Flexible Graphite/PPG Hybrid Composite-Based Resistive Sensor for Sensing Organic Compounds.

Our objective in this study was to investigate a sensor for volatile organic compounds based on a graphite (G)/polypropylene glycol (PPG) hybrid composite (HC) for sensing hybrid elements. The G/PPG HC sensor films for organic-matter detection were successfully fabricated on polyethylene terephthalate (PET) film with a simple blade-coating method. The sensing paste based on G/PPG (1:2) HC showed good dispersibility and stability. In addition, G/PPG HC sensor films with organic compounds showed different thickness changes as a function of the G/PPG ratio because of the swelling effect of the polymer. The observed differences in resistance of the G/PPG HC films corresponded to those of common organic compounds, suggesting that the disconnection of graphite caused by the swollen PPG matrix caused explosive resistance change. Moreover, we evaluated the sensitivity of typical hydrocarbon materials, such as benzene and toluene, in the sensor film as well as petroleum materials without moisture-induced malfunctions. This study could provoke knowledge about superior sensing with cost-effective and easily scalable materials using polymer/graphite composite-based sensors to improve the sensitivity, selectivity, and stability of chemical sensor applications.

Innovatively Continuous Mass Production Couette-taylor Flow: Pure Inorganic Green-Emitting Cs4PbBr6 Perovskite Microcrystal for display technology.

We report for the first time the mass production of Cs4PbBr6 perovskite microcrystal with a Couette-Taylor flow reactor in order to enhance the efficiency of the synthesis reaction. We obtained a pure Cs4PbBr6 perovskite solid within 3 hrs that then realized a high photoluminescence quantum yield (PLQY) of 46%. Furthermore, the Cs4PbBr6 perovskite microcrystal is applied with red emitting K2SiF6 phosphor on a blue-emitting InGaN chip, achieving a high-performance luminescence characteristics of 9.79 lm/W, external quantum efficiency (EQE) of 2.9%, and correlated color temperature (CCT) of 2976 K; therefore, this perovskite is expected to be a promising candidate material for applications in optoelectronic devices.

Long-term stable stacked CsPbBr3 quantum dot films for highly efficient white light generation in LEDs.

We report highly efficient ethyl cellulose with CsPbBr3 perovskite QD films for white light generation in LED application. Ethyl cellulose with CsPbBr3 quantum dots is applied with Sr2Si5N8 : Eu2+ red phosphor on an InGaN blue chip, achieving a highly efficient luminous efficacy of 67.93 lm W-1 under 20 mA current.

Effective passivation of Ag nanowire-based flexible transparent conducting electrode by TiO2 nanoshell.

Silver nanowire-based flexible transparent electrodes have critical problem, in spite of their excellent electrical and optical properties, that the electrical conductance and transparency degrade within several days in air because of oxidation of silver. To prevent the degradation of the silver nanowire, we encapsulated Ag-NWs with thin TiO2 barrier. Bar-coated silver nanowires on flexible polymer substrate were laminated at 120 °C, followed by atomic layer deposition of TiO2 nanoshell. With 20 nm of TiO2 nanoshells on silver nanowires, the transparent electrode keeps its electrical and optical properties over 2 months. Moreover, the TiO2-encapsulated silver nanowire-based transparent electrodes exhibit excellent bending durability.

Short-term effect of botulinum toxin a injection on spastic equinovarus foot in cerebral palsy patients: a study using the foot pressure measurement system.

OBJECTIVE: To evaluate the therapeutic effect of botulinum toxin A (BTX-A) injection on spastic gastrocnemius (GCM) and tibialis posterior muscles (TPo) by using the foot pressure measurement system (FPMS). METHODS: Eighteen ambulatory CP patients were recruited in this study. BTX-A was injected into the GCM at a dose of 6-12 units/kg and TPo at a dose of 4-9 units/kg according to the severity of equinus and varus deformity. Foot contact pattern, pressure time integral (PTI), coronal index using the FPMS and Modified Ashworth Scale (MAS), and visual inspection of gait pattern were used for evaluation of the therapeutic effect of BTX-A injection. Clinical and FPMS data were statistically analyzed according to the muscle group. RESULTS: A significant decrease in the MAS score of the GCM and TPo was observed, and spastic equinovarus pattern during gait showed improvement after injection. The GCM+TPo injection group showed a significant decrease in forefoot, lateral forefoot pad, and lateral column PTI, and a significant increase in hindfoot PTI and coronal index. In the GCM only injection group, forefoot PTI and lateral column PTI were significantly decreased and hindfoot PTI was significantly increased. The TPo only injection group showed a significant decrease in lateral column PTI and a significant increase in the coronal index. Change in PTI in the hindfoot showed a significant correlation with the change in MAS score of the GCM. Change in PTI of the lateral column and coronal index showed a significant correlation with the change in MAS score of the TPo. CONCLUSION: The FPMS demonstrated the quantitative therapeutic effect of BTX-A on abnormal pressure distribution in equinovarus foot in detail. The FPMS can be a useful additional tool for evaluation of the effect of BTX-A injection.

Characteristics of injury of the corticospinal tract and corticoreticular pathway in hemiparetic patients with putaminal hemorrhage.

BACKGROUND: No study on the characteristics of injury of the corticospinal tract (CST) or corticoreticular pathway (CRP) in patients with putaminal hemorrhage has been reported. In this study, using diffusion tensor tractography, we attempted to investigate the characteristics of injury of the CST and CRP in hemiparetic patients with putaminal hemorrhage. METHOD: Fifty seven consecutive patients with putaminal hemorrhage and 57 healthy control subjects were recruited for this study. Diffusion tensor imaging was performed during the early period (8 ~ 30 days) after onset. We defined injury of the CST or CRP in terms of the configuration (discontinuation of a neural tract) or abnormal DTT parameters (the fractional anisotrophy value or fiber number was more than two standard deviations lower than that of normal control subjects). The Motricity Index, the modified Brunnstrom Classification, and the Functional Ambulation Categories were used for evaluation of motor function. RESULTS: Among 57 patients, injury of the CST was found in 41 patients (71.9%) and injury of the CRP was found in 50 patients (87.8%), respectively, and 37 patients (64.9%) had injury of both the CST and CRP. All three motor functions of patients with injury of both the CST and CRP were significantly lower than those of patients with injury of either the CST or CRP (p < 0.05). CONCLUSION: Our results indicate that the putaminal hemorrhage frequently accompanies injury of both the CST and CRP, and the CRP appears to be more vulnerable to putaminal hemorrhage than the CST. These findings suggest the necessity for evaluation of both the CRP and the CST in patients with putaminal hemorrhage.

Relation between cognition and neural connection from injured cingulum to brainstem cholinergic nuclei in chronic patients with traumatic brain injury.

BACKGROUND: This study investigated the relation between cognition and the neural connection from injured cingulum to brainstem cholinergic nuclei in patients with traumatic brain injury (TBI), using diffusion tensor tractography (DTT). METHODS: Among 353 patients with TBI, 20 chronic patients who showed discontinuation of both anterior cingulums from the basal forebrain on DTT were recruited for this study. The Wechsler Intelligence Scale and the Memory Assessment Scale (MAS; short-term, verbal, visual and total memory) were used for assessment of cognition. Patients were divided into two groups according to the presence of a neural connection between injured cingulum and brainstem cholinergic nuclei. RESULTS: Eight patients who had a neural connection between injured cingulum and brainstem cholinergic nuclei showed better short-term memory on MAS than 12 patients who did not (p < 0.05). However, other results of neuropsychological testing showed no significant difference (p > 0.05). CONCLUSIONS: Better short-term memory in patients who had the neural connection between injured cingulum and brainstem cholinergic nuclei appears to have been attributed to the presence of cholinergic innervation to the cerebral cortex through the neural connection instead of the injured anterior cingulum. The neural connection appears to compensate for the injured anterior cingulum in obtaining cholinergic innervation.