Proper Indication of Decompressive Craniectomy for the Patients with Massive Brain Edema after Intra-arterial Thrombectomy.

OBJECTIVE: Numerous studies have indicated that early decompressive craniectomy (DC) for patients with major infarction can be life-saving and enhance neurological outcomes. However, most of these studies were conducted by neurologists before the advent of intra-arterial thrombectomy (IA-Tx). This study aims to determine whether neurological status significantly impacts the final clinical outcome of patients who underwent DC following IA-Tx in major infarction. METHODS: This analysis included 67 patients with major anterior circulation major infarction who underwent DC after IA-Tx, with or without intravenous tissue plasminogen activator. We retrospectively reviewed the medical records, radiological findings, and compared the neurological outcomes based on the "surgical time window" and neurological status at the time of surgery. RESULTS: For patients treated with DC following IA-Tx, a Glasgow coma scale (GCS) score of 7 was the lowest score correlated with a favorable outcome (p=0.013). Favorable outcomes were significantly associated with successful recanalization after IA-Tx (p=0.001) and perfusion/diffusion (P/D)-mismatch evident on magnetic resonance imaging performed immediately prior to IA-Tx (p=0.007). However, the surgical time window (within 36 hours, p=0.389; within 48 hours, p=0.283) did not correlate with neurological outcomes. CONCLUSION: To date, early DC surgery after major infarction is crucial for patient outcomes. However, this study suggests that the indication for DC following IA-Tx should include neurological status (GCS ≤7), as some patients treated with early DC without considering the neurological status may undergo unnecessary surgery. Recanalization of the occluded vessel and P/D-mismatch are important for long-term neurological outcomes.

Highly Efficient and Stable Inverted Perovskite Solar Cell Using Pure δ-FAPbI3 Single Crystals.

Pure δ-formamidinium lead triiodide (δ-FAPbI3 ) single crystal for highly efficient perovskite solar cell (PCS) with long-term stability is prepared by a new method consisting of liquid phase reaction of FAI and PbI2 in N,N-dimethyl formamide and antisolvent crystallization using acetonitrile. In this method, the incorporation of any impurity into the crystal is excluded by the molecular recognition of the crystal growth site. This pure crystal is used to fabricate α-FAPbI3 inverted PSCs which showed excellent power conversion efficiency (PCE) due to much-reduced trap-states. The champion device exhibited a high PCE of 23.48% under the 1-Sun condition. Surface-treated devices with 3-(aminomethyl)pyridine showed a significantly improved PCE of 25.07%. In addition, the unencapsulated device maintained 97.22% of its initial efficiency under continuous 1-Sun illumination for 1,000 h at 85 °C in an N2 atmosphere ensuring long-term thermal and photo stabilities of PSCs, whereas the control device kept only 89.93%.

Morphology and Performance Enhancement through the Strong Passivation Effect of Amphoteric Ions in Tin-based Perovskite Solar Cells.

Despite the optoelectronic similarities between tin and lead halide perovskites, the performance of tin-based perovskite solar cells remains far behind, with the highest reported efficiency to date being ≈14%. This is highly correlated to the instability of tin halide perovskite, as well as the rapid crystallization behavior in perovskite film formation. In this work, l-Asparagine as a zwitterion plays a dual role in controlling the nucleation/crystallization process and improving the morphology of perovskite film. Furthermore, tin perovskites with l-Asparagine show more favorable energy-level matching, enhancing the charge extraction and minimizing the charge recombination, leading to an enhanced power conversion efficiency of 13.31% (from 10.54% without l-Asparagine) with remarkable stability. These results are also in good agreement with the density functional theory calculations. This work not only provides a facile and efficient approach to controlling the crystallization and morphology of perovskite film but also offers guidelines for further improved performance of tin-based perovskite electronic devices.

Recanalization Rate and Clinical Outcomes of Intravenous Tissue Plasminogen Activator Administration for Large Vessel Occlusion Stroke Patients.

OBJECTIVE: Stroke caused from large vessel occlusion (LVO) has emerged as the most common stroke subtype worldwide. Intravenous tissue plasminogen activator administration (IV-tPA) and additional intraarterial thrombectomy (IA-Tx) is regarded as standard treatment. In this study, the authors try to find the early recanalization rate of IV-tPA in LVO stroke patients. METHODS: Total 300 patients undertook IA-Tx with confirmed anterior circulation LVO, were analyzed retrospectively. Brain computed tomography angiography (CTA) was the initial imaging study and acute stroke magnetic resonance angiography (MRA) followed after finished IV-tPA. Early recanalization rate was evaluated by acute stroke MRA within 2 hours after the IV-tPA. In 167 patients undertook IV-tPA only and 133 non-recanalized patients by IV-tPA, additional IA-Tx tried (IV-tPA + IA-Tx group). And 131 patients, non-recanalized by IV-tPA (IV-tPA group) additional IA-Tx recommend and tried according to the patient condition and compliance. RESULTS: Early recanalization rate of LVO after IV-tPA was 12.0% (36/300). In recanalized patients, favorable outcome (modified Rankin Scale, 0-2) was 69.4% (25/36) while it was 32.1% (42/131, p<0.001) in non-recanalized patients. Among 133 patients, nonrecanalized after intravenous recombinant tissue plasminogen activator and undertook additional IA-Tx, the clinical outcome was better than not undertaken additional IA-Tx (favorable outcome was 42.9% vs. 32.1%, p=0.046). Analysis according to the perfusion/diffusion (P/D)-mismatching or not, in patient with IV-tPA with IA-Tx (133 patients), favorable outcome was higher in P/ D-mismatching patient (52/104; 50.0%) than P/D-matching patients (5/29; 17.2%; p=0.001). Which treatment tired, P/D-mismatching was favored in clinical outcome (iv-tPA only, p=0.008 and IV-tPA with IA-Tx, p=0.001). CONCLUSION: The P/D-mismatching influences on the recanalization and clinical outcomes of IV-tPA and IA-Tx. The authors would like to propose that we had better prepare IA-Tx when LVO is diagnosed on initial diagnostic imaging. Furthermore, if the patient shows P/D-mismatching on MRA after IV-tPA, additional IA-Tx improves treatment results and lessen the futile recanalization.

Fully Scalable and Stable CsPbI2Br Solar Cells Realized by an All-Spray-Coating Process.

Spray-coating is a scalable and time-efficient technique for the development of large-area metal halide perovskite (MHP) solar cells. However, a bottleneck still exists toward the development of fully scalable n-i-p-type MHP solar cells particularly on spray-coating the hole transporting layer (HTL). Here, we present a reliable strategy of spray-coating the HTL by using MoO2 nanoparticles with small amounts of poly(triarylamine) (PTAA) binders to ensure uniform coverage and efficient charge extraction. By spray-coating all layers except the Au electrode, we achieve high and scalable efficiencies of 14.26 and 13.88% for CsPbI2Br unit cells (0.12 cm2) and submodules (25 cm2), respectively. We then extend toward an all-spray-coating process by spray-coating carbon black as the top counter electrode, resulting in a submodule efficiency of 10.08%. Finally, we also demonstrate good long-term stability of the submodules under damp heat conditions (85 °C/85% relative humidity) over 1000 h.

Effects of an Infection Control Protocol for Coronavirus Disease in Emergency Mechanical Thrombectomy.

OBJECTIVE: Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic, neurointerventionists have been increasingly concerned regarding the prevention of infection and time delay in performing emergency thrombectomy procedures in patients with acute stroke. This study aimed to analyze the effects of changes in mechanical thrombectomy protocol before and after the COVID-19 pandemic on procedure time and patient outcomes and to identify factors that significantly impact procedure time. METHODS: The last-normal-to-door, first-abnormal-to-door, door-to-imaging, door-to-puncture, and puncture-to-recanalization times of 88 patients (45 treated with conventional pre-COVID-19 protocol and 43 with COVID-19 protection protocol) were retrospectively analyzed. The recanalization time, success rate of mechanical thrombectomy, and modified Rankin score of patients at discharge were assessed. A multivariate analysis was conducted to identify variables that significantly influenced the time delay in the door-to-puncture time and total procedure time. RESULTS: The door-to-imaging time significantly increased under the COVID-19 protection protocol (p=0.0257) compared to that with the conventional pre-COVID-19 protocol. This increase was even more pronounced in patients who were suspected to be COVID-19-positive than in those who were negative. The door-to-puncture time showed no statistical difference between the conventional and COVID-19 protocol groups (p=0.5042). However, in the multivariate analysis, the last-normal-to-door time and door-to-imaging time were shown to affect the door-to-puncture time (p=0.0068 and 0.0097). The total procedure time was affected by the occlusion site, last-normal-to-door time, door-to-imaging time, and type of anesthesia (p=0.0001, 0.0231, 0.0103, and 0.0207, respectively). CONCLUSION: The COVID-19 protection protocol significantly impacted the door-to-imaging time. Shortening the door-to-imaging time and performing the procedure under local anesthesia, if possible, may be required to reduce the door-to-puncture and doorto- recanalization times. The effect of various aspects of the protection protocol on emergency thrombectomy should be further studied.

Long-term mortality in patients with moyamoya angiopathy according to stroke presentation type in South Korea.

BACKGROUND: Incidence, prevalence, and long-term survival outcomes in patients with moyamoya angiopathy (MMA) according to stroke presentation type and age group have not been clearly elucidated. METHODS: We investigated mortality in patients with MMA (moyamoya disease, probable moyamoya disease, moyamoya syndrome) of whose International Classification Disease 10 code was I67.5 from 2006 to 2015 using the Korean National Health Insurance database. MMA at diagnosis was classified into 3 types (ischemic, hemorrhagic, and asymptomatic or else) according to stroke presentation. Survival analysis was performed according to stroke presentation type and age group (< 15 years and ≥ 15 years) using the Kaplan-Meier method. RESULTS: There were 12,146 newly diagnosed moyamoya cases, with a female-to-male ratio of 1.81; the ischemic type was identified in 3671 (30.2%) patients, the hemorrhagic type in 2449 (20.2%) patients, and the asymptomatic or else type in 6026 (49.6%) patients. The mean age at diagnosis according to stroke presentation was 33.1 (± 14.8) years in asymptomatic or else type, 41.2 (± 17.3) years in ischemic type, and 45.4 (± 14.3) years in hemorrhagic type (P < 0.001). The 10-year survival rates in ischemic-, hemorrhagic-, and asymptomatic or else-type patients were 88.9%, 76.3%, and 94.3%, respectively (log-rank test; P < 0.001). Pediatric MMA (< 15 years) and adult MMA (≥ 15 years) showed different survival curves according to stroke presentation type (log-rank test; P = 0.017, P < 0.001, respectively). CONCLUSIONS: Our study showed that moyamoya patients had different diagnosis ages and distinct survival courses according to stroke presentation type. Adult moyamoya patients with hemorrhagic presentation had the worst survival outcomes.

CuInS2 Photocathodes with Atomic Gradation-Controlled (Ta,Mo)x(O,S)y Passivation Layers for Efficient Photoelectrochemical H2 Production.

An atomic gradient passivation layer, (Ta,Mo)x(O,S)y, is designed to improve the charge transportation and photoelectrochemical activity of CuInS2-based photoelectrodes. We found that Mo spontaneously diffused to the a-TaOx layer during e-beam evaporation. This result indicates that the gradient profile of MoOx/TaOx is formed in the sublayer of (Ta,Mo)x(O,S)y. To understand the atomic-gradation effects of the (Ta,Mo)x(O,S)y passive layer, the composition and (photo)electrochemical properties have been characterized in detail. When this atomic gradient-passive layer is applied to CuInS2-based photocathodes, promising photocurrent and onset potential are seen without using Pt cocatalysts. This is one of the highest activities among reported CuInS2 photocathodes, which are not combined with noble metal cocatalysts. Excellent photoelectrochemical activity of the photoelectrode can be mainly achieved by (1) the electron transient time improved due to the conductive Mo-incorporated TaOx layer and (2) the boosted electrocatalytic activity by Mox(O,S)y formation.

Self-powered flexible all-perovskite X-ray detectors with high sensitivity and fast response.

Perovskite materials have demonstrated superior performance in many aspects of optoelectronic applications including X-ray scintillation, photovoltaic, photodetection, and so on. In this work, we demonstrate a self-powered flexible all-perovskite X-ray detector with high sensitivity and fast response, which can be realized by integrating CsPbBr3 perovskite nanocrystals (PNCs) as the X-ray scintillator with a CH3NH3PbI3 perovskite photodetector. The PNCs scintillator exhibits ultra-fast light decay of 2.81 ns, while the perovskite photodetector gives a fast response time of ∼0.3 µs and high-specific detectivity of ∼2.4×1012 Jones. The synergistic effect of these two components ultimately leads to a self-powered flexible all-perovskite X-ray detector that delivers high sensitivity of 600-1,270 µC/mGyaircm3 under X-ray irradiation and fast radiation-to-current response time.

Enhanced Weak-Light Detection of Perovskite Photodetectors through Perovskite/Hole-Transport Material Interface Treatment.

Enhancement in weak-light detection and other photodetection properties was observed for organic-inorganic halide perovskite photodetectors as a result of benzylammonium iodide (BzAI) treatment at the methylammonium lead triiodide (MAPbI3) and hole-transport layer (HTL) interface. After treatment, growth of the two-dimensional Ruddlesden-Popper perovskite phase was observed at the MAPbI3 surface, which shifted the overall surface work function upwards and thus effectively facilitated charge transfer across the MAPbI3/HTL interface. As a result, the fully fabricated device with 10 mg/mL (BzAI/isopropanol) treatment exhibited shorter rise time (trise) and decay time (tdecay) of 53 and 38 µs, respectively, compared to trise and tdecay of 214 and 120 µs, respectively, for the pristine MAPbI3 sample. In addition, the BzAI-treated device exhibited larger linearity compared to the pristine MAPbI3 sample, demonstrating a high and stable specific detectivity of 1.49 × 1013 to 2.14 × 1013 Jones under incident light intensity of 10-3 to 100 mW/cm2, respectively.

Recent Progress in Metal Halide Perovskite-Based Tandem Solar Cells.

Metal halide perovskite (MHP)-based tandem solar cells are a promising candidate for use in cost-effective and high-performance solar cells that can compete with fossil fuels. To understand the research trends for MHP-based tandem solar cells, a general introduction to single-junction and multiple-junction MHP solar cells and the configuration of tandem devices is provided, along with an overview of the recent progress regarding various MHP-based tandem cells, including MHP/crystalline silicon, MHP/CuInGaS, MHP/organic photovoltaic, MHP/quantum dot, and all-perovskite tandem cell. Future research directions for MHP-based tandem solar cells are also discussed.

Phase Selection of Cesium Lead Triiodides through Surface Ligand Engineering.

The cesium lead triiodide (CsPbI3) perovskite is a promising candidate for stable light absorbers and red-light-emitting sources due to its outstanding stability. Phase engineering is the most important approach for the commercialization of CsPbI3 because the optically inactive nonperovskite structure is more stable than three-dimensional (3-D) perovskite lattices at ambient temperature. This study presents an in-depth evaluation to find the optimum surface ligand and to reveal the mechanism of phase stabilization by surface ligands. Thermodynamic evaluations combined with density functional theory calculations indicate the criteria for forming stable 3-D CsPbI3 perovskites under surface and volume free energy competition between perovskite and nonperovskite phases. Comparative calculations for ammonium, alcohol, and thiol groups show that ammonium groups enhance the phase stability of 3-D perovskites the most. In addition, ammonium-passivated CsPbI3 is relatively robust against defect formation and H2O adsorption.

Understanding the Performance of Organic Photovoltaics under Indoor and Outdoor Conditions: Effects of Chlorination of Donor Polymers.

Understanding the effects of the chemical structures of donor polymers on the photovoltaic properties of their corresponding organic photovoltaic (OPV) devices under various light-intensity conditions is important for improving the performance of these devices. We synthesized a series of copolymers based on poly[(2,6-(4,8-bis(5-(2-thioethylhexyl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophene))-alt-(5,5-(1',3'-di-2-thienyl-5',7'-bis(2-ethylhexyl)benzo[1',2'-c:4',5'-c']dithiophene-4,8-dione))] (PBDB-TS) and studied the effects of chlorine substitution of its thiophene-substituted benzodithiophene (BDT-Th) unit on its photovoltaic properties. Chlorination of the polymer resulted in a bulk heterojunction (BHJ) morphology optimized for efficient charge transport with suppressed leakage current and an increased open-circuit voltage of the OPV device; this optimization led to a remarkable enhancement of the OPV device's power conversion efficiency (PCE) not only under the condition of 1 sun illumination but also under a low light intensity mimicking indoor light; the PCE increased from 8.7% for PBDB-TS to ∼13% for the chlorinated polymers, PBDB-TS-3Cl, and PBDB-TS-4Cl under the 1 sun illumination condition and from 5.3% for PBDB-TS to 21.7% for PBDB-TS-4Cl under 500 lx fluorescence illuminance. Interestingly, although the OPV PCEs under 1 sun illumination were independent of the position of chlorine substitution onto the polymer, PBDB-TS-4Cl exhibited better performance under simulated indoor light than its derivative PBDB-TS-3Cl. Our results demonstrate that efficient light absorption and charge-carrier generation play key roles in achieving high OPV efficiency under low-light-intensity conditions.

Reproducible Dry Stamping Transfer of PEDOT:PSS Transparent Top Electrode for Flexible Semitransparent Metal Halide Perovskite Solar Cells.

A semitransparent flexible metal halide perovskite (MHP) solar cells were demonstrated by reproducible dry stamping transfer of a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonic acid) (PEDOT:PSS, PH1000) transparent flexible top electrode onto poly(ethylene terephthalate) (PET)/indium tin oxide (ITO)/PEDOT:PSS (AI4083)/MHP/[6,6]-phenyl-C61-butyric acid methyl ester (PCBM). The reproducible transfer of the PEDOT:PSS top electrode was enabled by the modification of PEDOT:PSS with poly(ethylene imine) (PEI)/2-methoxyethanol (2-MEA) solution. In addition, the PEI/2-MEA modification to PEDOT:PSS resulted in improved conductivity and reduced work function of the top electrode. Therefore, we could fabricate highly efficient flexible semitransparent MHP solar cells with >13% (active area = 1 cm2) power conversion efficiency.

Large-Scale Synthesis of Uniform PbI2(DMSO) Complex Powder by Solvent Extraction Method for Efficient Metal Halide Perovskite Solar Cells.

PbI2(DMSO) complex powder, which is essential to fabricate efficient metal halide perovskite solar cells (MHP SCs), was synthesized by liquid phase solvent extraction process irrespective of reaction volume scale. The isopropanol (IPA) solvent could selectively extract the DMSO from PbI2(DMSO)2 powder during extraction process so that compositionally uniform PbI2(DMSO) powder could be obtained in a large scale process, whereas the vacuum drying process could not produce uniform PbI2(DMSO) powder. Due to the compositional uniformity of PbI2(DMSO) powders prepared by solvent extraction process, the MHP SCs could be fabricated very reproducibly.

Dual-site mixed layer-structured FA x Cs3-x Sb2I6Cl3 Pb-free metal halide perovskite solar cells.

Structure engineering of trivalent metal halide perovskites (MHPs) such as A3Sb2X9 (A = a monovalent cation such as methyl ammonium (MA), cesium (Cs), and formamidinium (FA) and X = a halogen such as I, Br, and Cl) is of great interest because a two dimensional (2D) layer structure with direct bandgap has narrower bandgap energy than a zero dimensional (0D) dimer structure with indirect bandgap. Here, we demonstrated 2D layer structured FACs2Sb2I6Cl3 MHP by dual-site (A and X site) mixing. Thanks to the lattice-symmetry change by I-Cl mixed halide, the shortest ionic radius of Cs, and the lower solution energy due to dual-site mixing, the FACs2Sb2I6Cl3 MHP had 2D layer structure and thereby the MHP solar cells exhibited improved short-circuit current density.

Wetting-induced formation of void-free metal halide perovskite films by green ultrasonic spray coating for large-area mesoscopic perovskite solar cells.

A void-free metal halide perovskite (MHP) layer on a mesoscopic TiO2 (m-TiO2) film was formed via the wetting-induced infiltration of MHP solution in the m-TiO2 film via a green ultrasonic spray coating process using a non-hazardous solvent. The systematic investigation of the behavior of ultrasonic-sprayed MHP micro-drops on the m-TiO2 film disclosed that the void-free MHP layer on the m-TiO2 film can be formed if the following conditions are satisfied: (1) the sprayed micro-drops are merged and wetted in the mesoscopic scaffold of the m-TiO2 film, (2) the MHP solution infiltrated into the m-TiO2 film by wetting is leveled to make a smooth wet MHP film, and (3) the smooth wet MHP film is promptly heat treated to eliminate dewetting and the coffee ring effect by convective flow in order to form a uniform void-free MHP layer. A void-free MHP layer on the m-TiO2 film was formed under optimal ultrasonic spray coating conditions of substrate temperature of ∼30 °C, spray flow rate of ∼11 mL h-1, nozzle to substrate distance of ∼8 cm, and MHP solution-concentration of ∼0.6 M under a fixed scan speed of 30 mm s-1 and purged N2 carrier gas pressure of 0.02 MPa. The mesoscopic MHP solar cells with an aperture area of 0.096, 1, 25, and 100 cm2 exhibited 17.14%, 16.03%, 12.93%, and 10.67% power conversion efficiency at 1 sun condition, respectively.

Efficient Metal Halide Perovskite Solar Cells Prepared by Reproducible Electrospray Coating on Vertically Aligned TiO2 Nanorod Electrodes.

Vertically aligned TiO2 nanorod (NR) electrodes with straight macropores enabled a metal halide perovskite (MHP) solution to be fully infiltrated within their structure and, as a result, formed void-free dense MHP films reproducibly during an electrospray-coating process, whereas conventional mesoporous TiO2 (m-TiO2) electrodes with three-dimensionally interconnected mesopores formed internal voids by imperfect infiltration of MHP solution. Hence, TiO2 NR-based MHP solar cells could be more reproducibly fabricated by an electrospray-coating process and exhibited smaller current density-voltage hysteresis with respect to the scan direction and scan rate than the m-TiO2-based MHP solar cells due to the short and straight electron pathway either by a one-dimensional TiO2 NR electrode or a densely formed MHP layer within the TiO2 NR electrode.

Performance data of CH3NH3PbI3 inverted planar perovskite solar cells via ammonium halide additives.

The data provided in this data set is the study of organic-inorganic hybrid perovskite solar cells fabricated through incorporating the small amounts of ammonium halide NH4X (X = F, Cl, Br, I) additives into a CH3NH3PbI3 (MAPbI3) perovskite solution and is published as "High-Performance CH3NH3PbI3 Inverted Planar Perovskite Solar Cells via Ammonium Halide Additives", available in Journal of Industrial and Engineering Chemistry [1]. A compact and uniform perovskite absorber layer with large perovskite crystalline grains, is realized by simply incorporating small amounts of additives into precursor solutions, and utilizing the anti-solvent engineering technique to control the nucleation and growth of perovskite crystal, turning out the enhanced device efficiency (NH4F: 14.88 ± 0.33%, NH4Cl: 16.63 ± 0.21%, NH4Br: 16.64 ± 0.35%, and NH4I: 17.28 ± 0.15%) compared to that of a reference MAPbI3 device (Ref.: 12.95 ± 0.48%). In addition, this simple technique of ammonium halide addition to precursor solutions increase the device reproducibility as well as long term stability.