Helical van der Waals crystals with discretized Eshelby twist.

The ability to manipulate the twisting topology of van der Waals structures offers a new degree of freedom through which to tailor their electrical and optical properties. The twist angle strongly affects the electronic states, excitons and phonons of the twisted structures through interlayer coupling, giving rise to exotic optical, electric and spintronic behaviours1-5. In twisted bilayer graphene, at certain twist angles, long-range periodicity associated with moiré patterns introduces flat electronic bands and highly localized electronic states, resulting in Mott insulating behaviour and superconductivity3,4. Theoretical studies suggest that these twist-induced phenomena are common to layered materials such as transition-metal dichalcogenides and black phosphorus6,7. Twisted van der Waals structures are usually created using a transfer-stacking method, but this method cannot be used for materials with relatively strong interlayer binding. Facile bottom-up growth methods could provide an alternative means to create twisted van der Waals structures. Here we demonstrate that the Eshelby twist, which is associated with a screw dislocation (a chiral topological defect), can drive the formation of such structures on scales ranging from the nanoscale to the mesoscale. In the synthesis, axial screw dislocations are first introduced into nanowires growing along the stacking direction, yielding van der Waals nanostructures with continuous twisting in which the total twist rates are defined by the radii of the nanowires. Further radial growth of those twisted nanowires that are attached to the substrate leads to an increase in elastic energy, as the total twist rate is fixed by the substrate. The stored elastic energy can be reduced by accommodating the fixed twist rate in a series of discrete jumps. This yields mesoscale twisting structures consisting of a helical assembly of nanoplates demarcated by atomically sharp interfaces with a range of twist angles. We further show that the twisting topology can be tailored by controlling the radial size of the structure.

The Mechanism of Guerbet Reaction by Metal Ligand Cooperation.

The Guerbet reaction is important for the synthesis of longer-chain monoalcohols like isobutanol through catalytic transfer hydrogenation from short-chain methanol and ethanol. However, the mechanism becomes complicated, especially considering the variations in the different metal-ligand cooperation (MLC) catalysts used. In order to further understand the Guerbet reaction, DFT studies were performed to figure out the detailed mechanism initiated by the unique Mn-PCP MLC Catalyst. Our results suggest that even with the assistance of the carbanion site of the PCP ligand, the direct substitution mechanism is less favored than the condensation-reduction mechanism. The key step of the reaction is the final reduction of the carbonyl, in which the 1,4-reduction of the unsaturated aldehyde is prior to the 3,4-reduction or 1,2-reduction due to the stronger interaction between the catalyst and the substrate. It is found that the production of isobutanol is preferred over n-butanol because of the lower total free energy barrier and lower relative free energy of the product. Finally, by changing the electronic effect of the carbanion site of the catalyst, we found that the relation between the electronic effect and the highest free energy span was not monotonous and a point with optimal electronic effect exists numerically.

A Bibliometric Analysis of the Spatial Transcriptomics Literature from 2006 to 2023.

In recent years, spatial transcriptomics (ST) research has become a popular field of study and has shown great potential in medicine. However, there are few bibliometric analyses in this field. Thus, in this study, we aimed to find and analyze the frontiers and trends of this medical research field based on the available literature. A computerized search was applied to the WoSCC (Web of Science Core Collection) Database for literature published from 2006 to 2023. Complete records of all literature and cited references were extracted and screened. The bibliometric analysis and visualization were performed using CiteSpace, VOSviewer, Bibliometrix R Package software, and Scimago Graphica. A total of 1467 papers and reviews were included. The analysis revealed that the ST publication and citation results have shown a rapid upward trend over the last 3 years. Nature Communications and Nature were the most productive and most co-cited journals, respectively. In the comprehensive global collaborative network, the United States is the country with the most organizations and publications, followed closely by China and the United Kingdom. The author Joakim Lundeberg published the most cited paper, while Patrik L. Ståhl ranked first among co-cited authors. The hot topics in ST are tissue recognition, cancer, heterogeneity, immunotherapy, differentiation, and models. ST technologies have greatly contributed to in-depth research in medical fields such as oncology and neuroscience, opening up new possibilities for the diagnosis and treatment of diseases. Moreover, artificial intelligence and big data drive additional development in ST fields.

Topotactic Growth of Free-Standing Two-Dimensional Perovskite Niobates with Low Symmetry Phase.

Here, we report a novel topotactic method to grow 2D free-standing perovskite using KNbO3 (KN) as a model system. Perovskite KN with monoclinic phase, distorted by as large as ∼6 degrees compared with orthorhombic KN, is obtained from 2D KNbO2 after oxygen-assisted annealing at relatively low temperature (530 °C). Piezoresponse force microscopy (PFM) measurements confirm that the 2D KN sheets show strong spontaneous polarization (Ps) along [101̅]pc direction and a weak in-plane polarization, which is consistent with theoretical predictions. Thickness-dependent stripe domains, with increased surface displacement and PFM phase changes, are observed along the monoclinic tilt direction, indicating the preserved strain in KN induces the variation of nanoscale ferroelectric properties. 2D perovskite KN with low symmetry phase stable at room temperature will provide new opportunities in the exploration of nanoscale information storage devices and better understanding of ferroelectric/ferroelastic phenomena in 2D perovskite oxides.

Status Epilepticus Related Takotsubo Syndrome - A Case Report.

PURPOSE: Takotsubo syndrome (TTS) is characterized angiographically by transient left ventricular systolic dysfunction sparing the basal segments of the left ventricle and absence of obstructive coronary artery disease. Epileptic seizures as triggering events for TTS are uncommon, having only been described in approximately 100 previous cases Case report: A 64-year-old woman with a history of recent stroke-related seizures was admitted for an acute onset of right hemiparesis with dull response. Neurological examination revealed a forced deviation of the eyeballs to the left side and quadriplegia. No large intracranial artery occlusion was disclosed through computed tomography angiography, but an acute infarction at the right corona radiata was identified through magnetic resonance imaging. Electroencephalography showed frequent spike-and-wave complexes over the right cerebral hemisphere indicating subtle status epilepticus. Her consciousness deteriorated to a stuporous state, and her eyeballs were forced deviated to the right side with persistent twitching of the right limbs 10 hours later. The convulsive status epilepticus (CSE) subsided after intravenous infusion of midazolam. However, atrial flutter with inverted T-wave and elevated high-sensitivity troponin I were observed 12 hours after CSE. Arrhythmia was soon alleviated through appropriate treatment. A further coronary angiography did not show significant coronary artery stenosis but indicated that the midsection and the apex of the left ventricle ballooned out during systole as the base contracted normally, indicating a Takotsubo syndrome. CONCLUSION: Physicians need to monitor unusual arrhythmias, particularly atrial and ventricular arrhythmias, for the possibility of TTS in patients with epileptic seizure.

Flat Bands in Magic-Angle Bilayer Photonic Crystals at Small Twists.

The new physics of magic-angle twisted bilayer graphene (TBG) motivated extensive studies of flat bands hosted by moiré superlattices in van der Waals structures, inspiring the investigations into their photonic counterparts with potential applications including Bose-Einstein condensation. However, correlation between photonic flat bands and bilayer photonic moiré systems remains unexplored, impeding further development of moiré photonics. In this work, we formulate a coupled-mode theory for low-angle twisted bilayer honeycomb photonic crystals as a close analogy of TBG, discovering magic-angle photonic flat bands with a non-Anderson-type localization. Moreover, the interlayer separation constitutes a convenient degree of freedom in tuning photonic moiré bands without high pressure. A phase diagram is constructed to correlate the twist angle and separation dependencies to the photonic magic angles. Our findings reveal a salient correspondence between fermionic and bosonic moiré systems and pave the avenue toward novel applications through advanced photonic band or state engineering.

Three-dimensional Architecture Enabled by Strained Two-dimensional Material Heterojunction.

Engineering the structure of materials endows them with novel physical properties across a wide range of length scales. With high in-plane stiffness and strength, but low flexural rigidity, two-dimensional (2D) materials are excellent building blocks for nanostructure engineering. They can be easily bent and folded to build three-dimensional (3D) architectures. Taking advantage of the large lattice mismatch between the constituents, we demonstrate a 3D heterogeneous architecture combining a basal Bi2Se3 nanoplate and wavelike Bi2Te3 edges buckling up and down forming periodic ripples. Unlike 2D heterostructures directly grown on substrates, the solution-based synthesis allows the heterostructures to be free from substrate influence during the formation process. The balance between bending and in-plane strain energies gives rise to controllable rippling of the material. Our experimental results show clear evidence that the wavelengths and amplitudes of the ripples are dependent on both the widths and thicknesses of the rippled material, matching well with continuum mechanics analysis. The rippled Bi2Se3/Bi2Te3 heterojunction broadens the horizon for the application of 2D materials heterojunction and the design and fabrication of 3D architectures based on them, which could provide a platform to enable nanoscale structure generation and associated photonic/electronic properties manipulation for optoelectronic and electromechanic applications.

Ecological risk assessment and distribution of potentially harmful trace elements in lake sediments of Songnen Plain, NE China.

In order to understand the distribution and the ecological risk of the potentially harmful trace elements (PHTEs) in lake sediments of Songnen Plain, northeast (NE) China, an integrated survey of PHTEs (As, Cd, Cr, Cu, Ni, Pb, Zn and Ti) was conducted in July 2015 in 11 shallow lakes adjacent to Qiqihar and Daqing. The enrichment factor (EF) and Index of geoaccumulation (Igeo) results showed that Cd was obviously enriched in all lakes and reached the moderate pollution level. A comparison of PHTE concentrations in the lake sediments from 2005 to 2015 found the PHTEs pollution status doubled. Multivariate statistical analysis identified the heavy industries of petroleum and steel in the cities close to lakes and excessive agricultural fertilizing in the region as possible pollution sources of the PHTEs. The Håkanson index method (RI) and the sediment quality guidelines (SQGs) were used to assess the potential risk of PHTEs in sediments. The risk degree of 11 lakes had reached a medium level of potential ecological risk except for one lake which had a low potential ecological risk status. The Songnen Plain has been significantly affected by anthropogenic activities and this study provides an effective reference for the environmental protection and management of lakes (heavy metal pollution and control) around the heavy industrial cities of China and the world.

Evaluation of cerebral blood flow in acute ischemic stroke patients with atrial fibrillation: A sonographic study.

BACKGROUND/PURPOSE: Although cerebral emboli are a frequent cause of cardiogenic stroke, the possibility of a reduction in cerebral perfusion consequent to arrhythmia or impaired cardiac function should be considered in patients with atrial fibrillation (AF). METHODS: We reviewed sonographic studies and clinical features of patients with acute ischemic stroke. A total of 144 patients with AF and 144 age- and sex-matched patients with small vessel occlusion but without AF were included. RESULTS: Patients with AF had significantly lower peak systolic velocity (PSV), mean velocity, flow volume (p < 0.001), and end-diastolic velocity (p = 0.035) of the internal carotid artery (ICA); significantly lower cerebral blood flow (p < 0.001); and lower flow velocities of the middle cerebral artery (p < 0.01) than patients with small vessel occlusion but without AF. In patients with AF, there was an inverse linear correlation between ICA end-diastolic velocity, mean velocity (p < 0.001), flow volume (p = 0.025), middle cerebral artery flow velocities (p < 0.05), and age. Cardiac ejection fraction had a positive linear correlation with ICA PSV (p = 0.016) but an inverse correlation with the heart rate (p = 0.009). There was a significant decline in PSV (p = 0.002), resistance index (p < 0.001), and flow volume (p = 0.0121) of the ICA as well as cerebral blood flow (p = 0.009) as the heart rate increased. CONCLUSION: Cerebral blood flow is markedly reduced in ischemic stroke patients with AF as compared with that in patients with small vessel disease but without AF.

Reduced Internal Carotid Artery Flow in Color-coded Carotid Duplex Sonography.

PURPOSE: Reduced flow in the internal carotid artery (ICA) is related to cerebral ischemia. We established a classification of reduced ICA flow through color-coded carotid duplex (CCD) sonography. METHODS: We retrospectively reviewed 25,000 CCD images in sonography laboratory. RESULTS: Reduced ICA flow [flow volume (FV) less than 100 mL/min] was found in 1.2% of all studies, and 270 patients were enrolled. We included 8% patients with lesions proximal to the ICA in Group A, 27% with lesions at the proximal ICA in Group B, 49% with lesions distal to the visible ICA in Group C, and 16% with unknown causes in Group D. Distal ICA stenosis or occlusion is the most common cause of reduced ICA flow. Moyamoya disease, ICA hypoplasia, and ICA dissection were more prevalent in younger patients. CCD of the aforementioned diseases showed similar patterns of upstream high flow resistance with reduced FV in the ICA and were indistinguishable. The collateral flow from bilateral vertebral arteries increased in common carotid artery (CCA) or ICA disease (p less than 0.05) and was exceptionally high in ICA hypoplasia (p less than 0.001). Compared with the FV in the contralateral CCA, that of the ipsilateral CCA decreased in all groups (p less than 0.001), except in patients with low cardiac output. CONCLUSION: CCD should be carefully performed and appropriately interpreted in reduced ICA flow. Additional magnetic resonance angiography is helpful in distinguishing stenosis or occlusion from ICA dissection and moyamoya disease, and skull base computed tomography is warranted for the confirmatory diagnosis of ICA hypoplasia. Key Words: color-coded carotid duplex sonography, dissection, hypoplasia, internal carotid artery, reduced flow, stenosis.

Thyroid disease as a risk factor for cerebrovascular disease.

BACKGROUND: Thyroid disease is the medical condition impairing function of the thyroid. Among this disorder category, hyperthyroidism is that the thyroid gland produces excessive amounts of thyroid hormones whereas hypothyroidism is that the thyroid gland does not produce enough thyroid hormone. Various studies have supported the comorbid association between thyroid disease and cardiovascular disorder. However, there is insufficient evidence to prove the relationship between cerebrovascular disease (CVD) and thyroid disease. METHODS: In this study, we tried to verify that thyroid disease increases the risk of CVD development employing a population-based database, National Health Insurance Research Database of Taiwan. A total of 16,808 hyperthyroidism cases and 5793 hypothyroidism patients with corresponding control subjects were studied, respectively. Hazard ratio (HR) by the Cox regression was used to quantify risk of CVD in different groups of subjects, that is, case patients versus matched controls. Further stratification studies for risk factors of CVD were performed to evaluate the comorbid association between CVD and hyperthyroidism/hypothyroidism. RESULTS: Evaluation results have shown that hyperthyroidism increased 38% of the hazard of developing follow-up CVD (adjusted HR, 1.38) whereas hypothyroidism increased even higher the risk (adjusted HR, 1.89). Further stratification studies for risk factors of CVD suggested that the comorbid association between hypothyroidism and CVD was comparable to those influences from cardiac risk factors, such as diabetes mellitus, hyperlipidemia, hypertension, or renal failure and so forth. CONCLUSIONS: Thyroid disease may predispose to onset of CVD. Advanced analysis is required to investigate the pathologic mechanism underlying the association between CVD and thyroid disease.

Propyl gallate exposure affects the mouse 2-cell stage embryonic development through inducing oxidative stress and autophagy.

Propyl gallate (PG), owing to its exceptional antioxidant properties, is extensively used in industries such as food processing. The potential harmful impacts of PG have sparked concern among people. It has been reported that exposure of PG has certain reproductive toxicity, which can affect the maturation of mouse oocytes and induce testicular dysfunction. However, its impact on early embryonic development is still unclear. In this study, we explored the toxic effects and potential mechanisms of PG on mouse 2-cell stage embryonic development. The results showed that exposure of PG can decrease the development of 2-cell stage embryos and repress the development of 4-cell stage embryos. Further study found that PG could induce intracellular oxidative stress and the accumulation of DNA damage in 2-cell stage embryos. Moreover, exposure of PG impaired the function of mitochondria and lysosomes in 2-cell stage embryos, thereby triggering the occurrence of autophagy. In addition, exposure of PG altered the epigenetic modification of 2-cell stage embryos, displaying a decreased level of DNA methylation and an increased level of H3K4me3. In summary, our results indicated that exposure of PG can damage the development of mouse 2-cell stage embryos by inducing oxidative stress, DNA damage, and autophagy, and altering epigenetic modification.

Ultra-Light Clay Intervention Improves Responsiveness and Initiates the Communication of Children With ASD.

The barriers to responsiveness and the initiation of communication are the two key problems encountered by children with autism spectrum disorders (ASD). Prior interventions based on behavioral reinforcement have had an obvious effect on responsive communication but a weak effect on the initiation of communication. Based on psychological development theory, we designed ultra-light clay interventions involving hands-on production or multi-interaction around key concepts and themes, teaching children about basic concepts, relationships, and logic, making abstract knowledge concrete and experience. Two studies (Study 1: N = 3, one-to-one intervention; Study 2: N = 8, one-to-two intervention) showed that ultra-light clay intervention improved both the initiation of and response to communication among children with ASD, but that such improvements show a peer-generalization effect in initiation communication, not in responsive communication. These findings provide a set of ultra-light clay interventions for communication in children with ASD and suggest a relationship between endogenous interventions and the initiation of communication.

Attentional Engagement and Disengagement Differences for Circumscribed Interest Objects in Young Chinese Children with Autism.

The current study aimed to investigate attentional processing differences for circumscribed interest (CI) and non-CI objects in young Chinese children with autism spectrum condition (ASC) and typically developing (TD) controls. In Experiment 1, a visual preference task explored attentional allocation to cartoon CI and non-CI materials between the two groups. We found that ASC children (n = 22, 4.95 ± 0.59 years) exhibited a preference for CI-related objects compared to non-CI objects, and this effect was absent in the TD children (n = 22, 5.14 ± 0.44 years). Experiment 2 utilized the traditional gap-overlap paradigm (GOP) to investigate attentional disengagement from CI or non-CI items in both groups (ASC: n = 20, 5.92 ± 1.13 years; TD: n = 25, 5.77 ± 0.77 years). There were no group or stimulus interactions in this study. Experiment 3 adopted a modified GOP (MGOP) to further explore disengagement in the two groups (ASC: n = 20, 5.54 ± 0.95 years; TD: n = 24, 5.75 ± 0.52 years), and the results suggested that exogenous disengagement performance was preserved in the ASC group, but the children with ASC exhibited increased endogenous attentional disengagement compared to TD peers. Moreover, endogenous disengagement was influenced further in the presence of CI-related objects in the ASC children. The current results have implications for understanding how the nature of engagement and disengagement processes can contribute to differences in the development of core cognitive skills in young children with ASC.

Resilient control design for networked DC microgrids under time-constrained DoS attacks.

This paper studies the resilient current controller design for the networked DC microgrid system with multiple constant power loads (CPLs) under a new type of time-constrained denial-of-service (DoS) attack. Different from the existing DoS attack models, which are often characterized by DoS frequency and DoS duration, this paper only considers the duration characteristics of the sporadic/aperiodic DoS attacks, and proposes a new type of time-constrained DoS attack model. Under the effects of such DoS attacks, a switching state feedback control law is constructed and a switching-like DC microgrid system model is then established. Furthermore, based on an attack-parameter-dependent time-varying Lyapunov function (TVLF) method, the exponential stability criterion of the resulting DC microgrid system under aperiodic DoS attacks is derived, and a new resilient controller design method is proposed. Finally, simulation studies are given to verify the effectiveness and merits of the proposed resilient control design scheme on achieving the desired control performance and attack resilience.

Comparison of Clinical Features, Immune-Inflammatory Markers, and Outcomes Between Patients with Acute In-Hospital and Out-of-Hospital Ischemic Stroke.

PURPOSE: We investigated the differences of clinical features, four immune-inflammatory markers, namely neutrophil counts, platelet-to-lymphocyte ratio, neutrophil-to-lymphocyte ratio (NLR), and systemic immune-inflammation index (SII), as well as outcomes between patients with in-hospital ischemic stroke (IHIS) and out-of-hospital ischemic stroke (OHIS). PATIENTS AND METHODS: We retrospectively enrolled 72 patients with IHIS and 3330 patients with OHIS. RESULTS: IHIS accounted for 2% of all patients with ischemic stroke and occurred more often in cardiology and orthopedic surgery wards. Infection, cardiac disease, and pulmonary disorder were the most common causes of hospitalization. Compared with those with OHIS, patients with IHIS had higher levels of immune-inflammatory markers, initial National Institute of Health Stroke Scale (NIHSS) scores, longer hospital stays, higher rates of heart disease, large-artery atherosclerosis or cardioembolism, received more intravenous thrombolysis (IVT) or endovascular thrombectomies (EVTs), more complications, unfavorable outcomes, and mortality. Every immune-inflammatory marker exhibited positive correlations with initial NIHSS scores and discharge modified Rankin Scale scores among patients with OHIS. NLR and SII were higher among patients with a fatal outcome in both groups. Among patients receiving IVT, most of treatment time intervals were shorter for those with IHIS than those with OHIS. Significant factors for mortality were NLR >5.5, atrial fibrillation, and complications, with a C-statistic of 0.897 in those with IHIS; in those with OHIS, these factors were an initial NIHSS score of >10, NLR >6.0, atrial fibrillation, prior stroke, cancer history, and complications with a C-statistic of 0.902. The results were similar after replacing the NLR with SII. CONCLUSION: Patients with IHIS had more complicated clinical features, higher levels of immune-inflammatory markers, and higher rates of mortality than patients with OHIS. The most significant predictor for mortality among those with OHIS was NIHSS score >10, and the predictors among patients with IHIS were NLR >5.5 and SII >2120.

Percheron Artery-Plus Syndrome: A Syndrome Beyond Stroke Chameleon.

The artery of Percheron (AOP) is an anatomical variant of the thalamoperforating arteries. AOP occlusion can cause bilateral paramedian thalamic infarctions and is referred to as a "stroke chameleon" because it lacks the classic signs of stroke. Coexistence of AOP occlusion and other neurologic disease is rare and can cause disturbance of consciousness. A 78-year-old woman had acute onset of left limb weakness and drowsy consciousness. Brain magnetic resonance angiography (MRA) revealed acute bilateral paramedian thalamic infarctions. However, serum and cerebrospinal fluid (CSF) cryptococcal antigen titers were 1:16 and 1:128, respectively. The CSF culture grew Cryptococcus neoformans. Although consciousness and muscle power improved after treatment, the patient later died of pneumonia. A 68-year-old woman developed acute disturbance of consciousness followed by delirium. Brain MRA revealed acute bilateral paramedian thalamic infarctions. Elevated free thyroxine, anti-thyroperoxidase, and anti-thyroglobulin antibodies were detected. She received 3 days of steroid pulse therapy followed by oral prednisolone. Her consciousness gradually improved after Hashimoto encephalopathy and stroke were controlled. AOP occlusion was diagnosed early in these two patients. However, other concomitant life-threatening diseases could have been overlooked because of the complicated diagnostic determination. Further serum cryptococcal antigen, anti-TPO Ab, and anti-TG Ab surveys might help to exclude cryptococcal meningitis and Hashimoto encephalopathy. CSF study is warranted when central nervous system infection is strongly suspected. This "Percheron artery-plus syndrome" comprises multifaceted disorders beyond the stroke chameleon and requires attention.

Association of a High Neutrophil-to-Lymphocyte Ratio with Hyperdense Artery Sign and Unfavorable Short-Term Outcomes in Patients with Acute Ischemic Stroke.

PURPOSE: Immune-inflammatory processes are involved in all the stages of stroke. This study investigated the association of the neutrophil-to-lymphocyte ratio (NLR) with the hyperdense artery sign (HAS) observed on brain computed tomography (CT) and with clinical features in patients with acute ischemic stroke. METHODS: We retrospectively enrolled 2903 inpatients with acute ischemic stroke from May 2010 to May 2019. Data collected included imaging studies, risk factors, laboratory parameters, and clinical features during hospitalization. RESULTS: The HAS was identified in 6% of the 2903 patients and 66% of the 236 patients with acute middle cerebral artery occlusion. Patients with the HAS had a higher NLR. HAS prevalence was higher in men and patients with cardioembolism. The NLR exhibited positive linear correlations with age, glucose and creatinine levels, length of hospital stay, initial National Institutes of Health Stroke Scale (NIHSS) scores, and mRS scores at discharge. The NLR was significantly higher in patients with large-artery atherosclerosis and cardioembolism and was the highest in patients with other determined etiology. Multivariate analysis revealed that an initial NIHSS score of ≥10 and an NLR of >3.5 were significant positive factors, whereas diabetes mellitus and age > 72 years were significant negative factors for the HAS, with a predictive performance of 0.893. An initial NIHSS score of ≥5, positive HAS, age > 75 years, diabetes mellitus, an NLR of >3.5, female sex, a white blood cell count of >8 × 103/mL, and elevated troponin I were significant predictors of unfavorable outcomes, with a predictive performance of 0.886. CONCLUSION: An NLR of >3.5 enabled an efficient prediction of CT HAS. In addition to conventional risk factors and laboratory parameters, both an NLR of >3.5 and CT HAS enabled improved prediction of unfavorable stroke outcomes.

Tunable room-temperature ferromagnetism in Co-doped two-dimensional van der Waals ZnO.

The recent discovery of ferromagnetism in two-dimensional van der Waals crystals has provoked a surge of interest in the exploration of fundamental spin interaction in reduced dimensions. However, existing material candidates have several limitations, notably lacking intrinsic room-temperature ferromagnetic order and air stability. Here, motivated by the anomalously high Curie temperature observed in bulk diluted magnetic oxides, we demonstrate room-temperature ferromagnetism in Co-doped graphene-like Zinc Oxide, a chemically stable layered material in air, down to single atom thickness. Through the magneto-optic Kerr effect, superconducting quantum interference device and X-ray magnetic circular dichroism measurements, we observe clear evidences of spontaneous magnetization in such exotic material systems at room temperature and above. Transmission electron microscopy and atomic force microscopy results explicitly exclude the existence of metallic Co or cobalt oxides clusters. X-ray characterizations reveal that the substitutional Co atoms form Co2+ states in the graphitic lattice of ZnO. By varying the Co doping level, we observe transitions between paramagnetic, ferromagnetic and less ordered phases due to the interplay between impurity-band-exchange and super-exchange interactions. Our discovery opens another path to 2D ferromagnetism at room temperature with the advantage of exceptional tunability and robustness.

Solution-Based Synthesis of Layered Two-Dimensional Oxides as Broadband Emitters.

Preparing transition-metal oxides in their two-dimensional (2D) form is the key to exploring their unrevealed low-dimensional properties, such as the p-type transparent superconductivity, topological Mott insulator state, existence of the condensed 2D electron/hole gas, and strain-tunable catalysis. However, existing approaches suffer from the specific constraint techniques and precursors that limit their product types. Here, we report a solution-based method to directly synthesize KNbO2 in 2D by an out-of-the-pot growth process at low temperature, which is observed directly in real time. The developed method can also be applied to other 2D ternary oxide syntheses, including CsNbO2 and composited NaxK1-xNbO2, and it can be extended to the preparation of self-assembled nanofilms. In addition, We demonstrate the emission of broadband photoluminescence (PL, λ ∼ 350-800 nm) from as-synthesized single-crystal 2D KNbO2 sheets down to a single unit cell thickness. The ultra-broadband emission is ascribed to the self-trapped excitation state (STEs) from the in-phase distortion of the NbO6 octahedrons in 2D NbO2- layers. Beyond the broader luminescent range and the robust material thermal stability of niobates, the absence of sample size restrictions and the large aspect ratio of the 2D oxide sheets will provide opportunities in miniaturizing and advancing 2D-materials integrated optoelectronic devices.