4,454 research outputs found

    Brain-Computer Interfacing for Wheelchair Control by Detecting Voluntary Eye Blinks

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    The human brain is considered as one of the most powerful quantum computers and combining the human brain with technology can even outperform artificial intelligence. Using a Brain-Computer Interface (BCI) system, the brain signals can be analyzed and programmed for specific tasks. This research work employs BCI technology for a medical application that gives the unfortunate paralyzed individuals the capability to interact with their surroundings solely using voluntary eye blinks. This research contributes to the existing technology to be more feasible by introducing a modular design with three physically separated components: a headwear, a computer, and a wheelchair. As the signal-to-noise ratio (SNR) of the existing systems is too high to separate the eye blink artifacts from the regular EEG signal, a precise ThinkGear module is used which acquired the raw EEG signal through a single dry electrode. This chip offers an advanced filtering technology that has a high noise immunity along with an embedded Bluetooth module using which the acquired signal is transferred wirelessly to a computer. A MATLAB program captures voluntary eye blink artifacts from the brain waves and commands the movement of a miniature wheelchair via Bluetooth. To distinguish voluntary eye blinks from involuntary eye blinks, blink strength thresholds are determined. A Graphical User Interface (GUI) designed in MATLAB displays the EEG waves in real-time and enables the user to determine the movements of the wheelchair which is specially designed to take commands from the GUI.  The findings from the testing phase unveil the advantages of a modular design and the efficacy of using eye blink artifacts as the control element for brain-controlled wheelchairs. The work presented here gives a basic understanding of the functionality of a BCI system, and provides eye blink-controlled navigation of a wheelchair for patients suffering from severe paralysis

    Toroidal momentum transport in a tokamak caused by symmetry breaking parallel derivatives

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    A new mechanism for toroidal momentum transport in a tokamak is investigated using the gyro-kinetic model. First, an analytic model is developed through the use of the ballooning transform. The terms that generate the momentum transport are then connected with the poloidal derivative of the ballooning envelope, which are one order smaller in the normalised Larmor radius, compared with the derivative of the eikonal. The mechanism, therefore, does not introduce an inhomogeneity in the radial direction, in contrast with the effect of profile shearing. Numerical simulations of the linear ion temperature gradient mode with adiabatic electrons, retaining the finite rho* effects in the ExB velocity, the drift, and the gyro-average, are presented. The momentum flux is found to be linear in the normalised Larmor radius (\rho*) but is, nevertheless, generating a sizeable counter-current rotation. The total momentum flux scales linear with the aspect ratio of the considered magnetic surface, and increases with increasing magnetic shear, safety factor, and density and temperature gradients

    Rocaglates induce gain-of-function alterations to eIF4A and eIF4F

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    Rocaglates are a diverse family of biologically active molecules that have gained tremendous interest in recent years due to their promising activities in pre-clinical cancer studies. As a result, this family of compounds has been significantly expanded through the development of efficient synthetic schemes. However, it is unknown whether all of the members of the rocaglate family act through similar mechanisms of action. Here, we present a comprehensive study comparing the biological activities of >200 rocaglates to better understand how the presence of different chemical entities influences their biological activities. Through this, we find that most rocaglates preferentially repress the translation of mRNAs containing purine-rich 5' leaders, but certain rocaglates lack this bias in translation repression. We also uncover an aspect of rocaglate mechanism of action in which the pool of translationally active eIF4F is diminished due to the sequestration of the complex onto RNA.P50 GM067041 - NIGMS NIH HHS; R24 GM111625 - NIGMS NIH HHS; R35 GM118173 - NIGMS NIH HHSPublished versio

    997-90 Right (RV) and Left Ventricular (LV) Geometry and Myocyte Contractile Processes with Dilated Cardiomyopathy (DCM): Disparity Between Myocyte Growth and β-Adrenergic Responsiveness

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    The progression of DCM has been assumed to be a homogenous process for both the RV and LV. However, this assumption has never been tested. Accordingly, we measured myocyte contractile performance (velocity of shortening, VELSHORT; percent shortening, PERSHORT) at baseline (BASE) and after β-adrenergic receptor stimulation (βAR, 25 nM isoproterenol) of isolated myocytes taken from the RV and LV of 5 pigs with pacing induced DCM (240 bpm, 3 weeks) and 5 control pigs (CON). RV and LV mass/body weight (MASS) and myocyte length and cross-sectional area (CSA) were also determined.CON-RVCON-LVDCM-RVDCM-LVVELSHORT-BASE (μm/s)90±5+50±148±2*,+32±1*VELSHORT-βAR (μm/s)206±8+150±5123±8*111±9*PERSHORT-BASE (%)5.8±0.2+4.6±0.13.1±0.1*,+2.2±0.1*PERSHORT-βAR (%)11.5±0.3+10.2±0.359±0.3*5.2±0.4*Length (μm)150±2+137±1179±2*,+173±2*CSA (μm2)176±4+362±8232±4*,+292±5*Mass (gm/kg)0.8±0.1+2.8±0.11.6±0.1*,+2.9±0.2+p<0.05 vs LV*p<005 vS CONIn controls, RV myocytes were longer and had a smaller CSA, but enhanced contractile performance at baseline and with β-adrenergic stimulation. With DCM, no LV hypertrophy occurred. In contrast, RV chamber and cellular hypertrophy occurred and was associated with a persistent increase of RV myocyte baseline contractile function.SummaryThis study demonstrated, for the first time, that differences in RV and LV myocyte function and β-adrenergic responsiveness exist in normal and DCM states. More importantly, a disparity in RV and LV myocyte growth with DCM occurred. Thus, in this model of DCM, RV and LV growth and changes in contractile performance are not a homogenous process, and suggest that inherent differences exist in the response of RV and LV myocytes to stress

    Conventional intramuscular sedatives versus ziprasidone for severe agitation in adolescents: case-control study

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    <p>Abstract</p> <p>Objective</p> <p>The objective of this study was to compare intramuscular (IM) ziprasidone to conventional IM medications (haloperidol combined with lorazepam) for the treatment of severe agitation in adolescents (age 12–17).</p> <p>Methods</p> <p>We retrospectively identified consecutive severe agitation episodes (defined as requiring physical restraint) in adolescents treated with either IM ziprasidone or conventional IM agents in a psychiatric emergency room. For ziprasidone, the dosage was 20 mg for 23 episodes and 10 mg for 5 episodes. For 24 episodes treated with combined haloperidol and lorazepam, the dosages were 4.8 ± 0.3 SEM mg and 1.9 ± 0.4 mg respectively. Outcomes were the duration of restraint and need for adjunctive "rescue" medications within 60 minutes. These outcomes were decided prior to reviewing any records.</p> <p>Results</p> <p>No difference was found in restraint duration (ziprasidone, N = 28, 55 ± 5 minutes; haloperidol with lorazepam N = 24, 65 ± 7 minutes, P = NS). Use of "rescue" medications did not differ between the two groups. No changes in blood pressure were found, but pulse decreased 8.3 ± 2.4 for haloperidol with lorazepam and 8.9 ± 4.24 for ziprasidone (P = NS). No instances of excessive sedation or extra-pyramidal symptoms were documented.</p> <p>Conclusion</p> <p>In this study, IM ziprasidone appeared effective, well tolerated, and similar in clinical profile to combined conventional IM medications for treating severe agitation in adolescents. Given the reportedly favorable acute side effect profile of parenteral atypical agents, they may provide an alternative to conventional antipsychotics for treating acute agitation in both adult and adolescent populations. Future randomized, controlled studies are needed.</p

    The effect of basic fibroblast growth factor on the blood flow and morphologic features of a latissimus dorsi cardiomyoplasty

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    AbstractPrevious studies designed to determine whether latissimus cardiomyoplasty could be used to revascularize ischemic myocardium showed that after operation the latissimus was ischemic and had severely deteriorated. This study was undertaken to determine whether basic fibroblast growth factor, a potent angiogenic peptide, would improve the vascularity of the latissimus and enhance collateral formation between the muscle of the cardiomyoplasty and ischemic myocardium. In goats, myocardial ischemia was induced with an ameroid constrictor and cardiomyoplasty performed. The latissimus was continuously stimulated electrically at 2 Hz for 6 weeks and given four weekly bolus injections of human recombinant basic fibroblast growth factor (80 μg infused into the left subclavian artery). In eight animals, rates of regional blood flow were measured and both the heart and latissimus were evaluated histochemically. The latissimus blood flow rate was 0.114 ± 0.029 ml/gm per minute, which was three times greater than that of historical controls (chronically stimulated latissimus cardiomyoplasty without basic fibroblast growth factor treatment; 0.042 ± 0.007 ml/gm per minute, p < 0.05). Associated with the improved blood flow, there was significantly less evidence of skeletal muscle fiber dropout and muscle fibrosis in the animals treated with basic fibroblast growth factor. Latissimus-derived collateral flow to ischemic myocardium developed in five of the eight goats and averaged 0.288 ± 0.075 ml/gm per minute. This flow was 42.8% ± 15.7% ( n = 5) of the flow required by normal myocardium (which was 0.728 ± 0.095 ml/gm per minute). This value for latissimus-derived collateral blood flow was almost twice that of the historical controls (24.0% ± 3.9%), but the increase did not achieve statistical significance ( p = 0.08). These results hold the promise that basic fibroblast growth factor treatment might enhance the formation of extramyocardial collaterals to the heart and improve skeletal muscle function. (J THORAC CARDIOVASC SURG 1996;111:19-28
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