Structural refinement and electrochemical properties of one dimensional (ZnO NRs)1-x(CNs )x functional hybrids for serotonin sensing studies

Herein, the efficient serotonin (5-HT) sensing studies have been conducted using the (ZnO NRs) 1−x(CNs) x nanocomposites (NCs) having appropriate structural and electrochemical properties. Initially, the different compositions of ZnO nanorods (NRs), with varying content of carbon nanostructures (CNs=MWCNTs and RGO), are prepared using simple in-situ wet chemical method and thereafter these NCs have been characterized for physico-chemical properties in correlation to the 5-HT sensing activity. XRD Rietveld refinement studies reveal the hexagonal Wurtzite ZnO NRs oriented in (101) direction with space group ‘P6 3mc’ and both orientation as well as phase of ZnO NRs are also retained in the NCs due to the small content of CNs. The interconnectivity between the ZnO NRs with CNs through different functional moieties is also studied using FTIR analysis; while phases of the constituents are confirmed through Raman analysis. FESEM images of the bare/NCs show hexagonal shaped rods with higher aspect ratio (4.87) to that of others. BET analysis and EIS measurements reveal the higher surface area (97.895 m 2/g), lower charge transfer resistance (16.2 kΩ) for the ZCNT 0.1 NCs to that of other NCs or bare material. Thereafter, the prepared NCs are deposited on the screen printed carbon electrode (SPCE) using chitosan as cross-linked agent for 5-HT sensing studies; conducted through cyclic voltammetry (CV) and square wave voltammetry (SWV) measurements. Among the various composites, ZCNT0.1 NCs based electrodes exhibit higher sensing activity towards 5-HT in accordance to its higher surface area, lower particle size and lower charge transfer resistance. SWV measurements provide a wide linear response range (7.5–300 μM); lower limit of detection (0.66 μM), excellent limit of quantification (2.19 μM) and good reproducibility to ZCNT 0.1 NCs as compared to others for 5-HT sensing studies

Biomarkers in motor neuron disease: A state of the art review

Motor neuron disease can be viewed as an umbrella term describing a heterogeneous group of conditions, all of which are relentlessly progressive and ultimately fatal. The average life expectancy is 2 years, but with a broad range of months to decades. Biomarker research deepens disease understanding through exploration of pathophysiological mechanisms which, in turn, highlights targets for novel therapies. It also allows differentiation of the disease population into sub-groups, which serves two general purposes: (a) provides clinicians with information to better guide their patients in terms of disease progression, and (b) guides clinical trial design so that an intervention may be shown to be effective if population variation is controlled for. Biomarkers also have the potential to provide monitoring during clinical trials to ensure target engagement. This review highlights biomarkers that have emerged from the fields of systemic measurements including biochemistry (blood, cerebrospinal fluid, and urine analysis); imaging and electrophysiology, and gives examples of how a combinatorial approach may yield the best results. We emphasize the importance of systematic sample collection and analysis, and the need to correlate biomarker findings with detailed phenotype and genotype data

Speech Network Regional Differences in Bulbar Amyotrophic Lateral Sclerosis: Neuroimaging and Neuropathology Investigations

Bulbar ALS has devastating consequences on survival and quality of life, and may be linked to increased burden of extramotor deficits. This dissertation is comprised of three studies addressing the goal of better understanding the neural anatomical underpinnings of bulbar Amyotrophic Lateral Sclerosis (ALS) with a particular focus on the cortical speech network (SpN). The work has significant impact on ALS subtyping which is crucial for understanding disease pathogenesis, and clinical implications for diagnosis, prognosis, and recruitment into clinical trials. The first study characterized structural abnormalities in the SpN regions with relation to bulbar motor dysfunction using T1 and DTI neuroimaging in 16 patients with bulbar ALS. The results revealed left-lateralized differences in extramotor SpN regions with thinning in left inferior frontal gyrus (IFG) and diffusivity abnormalities underlying left primary auditory cortex (PAC) and posterior superior temporal gyrus (pSTG). Greater bulbar motor dysfunction was associated with greater structural abnormalities in selected SpN regions, while limb and disease severity were not. The second study systematically reviewed and compared published neuropathology data between bulbar-onset ALS (bALS) and spinal-onset ALS (sALS) in order to distinguish bulbar from spinal ALS. Neuropathology in IFG and pSTG were variable in bALS cases, however consistently spared in sALS. A subset of bALS cases also showed widespread tauopathy. Study three compared the anatomic distribution and types of neuropathology between 3 groups, namely: 3 bALS cases, 3 sALS with antemortem bulbar dysfunction (sALSwB), and 3 sALS without antemortem bulbar dysfunction (sALSnoB). SpN regions were most severely and extensively affected in the bALS cases, followed by sALSwB cases. Neuropathology in SpN regions was absent in sALSnoB cases. Two of the three bALS cases presented with atypical proteinopathy. Findings from the studies suggested that cortical SpN may be exclusively affected in bulbar ALS. The extent and severity of damage in SpN regions may be related to the severity of bulbar motor disease. Further, bALS may be associated with unique morphology and co-existing proteinopathy.Ph.D

Articulatory Compensation in Amyotrophic Lateral Sclerosis: Tongue and Jaw in Speech

This study investigated range, maximum speed, and duration of tongue and jaw movements in Amyotrophic Lateral Sclerosis (ALS; n=26) and healthy controls (n=16). The study objectives were to examine tongue and jaw movements and their interactions at varying stages of bulbar impairment. The patient group was classified based on the severity of bulbar impairment, via the measure of speaking rate. Kinematic measures were obtained from a sentence produced at individual's comfortable speaking rate and loudness. With ALS, the jaw movements decreased in maximum speed at a later stage of disease compared to the tongue. A positive correlation between range of tongue and jaw movements was observed at an early stage of disease. This correlation was lost at a later stage. Changes in jaw movements may be a compensatory response to tongue impairment. The findings of this study contribute to the understanding of disease progression and speech preservation in ALS.M.Sc

Speech Network Regional Differences in Bulbar Amyotrophic Lateral Sclerosis: Neuroimaging and Neuropathology Investigations

Bulbar ALS has devastating consequences on survival and quality of life, and may be linked to increased burden of extramotor deficits. This dissertation is comprised of three studies addressing the goal of better understanding the neural anatomical underpinnings of bulbar Amyotrophic Lateral Sclerosis (ALS) with a particular focus on the cortical speech network (SpN). The work has significant impact on ALS subtyping which is crucial for understanding disease pathogenesis, and clinical implications for diagnosis, prognosis, and recruitment into clinical trials. The first study characterized structural abnormalities in the SpN regions with relation to bulbar motor dysfunction using T1 and DTI neuroimaging in 16 patients with bulbar ALS. The results revealed left-lateralized differences in extramotor SpN regions with thinning in left inferior frontal gyrus (IFG) and diffusivity abnormalities underlying left primary auditory cortex (PAC) and posterior superior temporal gyrus (pSTG). Greater bulbar motor dysfunction was associated with greater structural abnormalities in selected SpN regions, while limb and disease severity were not. The second study systematically reviewed and compared published neuropathology data between bulbar-onset ALS (bALS) and spinal-onset ALS (sALS) in order to distinguish bulbar from spinal ALS. Neuropathology in IFG and pSTG were variable in bALS cases, however consistently spared in sALS. A subset of bALS cases also showed widespread tauopathy. Study three compared the anatomic distribution and types of neuropathology between 3 groups, namely: 3 bALS cases, 3 sALS with antemortem bulbar dysfunction (sALSwB), and 3 sALS without antemortem bulbar dysfunction (sALSnoB). SpN regions were most severely and extensively affected in the bALS cases, followed by sALSwB cases. Neuropathology in SpN regions was absent in sALSnoB cases. Two of the three bALS cases presented with atypical proteinopathy. Findings from the studies suggested that cortical SpN may be exclusively affected in bulbar ALS. The extent and severity of damage in SpN regions may be related to the severity of bulbar motor disease. Further, bALS may be associated with unique morphology and co-existing proteinopathy.Ph.D

Influence of Electrode Design and Lithium Source Format on the Performance Metrics of Pre-Lithiation of Anodes in an Energy Storage Device

Energy storage devices like batteries and supercapacitors, have become the crucial part of electrification of transportation. Better and more efficient energy storage devices are the need of the hour, critical to achieving this goal. In our earlier work [1,2], we have shown that several fabrication and design measures, like an advanced dry method of electrode fabrication, an optimized design of anode to cathode capacity ratio, an array of pre-lithiation methods, a composite cathode, etc., can be ingeniously combined to enhance the performance characteristics of energy storage devices in terms of specific energy (Wh.kg-1), specific power (W.kg-1), cycle life and cost. Among these performance enhancing measures, the process of pre-lithation is a necessary measure on multiple fronts, namely, to compensate for the initial cycle loss from solid electrolyte interface formation on anodes, to improve first cycle coulombic efficiency, to prevent the loss of active Li content in electrolyte and to achieve an improved cell working voltage range by initially driving the anode potential to lower permissible limits. We have also shown in our previous work [3] that an array of Li metal sources can be employed for achieving pre-lithiation through the internal short method in carbon electrodes. Over a time limited condition, we demonstrated the importance of different lithium source structures and their effect on the rate of pre-lithiation and pre-lithiation capacities that can be achieved. In our present work, we have eliminated the time limiting condition, allowing for the complete ionization of the Li-sources employed, hence enabling a complete pre-lithiation process in all Li-source formats that were employed. We have also performed a comparative study between the internal short circuit method of pre-lithiation and the external short circuit method. Different Li-source formats, based on their surface area and structure, exhibit different ionization and pre-lithiation speeds, capacities and efficiencies. Fig. 1 presents an illustration of different pre-lithiation methods organized based on their speed of pre-lithiation, with the fastest process being stabilized Li-metal powder (SLMP - leftmost) and slowest of the pre-lithiation processes occouring in lithium strip in electrode gap method and in an external short circuit method using an appropriate current limiting resistor (rightmost). On account of spherical micro nature of SLMP particles, they possess a larger active surface area for the ionization process to continue more vigorously and hence faster speed of pre-lithiation. Our analysis of reversible capacities after pre-lithiation, electrode cycle life, DC life, safety and cost aspects, etc., will also be presented. Figure 1 <jats:p /

Lithium-Ion Capacitor Safety Testing for Commercial Application

The lithium-ion capacitor (LIC) is a recent innovation in the area of electrochemical energy storage that hybridizes lithium-ion battery anode material and an electrochemical double layer capacitor cathode material as its electrodes. The high power compared to batteries and higher energy compared to capacitors has made it a promising energy-storage device for powering hand-held and portable electronic systems/consumer electronics, hybrid electric vehicles, and electric vehicles. The swelling and gassing of the LIC when subjected to abuse conditions is still a critical issue concerning the safe application in power electronics and commercial devices. However, it is imperative to carry out a thorough investigation that characterizes the safe operation of LICs. We investigated and studied the safety of LIC for commercial applications, by conducting a comprehensive abuse tests on LIC 200 F pouch cells with voltage range from 3.8 V to 2.2 V manufactured by General Capacitors LLC. The abuse tests include overcharge, external short circuit, crush (flat metal plate and blunt indentation), nail penetration test, and external heat test.</jats:p