Effect of Non-invasive Spinal Stimulation on Self-sustained Firing Motoneuron Model: In-Silico Study Using Human Body Model.

Transcutaneous spinal electrical stimulation (tSCS) is a non-invasive neuromodulation approach using a low intensity direct current. Recent developments in the technique have opened the possibility that tSCS can help restore motor function after spinal cord injury (SCI). However, the exact mechanism of action tSCS has on the spinal circuits is still unknown. Due to the complexity of experimental synthesis in a human model to delineate the mechanisms, models that link the stimulation paradigm and circuit behaviors are advantageous. Thus, this study aims to simulate the underlying changes in motor circuit firing rates in response to external stimuli induced by tSCS. Serial stimulations combining a high-fidelity finite element model with the human torso and spinal cord with a lumped motor neuron model is constructed. The parameters for both components of the model were derived from previous studies. We focused our analysis on a lumped motor neuron model that describes sustained firing behavior of the motor neuron driven primarily by persistent inward current (PIC), a signature behavior of the motor neuron after SCI. Modulation of the PIC behaviors was achieved by stimulating voltage-dependent calcium and sodium channels in the dendrite using a tSCS-induced electric field (E-field) expressed at different a spatial locations of the motor neuron in the gray matter. The PIC behaviors of spinal motor neurons in the left ventral horn were suppressed, while for the most part invariant in the right ventral horn. These initial simulations will provide a steppingstone for future examinations that incorporate additional neuronal models of inhibitory and excitatory interneurons to access the circuit-level effect of spinal stimulation.

Shoulder pain and ultrasound findings: A comparison study of wheelchair athletes, nonathletic wheelchair users, and nonwheelchair users.

BACKGROUND: Shoulder pain is one of the most common musculoskeletal concerns in manual wheelchair users including among athletes. However, there is a paucity of research characterizing both shoulder pain and shoulder pathology in this population. OBJECTIVE: To characterize and compare the prevalence of current shoulder pain and ultrasound metrics of shoulder pathology between wheelchair athletes, nonathletic wheelchair users, and nonwheelchair users. DESIGN: Cross-sectional. SETTING: Chicago-area adaptive sport teams/programs and musculoskeletal clinics. PARTICIPANTS: Thirty-four wheelchair athletes, six nonathletic wheelchair users, and 12 nonwheelchair users. METHODS: Self-reported shoulder pain was assessed by questionnaire and Wheelchair User Shoulder Pain Index (WUSPI). Shoulder physiology and pathology were assessed by physical and ultrasound evaluation of both shoulders by a sports medicine physician. MAIN OUTCOME MEASURES: Questionnaire outcomes: Prevalence of current shoulder pain, total WUSPI score. Physical examination outcomes: total Physical Examination of Shoulder Scale (PESS) score. Sonographic outcomes: Acromiohumeral distance (AHD) and presence of shoulder pathology. RESULTS: The majority of wheelchair athletes (68%) and nonathletic wheelchair users (67%) experienced shoulder pain since using a manual wheelchair. Wheelchair basketball players had a mean WUPSI score of 17.2 (SD = 21.8), and athletes participating in handcycling, sled hockey, and quad rugby had mean scores of 4.91 (SD = 8.32), 7.76 (SD = 13.1), and 4.29 (SD = 7.75), respectively. Shoulder pathology was observed in 14 of 31 (45%) wheelchair athletes and 4 of 6 (67%) nonathletic wheelchair users (p = .41). CONCLUSIONS: Although wheelchair use is a risk factor for shoulder pain, participation in amateur wheelchair sports may not be associated with increased risk of shoulder pain. It is possible that overhead sports such as wheelchair basketball may define a unique high-risk group. Further study is needed to examine this relationship and to determine whether there are differences between specific wheelchair sports.

Modulation of the clinically accessible gelation time using glucono-d-lactone and pyridoxal 5'-phosphate for long-acting alginate in situ forming gel injectable.

The purpose of this study was to design alginate in situ forming gel (ISFG) injectable with clinically acceptable gelation time and controlled release of hydrophobic drug. Milled or unmilled paliperidone palmitate (PPP) was used. The gelation time was controlled by varying the ratios of glucono-d-lactone (GDL) and pyridoxal 5'-phosphate (PLP) in prefilled alginate solution mixtures (ASMs) containing PPP, CaCO3, GDL and PLP for clinically acceptable injectability. However, the gelation time was varied by the alginate type (M/G ratio), storage condition, and drug solubilizers. This ISFG exhibited 32.15 kPa of the maximal compressive stress without causing pain and stiffness. The ISFG containing conically milled PPP released PPP in a controlled manner without exhibiting any initial burst release for 4 weeks. The current alginate ISFG injectable using new combination of PLP and GDL could be used to deliver long-acting injectable drugs.

Fecitrate converted from Fe2O3 particles in coal-fired flue gas promoted microalgal biomass and lipid productivities.

In order to reutilize Fe2O3 particles in flue gas from coal-fired power plant as a ferrum nutrient for improving microalgae growth, Na-Citrate was proposed to chelate FeCl3 derived from Fe2O3 and HCl reactions to promote biomass and lipid productivities of Chlorella PY-ZU1. Fe-Citrate gave much higher biomass and lipid productivities than FeCl3, Fe-EDTA, Fe-DTPA and Fe-HEDTA, because organic chelator prevented Fe3+ from depositing, lower stability constant resulted in easier dissociation of ferric chelate, smaller chelate facilitated Fe2+ (reduced from Fe3+) transportation through cell membranes. The biomass growth and photosynthetic capacity of Chlorella PY-ZU1 cultivated with Fe-Citrate (converted from Fe2O3 particles) medium were similar to those with commercial ferric ammonium citrate medium. The biomass and lipid productivities of Chlorella PY-ZU1 cultivated with 5 mg L-1 Fe-Citrate medium were 1.30 and 1.72 times, respectively, higher than those with FeCl3 growth medium.

Enhancing microalgal biomass productivity with an optimized flow field generated by double paddlewheels in a flat plate photoreactor with CO2 aeration based on numerical simulation.

Computational fluid dynamics were used to analyze the flash light effect and CO2 bubble behavior in an optimized flow field generated by double paddlewheels in a flat plate photoreactor to enhance microalgal biomass productivity. The increased D/w ratio significantly enhanced the average turbulent kinetic energy and flash cycle frequency. However, the effects became weak when the D/w ratio was over 0.67. Appliance of double paddlewheels increased flash cycle frequency from 0.035 to 0.121 Hz and increased light time ratio from 8.3% to 31.5%. Meanwhile, the bubble dynamic behavior was characterized using population balance model. The average bubble size reduced by 24.4% and the bubble rising velocity reduced by 10.6%, which facilitated CO2 mixing and mass transfer in microalgal solution. Therefore, biomass accumulation of microalgae Chlorella in the photoreactor with double paddlewheels increased by 62.3% under 15% CO2.

The Role of Plasmacytoid Dendritic Cells in Gut Health.

Plasmacytoid dendritic cells (pDCs) are a unique subset of cells with different functional characteristics compared to classical dendritic cells. The pDCs are critical for the production of type I IFN in response to microbial and self-nucleic acids. They have an important role for host defense against viral pathogen infections. In addition, pDCs have been well studied as a critical player for breaking tolerance to self-nucleic acids that induce autoimmune disorders such as systemic lupus erythematosus. However, pDCs have an immunoregulatory role in inducing the immune tolerance by generating Tregs and various regulatory mechanisms in mucosal tissues. Here, we summarize the recent studies of pDCs that focused on the functional characteristics of gut pDCs, including interactions with other immune cells in the gut. Furthermore, the dynamic role of gut pDCs will be investigated with respect to disease status including gut infection, inflammatory bowel disease, and cancers.