (HWT); second, three search criteria are introduced in terms of the statistic and variance fluctuations in the diagnosed time series; last, an optimal search path is detected from the root to leaf nodes of two BSTs. The studies on both the synthetic time series samples and the real electroencephalograph (EEG) recordings indicate that the proposed BSTKS can detect abrupt change more quickly and efficiently than KS, t-statistic (t), and Singular-Spectrum Analyses (SSA) methods, with the shortest computation time, the highest hit rate, the smallest error, and the highest accuracy out of four methods. This study suggests that the proposed BSTKS is very helpful for useful information inspection on all kinds of bioelectric time series signals. PMID:27413364

Explore various co-substrates for simultaneous electricity generation and Congo red degradation in air-cathode single-chamber microbial fuel cell.

PubMed

Cao, Yunqing; Hu, Yongyou; Sun, Jian; Hou, Bin

2010-08-01

Microbial fuel cell (MFC) holds a great promise to harvest electricity directly from a wide range of ready degradable organic matters and enhance degradation of some recalcitrant contaminants. Glucose, acetate sodium and ethanol were separately examined as co-substrates for simultaneous bioelectricity generation and Congo red degradation in a proton exchange membrane (PEM) air-cathode single-chamber MFC. The batch test results showed that more than 98% decolorization at the dye concentration of 300 mg/L were achieved within 36 h for all tested co-substrates during electricity generation. The decolorization rate was different with the co-substrates used. The fastest decolorization rate was achieved with glucose followed by ethanol and sodium acetate. Accumulated intermediates were observed during Congo red degradation which was demonstrated by UV-Visible spectra and high performance liquid chromatography (HPLC). Electricity generation was sustained and not significantly affected by the Congo red degradation. Glucose, acetate sodium and ethanol produced maximum power densities of 103 mW/m(2), 85.9 mW/m(2) and 63.2 mW/m(2), respectively, and the maximum voltage output decreased by only 7% to 15%. Our results demonstrated the feasibility of using various co-substrates for simultaneous decolorization of Congo red and bioelectricity generation in the MFC and showed that glucose was the preferred co-substrate. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Bioelectrical Impedance Phase Angle as an Indicator of Malnutrition in Hospitalized Children with Diagnosed Inflammatory Bowel Diseases-A Case Control Study.

PubMed

Więch, Paweł; Dąbrowski, Mariusz; Bazaliński, Dariusz; Sałacińska, Izabela; Korczowski, Bartosz; Binkowska-Bury, Monika

2018-04-17

The phase angle (PhA) seems to be a reliable screening tool for the identification of malnutrition risk in hospitalized children with inflammatory bowel disease (IBD). The aim of the present study was to assess the body composition and nutritional status of hospitalized children and adolescents with IBD by using bioelectrical impedance analysis (BIA) with phase angle (PhA) calculation, which has not been evaluated in hospitalized children with IBD yet. A total of 59 children and adolescents aged 4–18 years, with IBD: 34 ulcerative colitis (UC) and 25 Crohn’s disease (CD) were included in the study. The control group consisted of healthy children and adolescents, strictly matched for gender and age in a 1:1 case-control manner. In both groups, BIA was performed and PhA was calculated. IBD patients had significantly lower PhA (UC: 5.34 ± 1.34 vs. 5.96 ± 0.76, p = 0.040; CD: 5.16 ± 1.18 vs. 5.90 ± 0.62, p = 0.009) compared to the control subjects. Significant changes in selected body composition parameters were observed particularly in CD, especially in fat free mass components. Lower phase angle score together with lower body composition parameters and selected nutrition indicators in children and adolescents with IBD demonstrate their worse nutritional and functional status compared to healthy subjects.