Propagating spatiotemporal activity patterns across macaque motor cortex carry kinematic information.

Propagating spatiotemporal neural patterns are widely evident across sensory, motor, and association cortical areas. However, it remains unclear whether any characteristics of neural propagation carry information about specific behavioral details. Here, we provide the first evidence for a link between the direction of cortical propagation and specific behavioral features of an upcoming movement on a trial-by-trial basis. We recorded local field potentials (LFPs) from multielectrode arrays implanted in the primary motor cortex of two rhesus macaque monkeys while they performed a 2D reach task. Propagating patterns were extracted from the information-rich high-gamma band (200 to 400 Hz) envelopes in the LFP amplitude. We found that the exact direction of propagating patterns varied systematically according to initial movement direction, enabling kinematic predictions. Furthermore, characteristics of these propagation patterns provided additional predictive capability beyond the LFP amplitude themselves, which suggests the value of including mesoscopic spatiotemporal characteristics in refining brain-machine interfaces.

Multivalency-induced structural variations of 2D selenium nanosheets: facile solution-phase synthesis and optical properties.

The structural stability of two-dimensional (2D) phases derived from bulk selenium (Se) is intrinsically rooted in the multivalent nature of the material. The emergence of 2D Se, as its morphology evolves from 1D to 2D, was initially inspired by theoretical predictions of various quasi-stable structural phases of 2D Se. Here, we report a facile liquid-phase synthesis of free-standing few-layer selenium nanosheets (SeNS) employing a simple magnetic stirring of their bulk counterpart in N-methyl pyrrolidone (NMP). The synthesized SeNS possess lateral dimensions ranging from several hundreds of nanometers to a few microns, with a minimum thickness of ∼1 nm. High-resolution transmission electron microscopy reveals the existence of α- and ß-selenene. Fourier transform infrared analysis suggests that the inherent surface/edge functionalization of 2D SeNS by NMP enhances their dispersion stability. The UV-vis-NIR absorption spectrum of SeNS exhibits a shoulder peak at 330 nm, attributed to surface/edge functionalization, and multiple peaks across the vis-NIR region, stemming from size quantization effects. The functionalized selenium nanosheets generate photoluminescence that spans the blue-green range, while the size quantization of SeNS leads to green-orange luminescence. The non-linear optical studies following Z-scan experiments with an open aperture revealed reverse saturable absorption (RSA) and strong optical limiting in 2D SeNS under 532 nm, 10 ns laser pulses. Notably, a transition from RSA to saturable absorption (SA) has also been observed in samples stirred over an extended period. In this perspective, the results illustrate the first experimental realization of free-standing multivalent 2D selenium in allotropic forms with unique optical properties.

Plasmon induced enhancement of surface optical phonon modes and magnon properties of NiO nanoparticles: Raman spectral probe.

In the present work, the influence of Ag-induced plasmons on the surface optical (SO) phonon modes of NiO nanoparticles was extensively studied using room temperature Raman spectroscopy. Remarkable intensity enhancements were observed for the rarely reported SO phonon modes compared to the other first-order phonon modes of NiO nanoparticles. The occurrence of SO modes was further studied using an approximate dielectric continuum (DC) model and a difference between the calculated and experimental SO frequencies was observed, which can be attributed to the presence of one magnon background over the first order phonon modes. The experimental and theoretical SO frequencies became closer at higher Ag concentration and the second-order magnon (2M) and phonon bands disappeared in the NiO:Ag samples. The absence of magnon and higher order phonon modes in the NiO:Ag samples indicates changes in the magnetic properties of the nanomaterials, which has been further supported by the vibrating-sample magnetometer (VSM) measurements.

Laser induced Fano scattering, electron-phonon coupling, bond length and phonon lifetime changes in α-Fe2O3 nanostructures.

We have extensively studied the laser-induced Fano scattering, electron-phonon coupling, bond length and phonon lifetime of the α-Fe2O3 nanostructure prepared through a simple co-precipitation method. A noticeable red shift and asymmetry have been observed in the phonon modes of the prepared α-Fe2O3 nanostructure. The traditional assessment of asymmetric broadening and a red shift in the Raman spectra of a nanomaterial was due to the quantum confinement effect. In the present investigation, the red shift and the asymmetry in the phonon modes of the α-Fe2O3 nanostructure have been studied on the basis of the heating effect and Fano interference between the discrete phonon and the laser-induced electron plasma in the nanomaterial. The observed asymmetrical factors of the A1g(1) and Eg(4) phonon modes were positive and negative respectively and are seen to be decreasing with the laser power. The laser-induced surface temperature of the material has been studied using the Stokes/anti-Stokes method. The bond lengths of the Fe-O molecules present in the α-Fe2O3 nanomaterial increased and the calculated Fröhlich interactions decreased with the laser energy.

Emergent coordination underlying learning to reach to grasp with a brain-machine interface.

The development of coordinated reach-to-grasp movement has been well studied in infants and children. However, the role of motor cortex during this development is unclear because it is difficult to study in humans. We took the approach of using a brain-machine interface (BMI) paradigm in rhesus macaques with prior therapeutic amputations to examine the emergence of novel, coordinated reach to grasp. Previous research has shown that after amputation, the cortical area previously involved in the control of the lost limb undergoes reorganization, but prior BMI work has largely relied on finding neurons that already encode specific movement-related information. In this study, we taught macaques to cortically control a robotic arm and hand through operant conditioning, using neurons that were not explicitly reach or grasp related. Over the course of training, stereotypical patterns emerged and stabilized in the cross-covariance between the reaching and grasping velocity profiles, between pairs of neurons involved in controlling reach and grasp, and to a comparable, but lesser, extent between other stable neurons in the network. In fact, we found evidence of this structured coordination between pairs composed of all combinations of neurons decoding reach or grasp and other stable neurons in the network. The degree of and participation in coordination was highly correlated across all pair types. Our approach provides a unique model for studying the development of novel, coordinated reach-to-grasp movement at the behavioral and cortical levels. NEW & NOTEWORTHY Given that motor cortex undergoes reorganization after amputation, our work focuses on training nonhuman primates with chronic amputations to use neurons that are not reach or grasp related to control a robotic arm to reach to grasp through the use of operant conditioning, mimicking early development. We studied the development of a novel, coordinated behavior at the behavioral and cortical level, and the neural plasticity in M1 associated with learning to use a brain-machine interface.

Propagating motor cortical patterns of excitability are ubiquitous across human and non-human primate movement initiation.

A spatiotemporal pattern of excitability propagates across the primary motor cortex prior to the onset of a reaching movement in non-human primates. If this pattern is a necessary component of voluntary movement initiation, it should be present across a variety of motor tasks, end-effectors, and even species. Here, we show that propagating patterns of excitability occur during the initiation of precision grip force and tongue protrusion in non-human primates, and even isometric wrist extension in a human participant. In all tasks, the directions of propagation across the cortical sheet were bimodally distributed across trials with modes oriented roughly opposite to one another. Propagation speed was unimodally distributed with similar mean speeds across tasks and species. Additionally, propagation direction and speed did not vary systematically with any behavioral measures except response times indicating that this propagating pattern is invariant to kinematic or kinetic details and may be a generic movement initiation signal.

Neural network-based Bluetooth synchronization of multiple wearable devices.

Bluetooth-enabled wearables can be linked to form synchronized networks to provide insightful and representative data that is exceptionally beneficial in healthcare applications. However, synchronization can be affected by inevitable variations in the component's performance from their ideal behavior. Here, we report an application-level solution that embeds a Neural network to analyze and overcome these variations. The neural network examines the timing at each wearable node, recognizes time shifts, and fine-tunes a virtual clock to make them operate in unison and thus achieve synchronization. We demonstrate the integration of multiple Kinematics Detectors to provide synchronized motion capture at a high frequency (200 Hz) that could be used for performing spatial and temporal interpolation in movement assessments. The technique presented in this work is general and independent from the physical layer used, and it can be potentially applied to any wireless communication protocol.

Renal Allograft Cortical Necrosis in a COVID-19 Positive Patient.

The incidence of acute kidney injury (AKI) has been reported to be higher in kidney transplant recipients infected with SARS-CoV-2 compared with the general population. Here, we report a case of cortical necrosis in the graft kidney due to COVID infection in a patient with stable graft function over the years. The patient was started on hemodialysis and treated with steroids, and anticoagulants for COVID infection. Later, he had gradual improvement in his graft function and became dialysis independent on follow up.

Optimization System Based on Convolutional Neural Network and Internet of Medical Things for Early Diagnosis of Lung Cancer.

Recently, deep learning and the Internet of Things (IoT) have been widely used in the healthcare monitoring system for decision making. Disease prediction is one of the emerging applications in current practices. In the method described in this paper, lung cancer prediction is implemented using deep learning and IoT, which is a challenging task in computer-aided diagnosis (CAD). Because lung cancer is a dangerous medical disease that must be identified at a higher detection rate, disease-related information is obtained from IoT medical devices and transmitted to the server. The medical data are then processed and classified into two categories, benign and malignant, using a multi-layer CNN (ML-CNN) model. In addition, a particle swarm optimization method is used to improve the learning ability (loss and accuracy). This step uses medical data (CT scan and sensor information) based on the Internet of Medical Things (IoMT). For this purpose, sensor information and image information from IoMT devices and sensors are gathered, and then classification actions are taken. The performance of the proposed technique is compared with well-known existing methods, such as the Support Vector Machine (SVM), probabilistic neural network (PNN), and conventional CNN, in terms of accuracy, precision, sensitivity, specificity, F-score, and computation time. For this purpose, two lung datasets were tested to evaluate the performance: Lung Image Database Consortium (LIDC) and Linear Imaging and Self-Scanning Sensor (LISS) datasets. Compared to alternative methods, the trial outcomes showed that the suggested technique has the potential to help the radiologist make an accurate and efficient early lung cancer diagnosis. The performance of the proposed ML-CNN was analyzed using Python, where the accuracy (2.5-10.5%) was high when compared to the number of instances, precision (2.3-9.5%) was high when compared to the number of instances, sensitivity (2.4-12.5%) was high when compared to several instances, the F-score (2-30%) was high when compared to the number of cases, the error rate (0.7-11.5%) was low compared to the number of cases, and the computation time (170 ms to 400 ms) was low compared to how many cases were computed for the proposed work, including previous known methods. The proposed ML-CNN architecture shows that this technique outperforms previous works.

Charge transfer induced excitons and nonlinear optical properties of ZnO/PEDOT:PSS nanocomposite films.

In this current work, we have prepared zinc oxide (ZnO) nanorods by sol-gel method, and its composite films with a conducting polymer poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) also have been prepared by drop-casting method on the glass substrate. UV-Vis absorption and steady-state fluorescence studies revealed exciton dissociation and recombination at the interface of polymer chain and wide-bandgap semiconductor ZnO. Also, nonlinear optical properties of as-prepared nanocomposite films have been reported by employing an open aperture z-scan technique. A predominantly two-photon induced saturable absorption behavior, when excited with 532 nm, 10 ns laser pulses, appeared in nonlinear optical measurements. These results indicate that our as-synthesized composites can be useful in fabricating optical switch and saturable absorbers.

Effect of low dialysate sodium in the management of intradialytic hypertension in maintenance hemodialysis patients: A single-center Indian experience.

BACKGROUND: High dialysate sodium is a significant contributor to intradialytic hypertension (IDH) in maintenance hemodialysis patients. In this study, we aimed to study the effect of low dialysate sodium on IDH in Indian hemodialysis patients. MATERIALS AND METHODS: Fifty patients on maintenance hemodialysis for atleast 3 months with episodes of IDH were enrolled in this study. The study was performed in two different stages. In the first phase, patients were dialyzed with standard dialysate sodium (140 mEq/L) for eight consecutive sessions and in the second phase, they were dialyzed with low sodium dialysate (136 mEq/L) for eight consecutive sessions. Differences in pre, intradialytic, and post-HD blood pressure, interdialytic weight gain, mean serum sodium, intradialytic adverse events, and number of IDH episodes requiring intervention between the two phases were assessed. RESULTS: The mean age of the study population was 52 years (36 males,14 females). The mean post-HD systolic and diastolic BP was 163.26 ± 9.58 mmHg and 88.60 ± 5.27 mmHg in the standard dialysate phase and 142.38 ± 14.09 mmHg and 84.58 ± 4.276 mmHg, respectively, in the low dialysate phase (p < 0.01). Interdialytic weight gain was 3.34 ± 0.9 and 3.11 ± 0.86 in the standard and low sodium dialysate phases, respectively (p = 0.19).The mean pre-HD plasma sodium level was 138.48 ± 3.69 and 135.80 ± 1.35 mEq/dl, respectively, in standard and low dialysate phases (p = 0.01). There was significant reduction in number of IDH episodes requiring intervention. There was no difference in hypotensive episodes, adverse events between the two phases. CONCLUSION: In patients with intradialytic hypertension, low dialysate sodium significantly reduces the post-HD blood pressure and intradialytic hypertensive episodes, when compared with standard sodium dialysate.

XIAP inhibits gentamicin-induced hair cell damage and ototoxicity through the caspase-3/9 pathway.

Gentamicin (GM), an aminoglycoside antibiotic, is one commonly used clinical drugs with ototoxic side effects. One of the most principal mechanisms of its ototoxicity is that GM can activate caspase-mediated cell death pathways in the cochlea. Since the anti-apoptotic protein known as X-linked Inhibitor of Apoptosis Protein (XIAP) has been reported to directly bind to activated caspase protein and inhibit their activities, we hypothesized that it might protect cochlea hair cells from GM ototoxicity. To evaluate this hypothesis, postnatal day 2-3 (P2-3) transgenic (TG) mice, in which XIAP gene is over-expressed under a pure C57BL/6J genetic background was constructed. We first extracted the cochlea tissue of normal mice and treated them with different concentrations of GM, and the number of hair cells were observed to determine the concentration of GM used in subsequent experiments. Next, we used Western Blot experiment to examine the effect of GM on XIAP protein expression in normal mouse cochlea, and then Western Blot and RT-PCR experiments were used to identify the transgenic mice. Finally, immunofluorescence assays were used to detect the effect of GM on the expression of caspase protein and verify the protective effect of XIAP. We found that GM at a concentration of 0.5 mM significantly affected the function of cochlea hair cells, up-regulating the expression of cleaved-caspase-3 and cleaved-caspase-9 protein but down-regulating XIAP protein. In the cochlea tissues of TG mice, this effect of GM was suppressed, and the destruction of hair cells was significantly reduced, and the cleaved-caspase-3 and cleaved-caspase-9 proteins were significantly suppressed. These results suggested that XIAP reduces GM-induced ototoxicity and caspase-3/9 pathway is associated with this process.

A low-cost stand-alone platform for measuring motor behavior across developmental applications.

Motion tracking provides unique insights into motor, cognitive, and social development by capturing subtle variations into how movements are planned and controlled. Here, we present a low-cost, wearable movement measurement platform, KiD, specifically designed for tracking the movements of infants and children in a variety of natural settings. KiD consists of a small, lightweight sensor containing a nine-axis inertial measurement unit plus an integrated processor for computing rotations. Measurements of three-dimensional acceleration using KiD compare well with those of current state-of-the-art optical motion capture systems. As a proof of concept, we demonstrate successful classification of different types of sinusoidal right arm movements using KiD.

Reliability of clinical assessment in diagnosing cauda equina syndrome.

Cauda equina syndrome (CES) is a neurological syndrome presenting with non-specific symptoms and signs that often leads to diagnostic confusion and delay. Acute onset CES is a surgical emergency. The common aetiology is a prolapsed lumbar disc. If the diagnosis is missed, it can have devastating consequences for the patient and a high financial cost to healthcare providers. The objective of this study was to evaluate the efficacy of clinical assessment in clinching the diagnosis. Eighty patients who underwent urgent clinical assessment and magnetic resonance imaging (MRI) for suspected CES over a 1-year period (from January 1st 2008 to 31 December 2008) were included in the study. Fifteen of these patients had a CES and underwent urgent lumbar discectomy and decompression. Medical notes and MRI scans of all these patients were reviewed. The presenting symptoms and signs were analysed against a positive MRI scan. Chi-square test with Yates correction was used to test association of each clinical symptom and sign for a positive MRI. In this study, only 18.8% of assessed patients had a CES producing compression seen on the MRI. Presence of saddle sensory deficit was the only clinical feature with a statistically significant association with MRI positive CES (p = 0.03). This series shows that saddle sensory deficit has a higher predictive value than other clinical features in diagnosing a CES. However, as there is no symptom or sign which has an absolute predictive value in establishing the diagnosis of CES, any patient in whom a reasonable suspicion of CES arises must undergo urgent MRI to exclude this diagnosis.

Effect of laser power on force constant and phonon lifetime of stretching and bending vibration of Cu-doped WO3 nanostructures.

The influence of Cu-doping on their structural, vibrational and morphological properties of hydrothermally prepared Cu-doped WO3 has been studied. X-ray Diffraction studies confirm the tetragonal structure of WO3 and lower angle shift in doped samples indicates the incorporation of Cu in tungsten sites. Field emission scanning electron microscopy (FESEM) images exhibit micro rod-like morphology of the as-synthesized WO3 materials shows microstructure with rod-like projections slowly changes into nanorods and plates for doped samples. The absorption peak of pure and Cu-doped WO3 occurs in the region of 200 to 350 nm and centered at 314 nm. In Raman spectra, prominent peaks of WO3 have appeared at 676 and 810 cm-1 which represent the stretching mode of υa (OWO). Peak around 240 cm-1 represents the bending vibration of υ (WOW). Another peak at 322 cm-1 is the deformation mode δ (OWO). Force constant of the prepared samples has been calculated from the blue shift obtained in both stretching and bending vibrational mode by varying laser power from 0.045 to 11.25 mW. Phonon lifetime has been calculated by deconvoluting the peaks using Lorentzian function.

Propagating Motor Cortical Dynamics Facilitate Movement Initiation.

Voluntary movement initiation involves the modulations of large groups of neurons in the primary motor cortex (M1). Yet similar modulations occur during movement planning when no movement occurs. Here, we show that a sequential spatiotemporal pattern of excitability propagates across M1 prior to the movement initiation in one of two oppositely oriented directions along the rostro-caudal axis. Using spatiotemporal patterns of intracortical microstimulation, we find that reaction time increases significantly when stimulation is delivered against, but not with, the natural propagation direction. Functional connections among M1 units emerge at movement that are oriented along the same rostro-caudal axis but not during movement planning. Finally, we show that beta amplitude profiles can more accurately decode muscle activity when they conform to the natural propagating patterns. These findings provide the first causal evidence that large-scale, propagating patterns of cortical excitability are behaviorally relevant and may be a necessary component of movement initiation.

Dopant induced local vibrational modes and Fano scattering in Ag doped ZnO microrods.

We discussed the influence of Ag doping on the crystallite size of ZnO and enhanced Raman spectroscopy properties. We reported optical and vibrational properties of Ag-doped ZnO microrods which have been prepared through reflux method. Dopant induced shift and asymmetric broadening of Raman modes have been discussed. In Raman spectra, silver doping induces a lower wavenumber shift in E2H mode. Moreover, the appearance of some additional peaks after Ag-doping were successfully studied and the doping is confirmed by the local vibration modes obtained at 230 and 390cm-1. Effect of doping is studied by calculating the crystallite size and we discussed the variations in full width half maximum (FWHM), phonon lifetime with respect to varying crystallite size. Phonon lifetime decreases with increasing Ag concentration. The asymmetric broadening in Raman modes E2H and E2L with the addition of Ag are analysed with Fano fitting.

A Retrospective Analysis of Etiology and Outcomes of Refractory CAPD Peritonitis in a Tertiary Care Center from North India.

BACKGROUND: Refractory peritonitis is defined as failure of clearance of peritoneal fluid despite 5 days of appropriate antibiotic therapy. Catheter removal decreases morbidity and mortality. Data on the outcomes of refractory peritonitis and of reinitiation of peritoneal dialysis (PD) in this group of patients are sparse. The present study analyzed etiology, outcomes, and prognostic factors of refractory peritonitis as well as survival of the reinitiation of the technique. METHODS: This was a single-center retrospective study that included 90 patients of refractory continuous ambulatory PD (CAPD) peritonitis at a tertiary care center in North India. We collected information regarding symptomatology, causes, prognostic factors, and outcomes of refractory peritonitis. RESULTS: Ninety patients suffered 93 episodes of refractory peritonitis. Fungal peritonitis was the most common cause of refractory peritonitis. Twenty nine (31%) episodes were culture-negative. We observed no difference between culture-positive and culture-negative peritonitis. Out of 90 patients, 54 (60%) recovered while 36 (40%) died. Septic shock at presentation alone was significantly associated with mortality in our study. The immediate mortality of refractory peritonitis is high. Even in patients who were shifted to permanent hemodialysis, 33% died in the first 3 months. Mean duration of technique survival after reinitiation was 23 months (1 - 85 months). Among the 12 patients who were reinitiated on CAPD, 5 patients had technique failure due to refractory peritonitis or ultrafiltration (UF) failure. CONCLUSION: Refractory peritonitis is associated with significant morbidity and mortality despite catheter removal. Reinitiation is confounded by residual infection, which is a concern for poor technique survival, and high immediate mortality.

Surgical technique and results of cable graft interpositioning of the facial nerve in lateral skull base surgeries: experience with 213 consecutive cases.

OBJECTIVE The aim in this study was to review the technique and outcomes of cable graft interpositioning of the facial nerve (FN) in lateral skull base surgeries. METHODS The authors retrospectively evaluated data from patients who had undergone cable graft interpositioning after nerve sacrifice during skull base tumor removal between June 1987 and May 2015. All patients had undergone lateral skull base approaches to remove tumors at a quaternary referral center in Italy. Facial nerve function was evaluated before and after surgery using the House-Brackmann (HB) grading system. RESULTS Two hundred thirteen patients were eligible for study. The mean follow-up was 44.3 months. The most common pathology was vestibular schwannoma (83 cases [39%]), followed by FN tumor (67 cases [31%]). Facial nerve tumors had the highest incidence of nerve interruption (67 [66%] of 102 cases). Preoperative FN function was normal (HB Grade I) in 105 patients (49.3%) and mild (HB Grade II) in 19 (8.9%). At the last postoperative follow-up, 108 (50.7%) of the 213 patients had recovered to Grade III nerve function. Preoperative HB grading of the FN was found to have a significant effect on outcome (p = 0.002). CONCLUSIONS Cable graft interpositioning is a convenient and well-accepted procedure for immediate restoration of the FN. The study results, over a large number of patients, showed that the stitch-less fibrin glue-aided coaptation technique yields good results. The best possible postoperative result achieved was an HB Grade III. The chances of a good postoperative result increase when FN function is normal preoperatively. Slow-growing tumors of the cerebellopontine angle had a favorable outcome after grafting.

Optical, phonon and efficient visible and infrared photocatalytic activity of Cu doped ZnS micro crystals.

We report, the enhanced photocatalytic behaviour of Cu doped ZnS micro crystals. ZnS and different concentrations of Cu doped ZnS microcrystals were prepared. X-ray diffraction confirms the crystalline and phase of the particles. Morphology and sizes were studied using Scanning Electron Microscopy (SEM). Recorded optical absorption spectra show a band for around 365nm for pure ZnS, but there is a broad band in the near infrared regime for the Cu-doped ZnS microcrystals which are attributed to the d-d transitions of Cu2+ ions. Phonon properties of as-prepared samples were investigated using Raman spectroscopy. Present work we investigate the potential of ZnS and Cu doped ZnS as a photocatalyst. For this from the degradation of methylene blue dye in aqueous media the photocatalytic activity of pure and highest doped ZnS samples with the irradiation of white light and infrared, enhanced photocatalytic activity were observed. Mechanism of white light an IR light based photocatalytic activity is explained based on the electron-hole pair production.