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Ferroelectric HfO2‐based films incorporated in nonvolatile memory devices offer a low‐energy, high‐speed alternative to conventional memory systems. Oxygen vacancies have been rigorously cited in literature to be pivotal in stabilizing the polar noncentrosymmetric phase responsible for ferroelectricity in HfO2‐based films. Thus, the ability to regulate and control oxygen vacancy migration in operando in such materials would potentially offer step changing new functionalities, tunable electrical properties, and enhanced device lifespan. Herein, a novel in‐ operando approach to control both wake‐up and fatigue device dynamics is reported. Via clever design of short ad hoc square electrical pulses, both wake‐up can be sped up and both fatigue and leakage inside the film can be reduced, key factors for enhancing the performance of memory devices. Using plasmon‐enhanced photoluminescence and dark‐field spectroscopy (sensitive to <1% vacancy variation), evidence that the electrical pulses give rise to oxygen vacancy redistribution is provided and it is shown that pulse engineering effectively delays wake‐up and reduces fatigue characteristics of the HfO2‐based films. Comprehensive analysis also includes impedance spectroscopy measurements, which exclude any influence of polarization reversal or domain wall movement in interpretation of results. [ABSTRACT FROM AUTHOR]

0.92(K0.5Na0.5)NbO3‐0.02(Bi0.8Li0.2)TiO3‐0.06BaZrO3 (BZ6) is a lead‐free piezoelectric ceramic with excellent piezoelectric performance (such as the normalized strain d33∗$d_{33}^*$ reaches up to 476 pm/V). Considering potential device applications, it is essential to evaluate the ceramic's resistance to electrical fatigue. The bipolar fatigue behavior of (K,Na)NbO3 (KNN)‐based lead‐free piezoelectric ceramics was investigated. Comparative analysis shows that BaZrO3‐modified KNN ceramics have strong resistance to bipolar fatigue due to the coexistence of rhombohedral and tetragonal phase and the depinning of domain walls, whereas microstructural damage under mechanical stress makes pristine KNN ceramics susceptible to bipolar cycling. The hypothesis was systematically verified through the study of cycle‐dependent small and large signal parameters and microscopic morphology. Our findings can guide the future design of KNN compositions with high resistance to bipolar fatigue. [ABSTRACT FROM AUTHOR]

Background: Airway management in Duchenne patients can be challenging. We present a case of an anticipated difficult airway in a 24-year-old Duchenne patient that was managed by planning different suitable strategies based on the unanticipated difficult airway algorithm of the Difficult Airway Society (DAS). Case presentation: The patient initially presented with appendicitis, requiring a laparoscopic appendectomy within 6 h. Due to the underlying condition and a known difficult airway, we anticipated potential airway problems and successfully managed the "can ventilate but cannot intubate" situation using the algorithm. The difficult airway was attributed to reduced mandibular mobility, limited inclination or reclination, a large tongue, prominent incisors, and a posteriorly positioned epiglottis. Despite thorough preparation and team briefing, we experienced three failed intubation attempts. Considering limited nighttime resources, the urgency of the surgery, the need for a tube for laparoscopy, and the risk of exacerbating airway issues, we made the decision to awaken the patient and wait for a second attempt after the epiglottis swelling had subsided. We used reversible, short-acting agents for induction, enabling us to continue with the algorithm within the allotted timeframe. In a second stage, we successfully performed fiberoptic-guided intubation via a supraglottic airway device using the Aintree intubation catheter, utilizing more favorable resources. Conclusions: For a patient with Duchenne muscular dystrophy and a difficult airway, advanced expertise is critical. Detailed anesthesia planning, clear team communication, and the use of reversible, short-acting agents are crucial. Adherence to the Difficult Airway Society guidelines is essential for safe airway management. [ABSTRACT FROM AUTHOR]

Background: Wake-up stroke represents a significant challenge in acute treatment and care. Thrombolysis has been extensively studied in the wake-up stroke population. However, mechanical thrombectomy in wake-up stroke exclusively has not been well studied. We performed a systematic review and meta-analysis to assess the clinical and functional outcomes of patients undergoing mechanical thrombectomy for wake-up stroke. Methods: We performed a systematic review of the literature using publically accessible databases. Data extraction was completed using Nested Knowledge AutoLit software. Outcomes of interest included modified Rankin Scale (mRS) 0–2, mortality, symptomatic intracerebral hemorrhage (sICH), and thrombolysis in cerebral infarction (TICI) score 2b/3. Statistical analysis was performed using R software version 4.1.2. Results: A total of 12 studies were included in our study with a total of 510 patients included. Patients with wake-up stroke were found to have good functional outcome (mRS 0–2) in 46.2% of patients and successful reperfusion (TICI 2b/3) was seen in 83.5% of patients. Mortality was observed in 20.4% of patients with sICH seen in 8.3%. Conclusion: Mechanical thrombectomy for patients with wake-up stroke was found to have favorable rates of good functional outcomes and relatively low rates of adverse events. [ABSTRACT FROM AUTHOR]

This work experimentally investigated the wake-up behaviors of hafnium oxide-based ferroelectric capacitors by manipulating the interval time between each characterization cycle. Both Positive-Up–Negative-Down (PUND) and Negative-Down–Positive-Up (NDPU) waveforms were used as the stress and measurement waveforms in the experiments. It was found that the imprint occurs as the total interval time increases to a several-seconds level. However, this only affects the remnant polarization (PR) of ferroelectric capacitors when stressed by NDPU waveforms, since the voltage amplitude saturates under the PUND stress conditions and does not influence the PR. The wake-up behavior has been proved to be caused by the defects redistribution during electrical cycling. Notably, when using PUND waveforms, the change in the interval time can result in different increase rates of PR, indicating the possibility of recovery during the intervals. This recovery leads to a slower wake-up when cycling with a longer interval time. Moreover, it is observed that this PR recovery could reach saturation after several seconds of the interval time. This comprehensive investigation of wake-up and imprint behaviors can provide new insights to evaluate and enhance the reliability of ferroelectric memories. [ABSTRACT FROM AUTHOR]

The development of the new generation of non-volatile high-density ferroelectric memory requires the utilization of ultrathin ferroelectric films. The most promising candidates are polycrystalline-doped HfO2 films because of their perfect compatibility with silicon technology and excellent ferroelectric properties. However, the remanent polarization of HfO2 films is known to degrade when their thickness is reduced to a few nanometers. One of the reasons for this phenomenon is the wake-up effect, which is more pronounced in the thinner the film. For the ultrathin HfO2 films, it can be so long-lasting that degradation occurs even before the wake-up procedure is completed. In this work, an approach to suppress the wake-up in ultrathin Hf0.5Zr0.5O2 films is elucidated. By engineering internal built-in fields in an as-prepared structure, a stable ferroelectricity without a wake-up effect is induced in 4.5 nm thick Hf0.5Zr0.5O2 film. By analysis of the functional characteristics of ferroelectric structures with a different pattern of internal built-in fields and their comparison with the results of in situ piezoresponse force microscopy and synchrotron X-ray micro-diffraction, the important role of built-in fields in ferroelectricity of ultrathin Hf0.5Zr0.5O2 films as well as the origin of stable ferroelectric properties is revealed. [ABSTRACT FROM AUTHOR]

Background: Airway management in Duchenne patients can be challenging. We present a case of an anticipated difficult airway in a 24-year-old Duchenne patient that was managed by planning different suitable strategies based on the unanticipated difficult airway algorithm of the Difficult Airway Society (DAS). Case presentation: The patient initially presented with appendicitis, requiring a laparoscopic appendectomy within 6 h. Due to the underlying condition and a known difficult airway, we anticipated potential airway problems and successfully managed the “can ventilate but cannot intubate” situation using the algorithm. The difficult airway was attributed to reduced mandibular mobility, limited inclination or reclination, a large tongue, prominent incisors, and a posteriorly positioned epiglottis. Despite thorough preparation and team briefing, we experienced three failed intubation attempts. Considering limited nighttime resources, the urgency of the surgery, the need for a tube for laparoscopy, and the risk of exacerbating airway issues, we made the decision to awaken the patient and wait for a second attempt after the epiglottis swelling had subsided. We used reversible, short-acting agents for induction, enabling us to continue with the algorithm within the allotted timeframe. In a second stage, we successfully performed fiberoptic-guided intubation via a supraglottic airway device using the Aintree intubation catheter, utilizing more favorable resources. Conclusions: For a patient with Duchenne muscular dystrophy and a difficult airway, advanced expertise is critical. Detailed anesthesia planning, clear team communication, and the use of reversible, short-acting agents are crucial. Adherence to the Difficult Airway Society guidelines is essential for safe airway management.

Ferroelectric materials offer a low‐energy, high‐speed alternative to conventional logic and memory circuitry. Hafnia‐based films have achieved single‐digit nm ferroelectricity, enabling further device miniaturization. However, they can exhibit nonideal behavior, specifically wake‐up and fatigue effects, leading to unpredictable performance variation over consecutive electronic switching cycles, preventing large‐scale commercialization. The origins are still under debate. Using plasmon‐enhanced spectroscopy, a non‐destructive technique sensitive to <1% oxygen vacancy variation, phase changes, and single switching cycle resolution, the first real‐time in operando nanoscale direct tracking of oxygen vacancy migration in 5 nm hafnium zirconium oxide during a pre‐wake‐up stage is provided. It is shown that the pre‐wake‐up leads to a structural phase change from monoclinic to orthorhombic phase, which further determines the device wake‐up. Further migration of oxygen ions in the phase changed material is then observed, producing device fatigue. These results provide a comprehensive explanation for the wake‐up and fatigue with Raman, photoluminescence and darkfield spectroscopy, combined with density functional theory and finite‐difference time‐domain simulations. [ABSTRACT FROM AUTHOR]

Background and purpose: Sex‐based differences in acute ischemic stroke are a well‐known phenomenon. We aimed to explore these differences between women and men in the Efficacy and Safety of MRI‐Based Thrombolysis in Wake‐Up Stroke (WAKE‐UP) trial. Methods: We compared baseline demographic and imaging characteristics (visual fluid‐attenuated inversion recovery [FLAIR] positivity, relative FLAIR signal intensity, collateral status) between women and men in all screened patients. In randomized patients (i.e., those with diffusion‐weighted imaging (DWI)–FLAIR mismatch), we evaluated a modifying role of sex on the treatment effect of alteplase in multivariable logistic regression, with treatment adjusted for National Institute of Health Stroke Scale (NIHSS) score and age. Dependent variables were modified Rankin Scale (mRS) score of 0–1 at 90 days and distribution of mRS scores at 90 days. Results: Of 1362 screened patients, 529 (38.8%) were women. Women were older than men, had higher baseline NIHSS scores and smoked less frequently. FLAIR positivity of the DWI lesion was equally present in women (174/529, 33.1%) and men (273/833, 33.3%; p = 1.00) and other imaging variables also did not differ between the sexes. In a total of 503 randomized patients, of whom 178 were women (35.4%), sex did not modify the treatment effect of alteplase on mRS score 0–1 or on the total distribution of mRS scores. Conclusion: As in many other stroke trials, more men than women were included in the WAKE‐UP trial, but the presence of a visual DWI–FLAIR mismatch and the relative FLAIR signal intensity did not differ between the sexes. The treatment effect of alteplase was not modified by sex. [ABSTRACT FROM AUTHOR]

The development of the new generation of non-volatile high-density ferroelectric memory requires the utilization of ultrathin ferroelectric films. The most promising candidates are polycrystalline-doped HfO2 films because of their perfect compatibility with silicon technology and excellent ferroelectric properties. However, the remanent polarization of HfO2 films is known to degrade when their thickness is reduced to a few nanometers. One of the reasons for this phenomenon is the wake-up effect, which is more pronounced in the thinner the film. For the ultrathin HfO2 films, it can be so long-lasting that degradation occurs even before the wake-up procedure is completed. In this work, an approach to suppress the wake-up in ultrathin Hf0.5Zr0.5O2 films is elucidated. By engineering internal built-in fields in an as-prepared structure, a stable ferroelectricity without a wake-up effect is induced in 4.5 nm thick Hf0.5Zr0.5O2 film. By analysis of the functional characteristics of ferroelectric structures with a different pattern of internal built-in fields and their comparison with the results of in situ piezoresponse force microscopy and synchrotron X-ray micro-diffraction, the important role of built-in fields in ferroelectricity of ultrathin Hf0.5Zr0.5O2 films as well as the origin of stable ferroelectric properties is revealed.

This paper reports the performance characterization of a wake-up nano-gap gas sensor with ultra-high-sensitivity due to its dependence on the electron tunneling distance that was experimentally modulated by a structural nano-gap, a chemistry linker length and a molecular size of target gases. The wake-up sensor became activated when the nano-gap was bridged for electron flow by the capture of specific target gas molecules. The fabricated nano-gap sensor demonstrated highly sensitive and selective responses to the dimensional variations in the gaps, the linkers and the target VOCs: (1) only 5-Å difference in either the nano-gap distance or the linker length produced the output signal ratios of two to five orders in magnitudes, indicating ultra-highly-sensitive characteristics; (2) only two carbon length difference of 2.3-Å between target gases with the identical functional group resulted in the output signal ratios of up to four orders in magnitudes, implying the unique distinguish capability of molecular-level length differences, and (3) the selectivity against 7 major interference gas groups in high concentrations (>1,000 ppm) was measured as at least by four orders in magnitude indicating the benefits of size-matching in gas detection on top of conventional chemistry-matching. The fabricated nano-gap gas sensor ultimately showed ultra-low power consumption of 20.08 pW during the sleep mode and repeatability of >10 cycles. These results indicated that the nano-gap sensor can be $a$ highly sensitive and selective alternative in gas sensing especially in resource-limited environments. [2022-0039] [ABSTRACT FROM AUTHOR]

In this letter, wake-up free La-doped HfO2-ZrO2 (HZO) ferroelectrics are experimentally fabricated using an atomic layer-specific doping (ALSD) technique, which selectively introduces La dopants at effective locations to facilitate the formation of ferroelectric orthorhombic phase. With this technique, robust La-doped HZO ferroelectric devices that are mostly free from the undesired wake-up effect and anti-ferroelectricity were demonstrated over a large La doping range (from 2.9 to 11.5%). Moreover, large remanent polarization and good endurance were achieved at the same time (>107 cycles). The outstanding performances can be attributed to the effective stabilization of ferroelectric orthogonal phase and the suppression of tetragonal phase, through controlling of the dopants’ local environment. Thus, ALSD is an effective approach to achieve reliable, wake-up free and CMOS-compatible HZO-based ferroelectrics. [ABSTRACT FROM AUTHOR]

Despite the great potential of Hf0.5Zr0.5O2 (HZO) ferroelectrics, reliability issues, such as wake-up, fatigue, endurance limitations, imprint and retention loss, impede the implementation of HZO to nonvolatile memory devices. Herein, a study of the reliability properties in HZO-based stacks with the conventional TiN top electrode and Ru electrode, which is considered a promising alternative to TiN, is performed. An attempt to distinguish the mechanisms underlying the wake-up, fatigue and retention loss in both kinds of stacks is undertaken. Overall, both stacks show pronounced wake-up and retention loss. Moreover, the fatigue and retention loss were found to be worsened by Ru implementation. The huge fatigue was suggested to be because Ru does not protect HZO against oxygen vacancies generation during prolonged cycling. The vacancies generated in the presence of Ru are most likely deeper traps, as compared to the traps formed at the interface with the TiN electrode. Implementing the new procedure, which can separate the depolarization-caused retention loss from the imprint-caused one, reveal a rise in the depolarization contribution with Ru implementation, accompanied by the maintenance of similarly high imprint, as in the case with the TiN electrode. Results show that the mechanisms behind the reliability issues in HZO-based capacitors are very electrode dependent and simple approaches to replacing the TiN electrode with the one providing, for example, just higher remnant polarization or lower leakages, become irrelevant on closer examination. [ABSTRACT FROM AUTHOR]

The ferroelectric polarization stability and dielectric characteristics of ZrO2-HfO2 superlattice (SL) ferroelectric layer Metal-Ferroelectric-Metal (MFM) capacitor fabricated with various post-metal annealing (PMA) temperatures were presented. It was demonstrated that ZrO2-HfO2 SL MFM capacitors with increased post metallization PMA temperature (i.e., 600 °C) showed improved polarization stability with almost wake-up free and polarization fatigue free characteristics. In this work, we have shown that highly stable remanent polarization (2Pr@ 3MV $/$ cm) of ~ $30 ~\mu \text{C}/$ cm2 with small variation ($\Delta 2\text{P}_{r} \le 2 ~\mu \text{C}/$ cm2; $\Delta 2\text{P}_{r} / 2\text{P}_{r,pristine} \le9$ %) up to 1011 cycles of field cycling were exhibited by the atomic layer deposition (ALD) deposited ZrO2-HfO2 superlattice with 600 °C PMA. To our knowledge, the nearly “wake-up”-free and fatigue-free polarization behavior up to 1011 cycles are among the best polarization stability for the hafnium zirconium oxide based MFM capacitors sustained endurance tests for more than 1010 cycles. [ABSTRACT FROM AUTHOR]

Wake-up receivers (WuRXs) present an opportunity to reduce the average power consumption of Internet-of-Things (IoT) transceivers; however, achieving sensitivity and interferer tolerance, providing wideband matching, and sharing an antenna interface present a significant challenge for existing architectures. This article presents a primary/WuRX which utilizes a quadrature hybrid coupler-based $N$ -path mixer first architecture to simultaneously achieve low noise, wideband matching, and a shared antenna interface. The passive-mixer first approach and a two-code modulated multi-tone signaling scheme provide interferer tolerance in the WuRX. This article analyzes gain/power tradeoffs in the proposed architecture in the context of noise impact with multi-tone WuRX signaling. The proposed architecture is implemented in 65-nm CMOS and occupies 2.25 $\text {mm}^{2}$. The primary RX achieves 3.8-dB NF and 0.75-dBm out-of-band P1dB with 440- $\mu \text{W}$ power consumption. The WuRX achieves −86-dBm sensitivity for 10-kb/s data rate and up to −40-dB signal-to-interferer ratio (SIR) with 171- $\mu \text{W}$ power consumption. [ABSTRACT FROM AUTHOR]

High endurance of 1011 cycles is demonstrated in ~9–10-nm stoichiometric Hafnium Zirconate (HZO) metal–ferroelectric–metal (MFM) capacitors deposited using Cl precursors with La and Y dopants. La doping is shown to offer higher remnant polarization than Y. Investigation of doped layers with asymmetric polarization versus electric field (${P}$ – ${E}$) measurements and unipolar fatigue cycles suggests that in the pristine state, the HZO is comprised of ferroelectric domains with internal built-in electric field-induced pinned coercive field (${E}_{c}$). Doping is shown to increase the pinning effect and two distinct groups of ferroelectric domains emerge, which is antialigned at zero applied electric field (${E}$). The antiferroelectric-like (pinched ${P}$ – ${E}$ loop) behavior is therefore attributed to internal built-in ${E}$ -induced pinning of the domains during growth and/or annealing steps. The initial wake-up is attributed to gradual depinning of the domains with bipolar electric pulses. Suppression of monoclinic phase was observed in doped layers that survive 1011 cycles. The wake-up is shown to be dependent on total duration and magnitude of bipolar electric pulses. Precycling scheme is demonstrated for stable operation at a lower field. [ABSTRACT FROM AUTHOR]

The stability of remanent polarization (Pr) during multiple operations is critical for memory applications, as the degradation of Pr leads to misreading of stored information. In this letter, improved stabilization of Pr during field cycling in HfZrO4 (HZO)‐based ferroelectric devices by inserting a ZrO2 layer is reported. This optimization method is inspired by the fact that the wake‐up effect of HZO is not obvious. By inserting a ZrO2 layer, which prolongs the wake‐up period, the fatigue process is postponed. Thus, a stabilized Pr is achieved during cycling. The endurance limit can reach over 1010 cycles with no significant decrease in Pr (<5%), which is beneficial for improving the reliability of devices in practical applications. [ABSTRACT FROM AUTHOR]

Introduction: Higher white blood cell (WBC) count is associated with poor functional outcome in acute ischemic stroke (AIS). However, little is known about whether the association is modified by treatment with intravenous alteplase. Methods: WAKE-UP was a randomized controlled trial of the efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in unknown onset stroke. WBC count was measured on admission and again at 22–36 h after randomization to treatment (follow-up). Favorable outcome was defined by a score of 0 or 1 on the modified Rankin scale (mRS) 90 days after stroke. Further outcome were stroke volume and any hemorrhagic transformation (HT) that were assessed on follow-up CT or MRI. Multiple logistic regression analysis was used to assess the association between outcome and WBC count and treatment group. Results: Of 503 randomized patients, WBC count and baseline parameters were available in 437 patients (μ = 64.7 years, 35.2% women) on admission and 355 patients (μ = 65.1 years, 34.1% women) on follow-up. Median WBC count on admission was 7.6 × 109/L (interquartile range, IQR, 6.1–9.4 × 109/L) and 8.2 × 109/L (IQR, 6.7–9.7 × 109/L) on follow-up. Higher WBC count both on admission and follow-up was associated with lower odds of favorable outcome, adjusted for age, National Institutes of Health (NIH) Stroke Scale Score, temperature, and treatment (alteplase vs. placebo, adjusted odds ratio, aOR 0.85, 95% confidence interval [CI] 0.78–0.94 and aOR 0.88, 95% CI 0.79–0.97). No interaction between WBC count and treatment group was observed (p = 0.11). Furthermore, WBC count on admission and follow-up was significantly associated with HT (aOR 1.14, 95% CI 1.05–1.24 and aOR 1.13, 95% CI 1.00–1.26). Finally, WBC count on follow-up was associated with larger stroke volume (aOR 2.57, 95% CI 1.08–6.07). Conclusion: Higher WBC count is associated with unfavorable outcome, an increased risk of HT, and larger stroke volume, independent of treatment with alteplase. Whether immunomodulatory manipulation of WBC count improves stroke outcome needs to be tested. Trial Registration: ClinicalTrials.gov Identifier: NCT01525290. [ABSTRACT FROM AUTHOR]

The polarization wake‐up process is demonstrated here for ferroelectric switching in epitaxial Al0.93B0.07N films on W coated c‐axis oriented Al2O3 (sapphire) substrates. During the wake‐up process, the remanent polarization grows from ≈0 to >100 µC cm−2. As it does so, both the reversible and irreversible Rayleigh coefficients rise substantially, suggesting that the concentration of mobile interfaces that separate regions of opposite dipole orientation is increasing. The irreversible Rayleigh coefficient is very small (≈3.5 × 10−4 cm kV−1), four to five orders of magnitude below those of perovskite ferroelectric films such as PbZr0.52Ti0.48O3. These small values are consistent with the high coercive fields observed in the nitride ferroelectrics. The temperature dependence of the Rayleigh coefficients suggests that the interface motion is thermally activated. On increasing frequency, the Rayleigh coefficients drop, suggesting time‐dependent pinning processes also occur in this family of materials. With information from anisotropic etching experiments upon field‐cycling, a self‐consistent model that describes a polar domain microstructure evolution process during wake‐up is proposed. [ABSTRACT FROM AUTHOR]

IntroductionHigher white blood cell (WBC) count is associated with poor functional outcome in acute ischemic stroke (AIS). However, little is known about whether the association is modified by treatment with intravenous alteplase.MethodsWAKE-UP was a randomized controlled trial of the efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in unknown onset stroke. WBC count was measured on admission and again at 22–36 h after randomization to treatment (follow-up). Favorable outcome was defined by a score of 0 or 1 on the modified Rankin scale (mRS) 90 days after stroke. Further outcome were stroke volume and any hemorrhagic transformation (HT) that were assessed on follow-up CT or MRI. Multiple logistic regression analysis was used to assess the association between outcome and WBC count and treatment group.ResultsOf 503 randomized patients, WBC count and baseline parameters were available in 437 patients (μ = 64.7 years, 35.2% women) on admission and 355 patients (μ = 65.1 years, 34.1% women) on follow-up. Median WBC count on admission was 7.6 × 109/L (interquartile range, IQR, 6.1–9.4 × 109/L) and 8.2 × 109/L (IQR, 6.7–9.7 × 109/L) on follow-up. Higher WBC count both on admission and follow-up was associated with lower odds of favorable outcome, adjusted for age, National Institutes of Health (NIH) Stroke Scale Score, temperature, and treatment (alteplase vs. placebo, adjusted odds ratio, aOR 0.85, 95% confidence interval [CI] 0.78–0.94 and aOR 0.88, 95% CI 0.79–0.97). No interaction between WBC count and treatment group was observed (p = 0.11). Furthermore, WBC count on admission and follow-up was significantly associated with HT (aOR 1.14, 95% CI 1.05–1.24 and aOR 1.13, 95% CI 1.00–1.26). Finally, WBC count on follow-up was associated with larger stroke volume (aOR 2.57, 95% CI 1.08–6.07).ConclusionHigher WBC count is associated with unfavorable outcome, an increased risk of HT, and larger stroke volume, independent of treatment with alteplase. Whether immunomodulatory manipulation of WBC count improves stroke outcome needs to be tested.Trial RegistrationClinicalTrials.gov Identifier: NCT01525290.

Background: Fluid-attenuated inversion recovery (FLAIR) sequences have gained a role to guide treatment of patients with unknown time of stroke symptom onset. Evolution of signal intensities in FLAIR is associated with time since stroke onset with continuous linear increases. Aims: Estimating symptom onset during night-sleep in patients from the WAKE-UP trial based on relative signal intensities FLAIR (FLAIR-rSI) from acute stroke lesions an independent dataset (PRE-FLAIR study). Methods: FLAIR-rSI was quantified in stroke lesions in PRE-FLAIR and WAKE-UP. The PRE-FLAIR study was a multicenter observational trial establishing FLAIR as a surrogate parameter for time since stroke onset. WAKE-UP was a randomized controlled trial that revealed a benefit for alteplase in patients selected based on a DWI-FLAIR mismatch. Stroke onset times were recorded in PRE-FLAIR and used to fit a linear regression model with FLAIR-rSI, adjusted for patient age and lesion volume. The model was applied to FLAIR-rSI of stroke lesions to estimate onset times in those patients enrolled in WAKE-UP who had symptom onset during night-sleep. Results: FLAIR-rSI was quantified in 399 patients from PRE-FLAIR. Linear regression indicated a significant association of age (p = 0.001), lesion volume (p = 0.005) and FLAIR-rSI (p < 0.001) with time since symptom onset (adjusted R2 = 0.179). In 813 patients from WAKE-UP, distribution of times of last seen well, symptom recognition and MRI examination were recorded. Median times of last seen well were 1 h before midnight (IQR 2.4 h) and symptom recognition 7 h after midnight (IRQ 2.2 h). Based on the FLAIR-rSI profiles, we estimated median stroke onset 6.1 h after midnight (IQR 2.7 h). Conclusion: Nocturnal strokes during night-sleep may predominantly occur during the early morning hours. Our results are in line with evidence of characteristic diurnal patterns of cardiovascular events. [ABSTRACT FROM AUTHOR]

In this work, the low-frequency noise (LFN) characteristics of hafnium-zirconium oxide (HZO) ferroelectric field-effect transistors (FeFETs) with and without high-pressure forming gas annealing (HPA) treatment are investigated. The origin of $1/ {f}$ noise in the FeFET without HPA is changed from carrier number fluctuation to Hooge’s mobility fluctuation after wake-up due to the remote phonon scattering from the polarized HZO. Also, Hooge’s parameter is increased by the program/erase (P/E) cycling-induced stress. On the contrary, only the correlated mobility fluctuation is increased after the wake-up in the FeFET with HPA. Furthermore, the LFN of the FeFET with HPA shows robustness to P/E cycling-induced stress after the wake-up, showing superb endurance performance. [ABSTRACT FROM AUTHOR]

Abstract Background The anatomical distribution of acute lacunar infarcts has mainly been studied for supratentorial lesions. In addition, little is known about the association with distinct stroke symptoms, not summarized as classical lacunar syndromes. We aimed to describe the spatial lesion distribution of acute supra- and infratentorial lacunar infarcts and their association with stroke symptoms in patients eligible for thrombolysis. Methods All patients enrolled in the WAKE-UP trial (efficacy and safety of magnetic resonance imaging [MRI]-based thrombolysis in wake-up stroke) were screened for lacunar infarcts on diffusion-weighted imaging (DWI). The relationship between the anatomical distribution of supra- and infratentorial lacunar infarcts, their demographic characteristics and acute stroke symptoms, defined by the National Institutes of Health Stroke Scale (NIHSS) score, were correlated and compared. Results Maps of lesion distribution from 224 lacunar infarct patients (76 [33.9%] females, mean age [standard deviation] of 63.4 [11.5] years) were generated using computational image mapping methods. Median infarct volume was 0.73 ml (interquartile range [IQR] 0.37–1.15 ml). Median NIHSS sum score on hospital arrival was 4 (IQR 3–6). 165 (73.7%) patients had lacunar infarcts in the supratentorial deep white or grey matter, while 59 (26.3%) patients had infratentorial lacunar infarcts. Patients with supratentorial lacunar infarcts presented with a significantly lower occurrence of deficits in the NIHSS items gaze (p

In this article, we present the capacitance–voltage (${C}$ – ${V}$) characteristics of HfxZr1−xO2 metal–ferroelectric–metal (MFM) thin-film capacitors with various Zr doping, thicknesses, and annealing temperatures. The influence of doping, electric field cycling, and annealing temperature on tuning characteristics (tunability) was analyzed and an optimized bias region for the maximum tunability was defined. Additional focus was made on an antiferroelectric-like (AFE) behavior, which occurs for > 50% Zr doping. The presence of both the ferroelectric and the AFE phase manifests itself in specific ${C}$ – ${V}$ behavior, where a reduced bias range is required for tuning, however, at the cost of a smaller tunability. The suitability of this behavior for varactor applications is also discussed. [ABSTRACT FROM AUTHOR]

A self-powered micro-electromechanical systems (MEMS) inertial switch has been proposed for potential wake-up application without additional power consumption. In comparison with the previous inertial switches powered by constant voltage sources, the proposed device embedded with the charged electret could output a pulse signal without an external power supply. The self-powered inertial switch has two working states: It could harvest vibration energy under excitation of small acceleration when the applied vibration acceleration was smaller than its threshold; It would output a triggering signal once the applied vibration acceleration arrived up to its threshold. The dynamic responses of the switch in the two working states were analyzed. The drop hammer system and the vibrator system were used in conjunction to test the feasibility of the fabricated self-powered inertial switch. The experimental results showed that under excitation of 0.3 g at 137 Hz, the device could work as a vibration energy harvester (VEH), charging the capacitor of the self-charging power unit to 0.8 V in one minute. When a shock with an amplitude of 40 g was applied to the device, a pulse signal was generated. In addition, electrical measurements during energy harvesting indicated durability and adaptability of the device. [2021-0080] [ABSTRACT FROM AUTHOR]

Dexmedetomidine has a dose-dependent sedative and analgesic effect. To further evaluate the wake-up quality of dexmedetomidine in patients undergoing neurosurgery, a meta-analysis of dexmedetomidine in a randomized controlled trial of general anesthesia was performed. Firstly, an experimental algorithm was proposed, and then the data fusion algorithm was used to conduct randomized controlled trials. The clinical efficacy and safety of dexmedetomidine in the acupuncture of neurosurgical patients were evaluated one by one for quality evaluation and data extraction. The effect of different input variables on the depth of anesthesia was studied by using a multi-data fusion approach. The results show that the data fusion algorithm proposed can effectively connect redundant information and complementary information in multiple data, and estimate the real parameters of the measured object. In addition, data fusion brings great convenience to the design of control algorithms and controllers, and provides an effective basis for system simplification. Experiments have shown that dexmedetomidine is effective and safe in the operation of neurosurgical motor function, and the management of the recovery period is safe and effective. Based on the research, it can provide some reference for the awakening of patients undergoing neurosurgery, and promote the progress and development of medicine.

This paper focuses on the wake-up signal detection design for underwater acoustic communication (UAC) terminals. A wake-up signal detection unit can considerably reduce the power consumption of the terminals. Compared with terrestrial wireless counterparts, the wake-up signal detection design for UAC terminals is challenged by the severe underwater acoustic channels, which is characterized as doubly selective fading and low signal-to-noise ratio (SNR). This paper proposes a wake-up signal detection approach called channel-adaptive detection and location-assisted joint decision (ChAD-LaJD), for UAC terminals. ChAD-LaJD applies a group of linear frequency modulation (LFM) signals as a wake-up signal. In order to increase the detection probability while keeping a low false alarm rate, ChAD-LaJD consists of two procedures: channel-adaptive detection (ChAD) and location-assisted joint decision (LaJD). Besides a pre-determined threshold, ChAD procedure defines two special parameters which reflect instantaneous channel states to detect wake-up signals adaptively. LaJD procedure further exploits the location relationships of LFM signals detected by ChAD to achieve a joint decision. The simulations and field experiments are conducted to evaluate the performance of ChAD-LaJD. The results show that ChAD-LaJD outperforms the conventional methods that consider a fixed threshold (FixTh) and/or constant false alarm rate (CFAR).

In this paper, we present our study on investigating the effect of music for sleep induction and wake-up. Unlike existing studies that mostly focused on understanding how specific types of music affect sleep for insomnia patients or older people in laboratory conditions, we aim to study the effect of pop music with respect to the musical features on both sleep and wake-up of young adults without serious sleep disorder in the real-world environment. We conduct two extensive experiments, for which we carefully design a system consisting of hardware and software components for reliable data collection. Our analysis focuses on what types of musical features are effective for fast sleep induction and wake-up. Furthermore, we present two application scenarios of sleep music recommendation based on our findings.

Background and purpose: The aim was to study the effect of intravenous alteplase on the development of post‐stroke depression (PSD) in acute stroke patients, and to identify predictors of PSD. Methods: This post hoc analysis included patients with unknown onset stroke randomized to treatment with alteplase or placebo in the WAKE‐UP trial (ClinicalTrials.gov number, NCT01525290), in whom a composite end‐point of PSD was defined as a Beck Depression Inventory ≥10, medication with an antidepressant, or depression recorded as an adverse event. Multiple logistic regression was used to identify predictors of PSD at 90 days. Structural equation modelling was applied to assess the indirect effect of thrombolysis on PSD mediated by the modified Rankin Scale. Results: Information on the composite end‐point was available for 438 of 503 randomized patients. PSD was present in 96 of 224 (42.9%) patients in the alteplase group and 115 of 214 (53.7%) in the placebo group (odds ratio 0.63; 95% confidence interval 0.43–0.94; p = 0.022; adjusted for age and National Institutes of Health Stroke Scale at baseline). Prognostic factors associated with PSD included baseline medication with antidepressants, higher lesion volume, history of depression and assignment to placebo. While 65% of the effect of thrombolysis on PSD were caused directly, 35% were mediated by an improvement of the mRS. Conclusions: Treatment with alteplase in patients with acute stroke resulted in lower rates of depression at 90 days, which were only partially explained by reduced functional disability. Predictors of PSD including history and clinical characteristics may help in identifying patients at risk of PSD. [ABSTRACT FROM AUTHOR]

Background & aims: Previous studies have shown the association between smartphone addiction and sleep quality, prolonged bedtime, and chronotype of sleep. However, most reports use subjective reports may bias the measurement. In addition, the gender factor could be a moderating variable in the association between subjective and objective measurements. With the development of technology, a wearable device could be applied to measure sleep pattern and plays as an important role with more objective measurement. In order to explore the stabilities and differences between the subjective and objective markers of sleep measurement, this study proposed to investigate the relationship among smartphone addiction, gender, and subjective/objective sleep. Methods: Forty-nine university students (18Males, 31females) were recruited, and were evaluated using Ko Internet User Behavior Inventory - Smartphone Addiction Subscale (Cutoff =4/5) to define the group with Smartphone Addiction (SPA, n=19) and non-SPA (n=30). Each participant was assessed using Chinese version of Pittsburgh Sleep Quality Index (CPSQI) for the subjective measurements. In addition, each participant was required to wear a wearable device to measure their daily sleep patterns for a continuous month. Results: 3-Way MANOVA found a significant difference between the subjective and objective reports of the sleep onset(p<.05) and awake time(p<.05), but not the total sleep time(p>.05). Moreover, a significant difference of total sleep time(p<.05), total awakening time(p<.05) between the SPA and non-SPA group. Taking gender effect into account, the results showed a significant difference of wake-up time between male and female(p<.05). Furthermore, Pearson product moment correlations showed a significant association between the subjective reports of total sleep time(p<.05) and the sleep onset(p>.05) measured by the wearable device. Conclusions: In conclusion, university students with SPA may appear similar sleep chronotypes with those without SPA, however, the SPA group exhibits shorter sleep time and poorer sleep quality compared to the non-SPA. [ABSTRACT FROM AUTHOR]

Background and purpose: Polypharmacy is an important challenge in clinical practice. Our aim was to determine the effect of polypharmacy on functional outcome and treatment effect of alteplase in acute ischaemic stroke. Methods: This was a post hoc analysis of the randomized, placebo‐controlled WAKE‐UP trial of magnetic resonance imaging guided intravenous alteplase in unknown onset stroke. Polypharmacy was defined as an intake of five or more medications at baseline. Comorbidities were assessed by the Charlson Comorbidity Index (CCI). The primary efficacy variable was favourable outcome defined by a score of 0–1 on the modified Rankin Scale at 90 days. Logistic regression analysis was used to test for an association of polypharmacy with functional outcome, and for interaction of polypharmacy and the effect of thrombolysis. Results: Polypharmacy was present in 133/503 (26%) patients. Patients with polypharmacy were older (mean age 70 vs. 64 years; p < 0.0001) and had a higher score on the National Institutes of Health Stroke Scale at baseline (median 7 vs. 5; p = 0.0007). A comorbidity load defined by a CCI score ≥ 2 was more frequent in patients with polypharmacy (48% vs. 8%; p < 0.001). Polypharmacy was associated with lower odds of favourable outcome (adjusted odds ratio 0.50, 95% confidence interval 0.30–0.85; p = 0.0099), whilst the CCI score was not. Treatment with alteplase was associated with higher odds of favourable outcome in both groups, with no heterogeneity of treatment effect (test for interaction of treatment and polypharmacy, p = 0.29). Conclusion: In stroke patients, polypharmacy is associated with worse functional outcome after intravenous thrombolysis independent of comorbidities. However, polypharmacy does not interact with the beneficial effect of alteplase. [ABSTRACT FROM AUTHOR]

Background: Hemorrhagic transformation (HT) is an important complication of intravenous thrombolysis with alteplase. HT can show a wide range from petechiae to parenchymal hematoma with mass effect with varying clinical impact. We studied clinical and imaging characteristics of patients with HT and evaluated whether different types of HT are associated with functional outcome.Methods: We performed a post-hoc analysis of WAKE-UP, a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in unknown onset stroke. HT was assessed on follow-up MRI or CT and diagnosed as hemorrhagic infarction type 1 and type 2 (HI1 and HI2, combined as HI), and parenchymal hemorrhage type 1 and type 2 (PH1 and PH2, combined as PH). Severity of stroke symptoms was assessed using the National Institutes of Health Stroke Scale (NIHSS) at baseline. Stroke lesion volume was measured on baseline diffusion weighted imaging (DWI). Primary endpoint was a favorable outcome defined as a modified Rankin Scale score 0–1 at 90 days.Results: Of 483 patients included in the analysis, 95 (19.7%) showed HI and 21 (4.4%) had PH. Multiple logistic regression analysis identified treatment with alteplase (OR, 2.08 [95% CI, 1.28–3.40]), baseline NIHSS score (OR, 1.11 [95% CI, 1.05–1.17]), DWI lesion volume (OR, 1.03 [95% CI, 1.01–1.05]), baseline glucose levels (OR, 1.01 [95% CI, 1.00–1.01]) and atrial fibrillation (OR, 3.02 [95% CI, 1.57–5.80]) as predictors of any HT. The same parameters predicted HI. Predictors of PH were baseline NIHSS score (OR, 1.11 [95% CI, 1.01–1.22]) and as a trend treatment with alteplase (OR, 2.40 [95% CI, 0.93–6.96]). PH was associated with lower odds of favorable outcome (OR 0.25, 95% [CI 0.05–0.86]), while HI was not.Conclusion: Our results indicate that HI is associated with stroke severity, cardiovascular risk factors and thrombolysis. PH is a rare complication, more frequent in severe stroke and with thrombolysis. In contrast to HI, PH is associated with worse functional outcome. The impact of HT after MRI-guided intravenous alteplase for unknown onset stroke on clinical outcome is similar as in the trials of stroke thrombolysis within a known early time-window.

In this article, a body channel communication (BCC) transceiver (TRX) and low-power receiver (RX) that can cover wide applications are proposed. The IEEE 802.15.6 human body communication (HBC) physical layer (PHY) standard and high-speed data transmission are supported simultaneously with a single chip. First, the sinusoidal-modulated transmitter is proposed for the standard mode TRX, and it can reduce filtering power overhead 35%. Second, high-speed TRX is proposed that can support dual-band QPSK modulation to increase system data rate and bandwidth efficiency. Third, on-chip RC duplexer is proposed for full-duplex function in communication. Also, for the low-power RX, a wireless power transfer (WPT)-based wake-up receiver (WuRX) and a higher energy efficiency main RX is integrated into RX chip. The main HBC RX demodulates both ASK and frequency-shift keying (FSK) information with a sharing oscillator (OSC) with 31- $\mu \text{W}$ low-power consumption. The TRX and RX are implemented in 65-nm CMOS process. [ABSTRACT FROM AUTHOR]

This brief presents a digital capacitive MEMS microphone for speech recognition with fast wake-up feature using a sound activity detector. The proposed microphone wakes up only when an acoustic event within the voice-band occurs using the sound activity detector, which can significantly reduce the average current consumption. All wake-up processes are performed on-chip, which enables the fast wake-up feature to prevent missing keywords. In addition, the proposed deglitching technique is applied to prevent the sound activity detector from responding to non-acoustic signals such as glitch signals. An auxiliary low-dropout regulator is used to further reduce the wake-up time. Our microphone consumes only 16 $\mu \text{A}$ in deep-sleep mode. In active mode, a high-performance readout circuit converts the voice signal into a digital signal. The proposed microphone achieves an A-weighted signal-to-noise ratio (SNR) of 62.8 dBA and an acoustic overload point of 119.4 dB sound pressure level. The readout circuit itself of our microphone, fabricated in a 0.18 $\mu \text{m}$ CMOS process, has an A-weighted SNR of 65.8 dBA. [ABSTRACT FROM AUTHOR]

Purpose: Lacunar infarcts are thought to result from occlusion of small penetrating arteries due to microatheroma and lipohyalinosis, pathognomonic for cerebral small vessel disease (CSVD). Concurrent embolic ischemic lesions indicate a different stroke mechanism. The purpose of this study was to examine the clinical characteristics and outcome of patients with lacunar infarcts and concurrent embolic infarcts on diffusion-weighted imaging (DWI). Methods: All patients screened for the WAKE-UP trial (ClinicalTrials.gov number, NCT01525290) were reviewed for acute lacunar infarcts and concurrent embolic lesions on baseline DWI. Clinical characteristics and outcome were compared between lacunar infarct patients with and without concurrent embolic lesions. Results: Of 244 patients with an acute lacunar infarct, 20 (8.2%) had concurrent acute embolic infarcts. Compared to patients with a lacunar infarct only, patients with concurrent embolic infarcts were older (mean age 69 years vs. 63 years; p = 0.031), more severely affected (median National Institutes of Health Stroke Scale [NIHSS] score 5 vs. 4; p = 0.046), and—among those randomized—had worse functional outcome at 90 days (median modified Rankin Scale [mRS] 3 vs. 1; p = 0.011). Conclusion: Approximately 8% of lacunar infarct patients show concurrent embolic lesions suggesting a stroke etiology other than CSVD. These patients are more severely affected and have a worse functional outcome illustrating the need for a thorough diagnostic work-up of possible embolic sources even in patients with an imaging-defined diagnosis of lacunar infarcts. [ABSTRACT FROM AUTHOR]

Background: Hemorrhagic transformation (HT) is an important complication of intravenous thrombolysis with alteplase. HT can show a wide range from petechiae to parenchymal hematoma with mass effect with varying clinical impact. We studied clinical and imaging characteristics of patients with HT and evaluated whether different types of HT are associated with functional outcome. Methods: We performed a post-hoc analysis of WAKE-UP, a multicenter, randomized, placebo-controlled trial of MRI-guided intravenous alteplase in unknown onset stroke. HT was assessed on follow-up MRI or CT and diagnosed as hemorrhagic infarction type 1 and type 2 (HI1 and HI2, combined as HI), and parenchymal hemorrhage type 1 and type 2 (PH1 and PH2, combined as PH). Severity of stroke symptoms was assessed using the National Institutes of Health Stroke Scale (NIHSS) at baseline. Stroke lesion volume was measured on baseline diffusion weighted imaging (DWI). Primary endpoint was a favorable outcome defined as a modified Rankin Scale score 0–1 at 90 days. Results: Of 483 patients included in the analysis, 95 (19.7%) showed HI and 21 (4.4%) had PH. Multiple logistic regression analysis identified treatment with alteplase (OR, 2.08 [95% CI, 1.28–3.40]), baseline NIHSS score (OR, 1.11 [95% CI, 1.05–1.17]), DWI lesion volume (OR, 1.03 [95% CI, 1.01–1.05]), baseline glucose levels (OR, 1.01 [95% CI, 1.00–1.01]) and atrial fibrillation (OR, 3.02 [95% CI, 1.57–5.80]) as predictors of any HT. The same parameters predicted HI. Predictors of PH were baseline NIHSS score (OR, 1.11 [95% CI, 1.01–1.22]) and as a trend treatment with alteplase (OR, 2.40 [95% CI, 0.93–6.96]). PH was associated with lower odds of favorable outcome (OR 0.25, 95% [CI 0.05–0.86]), while HI was not. Conclusion: Our results indicate that HI is associated with stroke severity, cardiovascular risk factors and thrombolysis. PH is a rare complication, more frequent in severe stroke and with thrombolysis. In contrast to HI, PH is associated with worse functional outcome. The impact of HT after MRI-guided intravenous alteplase for unknown onset stroke on clinical outcome is similar as in the trials of stroke thrombolysis within a known early time-window. [ABSTRACT FROM AUTHOR]

This paper proposes an improved decoding scheme of emergency alert wake-up bits in Advanced Television Systems Committee (ATSC) 3.0. When a broadcast service is being provided, a bootstrap signal of ATSC 3.0 includes the minimal essential information that does not change at least for two consecutive physical layer frames. Then, the received signal can be further assumed to be binary modulated according to each wake-up bit, so as to achieve the improved decoding performance as well as reduced decoding complexity. The simulation results show that the proposed decoding scheme of wake-up bits can obtain signal-to-noise ratio (SNR) gains of approximately 1.6 dB and 2.5 dB at bit error rate (BER) of 10−4 compared to the conventional decoding scheme under fixed and mobile reception environments, respectively. In addition, the analysis on the computational complexity of the proposed decoding scheme is provided. [ABSTRACT FROM AUTHOR]

[Display omitted] • The remanent polarization and coercive field of Hf 0.5 Zr 0.5 O 2 with a Mo electrode were larger than those with a TiN electrode. • The Hf 0.5 Zr 0.5 O 2 with Mo electrode exhibits lower concentration of oxygen vacancies than Hf 0.5 Zr 0.5 O 2 with TiN electrode. • The 010-texture of the orthorhombic phase in Hf 0.5 Zr 0.5 O 2 with the TiN electrode may have undergone ferroelastic switching. • The dynamic phase evolution of Hf 0.5 Zr 0.5 O 2 and the wake-up effect could be avoided by adopting the Mo electrode. Ferroelectricity in (Hf,Zr)O 2 films under 10 nm has been correlated with various factors, including dopant, oxygen deficiency, strain, and surface energy. Owing to their ultrathin thickness, the interfaces between the (Hf,Zr)O 2 and the electrode can also influence the resultant ferroelectricity. Recently, ferroelectric (Hf,Zr)O 2 fabricated on electrodes, such as Mo, showed large remanent polarization and wake-up-free behavior. However, the accurate physical/chemical mechanism behind the ferroelectric (Hf,Zr)O 2 on Mo remains under debate. This study reports the structural, chemical, and electrical properties of Hf 0.5 Zr 0.5 O 2 with Mo and TiN as top and bottom electrodes. The remanent polarization and coercive field of Hf 0.5 Zr 0.5 O 2 with a Mo electrode (23.7 μC/cm2, 1.1 MV/cm) were higher than those with a TiN electrode (9.1 μC/cm2, 0.9 MV/cm). The X-ray diffraction analysis shows that Hf 0.5 Zr 0.5 O 2 with Mo electrode exhibits a higher ferroelectric orthorhombic phase fraction than the TiN electrode, explaining its higher remanent polarization. The X-ray photoelectron and electron energy loss spectroscopies revealed that the concentration of oxygen vacancies in Hf 0.5 Zr 0.5 O 2 with Mo electrode was significantly lower than that in Hf 0.5 Zr 0.5 O 2 with TiN electrode, explaining the wake-up free behavior. [ABSTRACT FROM AUTHOR]

B-doped AlN ferroelectric thin films are promising candidates for non-volatile memory device applications, due to their relatively low deposition temperatures, large remanent polarizations (up to 120 μC/cm2), and outstanding polarization retention properties. In this research, the polarization switching fatigue characteristics in epitaxial B-doped AlN thin films were investigated. Films were deposited via reactive RF magnetron sputtering onto W-coated c -plane sapphire substrates. Polarization switching fatigue measurements were conducted with triangular waveforms for frequencies between 50 and 1000 Hz from room temperature to 200°C. On repeated cycling, the films undergo wake-up; the wake-up process was characterized by an activation energy of 0.15 ± 0.05 eV. After a period of normal switching, the film leakage current increased with additional cycling, and finally the films underwent dielectric breakdown. Unpatterned Al 0.93 B 0.07 N films with 100 nm thick Pt top electrodes survived ∼104 bipolar cycles, whereas films with 1000 nm W top electrodes survived ∼105 cycles before dielectric breakdown. Modeling was used to design a field plate, which improved the performance to ∼106 fatigue cycles. It was found that dielectric failure during fatigue was not due to surface flashover but was associated with hard breakdown events in the dielectric. Failure for 100 Hz cycling was not associated with device self-heating but was exacerbated by field concentrations; at higher frequencies, the instantaneous temperature rise during the switching becomes prominent. Based on the fatigue process under 100 Hz under various ambient temperatures, the activation energy of the polarization switching fatigue of B-doped AlN thin films was found to be E a = 0.10 ± 0.03 eV. [Display omitted] [ABSTRACT FROM AUTHOR]

Introduction: In WAKE-UP (Efficacy and Safety of MRI-based Thrombolysis in Wake-Up Stroke), patients with an acute stroke of unknown onset time were randomized to treatment with intravenous alteplase or placebo, guided by MRI.Methods: In this exploratory post-hoc secondary analysis we compared clinical and imaging data, as well as treatment effects and safety of intravenous thrombolysis between patients with infra- vs. supratentorial stroke.Results: Forty-eight out of 503 randomized patients (9.5%) presented with a stroke involving the cerebellum or brainstem. Patients with infratentorial stroke were younger compared to patients with supratentorial stroke (mean age 60 vs. 66 years), more frequently male (85 vs. 62%), and less severely affected (median NIHSS 4.5 vs. 6.0). There was no heterogeneity for treatment effect between supratentorial (OR 1.67 95% CI 1.11–2.51) and infratentorial (OR 1.31 95% CI 0.41–4.22) sub-groups (test for interaction p = 0.70). In patients with infratentorial stroke, favorable outcome [a score of 0–1 on the modified Rankin scale (mRS) at 90 days] was observed in 12/22 patients (54.5%) in the alteplase group and in 13/25 patients (52.0%) in the placebo group (p = 0.59). The primary safety endpoint (death or mRS 4–6 at day 90) occurred in three patients of the alteplase group (13.6%) and three patients in the placebo group (12.0%); p = 0.74.Discussion: WAKE-UP was underpowered for demonstrating treatment effect in subgroup analyses however, based on our current results, there is no evidence to recommend withholding MRI-guided thrombolysis in patients with unknown onset stroke of infratentorial localization.

In recent times, there has been a notable surge of interests in hafnia (HfO 2 )-based ferroelectrics, primarily due to their remarkable ferroelectric properties employed in ultra-thin configurations, alongside their compatibility with the conventional CMOS manufacturing process. In order to harness the full potential of HfO 2 -based films for high-performance non-volatile memory applications, it is imperative to enhance their ferroelectric characteristics and durability. This study introduces a straightforward approach aimed at augmenting the ferroelectric performance of Hf x Zr 1- x O 2 (HZO) films deposited on silicon (Si) substrates through the engineering of oxygen vacancies ( V O ). The results of this endeavor demonstrate a significant enhancement in ferroelectric performance, characterized by a 2Pr value of 47 μ C cm -2 and impressive endurance, enduring up to 10 8 electric field without the need of a wake-up process. This marked improvement can be attributed to a dual-pronged approach, involving the incorporation of an Al -1 electric field without the need of a wake-up process. This marked improvement can be attributed to a dual-pronged approach, involving the incorporation of an Al 2 O 3 interlayer and the introduction of Al atoms into the HZO film. The Al 2 O 3 interlayer primarily serves to mitigate the presence of oxygen vacancies at the interface, while the introduction of Al dopants elevates the concentration of oxygen vacancies within the bulk material. This modulation of oxygen vacancy concentration proves instrumental in facilitating the formation of a ferroelectric o-III phase within the HZO-based films, thereby further augmenting their ferroelectric performance. This innovative and effective strategy offers an alternative avenue for enhancing the ferroelectric properties of materials characterized by a fluorite crystal structure., (© 2024 IOP Publishing Ltd.)

This article presents an application-optimized QVGA image sensor for low-power, always-on object detection using histograms of oriented gradients (HOG). In contrast to conventional CMOS imagers that feature linear and high-resolution ADCs, our readout scheme extracts logarithmic intensity gradients at 1.5 or 2.75 bits of resolution. This eliminates unnecessary illumination-related data and allows the HOG feature descriptors to be compressed by up to $25\times $ relative to a conventional 8-bit readout. As a result, the digital backend-detector, which typically limits system efficiency, incurs less data movement and computation, leading to an estimated $3.3\times $ energy reduction. The imager employs a column-parallel readout with analog cyclic-row buffers that also perform arbitrary-sized pixel-binning for multi-scale object detection. The log-digitization of pixel gradients is computed using a ratio-to-digital converter (RDC), which performs successive capacitive divisions to its input voltages. The prototype IC was fabricated in a 0.13- $\mu \text{m}$ CIS process with standard 4-T 5- $\mu \text{m}$ pixels and consumes 99 pJ/pixel. Experiments using a deformable parts model (DPM) detector for three object classes (persons, bicycles, and cars) indicate detection accuracies that are on par with conventional systems. [ABSTRACT FROM AUTHOR]

Introduction: In WAKE-UP (Efficacy and Safety of MRI-based Thrombolysis in Wake-Up Stroke), patients with an acute stroke of unknown onset time were randomized to treatment with intravenous alteplase or placebo, guided by MRI. Methods: In this exploratory post-hoc secondary analysis we compared clinical and imaging data, as well as treatment effects and safety of intravenous thrombolysis between patients with infra- vs. supratentorial stroke. Results: Forty-eight out of 503 randomized patients (9.5%) presented with a stroke involving the cerebellum or brainstem. Patients with infratentorial stroke were younger compared to patients with supratentorial stroke (mean age 60 vs. 66 years), more frequently male (85 vs. 62%), and less severely affected (median NIHSS 4.5 vs. 6.0). There was no heterogeneity for treatment effect between supratentorial (OR 1.67 95% CI 1.11–2.51) and infratentorial (OR 1.31 95% CI 0.41–4.22) sub-groups (test for interaction p = 0.70). In patients with infratentorial stroke, favorable outcome [a score of 0–1 on the modified Rankin scale (mRS) at 90 days] was observed in 12/22 patients (54.5%) in the alteplase group and in 13/25 patients (52.0%) in the placebo group (p = 0.59). The primary safety endpoint (death or mRS 4–6 at day 90) occurred in three patients of the alteplase group (13.6%) and three patients in the placebo group (12.0%); p = 0.74. Discussion: WAKE-UP was underpowered for demonstrating treatment effect in subgroup analyses however, based on our current results, there is no evidence to recommend withholding MRI-guided thrombolysis in patients with unknown onset stroke of infratentorial localization. [ABSTRACT FROM AUTHOR]

Objectives: The onset of ischemic stroke symptoms has been established to have a diurnal variation, with a sizeable proportion (8-28%) occurring during sleep. Obstructive sleep apnea (OSA) has been established as an important risk factor for ischemic stroke. However, data on the relationship between OSA and wake-up stroke (WUS) has been scarce. The aim of our study is to determine the relationship between OSA and WUS.Methods: This is a case-control study conducted on acute stroke patients who presented to one of two major medical centers in Riyadh of Saudi Arabia. Those who woke up with the symptoms were labeled as WUS, and those whose stroke occurred while awake were labeled as non wake-up stroke (NWUS). The Berlin Questionnaire, which was submitted to either the patient or his/her partner, was used to determine the frequency of OSA in the two groups.Results: One hundred seven patients (60% males) with acute stroke were admitted between March 2016 and March 2017. Of the 40 patients with WUS, 29 (72.5%) had underlying OSA based on the Berlin Questionnaire, whereas only 30 (45%) of the 67 patients with NWUS have underlying OSA. Logistic regression analysis showed OSA is highly prevalent in the patients with WUS (OR = 3.25; 95% CI = 1.397-8.38; p = 0.0053).Conclusion: OSA is an important risk factor for ischemic stroke during sleep. Health care providers must be vigilant in inquiring about symptoms suggestive of OSA in every ischemic stroke patient, especially the patient whose stroke occurred during sleep. [ABSTRACT FROM AUTHOR]