Significant Changes In Amplitude Research Articles

In situ monitoring of mechanochemical MOF formation by NMR relaxation time correlation.

In this paper, we present a new approach to monitoring mechanochemical transformations, based on a magnetic resonance (MR) method in which relaxation time correlation maps are used to track the formation of the popular metal-organic framework (MOF) materials Zn-MOF-74 and ZIF-8. The two-dimensional (2D) relaxation correlation measurement employed yields a spectrum which visually and analytically identifies different 1H environments in the sample of interest. The measurement is well-suited to analyzing solid mixtures, and liquids, in complex systems. Application in this work to monitoring MOF formation shows changes in signal amplitudes, and their MR lifetime coordinates, within the 2D plots as the reaction progresses, confirming reaction completion. This new measurement provides a simple way to analyse solid-state reactions without dissolution, and there is a logical pathway to benchtop measurement with a new generation of permanent magnet-based MR instruments. The methodology described permits measurement in an MR compatible milling container, which may be directly transferred from the shaker assembly to the MR magnet for in situ measurement of the entire reaction mixture.

Mechanism and rule of microwave pulse response of two-stage PIN limiter

<sec>This paper aims to analyze the failure mechanism of the two-stage PIN limiter after having been injected by a microwave pulse. A two-stage PIN limiter model with high computational efficiency and accuracy is built by using the method of field-circuit collaborative simulation. Using this model, the temperature change of the PIN diodes during the injection of microwave pulse is simulated. The melting temperature of the PIN diode is selected as the failure criterion of the PIN limiter. The time and energy required for the failure of the PIN limiter under injection of microwave pulses with different frequencies and amplitudes are simulated. Furthermore, the mechanisms that trigger off these effects are analyzed. The relationship between the microwave pulse parameters and the PIN limiter failure time is summarized by using an empirical formula.</sec><sec>According to the simulation results, the temperature change of the second-stage PIN diode is relatively small compared with that of the first-stage. During the injection of the microwave pulse, the failure time and energy consumption of limiter show a certain regularity with the variation of microwave pulse amplitude and frequency, and this work discusses this regularity from the following three aspects. Firstly, the failure time and energy consumption decrease in a similar trend with frequency increasing. And with the increase in signal amplitude, the failure time and energy consumption tend to stabilize. Secondly, the increase in the signal amplitude leads failure time to decrease, which is similar to the relationship between failure time and the signal frequency mentioned before. But as the signal’s amplitude increases, the energy consumption first increases and then decreases slightly when the amplitude reaches about 900 V. Based on the theoretical analysis and the physical image of the two-stage PIN limiter, the reasons for these effects can be explained as the changes in the I-region's impedance and heat distribution change caused by electric field changes. Thirdly, the failure time and energy consumption show different sensitivities to different parameters of the microwave pulse. The signal frequency change has greater influence on the energy consumption than the signal amplitude change, while the amplitude change can exert a greater influence on the failure time than the frequency change.</sec>

Exosomal preconditioning of human iPSC-derived cardiomyocytes beneficially alter cardiac electrophysiology during hypoxia

Abstract Introduction and purpose Cardiac-Exosomes (EXO) are nano-sized extracellular vesicles, continuously secreted by the myocardium. Despite previous misconceptions, cardiac-EXO are not just a way for the cell to dispatch waste, but functions as carriers of signaling molecules. Furthermore, the effects of cardiac-EXO signaling during hypoxic stress is not well understood. The present study aimed to determine the biological effects of EXO released from hypoxic cardiomyocytes, focusing on whether the EXO-cargo can benefit recipient cells during hypoxic stress. We hypothesize that cardiomyocytes exposed to hypoxic stress would display advantageous electrophysiological properties after preconditional treatment with isolated cardiac-EXO secreted from cardiomyocytes exposed to hypoxic stress. Methods For preconditional treatment we isolated EXO from human iPSC-derived cardiomyocytes (CM) exposed to hypoxia (1% O2) for 16 h (H-EXO). H-EXO was thereafter administrated as preconditional treatment to a secondary population of CM 24 h before subjection to 16 h of hypoxia. Electrophysiological effects of H-EXO precondition treatment were assessed with a multiwell microelectrode array (MEA) system. Using the MEA-system; field potential, beat period, spike slope, spike amplitude, excitation-contraction (EC) coupling, and cardiac action potentials were recorded and analyzed. Results We found that CM exposed to hypoxic stress conditions (16 hours) displayed significant increase in beat period when preconditioned with H-EXO compared to non-treated CM (+15.7%, p<0.05). Furthermore, precondition with H-EXO resulted in faster EC coupling compared with non-treated CM after 16 h of hypoxia (-25.3%, p<0.05). More efficient EC coupling indicates that the H-EXO recipient cells are less affected by the hypoxic stress. There were no significant changes in field potential, spike slope, spike amplitude and cardiac action potential between the two groups after 16 h of hypoxia. Conclusion The present study report that EXO secreted by CM under hypoxia alter electrophysiological properties in recipient cells exposed to 16 h hypoxic stress. The alterations indicate more efficient cardiomyocyte EC coupling and longer beat period.

Otoprotective Effects of Quercetin Against Oxidative Damage in the Rat's Cochlea Induced by Noise and Silver Nanoparticles.

The aim of this study was to investigate the otoprotective effects of Quercetin (Que) against both noise-induced hearing loss (NIHL) and the ototoxicity of silver nanoparticles (SNPs) in rats. Forty-two male Wistar rats were divided into seven groups (n=6): control, SNPs, Que (100mg/kg) plus SNPs (100mg/kg), noise (104dB), Que plus noise, noise plus SNPs, and noise plus Que plus SNPs. In the weight change results, there was no significant difference between the groups exposed to noise plus SNPs and SNPs compared to the control group. However, animals had significant changes in DPOAE amplitude at 1 and 3days post-exposure when compared to baseline. Additionally, the DPOAE value of rats administered with Que plus SNPs was higher than in all other groups. Que also decreased the levels of TACT, MDA, IL-6, TNF-α, and NOX3 in the groups exposed to noise and SNPs and increased the SOD level and expression of myosin heavy chain VII (MYH7) and β-tubulin III (TUBB3) proteins. Furthermore, Que decreased structural changes in the animals' cochlea. Our findings indicate that pretreatment with Que efficiently counteracted the adverse effects of noise and SNPs on inner hair cell, outer hair cell, and nerve cells, which are responsible for high-frequency perception.

Repetitive sensorimotor mu-alpha phase-targeted afferent stimulation produces no phase-dependent plasticity related changes in somatosensory evoked potentials or sensory thresholds.

Phase-dependent plasticity has been proposed as a neurobiological mechanism by which oscillatory phase-amplitude cross-frequency coupling mediates memory process in the brain. Mimicking this mechanism, real-time EEG oscillatory phase-triggered transcranial magnetic stimulation (TMS) has successfully induced LTP-like changes in corticospinal excitability in the human motor cortex. Here we asked whether EEG phase-triggered afferent stimulation alone, if repetitively applied to the peaks, troughs, or random phases of the sensorimotor mu-alpha rhythm, would be sufficient to modulate the strength of thalamocortical synapses as assessed by changes in somatosensory evoked potential (SEP) N20 and P25 amplitudes and sensory thresholds (ST). Specifically, we applied 100 Hz triplets of peripheral electrical stimulation (PES) to the thumb, middle, and little finger of the right hand in pseudorandomized trials, with the afferent input from each finger repetitively and consistently arriving either during the cortical mu-alpha trough or peak or at random phases. No significant changes in SEP amplitudes or ST were observed across the phase-dependent PES intervention. We discuss potential limitations of the study and argue that suboptimal stimulation parameter choices rather than a general lack of phase-dependent plasticity in thalamocortical synapses are responsible for this null finding. Future studies should further explore the possibility of phase-dependent sensory stimulation.

Mirror neuron activity depending on the content and stage of the observed action: a TMS study.

The firing rate of the mirror neuron system in monkeys decreases systematically with more repetitions. The aim of this study is to investigate whether the activity of the mirror neuron system varies based on the observed movement and the contents of the action, as well as whether there is inhibition in the mirror neuron system when humans observe repeated actions. If inhibition is present, the second question of the study is whether it is related to the organization of the observed action. Fourteen healthy volunteers participated in the study. Transcranial magnetic stimulation was applied to the left primary motor cortex and motor evoked potentials (MEPs) were recorded from the right first dorsal interosseous and abductor pollicis brevis muscles while the participants were watching videos specially prepared for the study. There were no significant changes in MEP amplitudes compared to baseline MEPs while observing aimless action. However, while participants watched the repeated action video, the mean MEP amplitude increased at the beginning of the movement, but neither facilitation nor inhibition was detected when the participants watched the phase of grasping the object of the action compared to the baseline MEP amplitude. On the other hand, while participants were watching different activities, an increased MEP amplitude was observed at the beginning of the movement and in the grasping of the object of the action. Additionally, there was no significant reduction in MEP amplitude during any movement stages while observing the repeated action video. The findings of this study suggest that the activation of the mirror neuron system in humans depends on the content and stages of the observed movement. Additionally, there was no inhibition or systematic reduction in MEP amplitudes while watching a repeated action.

Stability of steady-state visual evoked potential contrast response functions.

Repetitive sensory stimulation has been shown to induce neuroplasticity in sensory cortical circuits, at least under certain conditions. We measured the plasticity-inducing effect of repetitive contrast-reversal-sweep steady-state visual-evoked potential (ssVEP) stimuli, hoping to employ the ssVEP's high signal-to-noise electrophysiological readout in the study of human visual cortical neuroplasticity. Steady-state VEP contrast-sweep responses were measured daily for 4 days (four 20-trial blocks per day, 20 participants). No significant neuroplastic changes in response amplitude were observed either across blocks or across days. Furthermore, response amplitudes were stable within-participant, with measured across-block and across-day coefficients of variation (CV = SD/mean) of 15-20 ± 2% and 22-25 ± 2%, respectively. Steady-state VEP response phase was also highly stable, suggesting that temporal processing delays in the visual system vary by at most 2-3 ms across blocks and days. While we fail to replicate visual stimulation-dependent cortical plasticity, we show that contrast-sweep steady-state VEPs provide a stable human neurophysiological measure well suited for repeated-measures longitudinal studies.

Assessment of Retinal Side Effects of Fingolimod (Gilenya) Used in Treatment of Multiple Sclerosis Patients

Background Multiple sclerosis is an inflammatory demyelinating disease that affects CNS. It is thought that multiple factors were implicated in the pathology of MS such as immunological factors, vitamin d deficiency, vitamin b12 deficiency or infection by EBV or HHV6. It has a lot of ocular manifestations as optic neuritis, diplopia, oscillopsia, nystagmus and ophthalmoplegia. Fingolimod is the first approved oral drug for RRMS. Macular edema was reported as a side effect of fingolimod after 4 months of use. Aim of the Work The objectives of the study are screening of retinal side effects of fingolimod used for treatment of relapsing remitting multiple sclerosis patients having no previous ophthalmic complains before starting the treatment. To assess structural changes within the retina using SD-OCT and to correlate these structural changes with the function affection (visual acuity assessment and electrophysiological studies). Patients and Methods Thirty eyes of fifteen patients were included in this prospective one arm clinical trial study. These thirty eyes belonged to multiple sclerosis patients who will be candidate for treatment with fingolimod (Gilenya). Patients were recruited from MS unit, neurology department, Ain Shams University. Results We found that the mean best corrected visual acuity change after treatment slightly decreased but this was non-significant. IOP measurements were not changed after treatment. Despite the changes in visual acuity; fingolimod associated macular edema did not develop. Among 15 patients (30 eyes), 14 eyes have slightly increased MT, 5 eyes have stable MT and 11 eyes have slightly decreased MT. Regarding electrophysiology follow up there were significant change in P1 amplitude in MfERG in ring 1, and it happened without development of macular edema (ME), as 50% of patients had MfERG changes in spite of the absence of ME. So we recommend doing electrophysiological test (MfERG) in follow up protocol of fingolimod treatment. Conclusion Finglimod is an immunomodulatory drug used for treatment of RRMS, it is the first oral drug approved by FDA for MS. Fingolimod associated macular edema is a known complication with a low incidence. Patients on fingolimod should have baseline and 3 to 4 months ophthalmic examination as a part of their protocol OCT is non-invasive technique used for detection of macular edema and follow up, but in our study we found that after 4 months of treatment by fingolimod, affection of retinal function in same patients may happen before macular edema development, which spots the light on the importance of performing the mfERG as well in the follow up of patients who were treated with fingolimod. Further studies are needed to support our results.

Early Impact of Proton Beam Therapy on Electrophysiological Characteristics in a Porcine Model.

Particle therapy is a noninvasive, catheter-free modality for cardiac ablation. We previously demonstrated the efficacy for creating ablation lesions in the porcine heart. Despite several earlier studies, the exact mechanism of early biophysical effects of proton and photon beam delivery on the myocardium remain incompletely resolved. Ten normal and 9 infarcted in situ porcine hearts received proton beam irradiation (40 Gy) delivered to the left ventricular myocardium with follow-up for 8 weeks. High-resolution electroanatomical mapping of the left ventricular was performed at baseline and follow-up. Bipolar voltage amplitude, conduction velocity, and connexin-43 were determined within the irradiated and nonirradiated areas. The irradiated area in normal hearts showed a significant reduction of bipolar voltage amplitude (10.1±4.9 mV versus 5.7±3.2, P<0.0001) and conduction velocity (85±26 versus 55±13 cm/s, P=0.03) beginning at 4 weeks after irradiation. In infarcted myocardium after irradiation, bipolar voltage amplitude of the infarct scar (2.0±2.9 versus 0.8±0.7 mV, P=0.008) was significantly reduced as well as the conduction velocity in the infarcted heart (43.7±15.7 versus 26.3±11.4 cm/s, P=0.02). There were no significant changes in bipolar voltage amplitude and conduction velocity in nonirradiated myocardium. Myocytolysis, capillary hyperplasia, and dilation were seen in the irradiated myocardium 8 weeks after irradiation. Active caspase-3 and reduction of connexin-43 expression began in irradiated myocardium 1 week after irradiation and decreased over 8 weeks. Irradiation of the myocardium with proton beams reduce connexin-43 expression, conduction velocity, and bipolar conducted electrogram amplitude in a large porcine model. The changes in biomarkers preceded electrophysiological changes after proton beam therapy.

Research on Feature Extraction of Ship-Radiated Noise Based on Multiscale Fuzzy Dispersion Entropy

In recent years, fuzzy dispersion entropy (FDE) has been proposed and used in the feature extraction of various types of signals. However, FDE can only analyze a signal from a single time scale during practical application and ignores some important information. In order to overcome this drawback, on the basis of FDE, this paper introduces the concept of multiscale process and proposes multiscale FDE (MFDE), based on which an MFDE-based feature extraction method for ship-radiated noise is proposed. The experimental results of the simulated signals show that MFDE can reflect the changes in signal complexity, frequency, and amplitude, which can be applied in signal feature extraction; in addition, the measured experimental results demonstrate that the MFDE-based feature extraction method has a better feature extraction effect on ship-radiated noise, and the highest recognition rate is 99.5%, which is an improvement of 31.9% compared to the recognition rate of a single time scale. All the results show that MFDE can be better applied to the feature extraction and identification classification of ship-radiated noise.

Visual Evoked Potentials as an Early-Stage Biomarker in the rTg4510 Tauopathy Mouse Model.

Tauopathies such as Alzheimer's disease (AD) and frontotemporal dementia (FTD) are characterized by formation of neurofibrillary tangles consisting of hyperphosphorylated tau protein. Early pathophysiological and functional changes related to neurofibrillary tangles formation are considered to occur prior to extensive neurodegeneration. Hyperphosphorylated tau has been detected in postmortem retinas of AD and FTD patients, and the visual pathway is an easily accessible system in a clinical setting. Hence, assessment of the visual function may offer the potential to detect consequences of early tau pathology in patients. The aim of this study was to evaluate visual function in a tauopathy mouse model in relation to tau hyperphosphorylation and neurodegeneration. In this study we explored the association between the visual system and functional consequences of tau pathology progression using a tauopathy rTg4510 mouse model. To this end, we recorded full-field electroretinography and visual evoked potentials in anesthetized and awake states at different ages. While retinal function remained mostly intact within all the age groups investigated, we detected significant changes in amplitudes of visual evoked potential responses in young rTg4510 mice exhibiting early tau pathology prior to neurodegeneration. These functional alterations in the visual cortex were positively correlated with pathological tau levels. Our findings suggest that visual processing could be useful as a novel electrophysiological biomarker for early stages of tauopathy.

A rail defect detection system based on laser Doppler vibrometer measurements

This paper aims at introducing a non-contact rail damage detection system based on laser Doppler vibrometer (LDV) measurements. Specifically, the system consists of two LDVs mounted on a rail car, to record the waves induced on the rail head by random rail-wheel interaction forces.The developed damage detection framework associated with the system is based on a multivariate analysis that combines damage features which are based on the relative change in amplitude of the LDV signals that are caused by both reflected and transmitted waves. In this study, the damage detection system is introduced and validated through field tests which were carried out at the Transportation Technology Center (TTC) in Pueblo, CO. In these tests, a rail car installed with the damage detection system traveled over a track that consisted of a discontinuity in the rail (i.e., welded joint) at different speeds up to 48 km/h (30mph). Results show that the proposed system can identify the rail segment in which the propagating waves on the rail head are affected by the presence of the welded joint.

A novel oven structure for improving temperature uniformity of vapor cell in atomic sensors

Alkali-metal vapor cells are key elements of atomic sensors. The temperature uniformity in the vapor cell is important for the sensitivity of the atomic sensors especially highly-sensitive SERF atomic magnetometers. This study proposes a novel double-layer cylindrical oven to improve the heating performance and the temperature uniformity of the vapor cell. We use the finite element method to build the thermal simulation models of the conventional square oven and the novel double-layer cylindrical oven. The performances of two ovens are compared. Then we build the experimental system to carry out the measurement experiment of heating temperature of the conventional and novel ovens and the in-situ measurement experiment of temperature distribution of the vapor cell using different ovens. We also measure the change of output signal amplitude of the SERF atomic magnetometer with frequency, i.e. the frequency response R(f) using the conventional and novel ovens respectively to evaluate the performance of the SERF atomic magnetometer using different ovens. The experimental results demonstrate that the proposed oven structure can improve the temperature uniformity of the alkali-metal vapor cell by 63.63% and the amplitude of R(f) using the novel oven increases by 24.7% on average. The novel double-layer cylindrical oven improves the temperature uniformity in the alkali-metal vapor cell and increases amplitude of the output signal of the SERF atomic magnetometer. The study is of great significance for improving the sensitivity of the atomic sensors especially SERF atomic magnetometers.

Multifocal electroretinography increases following experimental glaucoma in nonhuman primates with retinal ganglion cell axotomy.

To determine whether short-latency changes in multifocal electroretinography (mfERG) observed in experimental glaucoma (EG) are secondary solely to retinal ganglion cell (RGC) loss or whether there is a separate contribution from elevated intraocular pressure (IOP). Prior to operative procedures, a series of baseline mfERGs were recorded from six rhesus macaques using a 241-element unstretched stimulus. Animals then underwent hemiretinal endodiathermy axotomy (HEA) by placing burns along the inferior 180° of the optic nerve margin in the right eye (OD). mfERG recordings were obtained in each animal at regular intervals following for 3-4months to allow stabilization of the HEA effects. Laser trabecular meshwork destruction (LTD) to elevate IOP was then performed; first-order kernel (K1) waveform root-mean-square (RMS) amplitudes for the short-latency segment of the mfERG wave (9-35ms) were computed for two 7-hexagon groupings-the first located within the superior (non-axotomized) macula and the second within the inferior (axotomized) macula. Immunohistochemistry for glial fibrillary acidic protein (GFAP) was done. By 3months post HEA, there was marked thinning of the inferior nerve fiber layer as measured by optical coherence tomography. Compared with baseline, no statistically significant changes in 9-35ms K1 RMS amplitudes were evident in either the axotomized or non-axotomized portions of the macula. Following LTD, mean IOP in HEA eyes rose to 46 ± 9 compared with 20 ± 2mmHg (SD) in the fellow control eyes. In the HEA + EG eyes, statistically significant increases in K1 RMS amplitude were present in both the axotomized inferior and non-axotomized superior portions of the OD retinas. No changes in K1 RMS amplitude were found in the fellow control eyes from baseline to HEA epoch, but there was a smaller increase from baseline to HEA + EG. Upregulation of GFAP in the Müller cells was evident in both non-axotomized and axotomized retina in eyes with elevated IOP. The RMS amplitudes of the short-latency mfERG K1 waveforms are not altered following axotomy but undergo marked increases following elevated IOP. This suggests that the increase in mfERG amplitude was not solely a result of RGC loss and may reflect photoreceptor and bipolar cell dysfunction and/or changes in Müller cells.

Оценка возможности контроля болтового соединения крышек сосудов с помощью ультразвуковых волн

The aim of the work is to study the applicability of the acoustic method for monitoring the loosening of fasteners on vessel lids, based on the change in signal amplitude during reflection and transmission of ultrasonic waves through the interface between plates. In the course of the work, theoretical dependences of the change in the amplitude of the received signal with a change in the applied pressure were obtained for the case of a flange connection without an additional gasket and in the presence of a gasket made of various materials. It has been established that in the absence of acoustic contact in the flange connection, the amplitude of the signal reflected from the interface is maximum, while in continuous contact it is minimal. The results obtained were verified experimentally using the shadow and echo method of ultrasonic testing. As a result of the study, it was found that the maximum change in the signal amplitude is observed at low frequencies, and when controlled by the shadow method, it is higher than when using the echo method.

Waveform Prediction of Blade Tip‐Timing Sensor Based on Kriging Model and Static Calibration Data

Blade tip clearance is an important parameter affecting the efficiency, stability, and safety of aero‐engines. During the high‐speed rotation of the blade, the blade tip clearance changes, which leads to changes in signal amplitude collected by the tip timing sensor. When the rotor is rotating at high speed, it is impractical to measure the tip‐timing signal under each tip clearance. Aiming at the previous problems, a prediction method of blade tip‐timing sensor waveform based on the combination of the Kriging model and static calibration data are proposed. The relationship between the output voltage of the tip timing sensor and the blade tip clearance and the angle of the blade tip cutting magnetic line is obtained by collecting the data of static calibration. Based on the collected static calibration experimental data and compared with the polynomial fit method and the RBF model, the accuracy of the Kriging model in predicting the waveform of the blade tip timing sensor was verified. The results show that the prediction accuracy of the Kriging model is basically the same as that of the RBF model, but the Kriging model has more advantages in predicting the waveform when the blade tip clearance is unknown. In contrast, the prediction accuracy of the polynomial fit is lower than that of the Kriging and RBF models, and the polynomial fit is prone to significant prediction errors.

The responses of SST annual cycle in the eastern equatorial Pacific to global warming

The eastern equatorial Pacific exhibits a pronounced westward propagating sea surface temperature annual cycle (SSTAC). The responses of the equatorial Pacific SSTAC to CO2-induced global warming are examined using 15 Coupled Model Intercomparison Project Phase 5 (CMIP5) experiments. The annual cycle patterns of global-warming simulations over 2006-2100 are compared with that of present-day simulations over 1850-2005. We see no statistically significant changes in SSTAC amplitude in the future. A coupled dynamical diagnostic framework is adopted to assess four factors, including the damping rate, phase speed and strength of the annual and semi-annual harmonic forcing of SSTAC. Under global warming, changes relative to the present-day simulations in these four diagnostic factors have a clear multi-model trend. Most coupled models exhibit relatively weaker (an average of 18%) propagation speed, and stronger annual (18%) and semi-annual (39%) external forcing. Half of the models show a relatively stronger (about one time) damping rate, while the rest show a weaker (30%) damping rate. When these four diagnostic factors are further condensed into a dynamical response factor and a forcing factor, it is revealed that the same annual cycle amplitudes with respect to the present-day simulations may result from the compensations in terms of bias in the dynamical response factor and forcing factor under increased CO2-induced warm climate.

Deep-fading hole avoidance for secure region detection using channel state information

One of the critical challenges in many wireless systems is the deep fading hole problem where signals interfere destructively to create an abrupt change in signal amplitude due to multipath fading. In this work, we tackle this challenge in the context of secure region detection (SRD) problem. Specifically, we propose SHARD, a novel hole avoidance technique that analyzes channel state information (CSI) to significantly improve the accuracy of CSI-based SRD. SHARD identifies potential fading holes in CSI amplitude, and removes an unreliable portion of data while utilizing the remaining unaffected part. To compensate for the loss of information, we define phase-distance for reliable use of time-varying CSI phase, and neighboring reference points are utilized for accurate matching. Our real-world experiments show that SHARD can achieve a near-perfect 99.96% true-negative ratio (successfully rejecting devices not in the secure region) and an excellent true-positive of 98.01% for practical usage, significantly better than state-of-the-art prior work. We believe our ideas can be generalized to many RF-based localization systems to mitigate the deep fading hole problem and improve their accuracy.

Adeno‐associated virus (AAV) knock‐down of amyloid precursor protein attenuates retinal ganglion cell degeneration in experimental glaucoma

AbstractPurpose: Retinal ganglion cell (RGC) degeneration and visual field loss are distinctive features of primary open angle glaucoma. Similar pathologies have been observed in Alzheimer's Disease patients, concomitant to amyloid‐β aggregation. Here, we investigated the effect of amyloid precursor protein (APP) modulation in the retina and examined the potential neuroprotective effects of APP knock‐down (APP‐KD) in experimental glaucoma.Methods: AAV‐PHP.eB constructs for APP‐KD (NM_000484) and positive scramble controls were transfected in SH‐SY5Y neuroblastoma cells to validate their expression. Wild‐type C57BL/6J mice (n = 30) were then transduced with APP‐KD (n = 10) or scramble (n = 10) vectors intravenously. Experimental chronic glaucoma was induced via weekly intraocular microbead injections for 8 weeks. Inner retinal function was assessed using positive scotopic threshold response (pSTR) amplitudes. Structural RGC changes were quantified using haematoxylin and eosin staining and manual cell count.Results: All microbead‐injected eyes showed significantly increased intraocular pressure (Mean ± SEM; Microbead vs. Control; 27.98 ± 0.78 mmHg vs. 10.01 ± 0.13 mmHg). In glaucomatous conditions, there was significant preservation of the RGC layer in APP‐KD treated eyes, compared to scramble and microbead‐only eyes (p &lt; 0.002) (Mean ± SEM; Microbead/APP‐KD vs. Microbead/Scramble vs. Microbead‐only; 41.57 ± 1.61 vs. 37.73 ± 1.50 vs. 35.43 ± 0.95 cells/300 μm). However, there was no significant changes in pSTR amplitudes of glaucomatous APP‐KD eyes, compared to scramble and microbead‐only eyes (p = 0.653).Conclusions: AAV‐PHP.eB mediated APP‐KD confers significant protection of the RGC layer in glaucomatous eyes, however this protection was not sustained functionally. The molecular mechanisms by which APP‐KD may impart neuroprotection and ameliorate APP neurotoxicity are unclear. Further studies will include biochemical evaluation of synaptic and cellular stress markers.

Effect of alternate nostril breathing on evoked potentials among internet addicts.

Increased availability of smartphones and easy access to the internet among adolescents has resulted in Internet Addiction (IA). Effects of IA and Pranayama on evoked potential are available but studies on the comparison of immediate and 6-week effects of alternate nostril breathing on evoked potentials among medicos with internet addiction are not available as per our search in PubMed, hence the study was chosen. In this comparative study 100 male and female medical students aged between 18-25 years, with internet addiction scores ≥ 50 were included as study participants. P300 auditory event-related potential and pattern reversal visual evoked potential (VEP) were recorded before, immediately, and 6 weeks after practicing pranayama. Repeated measure ANOVA shows statistically significant change (P<0.05) in P300 amplitude, P100 latency, N145 latency, and VEP amplitude. The post hoc Bonferroni test shows that P100 latency and N145 latency significantly reduced immediately after 15 minutes of pranayama. P300 amplitude and VEP amplitude significantly increased only after practicing pranayama for 6 weeks. Pranayama has an immediate effect on latency, but it takes 6 weeks of practice to significantly change amplitude.