Skin electronics from scalable fabrication of an intrinsically stretchable transistor array.

Skin-like electronics that can adhere seamlessly to human skin or within the body are highly desirable for applications such as health monitoring, medical treatment, medical implants and biological studies, and for technologies that include human-machine interfaces, soft robotics and augmented reality. Rendering such electronics soft and stretchable-like human skin-would make them more comfortable to wear, and, through increased contact area, would greatly enhance the fidelity of signals acquired from the skin. Structural engineering of rigid inorganic and organic devices has enabled circuit-level stretchability, but this requires sophisticated fabrication techniques and usually suffers from reduced densities of devices within an array. We reasoned that the desired parameters, such as higher mechanical deformability and robustness, improved skin compatibility and higher device density, could be provided by using intrinsically stretchable polymer materials instead. However, the production of intrinsically stretchable materials and devices is still largely in its infancy: such materials have been reported, but functional, intrinsically stretchable electronics have yet to be demonstrated owing to the lack of a scalable fabrication technology. Here we describe a fabrication process that enables high yield and uniformity from a variety of intrinsically stretchable electronic polymers. We demonstrate an intrinsically stretchable polymer transistor array with an unprecedented device density of 347 transistors per square centimetre. The transistors have an average charge-carrier mobility comparable to that of amorphous silicon, varying only slightly (within one order of magnitude) when subjected to 100 per cent strain for 1,000 cycles, without current-voltage hysteresis. Our transistor arrays thus constitute intrinsically stretchable skin electronics, and include an active matrix for sensory arrays, as well as analogue and digital circuit elements. Our process offers a general platform for incorporating other intrinsically stretchable polymer materials, enabling the fabrication of next-generation stretchable skin electronic devices.

Machine Learning-Based Etiologic Subtyping of Ischemic Stroke Using Circulating Exosomal microRNAs.

Ischemic stroke is a major cause of mortality worldwide. Proper etiological subtyping of ischemic stroke is crucial for tailoring treatment strategies. This study explored the utility of circulating microRNAs encapsulated in extracellular vesicles (EV-miRNAs) to distinguish the following ischemic stroke subtypes: large artery atherosclerosis (LAA), cardioembolic stroke (CES), and small artery occlusion (SAO). Using next-generation sequencing (NGS) and machine-learning techniques, we identified differentially expressed miRNAs (DEMs) associated with each subtype. Through patient selection and diagnostic evaluation, a cohort of 70 patients with acute ischemic stroke was classified: 24 in the LAA group, 24 in the SAO group, and 22 in the CES group. Our findings revealed distinct EV-miRNA profiles among the groups, suggesting their potential as diagnostic markers. Machine-learning models, particularly logistic regression models, exhibited a high diagnostic accuracy of 92% for subtype discrimination. The collective influence of multiple miRNAs was more crucial than that of individual miRNAs. Additionally, bioinformatics analyses have elucidated the functional implications of DEMs in stroke pathophysiology, offering insights into the underlying mechanisms. Despite limitations like sample size constraints and retrospective design, our study underscores the promise of EV-miRNAs coupled with machine learning for ischemic stroke subtype classification. Further investigations are warranted to validate the clinical utility of the identified EV-miRNA biomarkers in stroke patients.

Aspirin use and risk of hepatocellular carcinoma in patients with chronic hepatitis B with or without cirrhosis.

BACKGROUND AND AIMS: Studies on differential effect of aspirin therapy on HCC risk across the spectrum of liver diseases are lacking. We investigated the association between aspirin use and risks of HCC, liver-associated death, and major bleeding in chronic hepatitis B (CHB) patients with or without cirrhosis. APPROACH AND RESULTS: We identified 329,635 eligible adults with CHB from 2007 through 2017, using the Korean National Health Insurance Service database, including patients who received aspirin for ≥90 consecutive days (n = 20,200) and patients who never received antiplatelet therapy (n = 309,435). Risks of HCC, liver-associated mortality, and major bleeding were estimated in a propensity-score-matched cohort (19,003 pairs), accounting for competing risks. With a median follow-up of 6.7 years, 10-year cumulative incidence of HCC was 9.5% in the aspirin-treated group and 11.3% in the untreated group (adjusted subdistribution hazard ratio [aSHR], 0.85; 95% CI, 0.78-0.92). However, among patients with cirrhosis (2479 pairs), an association of aspirin use with HCC risk was not evident (aSHR, 1.00; 95% CI, 0.85-1.18). Cirrhosis status had a significant effect on the association between aspirin use and HCC risk (pinteraction , n = 0.04). Aspirin use was also associated with lower liver-associated mortality (aSHR, 0.80; 95% CI, 0.71-0.90). Moreover, aspirin use was not associated with major bleeding risk (aSHR, 1.09; 95% CI, 0.99-1.21). CONCLUSIONS: Aspirin use was associated with reduced risks of HCC and liver-associated mortality in adults with CHB. Cirrhosis status had a substantial effect on the association between aspirin use and HCC risk.

Multi-ancestry GWAS reveals excitotoxicity associated with outcome after ischaemic stroke.

During the first hours after stroke onset, neurological deficits can be highly unstable: some patients rapidly improve, while others deteriorate. This early neurological instability has a major impact on long-term outcome. Here, we aimed to determine the genetic architecture of early neurological instability measured by the difference between the National Institutes of Health Stroke Scale (NIHSS) within 6 h of stroke onset and NIHSS at 24 h. A total of 5876 individuals from seven countries (Spain, Finland, Poland, USA, Costa Rica, Mexico and Korea) were studied using a multi-ancestry meta-analyses. We found that 8.7% of NIHSS at 24 h of variance was explained by common genetic variations, and also that early neurological instability has a different genetic architecture from that of stroke risk. Eight loci (1p21.1, 1q42.2, 2p25.1, 2q31.2, 2q33.3, 5q33.2, 7p21.2 and 13q31.1) were genome-wide significant and explained 1.8% of the variability suggesting that additional variants influence early change in neurological deficits. We used functional genomics and bioinformatic annotation to identify the genes driving the association from each locus. Expression quantitative trait loci mapping and summary data-based Mendelian randomization indicate that ADAM23 (log Bayes factor = 5.41) was driving the association for 2q33.3. Gene-based analyses suggested that GRIA1 (log Bayes factor = 5.19), which is predominantly expressed in the brain, is the gene driving the association for the 5q33.2 locus. These analyses also nominated GNPAT (log Bayes factor = 7.64) ABCB5 (log Bayes factor = 5.97) for the 1p21.1 and 7p21.1 loci. Human brain single-nuclei RNA-sequencing indicates that the gene expression of ADAM23 and GRIA1 is enriched in neurons. ADAM23, a presynaptic protein and GRIA1, a protein subunit of the AMPA receptor, are part of a synaptic protein complex that modulates neuronal excitability. These data provide the first genetic evidence in humans that excitotoxicity may contribute to early neurological instability after acute ischaemic stroke.

Circulating Extracellular Vesicles in Stroke Patients Treated With Mesenchymal Stem Cells: A Biomarker Analysis of a Randomized Trial.

BACKGROUND: Mesenchymal stem cells (MSCs) secrete trophic factors and extracellular vesicles (EVs). However, the level and role of EVs after MSC therapy in patients with stroke are unknown. We investigated whether circulating EVs and trophic factors are increased after MSCs and are related to the therapeutic benefits in the STARTING-2 trial (Stem Cell Application Researches and Trials in Neurology-2) participants. METHODS: In this prospective randomized controlled trial, patients with chronic major stroke were assigned, in a 2:1 ratio, to receive autologous MSC intravenous injection (MSC group, n=39) or standard treatment (control group, n=15) and followed for 3 months. Detailed clinical assessment and neuroplasticity on diffusion tensor image and resting-state functional magnetic resonance imaging were evaluated. Serial samples were collected, before/after MSCs therapy. The primary outcome measure was circulating factors that are associated with the clinical improvement in the Fugl-Meyer Assessment (secondary end point of the trial) and neuroplasticity on diffusion tensor image and resting-state functional magnetic resonance imaging. Additional outcome measures were microRNAs and trophic factors enriched in the plasma EVs, obtained using quantitative polymerase chain reaction and ELISA, respectively. RESULTS: Circulating EV levels were increased ≈5-fold (mean±SD, from 2.7×109±2.2×109 to 1.3×1010±1.7×1010 EVs/mL) within 24 hours after injection of MSCs (P=0.001). After adjustment of age, sex, baseline stroke severity, and the time interval from stroke onset to treatment, only the EV number was independently associated with improvement in motor function (odds ratio, 5.718 for EV numberLog [95% CI, 1.144-28.589]; P=0.034). Diffusion tensor image and resting-state functional magnetic resonance imaging showed that integrity of the ipsilesional corticospinal tract and intrahemispheric motor network were significantly correlated with circulating EV levels, respectively (P<0.05). MicroRNAs related to neurogenesis/neuroplasticity (eg, microRNA-18a-5p) were significantly increased in circulating EVs after MSC therapy (P=0.0479). In contrast, trophic factor levels were not changed after MSC therapy. CONCLUSIONS: This trial is the first to show that treatment of ischemic stroke patients with MSCs significantly increases circulating EVs, which were significantly correlated with improvement in motor function and magnetic resonance imaging indices of plasticity. REGISTRATION: URL: https://www. CLINICAL TRIALS: gov; Unique identifier: NCT01716481.

Efficacy of Intravenous Mesenchymal Stem Cells for Motor Recovery After Ischemic Stroke: A Neuroimaging Study.

BACKGROUND AND PURPOSE: Stem cell-based therapy is a promising approach to repair brain damage after stroke. This study was conducted to investigate changes in neuroimaging measures using stem cell-based therapy in patients with ischemic stroke. METHODS: In this prospective, open-label, randomized controlled trial with blinded outcome evaluation, patients with severe middle cerebral artery territory infarct were assigned to the autologous mesenchymal stem cell (MSC) treatment or control group. Of 54 patients who completed the intervention, 31 for the MSC and 13 for the control groups were included in this neuroimaging analysis. Motor function was assessed before the intervention and 90 days after randomization using the Fugl-Meyer assessment scale. Neuroimaging measures included fractional anisotropy values of the corticospinal tract and posterior limb of the internal capsule from diffusion tensor magnetic resonance imaging and strength of connectivity, efficiency, and density of the motor network from resting-state functional magnetic resonance imaging. RESULTS: For motor function, the improvement ratio of the Fugl-Meyer assessment score was significantly higher in the MSC group compared with the control group. In neuroimaging, corticospinal tract and posterior limb of the internal capsule fractional anisotropy did not decrease in the MSC group but significantly decreased at 90 days after randomization in the control group. Interhemispheric connectivity and ipsilesional connectivity significantly increased in the MSC group. Change in interhemispheric connectivity showed a significant group difference. CONCLUSIONS: Stem cell-based therapy can protect corticospinal tract against degeneration and enhance positive changes in network reorganization to facilitate motor recovery after stroke. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01716481.

Impact of Renal Function on Short-Term Outcome After Reperfusion Therapy in Patients With Ischemic Stroke.

BACKGROUND: A high and low estimated glomerular filtration rate (eGFR) could affect outcomes after reperfusion therapy for ischemic stroke. This study aimed to determine whether renal function based on eGFR affects mortality risk in patients with ischemic stroke within 6 months following reperfusion therapy. METHODS: This prospective registry-based cohort study included 2266 patients who received reperfusion therapy between January 2000 and September 2019 and were registered in the SECRET (Selection Criteria in Endovascular Thrombectomy and Thrombolytic Therapy) study or the Yonsei Stroke Cohort. A high and low eGFR were based on the Chronic Kidney Disease Epidemiology Collaboration equation and defined, respectively, as the 5th and 95th percentiles of age- and sex-specific eGFR. Occurrence of death within 6 months was compared among the groups according to their eGFR such as low, normal, or high eGFR. RESULTS: Of the 2266 patients, 2051 (90.5%) had a normal eGFR, 110 (4.9%) a low eGFR, and 105 (4.6%) a high eGFR. Patients with high eGFR were younger or less likely to have hypertension, diabetes, or atrial fibrillation than the other groups. Active cancer was more prevalent in the high-eGFR group. During the 6-month follow-up, there were 24 deaths (22.9%) in the high-eGFR group, 37 (33.6%) in the low-eGFR group, and 237 (11.6%) in the normal-eGFR group. After adjusting for variables with P<0.10 in the univariable analysis, 6-month mortality was independently associated with high eGFR (hazard ratio, 2.22 [95% CI, 1.36-3.62]; P=0.001) and low eGFR (HR, 2.29 [95% CI, 1.41-3.72]; P=0.001). These associations persisted regardless of treatment modality or various baseline characteristics. CONCLUSIONS: High eGFR as well as low eGFR were independently associated with 6-month mortality after reperfusion therapy. Kidney function could be considered a prognostic factor in patients with ischemic stroke after reperfusion therapy.

Effects of Dose Titration on Dipyridamole-Induced Headache: A Randomized, Double-Blind Clinical Trial.

PURPOSE: The aim of this study is to investigate the effect of gradual dipyridamole titration and the incidence of dipyridamole-induced headache in patients with ischemic stroke or transient ischemic attack (TIA). METHODS: A randomized, double-blind, double-placebo, parallel group, phase 4 clinical trial (KCT0005457) was conducted between July 1, 2019, and February 25, 2020, at 15 medical centers in South Korea. The study included patients aged >19 years diagnosed with a noncardioembolic ischemic stroke or TIA within the previous 3 weeks. The participants were randomized 1:1:1 to receive Adinox® (aspirin 25 mg/dipyridamole 200 mg) and aspirin (100 mg) once daily for the first 2 weeks followed by Adinox® twice daily for 2 weeks (titration group), Adinox® twice daily for 4 weeks (standard group), and aspirin 100 mg once daily for 4 weeks (control group). The primary endpoint was incidence of headache over 4 weeks. The key secondary endpoint was mean cumulative headache. RESULTS: Ninety-six patients were randomized into the titration (n = 31), standard (n = 32), and control (n = 33) groups. The titration and standard groups (74.1% vs. 74.2%, respectively) showed no difference in the primary endpoint. However, the mean cumulated headache was significantly lower in the titration group than in the standard group (0.31 ± 0.46 vs. 0.58 ± 0.51, p = 0.023). Further, adverse drug reactions were more common in the standard group than in the titration group (28.1% vs. 9.7%, respectively, p = 0.054), although not significantly different. CONCLUSION: The titration strategy was effective in lowering the incidence of cumulative dipyridamole-induced headache.

Intrinsically stretchable and healable semiconducting polymer for organic transistors.

Thin-film field-effect transistors are essential elements of stretchable electronic devices for wearable electronics. All of the materials and components of such transistors need to be stretchable and mechanically robust. Although there has been recent progress towards stretchable conductors, the realization of stretchable semiconductors has focused mainly on strain-accommodating engineering of materials, or blending of nanofibres or nanowires into elastomers. An alternative approach relies on using semiconductors that are intrinsically stretchable, so that they can be fabricated using standard processing methods. Molecular stretchability can be enhanced when conjugated polymers, containing modified side-chains and segmented backbones, are infused with more flexible molecular building blocks. Here we present a design concept for stretchable semiconducting polymers, which involves introducing chemical moieties to promote dynamic non-covalent crosslinking of the conjugated polymers. These non-covalent crosslinking moieties are able to undergo an energy dissipation mechanism through breakage of bonds when strain is applied, while retaining high charge transport abilities. As a result, our polymer is able to recover its high field-effect mobility performance (more than 1 square centimetre per volt per second) even after a hundred cycles at 100 per cent applied strain. Organic thin-film field-effect transistors fabricated from these materials exhibited mobility as high as 1.3 square centimetres per volt per second and a high on/off current ratio exceeding a million. The field-effect mobility remained as high as 1.12 square centimetres per volt per second at 100 per cent strain along the direction perpendicular to the strain. The field-effect mobility of damaged devices can be almost fully recovered after a solvent and thermal healing treatment. Finally, we successfully fabricated a skin-inspired stretchable organic transistor operating under deformations that might be expected in a wearable device.

Atherosclerotic Burden and Vascular Risk in Stroke Patients With Atrial Fibrillation.

Background and Purpose: Data on the effect on vascular outcomes of concomitant atherosclerotic vascular disease (ASVD) with atrial fibrillation (AF) after stroke are limited. This study evaluated the effect of ASVD with AF versus AF only on the risk of vascular events. Methods: We retrospectively analyzed a prospectively registered multicenter database involving 3213 stroke patients with AF. ASVD included extracranial atherosclerosis measured in the proximal portion of the internal carotid artery, intracranial atherosclerosis (all ≥50% stenosis), coronary artery disease, and peripheral artery disease and was categorized into 4 strata depending on the number of ASVDs (0, 1, 2, and 3­4). The independent associations of ASVD with major adverse cardiovascular events, stroke, and all-cause death were assessed. Results: A total of 2670 patients were included (mean age, 73.5±9.8 years; median CHA2DS2-VASc score, 5; interquartile range, 4−6). During the follow-up (mean, 1.7 years), a total of 672 (25.2%) major adverse cardiovascular events, 170 (6.4%) stroke events, and 501 (18.8%) all-cause deaths were noted. The adjusted hazard ratio for major adverse cardiovascular events versus no ASVD was 1.25 (95% CI, 1.00­1.56) for ASVD 1, 1.34 (95% CI, 1.02­1.76) for ASVD 2, and 1.93 (95% CI, 1.24­2.99) for ASVD 3­4. The adjusted hazard ratio for all-cause death versus no ASVD was 1.32 (1.01­1.74), 1.47 (1.06­2.03), and 2.39 (1.47­3.89), respectively. Among ASVD components, the presence of symptomatic or asymptomatic extracranial atherosclerosis was a more potent predictor of major adverse cardiovascular events (1.27 [1.05­1.54]) and all-cause death (1.45 [1.17­1.81]). Conclusions: ASVD burden with AF can be a cumulative marker of a high risk for untoward vascular outcomes. Among ASVD components, extracranial atherosclerosis seems to have a predominant effect.

Immediate and Long-Term Outcomes of Reperfusion Therapy in Patients With Cancer.

Background and Purpose: Patients with acute stroke are often accompanied by comorbidities, such as active cancer. However, adequate treatment guidelines are not available for these patients. The purpose of this study was to evaluate the association between cancer and the outcomes of reperfusion therapy in patients with stroke. Methods: We compared treatment outcomes in patients who underwent reperfusion therapy, using a nationwide reperfusion therapy registry. We divided the patients into 3 groups according to cancer activity: active cancer, nonactive cancer, and without a history of cancer. We investigated reperfusion processes, 24-hour neurological improvement, adverse events, 3-month functional outcome, and 6-month survival and related factors after reperfusion therapy. Results: Among 1338 patients who underwent reperfusion therapy, 62 patients (4.6%) had active cancer, 78 patients (5.8%) had nonactive cancer, and 1198 patients (89.5%) had no history of cancer. Of the enrolled patients, 969 patients received intravenous thrombolysis and 685 patients underwent endovascular treatment (316 patients received combined therapy). Patients with active cancer had more comorbidities and experienced more severe strokes; however, they showed similar 24-hour neurological improvement and adverse events, including cerebral hemorrhage, compared with the other groups. Although the functional outcome at 3 months was poorer than the other groups, 36.4% of patients with active cancer showed functional independence. Additionally, 52.9% of the patients with determined stroke etiology showed functional independence despite active cancer. During the 6-month follow-up, 46.6% of patients with active cancer died, and active cancer was independently associated with poor survival (hazard ratio, 3.973 [95% CI, 2.528­6.245]). Conclusions: In patients with active cancer, reperfusion therapy showed similar adverse events and short-term outcomes to that of other groups. While long-term prognosis was worse in the active cancer group than the nonactive cancer groups, not negligible number of patients had good functional outcomes, especially those with determined stroke mechanisms.

A Design Strategy for Intrinsically Stretchable High-Performance Polymer Semiconductors: Incorporating Conjugated Rigid Fused-Rings with Bulky Side Groups.

Strategies to improve stretchability of polymer semiconductors, such as introducing flexible conjugation-breakers or adding flexible blocks, usually result in degraded electrical properties. In this work, we propose a concept to address this limitation, by introducing conjugated rigid fused-rings with optimized bulky side groups and maintaining a conjugated polymer backbone. Specifically, we investigated two classes of rigid fused-ring systems, namely, benzene-substituted dibenzothiopheno[6,5-b:6',5'-f]thieno[3,2-b]thiophene (Ph-DBTTT) and indacenodithiophene (IDT) systems, and identified molecules displaying optimized electrical and mechanical properties. In the IDT system, the polymer PIDT-3T-OC12-10% showed promising electrical and mechanical properties. In fully stretchable transistors, the polymer PIDT-3T-OC12-10% showed a mobility of 0.27 cm2 V-1 s-1 at 75% strain and maintained its mobility after being subjected to hundreds of stretching-releasing cycles at 25% strain. Our results underscore the intimate correlation between chemical structures, mechanical properties, and charge carrier mobility for polymer semiconductors. Our described molecular design approach will help to expedite the next generation of intrinsically stretchable high-performance polymer semiconductors.

Pre-Admission CHADS2 and CHA2DS2-VASc Scores on Early Neurological Worsening.

BACKGROUND: Stroke risk scores (CHADS2 and CHA2DS2-VASc) not only predict the risk of stroke in atrial fibrillation (AF) patients, but have also been associated with prognosis after stroke. OBJECTIVE: The aim of this study was to evaluate the relationship between stroke risk scores and early neurological deterioration (END) in ischemic stroke patients with AF. METHODS: We included consecutive ischemic stroke patients with AF admitted between January 2013 and December 2015. CHADS2 and CHA2DS2-VASc scores were calculated using the established scoring system. END was defined as an increase ≥2 on the total National Institutes of Health Stroke Scale (NIHSS) score or ≥1 on the motor NIHSS score within the first 72 h of admission. RESULTS: A total of 2,099 ischemic stroke patients with AF were included. In multivariable analysis, CHA2DS2-VASc score (adjusted odds ratio [aOR] = 1.17, 95% confidence interval [CI] = 1.04-1.31) was significantly associated with END after adjusting for confounders. Initial NIHSS score, use of anticoagulants, and intracranial atherosclerosis (ICAS) were also found to be closely associated with END, independent of the CHA2DS2-VASc score. Multivariable analysis stratified by the presence of ICAS demonstrated that both CHA2DS2-VASc (aOR = 1.20, 95% CI = 1.04-1.38) and CHADS2 scores (aOR = 1.24, 95% CI = 1.01-1.52) were closely related to END in only patients with ICAS. In patients without ICAS, neither of the risk scores were associated with END. CONCLUSIONS: High CHA2DS2-VASc score was associated with END in ischemic stroke patients with AF. This close relationship is more pronounced in patients with ICAS.

White matter hyperintensity determines ischemic stroke severity in symptomatic carotid artery stenosis.

INTRODUCTION: The aim of this study is to investigate the influence of white matter hyperintensity (WMH) on stroke severity and prognosis in patients with symptomatic carotid artery stenosis. METHODS: Patients with symptomatic carotid artery stenosis were retrieved from the Samsung Medical Center stroke registry from January 2011 to December 2016. Stroke severity was categorized into three levels according to National Institutes of Health Stroke Scale (NIHSS): transient ischemic attack (TIA) or transient symptoms with infarction (TSI), mild stroke, and moderate to severe stroke. WMH volume was measured with medical image processing and visualization. The clinical outcome was assessed using the modified Rankin scale on the 90th day from which the latest onset of the neurological symptom. Logistic regression was used to predict stroke severity, and ordinal regression was used to compare the clinical outcome. RESULTS: Among 158 patients, the numbers of patients with TIA or TSI, mild stroke, and moderate to severe stroke were 48 (30.4%), 59 (37.3%), and 51 (32.3%), respectively. The larger WMH volume was associated with moderate to severe strokes (TIA/TSI vs. moderate to severe strokes, odds ratio (OR) 2.318, 95% confidence interval (CI) 1.194-4.502, p = 0.007; mild vs. moderate to severe strokes, OR 1.972, 95% CI 1.118-3.479, p = 0.013). Patients with larger volume of WMH showed poorer clinical outcome (cutoff value: 9.71 cm3, OR 2.099, 95% CI 1.030-4.311, p = 0.042). CONCLUSION: Our study showed that larger WMH volume is associated with more severe stroke and poorer prognosis in patients with symptomatic carotid artery stenosis.

Improvement of luminescence properties of NaYF4 :Yb3+ /Er3+ upconversion materials by a cross-relaxation mechanism based on co-doped Ho3+ ion concentrations.

NaYF4 :Yb3+ /Er3+ /Ho3+ nanophosphors were successfully synthesized using a solvothermal method and with various concentrations of Ho3+ ions. The crystal structure, grain size, morphology, and luminescence properties were analyzed by X-ray diffraction, field-emission scanning electron microscopy, and photoluminescence measurements. All samples were crystallized as a cubic structure; it was confirmed that all samples exhibited strong green emission and weak red emission generated at a particular level of the activated ions. The strongest upconversion fluorescence intensity was observed in the Ho3+ and Er3+ ions co-doped NaYF4 materials with a Ho3+ ion concentration of 0.005 mol. Only the green fluorescence intensity at the 542 nm centre increased strongly due to the 4 S3/2 →4 I15/2 energy transfer. This increase in upconversion fluorescence intensity at a selected wavelength was described as a cross-relaxation mechanism due to the addition of Ho3+ ions.

Luminal and Wall Changes in Intracranial Arterial Lesions for Predicting Stroke Occurrence.

BACKGROUND AND PURPOSE: Luminal imaging (degree of stenosis) currently serves as the gold standard to predict stroke recurrence and guide therapeutic strategies in patients with intracranial large artery diseases (ILADs). We comparatively evaluated the importance of vessel wall and luminal changes in predicting stroke occurrence. METHODS: Consecutive patients with ILAD in the proximal middle cerebral artery or distal internal carotid artery without proximal sources of embolism from the carotid and heart underwent time-of-flight magnetic resonance angiography, high-resolution magnetic resonance imaging, and the ring finger protein 213 (RNF213) gene variant test. Patients were followed up for >3 months. RESULTS: Of the 675 patients, 241 (35.7%) had atherosclerotic ILAD and 434 (64.3%) showed nonatherosclerotic ILAD (315 [46.7%] moyamoya disease cases and 119 [17.6%] dissection cases). The RNF213 variant was detected in 74.9%, 33.6%, and 3.4% patients with moyamoya disease, atherosclerosis, and dissection, respectively. Three hundred (44.4%) patients had asymptomatic ILAD, whereas 375 (55.6%) patients had symptomatic ILAD. Multivariate analysis showed that vessel enhancement and etiological subtypes, not degree of stenosis, determined by high-resolution magnetic resonance imaging and RNF213 gene variant analysis were independently associated with symptomatic ILAD. The presence of the RNF213 variant was also independently associated with recurrent cerebrovascular events. CONCLUSIONS: This study demonstrates the prevalence of nonatherosclerotic ILAD in East Asian patients with ILAD. Unlike luminal changes, wall changes determined by high-resolution magnetic resonance imaging and presence of the RNF213 variant could predict stroke occurrence in patients with ILADs.

Multi-scale ordering in highly stretchable polymer semiconducting films.

Stretchable semiconducting polymers have been developed as a key component to enable skin-like wearable electronics, but their electrical performance must be improved to enable more advanced functionalities. Here, we report a solution processing approach that can achieve multi-scale ordering and alignment of conjugated polymers in stretchable semiconductors to substantially improve their charge carrier mobility. Using solution shearing with a patterned microtrench coating blade, macroscale alignment of conjugated-polymer nanostructures was achieved along the charge transport direction. In conjunction, the nanoscale spatial confinement aligns chain conformation and promotes short-range π-π ordering, substantially reducing the energetic barrier for charge carrier transport. As a result, the mobilities of stretchable conjugated-polymer films have been enhanced up to threefold and maintained under a strain up to 100%. This method may also serve as the basis for large-area manufacturing of stretchable semiconducting films, as demonstrated by the roll-to-roll coating of metre-scale films.

Intensive Statin Treatment in Acute Ischaemic Stroke Patients with Intracranial Atherosclerosis: a High-Resolution Magnetic Resonance Imaging study (STAMINA-MRI Study).

OBJECTIVE: Intracranial atherosclerosis is a major cause of ischaemic stroke worldwide. A number of studies have shown the effects of statin treatment on coronary and carotid artery plaques, but there is little evidence on the effects of statin treatment on intracranial atherosclerotic plaques. METHODS: The Intensive Statin Treatment in Acute Ischaemic Stroke Patients with Intracranial Atherosclerosis - High-Resolution Magnetic Resonance Imaging (STAMINA-MRI) Trial is a single-arm, prospective, observational study monitoring imaging and clinical outcomes of high-dose statin treatment among statin-naive patients with acute ischaemic stroke caused by symptomatic intracranial atherosclerosis. The primary outcome was the change in vascular remodelling and plaque characteristics before and after 6 months (median: 179 days, IQR 163-189 days) of statin treatment measured by high-resolution MRI (HR-MRI). RESULTS: A total of 77 patients (mean age: 62.6±13.7 years, 61.0% women) were included in this study. Low-density lipoprotein cholesterol (LDL-C) levels (mg/dL) at initial and follow-up assessments were 125.81±35.69 and 60.95±19.28, respectively. Overall, statin treatment significantly decreased enhancement of plaque volume (mm3, 32.07±39.15 vs 17.06±34.53, p=0.013), the wall area index (7.50±4.28 vs 5.86±4.05, p=0.016) and stenosis degree (%, 76.47±20.23 vs 64.05±21.29, p<0.001), but not the remodelling index (p=0.195). However, 35% patients showed no change or increased enhancement volume and stenosis degree after statin treatment. Higher reduction of LDL-C and longer duration of statin treatment were associated with decreased enhancement volume after statin treatment. CONCLUSIONS: High-dose statin treatment effectively stabilised symptomatic intracranial atherosclerotic plaques as documented by HR-MRI. Further study is needed to determine laboratory and genetic factors associated with poor response to statins and alternative therapeutic options, such as proprotein convertase subtilisin-kexin type 9 inhibitors, for these patients. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov NCT02458755.

Perfusion recovery on TTP maps after endovascular stroke treatment might predict favorable neurological outcomes.

OBJECTIVES: Early recanalization and adequate collateral blood flow are surrogates for functional recovery in endovascular stroke treatment (EVT). We evaluated the prognostic value of pre- and immediate post-thrombectomy perfusion-weighted magnetic resonance imaging (PWI) parameters. METHODS: Consecutive patients with acute ischemic stroke who underwent EVT were enrolled. Lesion volumes and their corresponding changes on diffusion-weighted (DWI) and PWI were assessed. Outcome was measured with modified Rankin Scale (mRS) at 90 days, and early neurological improvement (> 8 points improvement on National Institutes of Health Stroke Scale [NIHSS] or 0 to 1) at 7 days. RESULTS: Fifty-two patients were enrolled. After control of initial NIHSS and recanalization status, post-thrombectomy time-to-peak (TTP) hypoperfused volume and TTP hypoperfused volume change remained independent predictors of favorable functional outcome (odds ratio [OR] = 0.13, 95% confidence interval [CI] = 0.03-0.54, p = 0.005; OR = 1.018, 95% CI = 1.00-1.03, p = 0.017), and early neurological improvement (OR = 0.20, 95% CI 0.07-0.58, p = 0.003; OR = 1.02, 95% CI = 1.00-1.03, p = 0.010). The areas under the curve of post-thrombectomy TTP hypoperfused volume and TTP hypoperfused volume change were 0.90 and 0.82 (cutoff 68 mL and 56 mL) for favorable outcome and 0.86 and 0.82 (cutoff 76 mL and 58 mL) for early neurological improvement, which had better prognostic values than other MR parameters and recanalization grades. CONCLUSIONS: These results suggest a large amount of perfusion recovery on TTP is associated with favorable outcome as well as early neurological improvement after EVT, and may be a useful prognostic marker. KEY POINTS: • A large amount of perfusion recovery on TTP map is associated with favorable outcome and early neurological improvement after EVT. • The best cutoff value for favorable functional outcome was 68 mL for post-EVT TTP hypoperfused volume and 56 mL decrease for TTP hypoperfused volume. • Amount of perfusion recovery on TTP map has better performance on the prediction of favorable functional recovery and early neurological improvement than other diffusion- and perfusion-weighted MRI parameters and recanalization grades.

Circulating DNAs, a Marker of Neutrophil Extracellular Traposis and Cancer-Related Stroke: The OASIS-Cancer Study.

Background and Purpose- The role of circulating neutrophil extracellular traps (NETs) in cancer-related stroke is unknown. Methods- We conducted a prospective cohort study to test whether NETs are increased in cancer-related stroke and whether elevated NETs levels are associated with coagulopathy, assessed using D-dimer levels (≥2 µg/mL). Plasma DNA and nucleosome were assessed as NET-specific biomarkers. Results- In total, 138 patients were recruited; 38 patients had cancer-related stroke (active cancer and acute cryptogenic embolic stroke), 33 patients were healthy-controls, 27 patients were cancer-controls (active cancer but no stroke), and 40 patients were stroke-controls (acute ischemic stroke but no cancer). Plasma DNA and nucleosome levels were significantly elevated in cancer-related stroke patients than in healthy-controls (P<0.05). These levels were correlated with the D-dimer levels (P<0.01). In multiple regression analyses, increased plasma DNA levels were associated with cancer-related stroke (odds ratio=11.65 for highest quartile; 95% CI, 3.199-42.46) and D-dimer levels of ≥2 µg/mL (odds ratio=19.09 for highest quartile; 95% CI, 4.143-87.95) after adjusting for possible confounders. Conclusions- Increased circulating DNA levels were associated with cancer-related stroke, suggesting that NETosis is one of the molecular mechanisms of cancer-related stroke. Further long-term follow-up studies in large cohorts are needed to confirm the role of NET-specific biomarkers.