Polymerized Thermally Activated Delayed-Fluorescence Small Molecules: Long-Axis Polymerization Leads to a Nearly Concentration-Independent Luminescence.

Nowadays numerous thermally activated delayed fluorescence (TADF) polymers have been developed for PLEDs to realize high device performance and tunable emission colors. However, they often possess a strong concentration dependence on their luminescence including aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE). Herein, we first report a nearly concentration-independent TADF polymer based on the strategy of polymerized TADF small molecules. It is found that when a donor-acceptor-donor (D-A-D) type TADF small molecule is polymerized through its long-axis direction, the triplet state is distributed along the polymeric backbone to effectively suppress the unwanted concentration quenching. Unlike the short-axis one with an ACQ effect, the photoluminescent quantum yield (PLQY) of the resultant long-axis polymer remains almost unchanged with the increasing doping concentration. Accordingly, a promising external quantum efficiency (EQE) up to 20 % is successfully achieved in a whole doping control window of 5-100 wt. %.

Incidence of recurrent seizures following hospital discharge in patients with LPDs (PLEDs) and nonconvulsive seizures recorded on continuous EEG in the critical care setting.

PURPOSE: Continuous EEG (cEEG) has helped to identify nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE) along with lateralized periodic patterns (LPDs or PLEDs) in ICU patients with much higher frequency than previously appreciated, but understanding their implications may be more complex. The aim of this study was to investigate the incidence of recurrent seizures after hospital discharge and their associated factors in patients with PLEDs and NCS in the critical care setting. METHODS: After IRB approval, we used our EEG reporting database to find 200 consecutive patients who had PLEDs and/or NCSs on cEEG. Patients with less than 3 months of follow-up were excluded. Remaining patients were divided into three groups: PLEDs+Seizure (NCS/NCSE), PLEDs only, and Seizures (NCS/NCSE) only. Medical records were reviewed to gather demographical and clinical details. Univariate data analysis was done using JMP 9.0 (Marlow, Buckinghamshire, UK). RESULTS: There were 51 patients in 'PLEDs+Seizure' group, 45 in 'PLEDs only' group, and 22 in 'Seizure only' group. Ischemic stroke, hemorrhage, and tumors were the top three etiologies. Nearly 47% of our study population had postdischarge seizures during a mean follow-up period of 11.9 (+/-6) months. We found that 24.4% of patients in the PLEDs only group had seizures after discharge, which increased to 60.7% if they had seizures as well during their ICU stay. Slightly more than 52% of patients had a postdischarge EEG, of which, 59% was in the form of inpatient cEEG during a rehospitalization, accounting for 30.5% of the total study population. It was an indicator of high readmission rates in this population. CONCLUSION: Almost every other patient with PLEDs and/or NCS on cEEG had seizures after ICU discharge. A quarter of patients on cEEG in the ICU with PLEDs alone had seizures after discharge, and after excluding prior epilepsy, 17% of patients with PLEDs had seizures on follow-up. This was dramatically increased with the recording of PLEDs with NCS, with 60% of patients having seizures after discharge from the ICU and 48% of patients after excluding prior epilepsy. Patients with NCS on cEEG alone had 63% chance of seizure recurrence that dropped to 38% with exclusion of prior epilepsy. Future studies are needed to define the postdischarge outcomes including seizure recurrence in this patient population. This article is part of a Special Issue entitled "Status Epilepticus".

Periodic Epileptiform Discharges Clarified for the Nonneurologist Intensivist: Clinical Implications and Current Management.

Periodic epileptiform discharges (PEDs) are frequently encountered during continuous electroencephalography monitoring in the intensive care unit. Their implications and management are variable and highly dependent on the clinical context. This article is intended for the nonneurologist intensivist, reviews basic terminology and clinical implications (including causes, prognosis, and association with seizures), and suggests an approach to management. Several case vignettes are included to illustrate the clinical variability associated with PEDs.

Interrater agreement for Critical Care EEG Terminology.

OBJECTIVE: The interpretation of critical care electroencephalography (EEG) studies is challenging because of the presence of many periodic and rhythmic patterns of uncertain clinical significance. Defining the clinical significance of these patterns requires standardized terminology with high interrater agreement (IRA). We sought to evaluate IRA for the final, published American Clinical Neurophysiology Society (ACNS)-approved version of the critical care EEG terminology (2012 version). Our evaluation included terms not assessed previously and incorporated raters with a broad range of EEG reading experience. METHODS: After reviewing a set of training slides, 49 readers independently completed a Web-based test consisting of 11 identical questions for each of 37 EEG samples (407 questions). Questions assessed whether a pattern was an electrographic seizure; pattern location (main term 1), pattern type (main term 2); and presence and classification of eight other key features ("plus" modifiers, sharpness, absolute and relative amplitude, frequency, number of phases, fluctuation/evolution, and the presence of "triphasic" morphology). RESULTS: IRA statistics (κ values) were almost perfect (90-100%) for seizures, main terms 1 and 2, the +S modifier (superimposed spikes/sharp waves or sharply contoured rhythmic delta activity), sharpness, absolute amplitude, frequency, and number of phases. Agreement was substantial for the +F (superimposed fast activity) and +R (superimposed rhythmic delta activity) modifiers (66% and 67%, respectively), moderate for triphasic morphology (58%), and fair for evolution (21%). SIGNIFICANCE: IRA for most terms in the ACNS critical care EEG terminology is high. These terms are suitable for multicenter research on the clinical significance of critical care EEG patterns. A PowerPoint slide summarizing this article is available for download in the Supporting Information section http://dx.doi.org/10.1111/epi.12653/supinfo.

"Ictal" lateralized periodic discharges.

OBJECTIVE: Whether lateralized periodic discharges (LPDs) represent ictal or interictal phenomena, and even the circumstances in which they may represent one or the other, remains highly controversial. Lateralized periodic discharges are, however, widely accepted as being ictal when they are time-locked to clinically apparent symptoms. We sought to investigate the characteristics of "ictal" lateralized periodic discharges (ILPDs) defined by time-locked clinical symptoms in order to explore the utility of using this definition to dichotomize LPDs into "ictal" and "nonictal" categories. METHODS: Our archive of all continuous EEG (cEEG) reports of adult inpatients undergoing prolonged EEG monitoring for nonelective indications between 2007 and 2011 was searched to identify all reports describing LPDs. Lateralized periodic discharges were considered ILPDs when they were reported as being consistently time-locked to clinical symptoms; LPDs lacking a clear time-locked correlate were considered to be "nonictal" lateralized periodic discharges (NILPDs). Patient charts and available neuroimaging studies were also reviewed. Neurophysiologic localization of LPDs, imaging findings, presence of seizures, discharge outcomes, and other demographic factors were compared between patients with ILPDs and those with NILPDs. p-Values were adjusted for false discovery rate (FDR). RESULTS: One thousand four hundred fifty-two patients underwent cEEG monitoring at our institution between 2007 and 2011. Lateralized periodic discharges were reported in 90 patients, 10 of whom met criteria for ILPDs. Nine of the patients with ILPDs demonstrated motor symptoms, and the remaining patient experienced stereotyped sensory symptoms. Ictal lateralized periodic discharges had significantly increased odds for involving central head regions (odds ratio [OR]=11; 95% confidence interval [CI]=2.16-62.6; p=0.018, FDR adjusted), with a trend towards higher proportion of lesions involving the primary sensorimotor cortex (p=0.09, FDR adjusted). CONCLUSIONS: When defined by the presence of a time-locked clinical correlate, ILPDs appear to be strongly associated with a central EEG localization. This is likely due to cortical irritability in central head regions having greater propensity to manifest with positive, clinically apparent, and time-locked symptoms. Thus, dichotomization of ILPDs and NILPDs on this basis principally reflects differences in underlying anatomical locations of the periodic discharges rather than providing a clinically salient categorization.

Fluorescent Aromatic Polyether Sulfones: Processable, Scalable, Efficient, and Stable Polymer Emitters and Their Single-Layer Polymer Light-Emitting Diodes.

In this study, fully aromatic polyether sulfones were developed, bearing blue, yellow, and orange-red π-conjugated semiconducting units. Carbazole-, anthracene-, and benzothiadiazole-based fluorophores are copolymerized with a diphenylsulfone moiety. A diphenylpyridine comonomer was additionally utilized, acting as both a solubilizing unit and a weak blue fluorescent group. Using this rationale, fluorescent polyarylethers with high molecular weights, up to 70 kDa, were developed, showing film formation ability and high thermal stability, while preserving excellent solubility in common organic, nonvolatile, and nonchlorinated solvents. Fine-tuning of the emission color was achieved through subtle changes of the comonomers' type and ratio. Single-chromophore-bearing copolymers emitted in the blue or the yellow region of the visible spectrum, while the dual-chromophore-bearing terpolymers emitted throughout the visible spectrum, resulting in white light emission. Solutions of 20 wt% in polar aprotic solvents at ambient conditions allowed the deposition of fluorescent copolyethers and printing from non-chlorinated solvents. All polyethers were evaluated for their structural and optoelectronic properties, and selected copolymers were successfully used in the emitting layer (EML) of organic light-emitting diode (OLED) devices, using either rigid or flexible substrates. Remarkable color stability was displayed in all cases for up to 15 V of bias voltage. The Commission Internationale de L'Eclairage (CIE) of the fabricated devices is located in the blue (0.16, 0.16), yellow (0.44, 0.50), or white region of the visible spectrum (0.33, 0.38) with minimal changes according to the ratio of the comonomers. The versatile methodology toward semiconducting polyethersulfones for polymer light-emitting diodes (PLEDs) developed herein led to the scaled-up production of luminescent polymers of up to 25 g of high-molecular-weight single batches, demonstrating the effectiveness of this approach as a straightforward tool to facilitate the synthesis of flexible and printable EMLs for large-area PLED coverage.

Prolonged ictal monoparesis with parietal Periodic Lateralised Epileptiform Discharges (PLEDs).

We report a patient with prolonged monoparesis and parietal periodic lateralised epileptiform discharges (PLEDs). The patient was a 73-year-old man with chronic myelomonocytic leukaemia who developed persisting monoparesis of the right arm, sensory aphasia, and finger agnosia, initially associated with focal clonic seizures. These neurological deficits remained for seven days without subsequent focal clonic seizures. The EEG showed left-sided PLEDs, maximal in the left occipito-parietal area. Ten days later, following phenytoin treatment, these symptoms suddenly improved and parietal PLEDs disappeared. Sustained PLEDs in the left parietal region may have been causally associated with ictal paresis in this patient.

Hyperbranched Conjugated Polymer with Multiple Charge Transfer Enables High-Efficiency Nondoped Red Electroluminescence with Low Driving Voltage.

Conjugated polymers featuring thermally activated delayed fluorescence (TADF) attract tremendous attention in both academic and industry communities due to their easy solution processing for fabricating large-area and low-cost high-performance polymer light-emitting diodes (PLEDs). However, current nondoped solution-processed PLEDs frequently encounter significant efficiency roll-offs and unreasonably high operating voltages at high brightness, especially for red-emitting polymers. Herein, we design hyperbranched conjugated polymers (HCPs) with D-A-D type TADF characteristics for high-performance red-emitting PLEDs. Multiple intramolecular charge transfer (ICT) channels induced by quasi-equivalent donors of the TADF core strongly boost the reverse intersystem crossing (RISC) process and singlet excitons radiative transition. Coupling with the efficient energy transfer process generated by structure advantages of HCPs, the strongly electron-withdrawing oxygen atoms located on the TADF cores further accelerate hole transportation from the host chains to the TADF cores. Under a rational regulation of the TADF core ratio, the related nondoped red-emitting device performs an outstanding performance with an EQEmax of 8.39% and exhibits no roll-off while the luminance is less than 100 cd/m2 and only 3.3% decrease at 500 cd/m2. Simultaneously, the EQE can maintain 7.4% under 1000 cd/m2. Furthermore, the corresponding nondoped device exhibits a low turn-on voltage of around 2.5 V and achieves a luminance of 500 cd/m2 at 3.5 V and even 1000 cd/m2 at 3.9 V. To our knowledge, this is the best performance among all nondoped red PLEDs with high brightness obtained at low operating voltage.

Association Between Lateralized Periodic Discharge Amplitude and Seizure on Continuous EEG Monitoring in Patients With Structural Brain Abnormality in Critical Illness.

Objective: To investigate the association between lateralized periodic discharge (LPD) amplitude and seizure risk on an individual level in patients with structural brain abnormality. Methods: Retrospective case-control study of patients with structural brain abnormality undergoing continuous EEG monitoring was performed. We included 10 patients with LPDs and seizures as cases and 10 controls, patients with LPDs without seizure. Analysis was performed with a mixed-effects model with primary outcome measure of number of seizures per 8-h EEG epoch with fixed effects being variables of interest and random effect being subject ID. Results: Epochs with seizures showed a higher absolute amplitude (corrected p = 0.04) and a higher relative amplitude (corrected p = 0.04) of LPDs. Additionally, the number of seizures was higher in epochs that had LPDs with plus features (uncorrected p = 0.002) and LPDs with higher relative amplitude (uncorrected p = 0.005). Conclusion: Higher LPD amplitude is associated with increased risk of seizures on an individual patient level. A decreasing amplitude is suggestive of decreasing seizure risk, and may in fact be suggestive of decreasing ictal character of LPDs.

Role of diagnostic imaging in Rasmussen's encephalitis - A case report from Nepal.

Rasmussen's encephalitis (RE) is a relatively rare chronic inflammatory neurological disease that usually only affects one hemisphere of the brain. It primarily affects children under the age of 10, although it can also affect teens and adults, causing drug-resistant seizures, progressive hemiparesis, and dementia. RE presents as a challenging diagnosis with MRI as the cornerstone of the evaluation and nuclear imaging as a complementary tool. We'd like to present a case of a 12-year-old girl who was diagnosed with RE after an MRI. In this study, we examine the diagnostic criteria, differential diagnoses, and issues that underpin the diagnostic challenge in great detail.

LPDs - «Linked to penumbra¼ discharges or EEG correlate of excitotoxicity: A review based hypothesis.

Periodic lateralized epileptiform discharges (PLEDs) or lateralized periodic discharges (LPDs) are a well-known variant of pathological EEG activity. However, the mechanisms underpinning the appearance of this pattern are not completely understood. The heterogeneity of the features derived from LPDs patterns, and the wide range of pathological conditions in which they occur, raise a question about the unifying mechanisms underlying these phenomena. This paper reassesses the current opinion surrounding LPDs which considers glutamate excitotoxicity to be the primary pathophysiological basis, and the penumbral region to be the main morphological substrate. Arguments in favour of this hypothesis are presented, with interpretations supported by evidence from recent literature involving clinical and experimental data. Presently, no single hypothesis places considerable emphasis on the pathochemical properties of LPDs, which are implicitly meaningful towards better understanding of the clinical significance of this pattern.

Inkjet Printing of an Electron Injection Layer: New Role of Cesium Carbonate Interlayer in Polymer OLEDs.

Among solution-processable techniques, inkjet printing is a potential method for manufacturing low-cost and high-resolution polymer organic light-emitting diodes (PLEDs) for displays/solid-state lighting applications. Herein, we demonstrate use of the inkjet printed cesium carbonate (Cs2CO3) film as an electron injection interlayer. We have elaborated the Cs2CO3 ink using an alcohol-based solvent for the industrial-grade printhead. The printed Cs2CO3 layer morphology was investigated by means of an optical microscope and an atomic force microscope. The PLEDs based on emissive polymer (Super Yellow) with printed Cs2CO3 interlayer show a remarkable current efficiency and luminance compared to the PLEDs made without the Cs2CO3 layer. Such results suggest that the Cs2CO3 is a promising material for the formulation of the electron injecting inkjet inks. The possibility of inkjet printing of an efficient electron injecting layer enables in situ patterning of PLEDs' emission area. Such a simple and flexible technique can be applied for a wide range of applications such as signage, pictograms, advertising, smart packaging, etc.

Clinical neurophysiology of stroke.

Stroke constitutes the third most common cause of death and the leading cause of acquired neurologic handicap. During ischemic stroke, very early after the onset of the focal perfusion deficit, excitotoxicity triggers a number of events that can further contribute to tissue death. Such events include peri-infarct depolarizations and spreading depolarizations (SDs) within the ischemic penumbra. SDs spread slowly through continuous gray matter at a typical velocity of 2-5mm/min. SDs exacerbate neuronal injury through prolonged ionic breakdown and SD-related hypoperfusion (spreading ischemia). Scalp EEG alone is not yet sufficient to reliably diagnose SDs. Hyperexcitability occurs in parallel, both in the acute and chronic phases of stroke. Stroke is a common cause of new-onset epileptic seizures after middle age and is the leading cause of symptomatic epilepsy in adults. The last part of this chapter is dedicated to noninvasive neurophysiologic techniques that can be used to promote stroke rehabilitation. These techniques mainly include repetitive transcranial magnetic stimulation and tDCS. These approaches are based on the concept of interhemispheric rivalry and aim at modulating the imbalance of cortical activities between both hemispheres resulting from stroke.

Doping of Tetraalkylammonium Salts in Polyethylenimine Ethoxylated for Efficient Electron Injection Layers in Solution-Processed Organic Light-Emitting Devices.

For efficient electron injection, a method to control the work functions (WFs) of ZnO electrodes in organic light-emitting devices (OLEDs) is reported in this study. First, ZnO was modified by doping of tetraalkylammonium salts (TRAX) into polyethylenimine ethoxylated (PEIE) for the WF control. Tetrabutylammonium salts (TBAX), where X = chloride, bromide, iodide, acetate, thiocyanate, and tetrafluoroborate anions, were doped into PEIE. A WF of nondoped PEIE-modified ZnO was 3.65 eV, whereas TBAX-doped PEIE-modified ZnO exhibited WFs ranging from 3.52 to 3.00 eV depending on the anion. TBAX salts exhibited different electron-donating capabilities depending on the anion, and the doping of TBAX with a large electron-donating capability exhibited a large WF reduction effect. In addition, tetraethyl- and tetrahexylammonium chlorides were doped into PEIE. PEIE doped with TRACl containing long alkyl chains exhibited a large WF reduction effect due to its low electron-accepting capabilities. In addition, the WF reduction mechanism was considered by the depth direction analysis of the PEIE:TBAX films. Finally, the ZnO/PEIE:TRAX bilayers were applied as electron injection layers in poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] emissive-layer-based OLEDs with an inverted structure. The ZnO/PEIE:TBAX devices with low WFs exhibited low driving voltages.

Efficient Red Phosphorescent Polymers with Trap-Assisted Charge Balance: Molecular Design, Synthesis, and Electroluminescent Properties.

Three classes of red phosphorescent polymers (PF-H- x, PF-DPO- x, and PF-DPA- x, where x denotes the mole content of Ir complex) have been designed and synthesized, where the C∧N ligand of the tethered dopant bis(2,4-diphenylquinolyl)iridium(acetylacetonate) is substituted by hydrogen (H), diphenylphosphine oxide (DPO), and diphenylamine (DPA), respectively. It is found that the electron-withdrawing DPO group can lower the lowest unoccupied molecular orbital (LUMO) level of the phosphor, whereas the electron-donating DPA group leads to an upshifted highest occupied molecular orbital (HOMO) level of the phosphor. Following a sequence of PF-DPA- x, PF-H- x, and PF-DPO- x, the electron trap depth between dopant and host is gradually up from 0.43 to 1.01 eV, and the hole trap depth is correspondingly down from 0.74 to 0.46 eV. As a result, PF-DPO- x achieves the most balanced charge transport in the emitting layer among these polymers, revealing a record-high luminous efficiency (LE) of 10.3 cd/A and Commission Internationale de L'Eclairage (CIE) coordinates of (0.62, 0.33) on the basis of the simple single-layer device structure. Compared with PF-H- x (3.8 cd/A) and PF-DPA- x (1.2 cd/A) containing the same Ir content, the significantly improved performance indicates that trap-assisted charge balance is a promising strategy to optimize the device efficiency of red phosphorescent polymers.

Periodic focal epileptiform discharges.

OBJECTIVE: To report intraoperative periodic focal epileptiform discharges (PFEDs) during awake craniotomy using high-density electrocorticography (HD-ECoG). METHODS: We retrospectively analyzed 81 patients undergoing awake craniotomy between 9/29/2016 and 7/5/2018. Intraoperative HD-ECoG was performed with direct electrocortical stimulation (DECS) for functional brain mapping. Real-time interpretation was performed and compared to scalp EEG when performed. Perioperative seizures, surgical complications, and characteristics of PFEDs were assessed. RESULTS: 69/81 patients (mean age 48.5 years) underwent awake surgery; 55 operated for brain tumor, 11 for epilepsy and 3 for cavernomas. A focal abnormality on brain MRI was present in 63/69 (91.3%) patients. 43/69 (62.3%) patients had seizures preoperatively, 4/69 (5.7%) had seizures during DECS. PFEDs were identified in 11 patients (15.9%); 2 on depth recording and 9 during intraoperative HD-ECoG. 32 patients (46.3%) had preoperative EEG. HD-ECoG detected more epileptiform discharges (EDs) than standard EEG (32/43; 74.4% vs 9/32; 28.1%) (p = <0.001). Of 9/43 patients with PFEDs on HD-ECoG, 7 patients also had scalp EEG but only one case had EDs (p = 0.02), and 0/32 had periodic EDs. CONCLUSIONS: Intraoperative PFEDs are novel, highly focal EDs approximating a single gyrus. In patients with brain tumors, PFEDs did not demonstrate a relationship to pre-operative seizures though has similarities to other common waveforms in patients with epilepsy. SIGNIFICANCE: PFEDs expand our understanding of the interictal-ictal continuum and highlight improved temporo-spatial information obtained from increasing sensor density during intracranial EEG recording.

Mesial temporal extraventricular neurocytoma (mtEVN): A case report and literature review.

AIM: We describe a case of mesial temporal extraventricular neurocytoma (mtEVN) in a 23-year-old male presenting with drug-resistant seizures and review the literature on this rare tumor. METHODS: A PubMed search was queried using the MeSH term "neurocytoma" and key search terms "extraventricular", "temporal", and "epilepsy". Titles and abstracts were screened for temporal neurocytomas. References were reviewed to identify further studies. RESULTS: Twenty case reports were selected comparing the presentation, radiological, histopathological, and surgical outcomes of neocortex temporal EVNs (ntEVN) and mtEVNs. CONCLUSION: Gross total resection of mtEVNs under intraoperative electrocorticography monitoring typically affords an excellent prognosis and successful seizure control.

Role of Bimolecular Exciton Kinetics in Controlling the Efficiency of Organic Light-Emitting Diodes.

Here, we have carried out a spectroscopic investigation on the operational organic light-emitting diodes (OLEDs) to determine the role of emission layer thickness on the optoelectronic performance of OLEDs based on a poly(9,9-dioctylfluorene- alt-benzothiadiazole) (F8BT) copolymer system. Our study shows that delayed fluorescence (DF) via triplet-triplet annihilation (TTA) contributes significantly to boost the OLED efficiency through its fractional contribution. Interestingly, we note that DF contribution varies as a function of the emissive layer thickness. From the time-resolved electroluminescence (TREL) and triplet absorption (under electrical excitation) studies, we have seen that the emissive layer thickness controls triplet exciton generation and decay processes. From TREL, we have also shown that singlet-triplet annihilation (STA) is the dominant fluorescence quenching mechanism in bulk of the emissive layer, whereas thinner devices have significant exciton quenching at the interface of the injection layer/F8BT. The strength of STA differs in thin versus thick samples, which has been correlated with the spectral & spatial overlap integral of singlet and triplet states. Hence, STA strength and triplet population density are critical parameters for an explanation of high efficiency in unusually thick F8BT OLEDs.

Effect of Nonionic Surfactant Additive in PEDOT:PSS on PFO Emission Layer in Organic-Inorganic Hybrid Light-Emitting Diode.

Poly(9,9-dioctylfluorene) (PFO) has attracted significant interests owing to its versatility in electronic devices. However, changes in its optical properties caused by its various phases and the formation of oxidation defects limit the application of PFO in light-emitting diodes (LEDs). We investigated the effects of the addition of Triton X-100 (hereinafter shortened as TX) in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) to induce interlayer diffusion between PEDOT:PSS and PFO to enhance the stability of the PFO phase and suppress its oxidation. Photoluminescence (PL) measurement on PFO/TX-mixed PEDOT:PSS layers revealed that, upon increasing the concentration of TX in the PEDOT:PSS layer, the ß phase of PFO could be suppressed in favor of the glassy phase and the wide PL emission centered at 535 nm caused by ketone defects formed by oxidation was decreased considerably. LEDs were then fabricated using PFO as an emission layer, TX-mixed PEDOT:PSS as hole-transport layer, and zinc oxide (ZnO) nanorods as electron-transport layer. As the TX concentration reached 3 wt %, the devices exhibited dramatic increases in current densities, which were attributed to the enhanced hole injection due to TX addition, along with a shift in the dominant emission wavelength from a green electroluminescence (EL) emission centered at 518 nm to a blue EL emission centered at 448 nm. The addition of TX in PEDOT:PSS induced a better hole injection in the PFO layer, and through interlayer diffusion, stabilized the glassy phase of PFO and limited the formation of oxidation defects.

Periodic Lateralized Epileptiform Discharges can Survive Anesthesia and Result in Asymmetric Drug-induced Burst Suppression.

Drug-induced burst suppression (DIBS) is bihemispheric and bisymmetric in adults and older children. However, asymmetric DIBS may occur if a pathological process is affecting one hemisphere only or both hemispheres disproportionately. The usual suspect is a destructive lesion; an irritative or epileptogenic lesion is usually not invoked to explain DIBS asymmetry. We report the case of a 66-year-old woman with new-onset seizures who was found to have a hemorrhagic cavernoma and periodic lateralized epileptiform discharges (PLEDs) in the right temporal region. After levetiracetam and before anesthetic antiepileptic drugs (AEDs) were administered, the electroencephalogram (EEG) showed continuous PLEDs over the right hemisphere with maximum voltage in the posterior temporal region. Focal electrographic seizures also occurred occasionally in the same location. Propofol resulted in bihemispheric, but not in bisymmetric, DIBS. Remnants or fragments of PLEDs that survived anesthesia increased the amplitude and complexity of the bursts in the right hemisphere leading to asymmetric DIBS. Phenytoin, lacosamide, ketamine, midazolam, and topiramate were administered at various times in the course of EEG monitoring, resulting in suppression of seizures but not of PLEDs. Ketamine and midazolam reduced the rate, amplitude, and complexity of PLEDs but only after producing substantial attenuation of all burst components. When all anesthetics were discontinued, the EEG reverted to the original preanesthesia pattern with continuous non-fragmented PLEDs. The fact that PLEDs can survive anesthesia and affect DIBS symmetry is a testament to the robustness of the neurodynamic processes underlying PLEDs.